In the current work, mesoporous colloid imprinted carbon powders (CICs), with a ..... electrode's surface redistributes
Meeting Information Registration All presenters and attendees must be registered prior to the event to be allowed access. Unfortunately, payment can not be accepted on the day of the meeting. Registration for the 2018 Spring Meeting is now open until Friday May 11th, and can be accomplished through the ECS event profile here. The registration link is also available through the Canadian Section of the ECS website located at http://electrochem.ca/. Registration fees (note all prices in USD): ▪ Student (Non-Member): $80 ▪ Student (Member) $50 ▪ Other (Non-Member): $150 ▪ Other (Member): $120 Venue All meeting activities will occur within the Wild Rose room of the Lister Conference Centre, University of Alberta. The north campus map can be accessed here.
Getting Here/Parking Lister Conference Centre is located at 87 Avenue and 116 Street. Paid parking can be accessed in parking Lot M in front of the conference centre. Alternatively, the conference centre is a short (less than 5 minutes) walk from the Health Sciences LRT Station.
Accommodations 1. Lister Conference Centre – https://conference.ualberta.ca/accommodation ▪ Hotel Guest Rooms: Single or double occupancy starting at $109.00 per night plus applicable taxes ▪ Schäffer Residence Summer Accommodation: Single rooms $75.00 per night plus applicable taxes ▪ Traditional Residence Summer Accommodation: Single rooms $55.00 per night plus applicable taxes Twin rooms $65.00 per night plus applicable taxes 2. HI Edmonton (hostel) – http://hihostels.ca/en/destinations/alberta/hi-edmonton ▪ Private and Shared Rooms ~$32 to $82 per night plus applicable taxes 3. Campus Tower Suite Hotel – https://www.campustower.com/ ▪ Nightly Rate varies ~$186 per night plus applicable taxes Presenter Information
Canadian Section of the Electrochemical Society - 2018 Spring Meeting Oral Presentations: The meeting will be equipped with a PC laptop capable of running a powerpoint slide show. Presenters may bring their own computer but it is recommended using the computer provided. A laser pointer and remote slide changer will be available as well. All presenters will be responsible for ensuring their presentations are loaded on the designated presentation computer or that their own personal computer is correctly connecting to the projector.
Poster Session: All posters should be prepared and printed in advance of the meeting as there will be no facilities available at the meeting site. Poster presentations and judging will be held within the Wild Rose room during the lunch period. Each author must ensure their poster will fit within a horizontal poster board with the dimensions of 1.2 m vertical and 1.8 m horizontal (4’ x 6’). Please note that these dimensions are smaller than those provided by the 101st Canadian Chemistry Conference and Exhibition at the Shaw Conference Centre. Each board will indicate the corresponding poster abstract number (located within the meeting program booklet) in the upper right or left corner. An adequate number of pushpins will be made available for displaying each poster. Authors are responsible for mounting their posters a minimum of one hour before the beginning of the poster session and for removing them within one-half hour after the conclusion of the meeting.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Time
ORAL Presenter
7:30-8:00 8:00-8:10 8:10-8:40
MEETING CHECKIN AND POSTER SETUP WELCOME AND INTRODUCTORY REMARKS Prof. Christa Brosseau Spectroelectrochemical and computational studies of tetrahydrocannabinol: towards a point-of-need sensor
8:40-9:20
Prof. Greg Swain
KEYNOTE LECTURE - Advanced carbon electrodes for electroanalysis and spectroelectrochemistry
9:20-9:40
Gonzalo Montiel
Electrochemical techniques applied to the determination of carbon based materials performance at energy storage applications
9:40-10:00
Anna K. Farquhar
Electrochemistry of vertically aligned graphene nanoribbon electrodes
10:00-10:40
Prof. Viola Birss
INVITED LECTURE - Nanoscale templates and scaffolds for electrochemical applications
10:40-11:00 11:00-11:30
COFFEE BREAK Prof. Victor Nemykin
11:30-11:50
Mona Amiri
Modular construction of Ru- and Ir- chromophore photoanodes by covalent bonding and self-assembly
11:50-12:10
Soghra Jalil Pour
The effect of metal solution contamination on the electro-catalysts activities of polycrystalline Pt
12:10-12:30
Erwan Bertin
Oxygen reduction on Ag-Ni nanoparticles prepared by pulsed laser ablation in liquid
12:30-2:00 2:00-2:40
LUNCH AND POSTER SESSION Prof. Ian Burgess INVITED LECTURE - Micromachined Si wafers for electrochemical surface enhanced infrared spectroscopy Wendy Tran Potassium ion selective electrode with polyaniline and valinomycin based poly(vinyl chloride) membrane
2:40-3:00
Title
Tuning up redox and photophysical properties of donoracceptor (aza)BODIPY-based dyads and triads for a rational design of new light-harvesting materials
3:00-3:20
Kaylyn K. Leung
Investigating DC and pulsed modes of potentialassisted self-assembly of DNA monolayers
3:20-3:50
Prof. Antonella Badia
Using surface-confined redox and ion pairing reactions to detect micelle formation in solution
3:50-4:10 4:10-4:40 4:40-5:00
COFFEE BREAK Prof. Matiar Howlader Sourav Bag
5:00-5:20
5:20-5:30 5:30-6:00
Directly bonded sensor for trace lead detection Solid-state flexible polymer-ceramic composite electrolyte for all-solid-state-Li battery Aslan Kosakian A mathematical model for predicting the polarization curve hysteresis in proton exchange membrane fuel cells CLOSING REMARKS AND STUDENT AWARDS PRESENTATION ANNUAL GENERAL MEETING FOR THE CANADIAN SECTION OF THE ECS
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting No.
POSTER Presenter
Title
1
Fatemeh Abbasi (University of Guelph)
EIS and AFM studies of alamethicin ion pores formed in a floating phospholipid membrane supported on a gold electrode surface
2
Adrienne Allison (Dalhousie University)
Manganese oxide electrodes and the effect of substrate on electrochemical impedance spectroscopy
3
Marwa Atwa (University of Calgary)
Enhancing the corrosion resistance of PEM fuel cell carbon support materials using surface functionalization
4
Veronica Cavallari (UOIT)
Understanding the role of carbon morphology in sulfonated silica ceramic carbon electrodes for PEM fuel cell devices
5
Michael Clark (University of Alberta)
Atomic layer deposition of MnOx onto porous carbon electrodes for use in zinc-air batteries
6
Mallory Davis (Dalhousie University)
Self-discharge in rGO: effects of charge redistribution and carbon oxidation
7
Holly Fruehwald (UOIT)
Molecularly precise Fe-N3/C surface for modeling the active site for the oxygen reduction reaction
8
Boyang Gao (Memorial University)
Zn electrodeposits for water-repellent surfaces
9
Xiaoyi Gao (Simon Fraser University)
Exo I-hydrolysis assisted electrochemical quantitation of surfaceimmobilized DNA hairpins and improved HIV-1 gene detection
10
Annie Hoang (University of Calgary)
Ru@Pt core-shell nanoparticles as a catalyst for ethanol oxidation in fuel cells
11
Subiao Liu (University of Alberta)
Nanostructured catalysts for CO2 electroreduction: synthesizing high-value renewable fuels from CO2
12
Brian MacLean (StFX University)
Modifications of carbon substrates for charge storage with hybrid capacitors
13
Armando Marenco (University of Calgary)
Electrochemical detection of gram-negative bacteria using TLR-4 immunoproteins
14
Lin Qi (Simon Fraser University)
Host-guest interaction at molecular interface: cucurbit[7]uril as a probe of structural heterogeneity in ferrocenyl self-assembled monolayer on gold
15
Margaret Renaud-Young (University of Calgary)
Quantitative electrochemical measurement of Δ9-tetrahydrocannabinol (THC, cannabis) and its metabolites
16
Shailendra Saxena (University of Alberta)
Structure controlled photocurrent in bilayer molecular junctions
17
Mustafa Supur (University of Alberta)
Electron transport features of large area porphyrin molecular junctions
18
Wendy Tran (University of Alberta)
A study of alkaline gel electrolytes for metal-air batteries
19
Tao Wang (University of Calgary)
Artificially designed self-assembled monolayer-based DNA biosensor
20
Jing Xiao (University of Alberta)
Enhanced performance of electrochemical CO2 reduction with nanostructured catalysts
21
Ming Xiong (University of Alberta)
Rechargeable zinc-air batteries using separate electrodes fabricated by electrodeposition
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Sponsor Information
https://www.pineresearch.com/
https://www.heka.com/
Special Thanks
https://www.electrochem.org/
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Full Abstract List Presenter Page No. Abbasi, Fatemeh .................................................................................. 8 Allison, Adrienne .................................................................................. 9 Amiri, Mona ........................................................................................ 10 Atwa, Marwa ....................................................................................... 11 Badia, Antonella ................................................................................. 12 Bag, Sourav........................................................................................ 13 Bertin, Erwan ...................................................................................... 14 Birss, Viola ......................................................................................... 15 Brosseau, Christa ............................................................................... 16 Burgess, Ian ....................................................................................... 17 Cavallari, Veronica ............................................................................. 18 Clark, Michael..................................................................................... 19 Davis, Mallory ..................................................................................... 20 Farquhar, Anna .................................................................................. 21 Fruehwald, Holly ................................................................................. 22 Gao, Boyang ...................................................................................... 23 Gao, Xiaoyi ......................................................................................... 24 Hoang, Annie...................................................................................... 25 Howlader, Matiar ................................................................................ 26 Jalil Pour, Soghra ............................................................................... 27 Kosakian, Aslan .................................................................................. 28 Leung, Kaylyn ..................................................................................... 29 Liu, Subiao ......................................................................................... 30 MacLean, Brian .................................................................................. 31 Marenco, Armando ............................................................................. 32 Montiel, Gonzalo ................................................................................ 33 Nemykin, Victor .................................................................................. 34 Renaud-Young, Margaret ................................................................... 35 Qi, Lin ................................................................................................. 36 Saxena, Shailendra ............................................................................ 37 Supur, Mustafa ................................................................................... 38 Swain, Greg........................................................................................ 39 Tran, Wendy ....................................................................................... 40 Wang, Tao .......................................................................................... 41 Xiao, Jing............................................................................................ 42 Xiong, Ming ........................................................................................ 43
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting EIS and AFM Studies of Alamethicin Ion Pores Formed in a Floating Phospholipid Membrane Supported on a Gold Electrode Surface Fatemeh Abbasi,* Jacek Lipkowski Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
[email protected] The floating bilayer lipid membranes (fBLMs) of DMPC/Egg-PG vesicles in the absence and presence of alamethicin were investigated using electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM). A significant decrease in membrane resistivity was observed when alamethicin was inserted into the fBLM indicating that the peptides are forming ion conducting pores. A phase segregation observed for the pure DMPC/Egg-PG fBLMs was removed after incorporation of alamethicin suggesting that alamethicin has smoothening effect and creates a more uniform bilayer. A direct visualization of the alamethicin pores was obtained by molecular resolution AFM images revealing that the pores are not randomly dispersed throughout the bilayer, but instead form hexagonal aggregates. The diameter of an individual pore is consistent with the size of a hexameric pore predicted by molecular dynamics simulations.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Manganese Oxide Electrodes and the Effect of Substrate on Electrochemical Impedance Spectroscopy Adrienne Allison,* Heather Andreas
Department of Chemistry, Dalhousie University, Halifax, Nova Scotia
[email protected] Manganese oxides are environmentally-friendly, low-cost materials with promising applications in energy storage devices, such as electrochemical capacitors. One electrochemical technique that can be used to evaluate the performance of electrochemical capacitors is electrochemical impedance spectroscopy (EIS). EIS is a powerful technique, which can quantify various characteristics of an electrochemical system, including resistance and capacitance. In the literature, manganese oxide films are coated onto various substrates, such as a variety of carbon materials1–3 or metals such as stainless steel.4,5 However, research regarding how the substrate may impact EIS measurements has been widely neglected. In this work, manganese oxide electrodes are formed on various substrates via potentiostatic electrodeposition from 0.2 M MnSO4. EIS measurements on manganese oxide working electrodes in a three-electrode cell setup show dramatic changes in EIS data for different electrode substrates. Whereas a common conclusion would be that differences in EIS data suggest differences in the manganese oxide, this work suggests that substrate effects contribute extensively to EIS plots. The phenomena responsible for these differences in EIS data are explored, including substrate composition and roughness. This highlights the importance of considering how substrates may influence data when analyzing the electrochemical response of manganese oxide electrodes. References [1] Liu, X.; Pickup, P. G. J. Electrochem. Soc. 2011, 158 (3), A241. [2] Chang, H.-W.; Lu, Y.-R.; Chen, J.-L.; Chen, C.-L.; Lee, J.-F.; Chen, J.-M.; Tsai, Y.-C.; Chang, C.-M.; Yeh, P.-H.; Chou, W.-C.; Liou, Y.-H.; Dong, C.-L. Nanoscale 2015, 7 (5), 1725–1735. [3] Liu, M.; Gan, L.; Xiong, W.; Xu, Z.; Zhu, D.; Chen, L. J. Mater. Chem. A 2014, 2 (8), 2555–2562. [4] Chen, Y.; Wang, J. W.; Shi, X. C.; Chen, B. Z. Electrochim. Acta 2013, 109, 678–683. [5] Suhasini. J. Electroanal. Chem. 2013, 690, 13–18.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Modular Construction of Ru- and Ir- Chromophore Photoanodes by Covalent Bonding and Self-Assembly Mona Amiri,* Chao Wang, Octavio Martinez Perez, and Steven H. Bergens
Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada, T6G 2G2
[email protected] The Dye-sensitized photoelectrochemical cells (DSPECs) convert the energy of visible light into chemical bonds through water splitting.1 We report a reliable method to attach 1,10-phenanthroline (phen) to ITO or TiO2 semiconductors by a C(5)-Osurface single covalent bond. Reaction between the surface phen and the corresponding Ru- or Ir- precursors formed the [Ru(bipy)2(phen)]2+ (bipy = 2,2'-bipyridine) or [Ir(ppy)2(phen)]+ (ppy = 2-phenylpyridine) chromophores grafted at C(5) to ITO or TiO2. We investigated the photoelectrochemical activity of these photoanodes with hydroquinone and triethylamine as sacrificial electron donors under neutral and basic conditions. The covalent C(5)-Osurface linkage is quite resistant to hydrolysis under basic conditions, unlike phosphonate acid groups.2,3 The cationic surfaces were allowed to self assemble with colloidal, anionic mixed-oxide water oxidation catalysts as an approach towards modular photo anodes for water oxidation. The results from these studies will be presented as well. References [1] P. Xu et al. Nano Today, 14 (2017) 42-58. [2] M. K. Brennaman et al. J. Am. Chem. Soc. 138 (2016) 13085-13102. [3] K.-R. Wee et al. J. Am. Chem. Soc. 136 (2014) 13514-13517.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Enhancing the Corrosion Resistance of PEM Fuel Cell Carbon Support Materials Using Surface Functionalization Marwa Atwa,1,2,* Samantha Luong,1 Xiaoan Li,1 and Viola Birss1 1Department
of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada T2N 1N4 2Department of Chemistry, Suez Canal University, El Salam District Ismailia, Ismailia Governorate, Egypt
High surface area carbon materials are commonly used in a wide range of electrochemical applications, such as in PEM fuel cells, lithium ion batteries, capacitors, and redox flow batteries. However, these carbons can suffer from corrosion, especially in acidic media and depending on the conditions employed, such as potential and temperature. For instance, for proton exchange membrane (PEM) fuel cell cathodes, carbon corrosion under standard operating conditions is quite slow (at 0.5 V–0.95 V vs. the RHE), but it can become severe under start-up and shut-down conditions when the potential of the cathode can reach 1.4 -1.6 V vs. RHE. In the current work, mesoporous colloid imprinted carbon powders (CICs), with a pore diameter of 85 nm pore (CIC-85), were investigated both for their performance as a Pt nanoparticle catalyst support and for its corrosion resistance, in comparison with conventional microporous Vulcan carbon (VC) supports.1,2 CIC-85 is highly hydrophilic and was synthesized using 85 nm silica colloid templates, then surface-functionalized with either a hydrophobic (2,3,4,5,6-pentafluorophenyl (-PhF5)) or hydrophilic group (phenyl sulfonate, -PhSO3H) using the in-situ diazonium reduction reaction. For corrosion testing, a potential cycling-step sequence was used in room temperature 0.5 M H 2SO4. To obtain information about the extent of carbon oxidation and surface area changes, cyclic voltammetry and charge/time analysis of the double layer and pseudo-capacitive gravimetric charges of the carbons, prior to and after the application of these potential steps, has been carried out. The effect of surface modification of NCS-85 with the –PhF5 groups on both the CIC nanostructure and its corrosion resistance will be reported in this presentation. References [1] Forouzandeh, F. et al. J. Power Sources 378 (2018) 732–741. [2] Forouzandeh, F. et al. J. Electrochem. Soc. 165 (2018) F3230–F3240.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Using Surface-Confined Redox and Ion Pairing Reactions to Detect Micelle Formation in Solution Antonella Badia1,2* and Eric R. Dionne1,2 1Département
de chimie, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC H3C 3J7 2FRQNT Quebec Center for Advanced Materials
[email protected]
Self-assembled monolayers (SAMs) of ferrocenylalkanethiolates (FcC nS) chemisorbed to gold surfaces were originally designed for fundamental studies of long-range interfacial electron transfer across a welldefined and chemically tailorable organic layer. Oxidation of the SAM-bound ferrocene to ferrocenium proceeds via coupled electron-transfer and ion-pairing reactions: FcSAM ⇌ Fc+SAM + eFc+SAM + X-(aq) ⇌ (Fc+X-)SAM (1) The nature of the electrolyte anion X- strongly affects the electrochemistry and stability of the ferroceneterminated SAM in aqueous solution. Hydrophobic anions (e.g., PF 6- and ClO4-) pair more effectively with the poorly-solvated ferrocenium cation than hydrophilic ones (e.g., Cl - and F-). We have investigated the oxidation of FcC12SAu SAMs in the presence of ionic surfactants consisting of a hydrophobic hydrocarbon tail and hydrophilic anionic headgroup.1-2 The idea is to combine the tendency of surfactants to aggregate at solid/liquid interfaces with the preference of SAM-bound ferroceniums to pair with lipophilic anions. We show that the redox response in cyclic voltammetry (i.e., apparent redox potential, formal width at half-maximum of the anodic peak, and anodic-to-cathodic peak separation) is exquisitely sensitive to the surfactant aggregation state in solution (Fig. 1). The surfactant adsorbs to the SAM surface by specific ion-pairing interactions between the anionic headgroups and the oxidized ferroceniums. A longer alkyl chain length results in an increased ability of the surfactant anion to pair with the ferrocenium, resulting in ferrocene oxidation at lower potential. The work presented points to applications of ferrocenylalkanethiolate SAMs as probes of micelle formation and anion-selective membranes. 600
o' / mV E SAM
550 500
n=6 n=8 n = 10
450 400
n = 12 350 -1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
log([CnSO4Na]/cmc)
Fig. 1. Apparent SAM redox potential vs. logarithm of the sodium n-alkyl sulfate concentration expressed in units of the critical micelle concentration (cmc). n indicates the number of methylenes in the alkyl chain. References [1] E.R. Dionne et al., ACS Appl. Mater. Interfaces 9 (2017) 5607-5621. [2] E.R. Dionne et al., J. Am. Chem. Soc. 135 (2013) 17457-17468.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Solid-State Flexible Polymer-Ceramic Composite Electrolyte for AllSolid-State-Li Battery Sourav Bag,* Sanoop Palakkathodi Kammampata, Venkataraman Thangadurai
Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N1N4, Canada Corresponding author:
[email protected] All-solid-state lithium batteries (ASLBs) are very promising for wide range of applications from medical to military applications. Replacement of the conventional liquid phase organic electrolyte in lithium ion battery (LIB) with a solid electrolyte have several advantages such as safety, higher efficiency and reliability. 1 Moreover, metallic Li anode have a higher specific capacity than the graphite, Li anode also mitigate the polysulfide dissolution issue in Li-S batteries and prevent the oxidation of organic electrolyte in Li-O2 batteries. Employment of Li anode can be possible using solid electrolytes. 1 Solid electrolytes having good Li+ conduction mainly found in organic polymer and inorganic/ceramic material. Though polymer-based electrolytes have drawn a major attraction due to their non-brittle property and less interfacial resistance to Li-electrode compared to ceramic-based electrolytes, their flammable nature and electrochemical decomposition voltage are inadequate for commercial application.2 The inorganic/ceramic solid-state electrolyte are non-flammable having high ionic conductivity but their interfacial resistance towards the electrode are the major obstacle for practical utilization. 3 Herein, we will demonstrate our developed polymer-ceramic composite electrolyte membrane for all-solidstate Li battery. The synthesized composite electrolyte exhibits a high ionic conductivity (~ 10 -4 Scm-1 at 55 °C) and less interfacial resistance. The composite electrolyte membrane was characterized using X-ray diffraction pattern, thermogravimetric analysis and scanning electron microscopy. Electrochemical characterization was performed by cyclic voltammetry, electrochemical impedance spectroscopy, and Listripping-plating techniques. Results from electrochemical measurement of the composite membrane support its potential application towards ASLBs operated at 55°C. Synthesis, structural characterization and electrochemical results of polymer-ceramic composite will be demonstrated. References [1] S. P. Kammampata, V. Thangadurai, Ionics, 2017, doi.org/10.1007/s11581-017-2372-7. [2] P. G. Bruce, Solid state electrochemistry, Cambridge university press, 1997. [3] X. Han, Y. Gong, K. K. Fu, X. He, G. T. Hitz, et al. Nat. Mater. 16 (2017) 572–579.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Oxygen Reduction on Ag-Ni Nanoparticles Prepared by Pulsed Laser Ablation in Liquid Erwan Bertin,1,2 Vera Beermann,3 Saskia Buller,4 Robert Schlögl,4 Sven
Reichenberg,1,2 Swen Zerebecki,1,2 Peter Strasser,3 Stephan Barcikowski,1,2 and Galina Marzun1,2 1Technical
Chemistry I and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany 2NanoEnergieTechnikZentrum (NETZ), University of Duisburg-Essen, 47057 Duisburg, Germany 3The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Technische Universität Berlin, Department of Chemistry, 10623 Berlin, Germany 4Max-Planck-Institute for Chemical Conversion, 45470 Mülheim an der Ruhr, Germany Fuel cells represent promising candidates to replace internal combustion engines. While the development of proton exchange membrane fuel cells (PEMFCs) is more advanced, they require high Pt loadings at the cathode due to the sluggish kinetics of ORR.1 The harsh operating conditions of PEMFCs (60-80°C at pH 2-3) further restrict the choice of non Pt-based catalysts.2 On the other hand, Alkaline Fuel Cells (AFCs) allow the use of less expensive but still active catalysts. 3 Ag-based catalysts are especially interesting because, as Pt, they perform ORR through the 4e- pathway. Also, their performances can be further improved by alloying with Ni or Co. Unfortunately, the preparation of such materials is challenging.4 Hence, in this study, we prepared bimetallic Ag10-Ni90 nanoparticles by pulsed laser ablation in liquid (PLAL) of a bimetallic target in ethanol. As reference materials, pure Ag and Ni nanoparticles (NPs) of comparable size were also synthetized. TEM measurements revealed that the NPs size is between 13 nm (Ags NP) and 10 nm (Ag-Ni and Ni NPs). XPS analysis revealed that Ag NPs were mostly metallic, while the Ni NPs surface is mainly consisting of Ni(OH) 2. The combination of EDX and XRD results suggests the bimetallic alloy does not form solid solution crystal phase but displays segregated morphology. However, the investigation of these bimetallic catalysts for ORR in alkaline media reveals that the mass activity of the AgNi catalysts is 4x the one of the pure Ag NPs. These results are promising, as they demonstrate that despite having nearly 10 times less Ag, the Ag-Ni-NPs are more active for ORR. Further results, including XPS experiments on the catalysts conducted at various stages of electrochemical testing, will be presented at the ECS meeting. References [1] Debe, M. K. Nature 486 (2012) 43-51. [2] Kunusch, C.; Puleston, P.; Mayosky, M., PEM Fuel Cell Systems. In Sliding-Mode Control of PEM Fuel Cells, Springer London: London, 2012; pp 13-33. [3] Blizanac, B. B.; Ross, P. N.; Marković, N. M. J. Phys. Chem. B 110 (2006) 4735-4741. [4] Liu, X. J.; Gao, F.; Wang, C. P.; Ishida, K. J. Electron. Mater. 37 (2008) 210-217.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Nanoscale Templates and Scaffolds for Electrochemical Applications Viola Birss,* Anusha Abhayawardhana, Marwa Atwa, Farisa Forouzendeh, Annie
Hoang, and Xiaoan Li Department of Chemistry, University of Calgary Our fuel cell research efforts have a primary focus on increasing the lifetime of both anode and cathode electrocatalysts. In one area of our PEM fuel cell work, a new class of ordered, mesoporous carbon scaffold materials (both powders and free-standing membranes) with nano-engineered pore diameters and lengths, is being developed to better distribute and stabilize the catalytic nanoparticles attached to their surface. These carbons have also been surface modified to control their wettability and enhance their resistance to oxidation, as well to better anchor the catalytic nanoparticles. In other work, we are constructing ordered metal oxide nanotubular arrays and converting them to conducting forms for use as catalysts and/or support materials in PEM fuel cells. We are also taking advantage of the ordered nano-dimpled surface that is left behind when the nanotubes are released from the surface. These dimples are ideal templates for the formation of an electrochemically addressable nanoarray of metal nanoparticles, formed by the thermal or laser dewetting of thin metal or alloy films.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Spectroelectrochemical and Computational Studies of Tetrahydrocannabinol: Towards a Point-of-Need Sensor Christa Brosseau,* Najwan Albarghouthi, Shruti Bindesri, and Cory Pye Department of Chemistry, Saint Mary’s University, Halifax, NS, Canada
[email protected]
With upcoming legalization of cannabis in Canada, there is a need for fast, accurate and reliable methods of analysis for the active ingredient, tetrahydrocannabinol (THC) at the point-of-need. In this talk, I will discuss recent spectroelectrochemical and computational work aimed at better understanding the adsorption behaviour of THC at an electrified interface. Using disposable, modified screen-printed electrodes and a bench-top Raman spectrometer, we show that rapid and selective detection of THC in a biologically relevant matrix is possible, and that the THC molecule has a strong orientational dependence with applied potential.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Micromachined Si Wafers for Electrochemical Surface Enhanced Infrared Spectroscopy Ian J. Burgess*
Department of Chemistry, University of Saskatchewan, Saskatoon, CANADA, S7H 5C8 Thin, micromachined Si wafers, designed as internal reflection elements (IREs) for attenuated total reflectance infrared spectroscopy, are adapted to serve as low-cost substrates for electrochemical ATR surface enhanced infrared absorption spectroscopy (ATR-SEIRAS). Relative to conventional large Si hemisphere IREs, wafer based IREs are more transparent at long mid-IR wavelengths. The appeal of greater transparency is mitigated by smaller optical throughout at larger grazing angles and steeper angles of incidence at the reflecting plane that reduce the enhancement factor. Using the potential dependent adsorption of 4-methoxypyridine (MOP) as a test system, the microgroove IRE is shown to provide relatively strong electrochemical ATR-SEIRAS responses when the angle of incident radiation is between 50-550 corresponding to refracted angles through the crystal of ~ 40 0. The micromachined IREs are shown to outperform a 25 mm radius hemisphere in terms of S/N at wavenumbers less than ca. 1400 cm -1 despite the weaker signal enhancement derived from the steeper angle incident on the IRE/sample interface. The micromachined wafers also allow great potential for IR imaging of electrochemical microfluidic devices when combined with the brightness of synchrotron infrared radiation. References [1] T. Morhart et al, Anal. Chem., 89 (2017), 11818–11824.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Understanding the Role of Carbon Morphology in Sulfonated Silica Ceramic Carbon Electrodes for PEM Fuel Cell Devices Veronica J. Cavallari,1* Stefania Specchia,2 and E. Bradley Easton1 1University
of Ontario Institute of Technology, 2000 Simcoe St. N., Oshawa, ON, L1H 7K4 2 Department of Applied Science and Technology, Politecnico di Torino, Torino, Italy
Improvement in fuel cell electrode materials are required to increase performance and decrease cost of fuel cell devices. One particular limitation is the use of expensive, and precious, platinum within the catalyst layer. In this work, one focus is to work with 40 wt% Pt/C at loadings of 0.2 mg Pt cm-2, and lower, with the vision of a thinner catalyst layer that will increase reactant flow while reducing Pt content. Another limitation of conventional catalysts includes the use of an expensive fluorinated ionomer, Nafion®. Sulfonated-silica ceramic carbon electrodes (SS-CCEs) have demonstrated their ability to eliminate the need of Nafion® within the catalyst layer. Previous work within this group, using 20 wt% Pt/C, has shown that a stoichiometric ratio of a silicate with a sulfonated organosilane can act as the ionomer/ binder, at a fraction of the cost of Nafion®1,2. Due to the lower carbon content in 40 wt% Pt/C catalysts, the sulfonated silane ratio must be optimized for enhanced fuel cell performance. The third focus of this project includes the incorporation of ordered mesoporous carbon (OMC) as a catalyst support. Due to large pores within OMC, it is envisioned that there will be better gas transport and water retention at the cathode3. The larger pores will, presumably, allow for increased interaction between Pt and the ionomer which would increase oxygen reduction reaction kinetics. In this presentation, I will give an overview of recent advances in the fuel cell performance of SS-CCE materials with varying carbon support systems. References [1] Eastcott, J. I. & Easton, E. B. J. Power Sources 245, 487–494 (2014). [2] Eastcott, J. I. & Easton, E. B. J. Electrochem. Soc. 162, 764–771 (2015). [3] Shahgaldi, S. & Hamelin, J. Carbon N. Y. 94, 705–728 (2015).
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Atomic Layer Deposition of MnOx onto Porous Carbon Electrodes for Use in Zinc-Air Batteries Michael Clark,* K. Cadien, and D. Ivey
University of Alberta, 116 St & 85 Ave, Edmonton, AB T6G 2R3
[email protected] The rapidly falling cost of wind and solar energy has made these technologies economically competitive with fossil fuels, promoting large growth. Renewable energy grew by 14.1% in 2016 alone. 1,2 With the continuing growth of renewable technologies, comes the need for cheap, safe, and reliable energy storage solutions. Zinc-air batteries are an attractive option for grid-scale energy storage because they are inexpensive, safe, environmentally benign, and have excellent energy density.3 The cathode for Zn-air batteries has a number of design requirements in order to facilitate the reduction of oxygen from the air. Catalyst distribution on/in the cathode is very important, as effective surface area of the catalyst is critical to battery performance. Since the oxygen reduction reaction utilizes oxygen from the air, three phase boundaries between air, electrolyte, and catalyst are of key importance. 3 Atomic layer deposition (ALD) is a gas phase deposition technique capable of producing thin films of a wide variety of materials. ALD utilizes alternating pulses of reactants that each undergo self-limiting reactions on the sample surface, producing films with excellent uniformity, conformality, composition control, and thickness control on the order of Ångstroms.4 ALD can be used to deposit catalytic material directly onto high surface area electrodes, such as porous carbon paper. The internal surfaces of the electrode can all be coated, increasing effective catalyst surface area and three phase boundary area. In this work, an ALD process is developed to deposit Mn oxide (MnOx) catalytic films directly onto porous carbon for application as the air electrode in Zn-air batteries. MnOx has a variety of oxidation states and crystal structures, each with varying degrees of catalytic activity. In order to maximize performance, various deposition and annealing conditions will be used to generate different MnOx phases. Deposits are characterized using a variety of electrochemical and materials techniques including linear sweep voltammetry, electrochemical impedance spectroscopy, galvanostatic cycling, scanning and transmission electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. References [1] BP Statistical Review of World Energy 66th Edition, June 2017 [2] G. Jifan, “The next energy revolution is already here”, World Economic Forum, September 20 2017, [online] https://www.weforum.org/agenda/2017/09/next-energy-revolution-already-here/ [3] J. Lee, S. T. Kim, R. Cao, N. Choi, M. Liu, K. T. Lee, “Metal–Air Batteries with High Energy Density: Li–Air versus Zn–Air”, Adv. Energy Mater., 1 (2011) 34-50 [4] S. M. George, “Atomic Layer Deposition: An Overview”, Chem. Rev., 110 (2010) 111-131
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Self-Discharge in rGO: Effects of Charge Redistribution and Carbon Oxidation Mallory Davis,* and Heather Andreas
Dalhousie University, Department of Chemistry, Halifax, Nova Scotia, Canada, B3H 4R2
[email protected] Electrochemical capacitors (ECs) are devices that store energy in a double layer of charge at the electrode/electrolyte interface and/or through fast redox reactions (pseudocapacitance). Carbons are common EC materials owing to their high abundance, low cost, and environmental compatibility. In particular, graphene-based materials have sparked interest due to graphene’s high surface area and conductivity.1 In this work, reduced graphene oxide (rGO) is studied. One drawback to ECs is that they experience a considerable degree of self-discharge (SD), a spontaneous potential loss that occurs when the device rests in open-circuit configuration. In general, SD in carbon electrodes is more severe when the carbon is abundant in hetero-atom-containing surface functionalities.2,3 Recently, site-limited carbon oxidation has been identified as a cause of SD in ECs.4 However, in porous carbon materials, whose large surface areas prove desirable for use in ECs, the movement of charge to eliminate potential gradients within the electrode, termed charge redistribution (CR), becomes significant. When charge accumulated near an electrode’s surface redistributes towards the bulk, a potential decline at the surface is measured, resembling SD. Differentiating between CR and carbon oxidation poses a challenge since these processes result in similar SD profiles. This study discerns between SD from carbon oxidation and from CR by investigating both oxidized and unoxidized electrodes, with and without resetting the degree of CR before each charge/SD cycle. Results highlight CR as the dominant process responsible for SD in rGO electrodes. References [1] Simon, P.; Gogotsi, Y. Acc. Chem. Res. 46 (2013) 1094–1103. [2] Kierzek, K.; Frackowiak, E.; Lota, G.; Gryglewicz, G.; Machnikowski, J. Electrochim. Acta 49 (2004) 515–523. [3] Pandolfo, A. G.; Hollenkamp, A. F. J. Power Sources 157 (2006) 11–27. [4] Oickle, A. M.; Tom, J.; Andreas, H. A. Carbon 110 (2016) 232–242.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Electrochemistry of Vertically Aligned Graphene Nanoribbon Electrodes Anna K. Farquhar,* Mustafa Supur, and Richard L. McCreery
Department of Chemistry, National Institute for Nanotechnology, University of Alberta, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9
[email protected] Owing to their high conductivity and large surface area, graphene materials show promise as electrodes in electrical double layer capacitors (supercapacitors). Vertically aligned graphene nanoribbons are an excellent candidate for electrical double layer capacitors due to their high available surface area, and the abundance of easily accessible edge planes, that provide much higher capacitances than basal plane regions. Furthermore, growing graphene nanoribbons directly onto a conducting substrate minimizes the total resistance of the system.1 In this work, aryldiazonium chemistry was used to electrochemically deposit graphene nanoribbons onto a carbon substrate from a 1,8-diaminonapthalene (1,8 DAN) precursor (Fig. 1A). This modification was confirmed using Raman and UV-visible spectroscopy. Aryldiazonium chemistry provides a decidedly more convenient route to growing vertically aligned graphene nanoribbons on conducting substrates compared to the traditional approach of using plasma enhanced chemical vapour deposition. The graphene nanoribbons greatly increased the electrochemically accessible surface area of the electrode, demonstrated by an increased capacitance. Additionally, modification of the carbon substrate with an aminonapthalene (NAP) precursor via aryldiazonium chemistry, which is unable to produce the ribbon structure (Fig. 1B), provided no increase in capacitance compared with the substrate, confirming the importance of the nanoribbon structure for capacitance enhancement. This presentation will outline the preparation of vertically aligned graphene nanoribbon electrodes on a pyrolysed photoresist film (PPF) surface, and subsequent capacitance studies, using both cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS).
Fig. 1. (A) Chemical route for modification of PPF with 1,8 DAN resulting in graphene nanoribbons; (B) Structure resulting from modification of PPF with 1,8 DAN (left), and NAP (right). References [1] Miller, J. R.; Outlaw, R. A.; Holloway, B. C., Electrochimica Acta 56 (2011) 10443-10449.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Molecularly Precise Fe-N3/C Surface for Modeling the Active Site for the Oxygen Reduction Reaction Holly M. Fruehwald,* I. I. Ebralidze, O. V. Zenkina, and E. B. Easton
University of Ontario Institute of Technology 2000 Simcoe St N. Oshawa Ontario L1H 7K4
[email protected] Non-precious metal catalysts are of interest for various electrochemical energy systems due to their low cost and high availability of materials. Yet, there are few reports on the details into the exact structure of the catalytically active sites. It has been hypothesized that the most probable site belongs to a geometry of Fe-N2+2/C which is typically produced through high temperature pyrolysis.1 The high temperature pyrolysis step is disadvantageous due to a distribution of functional group that form on the surface which affects the desired application of the catalyst.2 Thus, it can be difficult when designing a catalyst for specific application. The work presented here demonstrates a model non-precious metal catalyst for the oxygen reduction reaction by functionalizing a commercial carbon support with a nitrogenous terpyridine ligand. The geometry of the ligand allow for the formation of an N3/C active site through a covalent bond. Metal to ligand coordination occurred at room temperature to produce Fe-N3/C active sites on the carbon without harsh reaction conditions and a pyrolysis step. The Fe-N3/C support was subjected to electrochemical studies in aqueous electrolyte and demonstrates its potential as a model Fe-N3/C active site for oxygen reduction.
References [1] M. Lefèvre, E. Proietti, F. Jaouen, J.-P. Dodelet, Science 324 (2009) 71-74. [2] F. Charreteur, F. Jaouen, S. Ruggeri, J.-P. Dodelet, Electrochimica Acta 53 (2008) 2925-2938.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Zn Electrodeposits for Water-Repellent Surfaces Boyang Gao,1* and Kristin M. Poduska1,2
of Chemistry, Memorial University of Newfoundland, St. John’s, NL A1B3X7, Canada; E-Mail:
[email protected] 2Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John’s, NL A1B3X7, Canada Corresponding author email address:
[email protected] 1Department
In this work, a mildly alkaline electrolytes are used to fabricate Zn films which improve the water repellent properties of stainless steel. These investigations are informed by Pourbaix diagrams, calculated by others, that are based on speciation and solubility trends for different Zn(II) complexes that form in the presence of chloride and ammonia. The zinc electrodeposition is under constant potential (-1.5 V vs. SCE) from electrolytes which contained ZnCl2, NH4Cl, and surfactant (polyethyleneimine). After electrodeposition, stearic acid was used to cover the zinc films, which not only prevent the oxidation of zinc but also provide a lower surface energy for water repellency. The combination of zinc film and stearic acid coating shows an impressive degree of water-repellent characteristic, including extremely low adhesion for water droplet. The morphology of zinc crystal under different potential and pH ranges were also investigated, which suggests that more negative potential and higher pH change the crystal growth morphologies and surface coverage. The chemical and physics factors which contribute to the water repellent behaviors of these electrodeposits will be discussed in the context of applications such as mitigating icing and corrosion in harsh offshore environment.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Exo I-Hydrolysis Assisted Electrochemical Quantitation of SurfaceImmobilized DNA Hairpins and Improved HIV-1 Gene Detection Xiaoyi Gao,1,2* Yunchao Li,1 Xinglin Wang,1 and Hua-Zhong Yu2 1Department
of Chemistry, Beijing Normal University, Beijing 100875, P. R. China of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada Corresponding authors:
[email protected] (Y.L.),
[email protected] (H.Y.)
2Department
Herein we report a simple and efficient electrochemical protocol for evaluating the yield of hairpin DNA (hpDNA) conformations upon self-assembling on gold. Taking advantage of the different Exonuclease I (Exo I) assisted hydrolysis towards single-stranded DNA (ssDNA) and hpDNA,1,2 we were able to determine the amounts of surface-tethered DNA nucleotides before and after Exo I hydrolysis using [Ru(NH3)6]3+ as redox indicators,3 by which we can quantitatively evaluate the ratio of hairpin configuration in the mixed film. It was discovered that the ratio of hairpin configuration formed on the surface is appreciably lower than that in the binary assembly solution. The accuracy of the Exo I-assisted electrochemical quantitative protocol has been validated by the DNA hybridization experiments. Besides, we have illustrated the relationship between DNA packing density and the yield of hairpin configuration. More importantly, taking HIV-1 detection as an example, the hpDNA-based biosensor shows better detection limit and broader detection range upon the background reduction by Exo I catalyzed hydrolysis.
References [1] S. K. C. Korada; T. D. Johns; C. E. Smith; N. D. Jones; K. A. McCabe; C. E. Bell. Nucleic Acids Res. 41 (2013) 5887–5897. [2] X. Y. Gao; M. X. Geng; Y. C. Li; X. L. Wang; H.-Z. Yu. Anal. Chem. 89 (2017) 2464−2471. [3] H.-Z. Yu; C. Y. Luo; C. G. Sankar; D. Sen. Anal. Chem. 75 (2003) 3902−3907.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Ru@Pt Core-Shell Nanoparticles as a Catalyst for Ethanol Oxidation in Fuel Cells Annie Hoang, Ehab El Sawy, and Viola Birss*
Department of Chemistry, University of Calgary, Calgary AB *
[email protected] Ethanol has been gaining more attention as a fuel for fuel cells because of its lower toxicity, higher energy density, and availability from biomass. Although Pt is a good catalyst for the ethanol oxidation reaction (EOR), it is an expensive metal and adsorbed intermediates (e.g., CH 3CHO)) can poison the surface. By using Pt-Ru alloys, the cost is lowered and the kinetics of the EOR can be enhanced by removing the intermediates. However, during fuel cell operation, dissolution of Ru from the Pt-Ru alloy catalyst can occur. Thus, our focus is on the construction of core@shell nanoparticles (NPs), where the Ru core is covered, at least partly, by a Pt shell, and Ru dissolution is minimized, while also gaining the benefits of the electronic effects of Ru on Pt. In this work, Ru@Pt NPs were synthesized on Vulcan carbon supports via the two-step polyol method (Method 1), where the Ru core size and Pt shell coverage (0.5 to 2 atomic layers) could be easily controlled. A second approach (Method 2), in which a one-step synthesis was used and no capping agent was required was also examined, where ethanol was used both as the reducing agent and solvent, resulting in a cleaner surface. Transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD) were used to determine the NP crystallinity and size. In addition, CO stripping was used to monitor the surface composition of the Ru@Pt NPs. To investigate the effects of the Pt shell coverage on the electrocatalytic activity of these catalysts, cyclic voltammetry (CV) was conducted in a room temperature 1 M ethanol + 0.5 M H2SO4 solution. It will be shown that the catalysts formed by using Method 2 exhibited better EOR activity than Method 1, especially at higher potentials.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Directly Bonded Sensor for Trace Lead Detection Taufique Z. Redhwan, Matiar M. R. Howlader,* and Yaser M. Haddara
Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON L8S 4K1, Canada *E-mail:
[email protected] Electrochemical sensing of toxic heavy metals such as lead (Pb) has gained considerable attention with the advent of miniaturized sensors. These heavy metal sensors can offer parts-per-billion (ppb) detection limit (LOD) and can replace conventional expensive procedures like atomic absorption spectrometry in point-of-care (POC) applications [1]. For such sensor applications, a wide range of electrode materials such as evaporated copper (Cu),1,2 mercury,3 bismuth,4 graphene,5 gold,6 platinum,7 and boron doped diamond with nanoparticles8 have been used before. Most of these electrodes are limited to thin-films due to fabrication challenges. In contrast, electrodeposition can yield thick film electrodes but rolled annealed (RA) films are an even better choice in terms of strong signal integrity. However, integration of RA films to the substrate may be challenging. This is further aggravated when heterogeneous materials integration is needed for sensing systems. For this, surface-activated bonding9 is an attractive option. In this work, we demonstrate a unique approach to fabricate Cu-based electrochemical sensors for trace Pb detection. One of the novelties reported in this work is the use of a direct bonding technique to bond RA Cu foil (50 μm-thick layer that becomes sensing electrodes) to a liquid crystal polymer (LCP) substrate. For bonding the films, the pre-cleaned Cu and LCP surfaces are activated using 100 W oxygen reactive ion etching plasma (O2-RIE) for 240 s. The activated surfaces are then contacted under pressure and heated to 230 °C in air for 1 hour. Once the bonded specimen cools down, the surface of the Cu film is polished using silicon carbide paper to remove any oxide layer. A 3-electrode etching mask is then printed on the Cu side using a low-cost laser printer. This is followed by wet etching of the non-masked area to develop the sensing electrodes on LCP. One of the electrodes is then chloridized in KCl to form the integrated Cu/CuCl2 reference electrode. This approach thus offers fabrication of all 3-electrodes on the same substrate and excellent repeatability (20×) for Pb sensing in analyte without delamination. Fig. 1 shows the square wave anodic stripping voltammetry (SWASV) peaks for Pb ions recorded using the directly bonded Cu-based sensor. The ASV was performed in 0.2 M, pH 5.2 sodium acetate buffer solutions containing 1 nM to 1 μM Pb ion concentrations. Even at very low concentrations (1 nM), the reported sensor still exhibits a strong current peak (200 nA). The sensor features the lowest reported LOD of 400 m 2g-1) were used as support for Pt and PtRu catalysts nanoparticles. The modification of the surface allowed to reduce 30% the diameter of the metal particles deposited over the support and a 10% increase of power density of membrane electrode assemblies compared with state of art of DMFC PtRu/carbon supported catalyst. 4 References [1] Wang, G., Zhang, L., & Zhang, J. Chemical Society Reviews, 41(2), 797–828 (2012). [2] Zhang, G. et al. J. Mater. Chem. A 3, 15413–15419 (2015). [3] Viva, F. A., Bruno, M. M., Jobbágy, M. & Corti, H. R. J. Phys. Chem. C 116, 4097–4104 (2012). [4] Xie, J., Zhang, Q., Gu, L., Xu, S., Wang, P., Liu, J. Nano Energy, 21, 247–257 (2016).
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Tuning Up Redox and Photophysical Properties of Donor-Acceptor (aza)BODIPY-Based Dyads and Triads for a Rational Design of New Light-Harvesting Materials Victor N. Nemykin,1* Yuriy V. Zatsikha,1 Yuriy P. Kovtun2 and David A. Blank3 1Department
of Chemistry, University of Manitoba, Winnipeg, Canada,
[email protected] 2Institute of Organic Chemistry, National Academy of Sciences Kiev, Ukraine 3Department of Chemistry, University of Minnesota, Minneapolis, USA The redox and photophysical properties of a large number of the BODIPY-, aza-BODIPY-, and BOPHYbased donor-acceptor dyads and triads (with representative examples given in Fig. 1)1,2 have been investigated by the variety of steady-state and time-resolved spectroscopic methods. An influence of the catechol bridge between organic chromophore and the nanocarbon-based acceptor was studied in details and correlated with the electronic structures of new compounds investigated by the Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) methods. It was found that catechol bridge is quite efficient electron-donor, which hinders the photo-induced electron-transfer processes in dyads and triads.
Figure 1. Representative examples of BODIPY-, aza-BODIPY-, and BOPHY-based dyads and triads. References [1] Y. V. Zatsikha et al., submitted to Chem. Eur. J. [2] Y. V. Zatsikha et al., submitted to J. Phys. Chem. C.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Quantitative Electrochemical Measurement of Δ9Tetrahydrocannabinol (THC, Cannabis) and its Metabolites Margaret Renaud-Young,1* Robert Mayall,1 Maciej Goledzinowski,2 Felix JE
Comeau,2 Justin MacCallum,1 Viola Birss1 1Department
of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, Canada T2N 1N4 2Alcohol Countermeasures Systems Corp (ACS) International Inc., 60 International Blvd., Toronto, Ontario, Canada, M9W 6J2
[email protected] With the ongoing legalization of recreational marijuana use, there is an urgent need for a roadside test that can accurately analyze human saliva samples for their Δ9-tetrahydrocannabinol (THC) content. Current detection methods are based on classical immunoassay methods, which are semi-quantitative1 and lack sensitivity,2-4 whereas electrochemical detection is rapid and very sensitive. Using a novel drug infusion method into carbon paper electrodes, a linear dependence between THC concentration and its oxidation charge was observed, exhibiting excellent sensitivity down to 5 pmol of THC by cyclic voltammetry and 1.5 pmol by square wave voltammetry. Notably, the oxidation peak potentials become more negative as the amount of drug deposited increases, suggesting improved oxidation kinetics with higher drug concentrations. Using this deposition method, we also demonstrate the electro-oxidation of the two major metabolites of THC, 11-hydroxy-tetrahydrocannabinol (OH-THC), and 11-nor-9-carboxytetrahydrocannabinol (COOH-THC). Similar to THC, the metabolites show a linear, dose-dependent change in CV peak charge. However, OH-THC demonstrates a Faradaic efficiency of twice that of THC and COOH-THC, reflecting the oxidation of its second hydroxyl group. Overall, this work provides new insights into the electro-oxidation of THC and its metabolites, with a model of the likely surface morphology of the deposited THC material also presented. References [1] K. Declues, S. Perez, A. Figueroa, J. Forensic Sci. 61, (2016) 1664–1670. [2] S. Strano-Rossi et al., Forensic Sci. Int. 221, (2012) 70–76. [3] B. K. Logan, A. L. A. Mohr, S. K. Talpins, J. Anal. Toxicol. 38, (2014) 444–450. [4] D. J. Beirness, D. R. Smith, Can. Soc. Forensic Sci. J. 50, (2017) 55–63.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Host-Guest Interaction at Molecular Interface: Cucurbit[7]uril as a Probe of Structural Heterogeneity in Ferrocenyl Self-Assembled Monolayer on Gold Lin Qi* and Hua-Zhong Yu
Department of Chemistry, Simon Fraser University, Burnaby, 8888 University Drive, British Columbia V5A 1S6, Canada Herein we combine host-guest recognition chemistry and electrochemical analysis to demonstrate that the nanometer-size, supramolecular hosts can be adapted as sensitive probes for the structural heterogeneity in organized molecular assemblies on surface. In particular, we carried out thorough cyclic voltammetric (CV) studies to monitor the binding of cucurbit[7]uril on mixed ferrocenylundecanethiolate/n-alkanethiolate SAMs on gold (FcC11S-/CnS-Au) prepared with different methods (co-adsorption vs. post-assembly exchanges) and with varied diluting n-alkanethiols. Based on the distinct CV responses of CB[7]@Fc complex and free Fc on the surface of SAMs, we were able to determine the conversion ratio from Fc to CB[7]@Fc, a direct indication of its overall density and uniformity. We have shown that the FcC11S-/C8SAu prepared by co-adsorption in a binary solution with low mole fraction of FcC11SH (5%) and by exchanging pre-assembled C8S-Au SAM with FcC11SH for short time (1 min) have the “ideal” structure with isolated and uniformly distributed Fc groups on the surface. In contrast, with similar Fc surface coverage, the FcC11S-/C8S-Au prepared by exchanging FcC11S-Au with C8SH for prolonged time (20 h) has clustered and non-uniformly distributed Fc groups at the surface. While consistent with previous studies based on conventional electrochemical or microscopic studies, the present study extends the potential of host-guest chemistry as a new tool to probe the structures of organized molecular assemblies at the nanometer scale.
References [1] L. Qi et al., J. Phys.Chem. C 121 (2017), 79857992. [2] H. Tian et al., J. Phys. Chem. C 118 (2014),1373313742. [3] W. S. Jeon et al., J. Am. Chem. Soc. 127 (2005), 12984-12989. [4] S. Fujii et al., Electrochim. Acta 52 (2007), 44364442.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Structure Controlled Photocurrent in Bilayer Molecular Junctions Shailendra K. Saxena,* Scott R. Smith, and Richard. L. McCreery
Department of Chemistry, University of Alberta Canada, T6G 2R3 Corresponding author email address:
[email protected] Molecular electronics (ME) is one of the active research area in the field of nanoelectronics. Molecular devices (molecular junctions) having the geometry metal/molecule-molecule/metal are used to study in this work. Light matter interactions are a very useful tool to characterize material as well as devices. Here in this study we have done photocurrent experiments for bilayer molecular junctions/devices. The obtained photocurrent spectrum is directly related with the relative electronic structure of molecules inside the solid state devices (having metal/molecule-molecule/metal) and is also consistent with the UV-Vis spectrum. The direction of photocurrent (positive/negative) is decided by the bottom molecular layer. Positive photocurrent is observed if the bottom molecular layer is an electron donor and negative photocurrent is observed when the bottom layer is an acceptor. Photocurrent spectrum always exhibits signatures of (i) bottom molecular layer (ii) top molecular layer and (iii) information of charge transfer. The charge transfer from one type of molecular layer to the other is very important to study in complete molecular devices which might be possible by the proposed photocurrent experiment which will be discussed.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Electron Transport Features of Large Area Porphyrin Molecular Junctions Mustafa Supur1* and Richard L. McCreery1,2 1Department
of Chemistry, university of Alberta, 11227 Sasketchewan Drive, Edmonton, Alberta T6G 2G2 2National Institute for Nanotechnology, Research Council Canada, 11421 Sasketchewan Drive, Edmonton, Alberta T6G 2M9
[email protected]
Porphyrins are large aromatic molecules, mostly employed as light-harvesters at visible region and electron donors in donor-acceptor pairs designed for photoinduced electron transfer. 1 Porphyrins have been also featured in various single molecule junctions2 and have shown low attenuation (β, nm–1) values3 as an indication of resonant charge transport reaching 10 nm range. 4 The electron transport properties of porphyrins in large area junctions have yet to be studied. In this study, we show the fabrication, characterization and electron transport features of the tetraphenyl porphyrin (TPP) nanolayers in all carbon, large area molecular electronic junctions. References [1] M. D. Peeks et al., J. Am. Chem. Soc. 139 (2017) 10461−10471. [2] S. Battacharyya et al., Nano Lett. 11 (2011) 2709–2714. [3] G. Sedghi et al., J. Am. Chem. Soc. 130 (2008) 8582–8583. [4] G. Kuang et al., J. Am. Chem. Soc. 138 (2016) 11140–11143.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Advanced Carbon Electrodes for Electroanalysis and Spectroelectrochemistry Greg M. Swain*
Department of Chemistry, Michigan State University, East Lansing, MI 48824 USA Carbon electrodes are routinely used for electrochemical detection and sensing applications to quantify electroactive analytes in a variety of media. By electroactive, one is referring to molecules that are easily oxidized or reduced at an electrode surface. Generally speaking, electrochemical measurements often involve measurement of the current that flows in response to the potential perturbation, which is reflective of the local analyte concentration. Carbon is one of the most abundant elements found on the planet and, from a materials perspective, is unique because of the microstructurally-distinct allotropes it forms. These range from single and polycrystalline diamond, to the stacked sheets of graphite, to the microstructurallydisordered glassy carbon, to nanotubes and fullerenes, and finally to the single sheet graphene. All of these carbon materials are used in electrochemical measurements as well as other technologies, in part, because of some common attributes: high mechanical strength, good thermal conductivity and stability, chemical inertness, high carrier mobility and good electrical conductivity, and rich surface chemistry. Boron-doped diamond (BDD) and nitrogen-incorporated tetrahedral amorphous carbon are two types of carbon electrodes that perform well in electroanalytical measurements, often providing superior detection figures of merit compared with conventional carbon electrodes like glassy carbon. In addition, BDD can function as an optically transparent electrode for transmission spectroelectrochemical measurements. In this presentation, some of the basic material and electrochemical properties of these electrode materials will be reviewed and some examples of how BDD has been used (i) for the determination of trace metal ions in solution by anodic stripping voltammetry and (ii) as an optically transparent electrode for transmission spectroelectrochemical measurements will be highlighted. The latter measurements make use of optically transparent diamond electrodes (i.e., thin films of conducting diamond deposited on quartz).
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting A Study of Alkaline Gel Electrolytes for Metal-Air Batteries T.N.T. Tran,* D. Ivey and H.J. Chung
Chemical and Materials Engineering Department, University of Alberta, 9203 116 St NW, Edmonton, AB T6G 1R1 Corresponding author email address:
[email protected] Gel polymers show considerable for use as electrolytes in metal-air batteries. They have high ionic conductivities like liquids but are not prone to leakage. There are challenges, however, including poor interfacial contact between the polymer electrolyte and the electrodes as well as degradation of the electrolyte over time due to charge/discharge cycles. Here, three different hydrogel networks are synthesized to fabricate polymer alkaline gel electrolytes; these are polyvinyl alcohol (PVA), polyacrylic acid (PAA) and polyampholyte (PAM). The morphology and structure of the membranes are characterized using scanning electron microscopy and Fourier-transform infrared spectroscopy (FTIR). Water uptake is determined through weight measurements before and after freeze-drying. Electrochemical properties are measured by electrochemical impedance spectroscopy and cyclic voltammetry. The mechanical strength is characterized by compression testing. PAA has the highest electrical conductivity in 6 M KOH (which is a typical electrolyte used for metal-air batteries) with a value of 258 mS/cm, while that of PVA and PAM in KOH are 156 and 42 mS/cm, respectively. The ionic conductivity of the gel electrolyte is primarily determined by the KOH solution composition; e.g., the water uptake for PAA, PVA and PAM in 6 M KOH is 268%, 183% and 93%, respectively. Hence, there is a trade-off between ionic conductivity and mechanical stability.
Potassium Ion Selective Electrode with Polyaniline and Valinomycin Based Poly(Vinyl Chloride) Membrane T.N.T. Tran,* S.D. Qiu and H.J. Chung Chemical and Materials Engineering Department, University of Alberta, 9203 116 St NW, Edmonton, AB T6G 1R1 Corresponding author email address:
[email protected] Potassium ion selective electrode (K+ ISE) has been one of the most developed ion selective electrodes to quantitatively determine K+ concentration presenting in a solution. The remaining challenge is the formation of water layer beneath ion selective membrane that causes potential drift. In this report, an extra intermediate layer (i.e. polyaniline) can help to minimize the problem. A K+ ISE constructed on the working electrode site (4 mm diameter) of a screen printed electrode was modified with polyaniline before drop casting polyvinyl chloride membrane impregnated with valinomycin ionophore. In addition, reference electrode surface was covered by polyvinyl butyral and sodium chloride layer to prevent leaking and maintain stability. Properties of K+ ISE were observed and analyzed by scanning electron microscopy (SEM), and electroanalytical techniques including chronopotentiometry, potentiometry, and electrochemical impedance spectroscopy (EIS). The ISE can detect K+ with high sensitivity (70 mV/decade), small limit of detection (10-5.9 M) and large detection range (10-5 – 1 M). Selectivity coefficients towards other ions were also measured including NH4+ (1.27×10-2), Na+ (4.14×10-3), Mg2+ (1.57×10-5), Ca2+ (1.03×10-4), and Fe3+ (2.08×10-5). This implicates that the ISE may be applied in agriculture (soils, fertilizers, plant materials), food industry (dairy products, fruit juices, brewing solutions), and biomedical applications (blood, plasma, serum, sweat) for determining the concentration of K+.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Artificially Designed Self-Assembled Monolayer-Based DNA Biosensor Tao Wang,* Margaret Renaud-Young, Robert M. Mayall and Viola I. Birss
Department of Chemistry, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, Canada T2N 1N4
[email protected] DNA biosensors are promising candidates for providing rapid detection of possible pathogenic agents, which is crucial to preventing the spread of infection. 1 In this work, we have designed and constructed a DNA biosensor that is based on a self-assembled monolayer (SAM) composed of single-stranded, thiolmodified DNA (ssDNA, which serves as a surface-bound probe) of different lengths. In order to stabilize SAM formation with the thiol modified ssDNA probes, a strong reducing agent 2 was used, with the benefits of this approach confirmed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy. The affinities of the different lengths of ssDNA probes (8, 16 and 24 mer) to a 48 base-pair ssDNA target in solution were studied using microscale thermophoresis (MST). When comparing probe adhesion at room temperature conditions (22 °C), we found that it’s easiest for the 8-base pair ssDNA probe to achieve optimum binding condition to its target. Comparisons between the binding affinity of different ssDNA probes were made, showing that while higher binding affinities can be achieved with a longer ssDNA probe on the Au electrode surface, these probes also require incubation at higher temperatures to achieve optimal binding. Based on this result, the performance of the SAM-based DNA biosensor was tested using a Hoechst 33258 dye, a molecule that has been shown to bind specifically to the minor groove of doublestranded DNA (dsDNA) 3 and thus should be present in greater quantities the longer the DNA strands are. When treated with the same amount of Hoechst dye solution, a larger current peak due to Hoechst dye oxidation is observed when the ssDNA probe is present. The DNA biosensor, based on the 8-base pair ssDNA probe, was able to successfully detect DNA with a limit of detection as low as 0.1 pM, making it a potent candidate for rapid and sensitive DNA detection. References [1] B. Meric, K. Kerman, et al, Talanta, 56 (2002) 837-846. [2] Y. Xiao, et al, PNAS, 103 (2006) 16677-16680. [3] I. Haq, et al, J. Mol. Biol., 271 (1997) 244-257.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Enhanced Performance of Electrochemical CO2 Reduction with Nanostructured Catalysts Jing Xiao,* Subiao Liu and Jing-Li Luo
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada Electrochemical reduction of CO2 to value-added products provides an attractive solution for the global warming issues.1 The biggest challenge faced by electrochemical CO 2 reduction reaction (CO2RR) is the low performance of catalysts, such as low Faradic and energy efficiency, low current density and high overpotential.2 Recently, nanostructured catalysts have attracted much attention due to the enhanced performance towards CO2RR as compared to the bulk counterparts.3-5 The increased active sites, high edge to corner ratio and more low-coordinated sites of nanostructured catalysts contribute to the improved performance of these catalysts toward CO2 reduction.3,4 In our previous work, the current density, Faradaic efficiency and stability, coupled with the energy efficiency, for CO 2RR were significantly improved by Agbased nanostructured catalysts. Tuning the particle size has also been demonstrated to greatly improve the catalytic activity for CO2RR.5-7 Nevertheless, there have been limited experimental and computational studies on the size effects (i.e., width and length) among metal nanowires (NWs), particularly the structureordered ultrathin NWs which are completely enclosed by energetically favorable specific facet. Therefore, it is highly imperative to investigate the nanostructure with energetically preferable facets for CO 2RR, with an emphasis on the nanostructured metal materials. References [1] C. Costentin et al. Chem. Soc. Rev. 42 (2013) 2423–2436. [2] J. Qiao et al. Chem. Soc. Rev. 43 (2014) 631–675. [3] Y. Zheng et al. Nano Energy 40 (2017) 512-539. [4] R. Reske et al. J. Am. Chem. Soc. 136 (2014) 6978-6986. [5] W. Zhu et al. J. Am. Chem. Soc. 135 (2013) 16833–16836. [6] C. Kim et al. J. Am. Chem. Soc. 137 (2015) 13844–13850. [7] D. Gao et al. J. Am. Chem. Soc. 137 (2015) 4288–4291.
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Canadian Section of the Electrochemical Society - 2018 Spring Meeting Rechargeable Zinc-Air Batteries Using Separate Electrodes Fabricated by Electrodeposition Ming Xiong,* Matthew Labbe, Michael P Clark and Douglas G Ivey
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 1H9
[email protected] The rapid growth of renewable energy production requires economical methods to store and deliver the electricity. Interest in rechargeable zinc-air batteries has been renewed in recent years because of their high theoretical energy density and low cost.1 However, large-scale industrial deployment of zinc-air batteries is limited by several issues; the most concerning of these are low round-trip energy efficiency and reduced cycling stability. Both problems are intimately related to air electrode degradation. There are competing electrode requirements for discharging and charging of zinc-air batteries. The discharge process is governed by the oxygen reduction reaction (ORR), requiring an air electrode that is not flooded by the electrolyte. The charging process (oxygen evolution reaction or OER), on the other hand, is enhanced by submersion of the electrode in the electrolyte. The ORR active sites at the air electrode can also be damaged by the oxidation potential during OER.2 As such, a battery design using separate decoupled electrodes for discharge and charge should be able to eliminate the adverse effects. In addition, bifunctional catalysts are not necessary for the air electrode, so that separate, inexpensive ORR and OER catalysts can be developed and optimized. In this study, ORR and OER active catalysts are electrodeposited on different current collectors. The ORR catalyst is manganese oxide based, while the OER catalyst is a cobalt-iron solid solution oxide. Both catalysts are nanostructured with large surface areas for electrochemical reactions. Electrochemical tests show that both catalysts have comparable or higher activity and durability relative to their commercial PtRu catalyst counterparts. The catalysts were assembled as decoupled electrodes into a zinc-air battery for discharge/charge tests. Preliminary cell testing shows that the discharge/charge efficiency is about 59% at a current density of 10 mA/cm2, with both electrodes showing excellent stability after 50 h of battery testing. References [1] E. Davari, D.G. Ivey, Sustainable Energy & Fuels 2 (2018) 39-67. [2] Y. Li and J. Lu, ACS Energy Letters 2 (2017) 1370-1377.
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