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Keywords: | nanomaterials, surface chemistry, battery research, hybrid materials, battery materials, photoluminescence, metamaterials, silicon chemistry, germanium chemistry |
FES Funded ProjectsOutputs
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Mn3O4 Nanoparticle-Decorated Hollow Mesoporous Carbon Spheres as an Efficient Catalyst for Oxygen Reduction Reaction in Zn-air BatteriesHybrids of Mn3O4 nanoparticles and hollow carbon spheres prepared from templated pyrolysis of polydopamine were assembled via a straightforward sonication procedure. The resulting hybrids exhibit excellent catalytic activity toward the oxygen reduction reaction (ORR) in prototype Zn–air batteries. Impressively, these catalysts exhibit higher discharge potential and exceptional stability when compared to commercial Pt–Ru catalysts while simultaneously showing comparable onset potential and maximum current density.T06-P03 University of Alberta | Publication | 2020-06-19 | | Hollow Mesoporous Carbon Nanospheres Decorated with Metal Oxide Nanoparticles as Efficient Earth-Abundant Zinc-Air Battery CatalystsHybrids comprising hollow mesoporous nitrogen doped carbon (HMC) nanospheres and metal oxide-nanoparticles were prepared via a hydrothermal synthesis. These materials exhibit excellent bifunctional catalytic activity in the oxygen reduction and evolution reactions (ORR and OER, respectively) that core to the efficient operation of Zn-air batteries. When incorporated into prototype devices, Co3O4 and MnCo2O4 nanoparticle decorated HMC exhibited discharge potentials of 1.26 and 1.28 V at 10 mA cm-2, respectively. ‘CoFeNiO’ decorated HMC exhibited a charging potential of 1.96 V at 10 mA cm-2. These metrics are much superior to benchmark Pt-Ru, which displayed discharge and charging potentials of 1.25 and 2.01 V, respectively, at the same current density. The battery equipped with Co3O4 decorated HMC demonstrated 63% initial efficiency before cycling. After cycling at 10 mA cm-2 for 200 hours, the battery efficiency was maintained at 56.5%, outperforming the battery with Pt-Ru (50.2% after 50 h).T06-P03 University of Alberta | Publication | 2021-01-07 | Yingjie He, Drew Aasen, Alexandra McDougall, Haoyang Yu, Matthew Labbe, Chuyi Ni, Sarah Milliken, Ivey, D., Jonathan G C Veinot | Front Cover: Hollow Mesoporous Carbon Nanospheres Decorated with Metal Oxide Nanoparticles as Efficient Earth-Abundant Zinc-Air Battery CatalystsThe Front Cover shows an artistic representation of a new class of bifunctional zinc‐air battery catalysts that consist of hollow mesoporous carbon nanospheres decorated with various precious‐metal‐free transition‐metal oxide nanoparticles.T06-P03 University of Alberta | Publication | 2021-03-22 | Yingjie He, Drew Aasen, Alexandra McDougall, Haoyang Yu, Matthew Labbe, Chuyi Ni, Sarah Milliken, Ivey, D., Jonathan G C Veinot | Exploring Structural Nuances in Germanium Halide Perovskites Using Solid-State $\less$sup$\greater$73$\less$/sup$\greater$Ge and $\less$sup$\greater$133$\less$/sup$\greater$Cs NMR SpectroscopyT06-Z01 | Publication | 2022-02-01 | Riley W Hooper, Chuyi Ni, Dylan G Tkachuk, Yingjie He, Victor V Terskikh, Jonathan G C Veinot, Vladimir K Michaelis | Interfacing Enzymes with Silicon-Based Nanoparticles through the Amide Coupling Reaction T02-Z01 | Activity | 2018-05-30 | Christopher Robidillo, Maryam Aghajamali, "Sinelnikov, R.", M A Islam,, A V Geisler,, "Zhang, Xiyu", "Faramus, A.", Jonathan G C Veinot | Ultrabright Fluorescent and Lasing Microspheres from a Conjugated PolymerT02-Z01 | Publication | 2018-06-21 | Kirsty Gardner, Maryam Aghajamali, "Vagin, S.", "Pille, J.", William Morrish, Jonathan G C Veinot, Al Meldrum, "Rieger, B." | Water-Assisted Transfer Patterning of NanomaterialsT06-Z01 University of Alberta | Publication | 2018-07-19 | | Silicon Nanocrystals: From Solution to Solid StateT06-Z01 | Publication | 2018-06-11 | Maryam Aghajamali | Hybrid Nanomaterials for Photocatalytic Conversion of CO2T06-Z01 | Activity | 2018-05-29 | Alyx Thiessen | Insights into the Structure of Silicon NanocrystalsT06-Z01 | Activity | 2019-02-12 | Alyx Thiessen, Michelle Ha, Riley Hooper, Jonathan G C Veinot, Vladimir K Michaelis | Endogenous Dynamic Nuclear Polarization NMR of Hydride-Terminated Silicon NanoparticlesT02-Z01 University of Alberta | Publication | 2019-04-13 | Michelle Ha, Alyx Thiessen, I V Sergeyev, Veinot, J., Vladimir K Michaelis | Understanding the Anatomy of a Silicon NanocrystalT06-Z01 | Activity | 2019-05-03 | Alyx Thiessen, Michelle Ha, Riley Hooper, Jonathan G C Veinot, Vladimir K Michaelis | Understanding the Anatomy of a Silicon NanocrystalT06-Z01 | Activity | 2019-06-01 | Alyx Thiessen, Michelle Ha, Riley Hooper, Jonathan G C Veinot, Vladimir K Michaelis | H-SiNP: Cutting Through the Layers Using 29Si MAS and DNP NMRT02-Z01 | Activity | 2019-09-01 | Michelle Ha, Alyx Thiessen, I V Sergeyv,, Jonathan G C Veinot, Vladimir K Michaelis | A Tale of Seemingly “Identical” Silicon Quantum Dot Families: Structural Insight into Silicon Quantum Dot PhotoluminescenceT06-Z01 University of Alberta | Publication | 2020-06-29 | Alyx Thiessen, Veinot, J., Lijuan Zhang, Anton O Oliynyk, Haoyang Yu, "Kevin O’Connor ", Al Meldrum | Dehydrocoupling – an alternative approach to functionalizing germanium nanoparticle surfacesT12-Z01 University of Alberta | Publication | 2020-02-05 | Md Asjad Hossain, "Morteza Javadi ", Haoyang Yu, Alyx Thiessen, Nduka Ikpo, " Anton O. Oliynyk Anton O Oliynyk ", Veinot, J. | Silicon Nanoparticles from the Inside Out: Exploring the Internal Structure of Silicon Nanoparticles and Its Impact on Their PhotoluminescenceT06-Z01 | Publication | 2020-08-24 | Alyx Thiessen | “Turning the dials”: controlling synthesis, structure, composition, and surface chemistry to tailor silicon nanoparticle propertiesT02-Z01, T06-Z01, T12-Z01, T12-Q01 | Publication | 2021-01-01 | Sarah Milliken, Alyx Thiessen, I Teng Cheong, Kevin O'Connor, Ziqi Li, Riley Hooper, Christopher Robidillo, Jonathan G C Veinot | Thermally Induced Dehydrogenative Coupling of Organosilanes and H-Terminated Silicon Quantum Dots onto Germanane SurfacesT06-Z01, T12-Z01 | Publication | 2020-04-01 | Haoyang Yu, Alyx Thiessen, Md Asjad Hossain, Marc Julian Kloberg, Bernhard Rieger, Jonathan G C Veinot | Synthesis, Properties, and Derivatization of Poly(dihydrogermane): A Germanium-Based Polyethylene AnalogueT02-Z01, T06-Z01 | Publication | 2021-04-16 | Haoyang Yu, Chuyi Ni, Alyx Thiessen, Ziqi Li, Jonathan G C Veinot | Hydride Terminated SiNP:Cutting through the Layers Using 29Si MAS and DNP NMR SpectroscopyT02-Z01, T06-Z01 | Activity | 2020-02-01 | Michelle Ha, Alyx Thiessen, Riley Hooper, I V Sergeyev, Jonathan G C Veinot, Vladimir K Michaelis | Shining in a New Size Regime: Silicon Nanoparticle AssembliesT06-Z01 | Activity | 2020-11-11 | Kevin O'Connor | Graduate Student ScholarshipT06-Z01 | Award | 2021-03-10 | Chuyi Ni | Photocatalytic mechanism control and study of carrier dynamics in CdS@C3N5 core-shell nanowiresWe present a potential solution to the problem of extraction of photogenerated holes from CdS nanocrystals and nanowires. The nanosheet form of C3N5 is a low bandgap (Eg = 2.03 eV), azo-linked graphenic carbon nitride framework formed by the polymerization of melem hydrazine (MHP). C3N5 nanosheets were either wrapped around CdS nanorods (NRs) following the synthesis of pristine chalcogenide or intercalated among them by an in situ synthesis protocol to form two kinds of heterostructures, CdS-MHP and CdS-MHPINS respectively. CdS-MHP improved the photocatalytic degradation rate of 4-nitrophenol by nearly an order of magnitude in comparison to bare CdS NRs. CdS-MHP also enhanced the sunlight-driven photocatalytic activity of bare CdS NWs for the decolorization of rhodamine B (RhB) by a remarkable 300% through the improved extraction and utilization of photogenerated holes due to surface passivation. More interestingly, CdS-MHP provided reaction pathway control over RhB degradation. In the absence of scavengers, CdS-MHP degraded RhB through the N-deethylation pathway. When either hole scavenger or electron scavenger was added to the RhB solution, the photocatalytic activity of CdS-MHP remained mostly unchanged while the degradation mechanism shifted to the chromophore cleavage (cycloreversion) pathway. We investigated the optoelectronic properties of CdS-C3N5 heterojunctions using density functional theory (DFT) simulations, FDTD simulations, time-resolved terahertz spectroscopy (TRTS) and photoconductivity measurements. TRTS indicated high carrier mobilities > 450 cm2Vs-1 and carrier relaxation times > 60 ps for CdS-MHP while CdS-MHPINS exhibited much lower mobilities < 150 cm2Vs-1 and short carrier relaxation times <20 ps. Hysteresis in the photoconductive J-V characteristics of CdS NWs disappeared in CdS-MHP confirming surface passivation. Dispersion-corrected DFT simulations indicated a delocalized HOMO and a LUMO localized on C3N5 in CdS-MHP. C3N5, with its extended π-conjugation and low bandgap can function as a shuttle to extract carriers and excitons in nanostructured heterojunctions, and enhance performance in optoelectronic devices. Our results demonstrate how carrier dynamics in core-shell heterostructures can be manipulated to achieve control over the reaction mechanism in photocatalysis. T12-P02, T12-P03, T06-Z01, T12-Z01 University of Alberta | Publication | 2021-04-30 | Kazi Alam, Charles Jensen, Pawan Kumar, Riley Hooper, Guy Bernard, "A. Patidar ", Ajay Manuel, "N.Amer ", "A. Palmgren ", Narendra Chaulagain, David Purschke, John Garcia, "P. Kirwin ", "L. Shoute ", "K. Cui ", "S. Gusarov ", "A. Kobryn ", Vladimir K Michaelis, Frank Hegmann, Shankar, K. | Transtion-metal doping SiNPsT06-Z01 | Activity | 2020-11-11 | Riley Hooper | Alexander Graham Bell Canada Graduate ScholarshipT12-Q01 | Award | 2020-09-19 | Riley Hooper | Goddard Yuk-Tat Lauw and Yau-Chun Lau (Mak) Memorial Graduate ScholarshipT12-Q01 | Award | 2020-09-20 | Riley Hooper | Silicon Quantum Dot–Polymer Fabry–Pérot Resonators with Narrowed and Tunable EmissionsT02-Z01, T06-Z01, T12-Z01 | Publication | 2021-05-01 | I Teng Cheong, William Morrish, William Sheard, Haoyang Yu, Bruno Luppi, Leanne Milburn, Alkiviathes Meldrum, Jonathan G C Veinot | Interfacing Enzymes with Silicon NanocrystalsConference posterT02-Z01 University of Alberta | Activity | 2018-09-18 | | Interfacing Enzymes with Silicon NanocrystalsConference presentationT02-Z01 University of Alberta | Activity | 2018-09-18 | | Ratiometric Detection of Nerve Agents by Coupling Complementary Properties of Silicon-Based Quantum Dots and Green Fluorescent ProteinT02-Z01 University of Alberta | Publication | 2019-08-15 | Christopher Robidillo, "Wandelt, S. ", "Dalangin, R. ", "Zhang, L. ", Haoyang Yu, Al Meldrum, "Campbell, R. ", Veinot, J. | Mesoporous GeOx/Ge/C as a Highly Reversible Anode Material with High Specific Capacity for Lithium-Ion BatteriesT06-Z01 University of Alberta | Publication | 2020-09-20 | "Nuri Hohn ", "Xiaoyan Wang ", Michael A Giebel, "Shanshan Yin ", "David Müller ", Andreas E Hetzenecker, "Lorenz Bießmann Bießmann Lorenz, Lucas P Kreuzer, Gilles E Möhl, Haoyang Yu, Veinot, J., Thomas F Fässler, "Ya-Jun Cheng ", "Peter Müller-Buschbaum " |
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