Vertically Aligned Ni Nanowires as Platform for Kinetically-Limited Water Splitting Electrocatalysis
| dc.contributor.author | Hao, Minghui H. | |
| dc.contributor.author | Garbarino, Sébastien | |
| dc.contributor.author | Prabhudev, Sagar | |
| dc.contributor.author | Borsboom-Hanson, Tory | |
| dc.contributor.author | Botton, Gianluigi A. | |
| dc.contributor.author | Harrington, David A. | |
| dc.contributor.author | Guay, Daniel | |
| dc.date.accessioned | 2020-02-28T20:43:27Z | |
| dc.date.available | 2020-02-28T20:43:27Z | |
| dc.date.copyright | 2019 | en_US |
| dc.date.issued | 2018 | |
| dc.description.abstract | Electrochemical templating through porous membranes is applied to form arrays of micrometer long Ni nanowires (NWs). Detailed structural and electrochemical characterization, including electrochemical impedance spectroscopy (EIS), was conducted to assess the electrocatalytic properties of these Ni NW arrays for the O2 evolution reaction (OER) in 1 M KOH. Detailed structural analysis showed that Ni NWs have a diameter of ca. 350 nm and a mean 80 nm average distance between the NW center. For the longest NWs (20 μm long), the ratio between the pore opening and pore length is 0.4%. From detailed HR-TEM and EELS analysis providing information on the chemical state of atoms from quantitative analysis of the signals, Ni NWs are composed of a Ni metallic core surrounded by a Ni(OH)2 layer that thickens from 10 to 20 nm after extensive electrochemical tests. Three different methods, namely, SEM geometry measurements, the α-Ni(OH)2 charge method, and the capacitance method, were used to assess how the current varies with the NW length. The three different methods are all in agreement, and the current increases with length (or mass) precisely and only because of the surface area effect. The most surprising result is that the OER process occurs with exactly the same intrinsic catalytic activity at the bottom of these deep pores, and gas is evolved without any significant effects of electrolyte resistance, mass transport of dissolved oxygen, or bubble occlusion of the pores. Accordingly, vertically aligned 1D NWs can be used as an effective platform that mitigates the negative effects of gas evolution. Increasing the intrinsic activity by incorporating more active materials will further improve this type of electrode. | en_US |
| dc.description.reviewstatus | Reviewed | en_US |
| dc.description.scholarlevel | Faculty | en_US |
| dc.description.sponsorship | This research was conducted as part of the Engineered Nickel Catalysts for Electrochemical Clean Energy project administered from Queen’s University and supported by Grant No. RGPNM 477963-2015 under the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Frontiers Program. Part of the electron microscopy work was carried out at the Canadian Centre for Electron Microscopy, a national facility supported by the Canada Foundation of Innovation under the MSI program, NSERC, and McMaster University. | en_US |
| dc.identifier.citation | Hao, M.H., Garbarino, S., Prabhudev, S., Borsboom-Hanson, T., Botton, G.A., Harrington, D.A. & Guay, D. (2018). Vertically Aligned Ni Nanowires as Platform for Kinetically-Limited Water Splitting Electrocatalysis. The Journal of Physical Chemistry C, 123(2), 1082-1093. https://doi.org/10.1021/acs.jpcc.8b10414 | en_US |
| dc.identifier.uri | https://doi.org/10.1021/acs.jpcc.8b10414 | |
| dc.identifier.uri | http://hdl.handle.net/1828/11592 | |
| dc.language.iso | en | en_US |
| dc.publisher | The Journal of Physical Chemistry C | en_US |
| dc.subject | Radiology | |
| dc.subject | Nanowire arrays | |
| dc.subject | Electrical properties | |
| dc.subject | Electrodes | |
| dc.subject | Membranes | |
| dc.subject.department | Department of Chemistry | |
| dc.title | Vertically Aligned Ni Nanowires as Platform for Kinetically-Limited Water Splitting Electrocatalysis | en_US |
| dc.type | Postprint | en_US |