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Non-noble metal based electrocatalysts for the hydrogen evolution reaction (HER) hold great potential for commercial applications. However, effective design strategies are greatly needed to manipulate the catalyst structures to achieve high activity and stability comparable to those of noble-metal based electrocatalysts. Herein, we present a facile route to synthesize layered Co 9 S 8 intercalated with Co cations (Co 2+ -Co 9 S 8 ) (with interlayer distance up to 1.08 nm) via a one-step solvothermal method. Benefiting from a large interlayer distance and efficient electron transfer between layers, the Co 2+ -Co 9 S 8 hybrid shows outstanding electrocatalytic hydrogen evolution performance in an acid electrolyte. The electrocatalytic performance is even better than that of 20% Pt/C at the <−0.54 V region with an overpotential of 86 mV at a current density of 10 mA cm −2 in 0.5 mol L −1 H 2 SO 4 . More importantly, the system can maintain excellent stability for more than 12 h without obvious decay. This study not only presents a novel and efficient approach to synthesize cobalt sulfide intercalated with Co cations for stable electrocatalytic HER but also provides an avenue for the design of intercalated materials used in other energy applications.
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Interfacing metals and compounds for enhanced hydrogen evolution from water splitting
Hydrogen production from water electrolysis with renewable energy input has been the focus of tremendous attention, as hydrogen is widely advocated as a clean energy carrier. In order to realize large-scale hydrogen generation from water splitting, it is essential to develop competent and robust electrocatalysts that will substantially decrease the overpotential requirement and improve energy efficiency. Recent advances in electrocatalyst design reveal that interfacial engineering is an effective approach in tuning the adsorption–desorption abilities of key catalytic intermediates on active sites, accelerating electron transfer, and stabilizing the active sites for long-term operation. Consequently, a large number of hybrid electrocatalysts consisting of metal/compound interfaces have been demonstrated to exhibit superior performance for electrocatalytic hydrogen evolution from water. This article highlights examples of these hybrid electrocatalysts, including noble metal and non-noble metal candidates interfaced with a variety of compounds. Specific emphasis is placed on the synthetic methods, reaction mechanisms, and electrocatalytic activities, which are envisioned to inspire the design and development of further improved electrocatalysts for hydrogen evolution from water splitting on an industrial scale.
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- Award ID(s):
- 1914546
- PAR ID:
- 10207451
- Date Published:
- Journal Name:
- MRS Bulletin
- Volume:
- 45
- Issue:
- 7
- ISSN:
- 0883-7694
- Page Range / eLocation ID:
- 548 to 554
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)Electrochemical water splitting is one of the most promising approaches for sustainable energy conversion and storage toward a future hydrogen society. This demands durable and affordable electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). In this study, we report the preparation of uniform Ni–P–O, Ni–S–O, and Ni–S–P–O electrocatalytic films on nickel foam (NF) substrates via flow cell-assisted electrodeposition. Remarkably, electrodeposition onto 12 cm 2 substrates was optimized by strategically varying critical parameters. The high quality and reproducibility of the materials is attributed to the use of a 3D-printed flow cell with a tailored design. Then, the as-fabricated electrodes were tested for overall water splitting in the same flow cell under alkaline conditions. The best-performing sample, NiSP/NF, required relatively low overpotentials of 93 mV for the HER and 259 mV for the OER to produce a current density of 10 mA cm −2 . Importantly, the electrodeposited films underwent oxidation into amorphous nickel (oxy)hydroxides and oxidized S and P species, improving both HER and OER performance. The superior electrocatalytic performance of the Ni–S–P–O films originates from the unique reconstruction process during the HER/OER. Furthermore, the overall water splitting test using the NiSP/NF couple required a low cell voltage of only 1.85 V to deliver a current density of 100 mA cm −2 . Overall, we demonstrate that high-quality electrocatalysts can be obtained using a simple and reproducible electrodeposition method in a robust 3D-printed flow cell.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1557/mrs.2020.169
