Ternary Porous Cobalt Phosphoselenide Nanosheets: An Efficient Electrocatalyst for Electrocatalytic and Photoelectrochemical Water Splitting |
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| Authors: | Yang Hou Ming Qiu Tao Zhang Xiaodong Zhuang Chang‐Soo Kim Chris Yuan Xinliang Feng |
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| Affiliation: | 1. Center for Advancing Electronics Dresden (cfaed) and Department of Chemistry and Food Chemistry, Technische Universit?t Dresden, Dresden, Germany;2. Key Laboratory of Biomass Chemical Engineering of Ministry of Education and College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China;3. Institute of Nanoscience and Nanotechnology, College of Physical Science and Technology, Central China Normal University, Wuhan, China;4. Department of Materials Science and Engineering, University of Wisconsin‐Milwaukee, Milwaukee, WI, USA;5. Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA |
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| Abstract: | Exploring efficient and earth‐abundant electrocatalysts is of great importance for electrocatalytic and photoelectrochemical hydrogen production. This study demonstrates a novel ternary electrocatalyst of porous cobalt phosphoselenide nanosheets prepared by a combined hydrogenation and phosphation strategy. Benefiting from the enhanced electric conductivity and large surface area, the ternary nanosheets supported on electrochemically exfoliated graphene electrodes exhibit excellent catalytic activity and durability toward hydrogen evolution in alkali, achieving current densities of 10 and 20 mA cm?2 at overpotentials of 150 and 180 mV, respectively, outperforming those reported for transition metal dichalcogenides and first‐row transition metal pyrites catalysts. Theoretical calculations reveal that the synergistic effects of Se vacancies and subsequent P displacements of Se atoms around the vacancies in the resulting cobalt phosphoselenide favorably change the electronic structure of cobalt selenide, assuring a rapid charge transfer and optimal energy barrier of hydrogen desorption, and thus promoting the proton kinetics. The overall‐water‐splitting with 10 mA cm?2 at a low voltage of 1.64 V is achieved using the ternary electrode as both the anode and cathode, and the performance surpasses that of the Ir/C–Pt/C couple for sufficiently high overpotentials. Moreover, the integration of ternary nanosheets with macroporous silicon enables highly efficient solar‐driven photoelectrochemical hydrogen production. |
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| Keywords: | cobalt phosphoselenide nanosheets P displacements Se vacancies synergistic effects water splitting |
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