Electrodeposition of Cobalt Phosphosulfide Nanosheets on Carbon Fiber Paper as Efficient Electrocatalyst for Oxygen Evolution

• DOI: 10.1002/celc.201800384
• Publication Date: 2018-04-26T17:22:39Z
• Authors: Zhenchuan Liu; Junfeng Zhang; Yangxing Liu; Weikang Zhu; Xiangwen Zhang; Qingfa Wang
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

AbstractTo maximize the activity and durability of transition metal sulfides for water oxidation is still a great challenge. Herein, we developed a new cobalt phosphosulfide nanosheet on carbon fiber paper (CFP) substrate electrocatalyst (Co2−xSP/CFP) following a simple two‐step electrodeposition method. The cobalt sulfide nanosheets were first deposited onto CFP by cyclic voltammetry. Then, the surface structure and P/S ratio as well as the Co3+/Co2+ ratio of the phosphosulfide nanosheets were well tuned by regulating the cycling numbers of the phosphorous electrodeposition. Benefiting from the hierarchical structure, distinct phosphosulfide species, as well as a high Co3+ content derived from partial S substitution with P and nonstoichiometric phase, the as‐synthesized Co2−xSP/CFP exhibits remarkable activity with an overpotential of 279 mV at a current density of 10 mA cm−2, a low Tafel slope of 54 mV dec−1 and excellent long‐term stability towards OER (overpotential increase of only 4.7 % within 60 h). Structural analysis after stability test indicates that cobalt oxide/hydroxide species are formed on the surface, which contribute to the high performance and excellent durability for oxygen evolution. This provides a simple and facile approach to rationally design and synthesize transition metal phosphosulfides for advanced electrochemical application.