Developing bifunctional electrocatalyst for overall water splitting using three-dimensional porous CoP3 nanospheres integrated on carbon cloth

Developing high-efficiency, low-cost and non-precious metal electrocatalysts for future renewable energy conversion systems is highly desired. In this work, self-supported three-dimensional porous CoP3 nanospheres on carbon cloth (CoP3 NSs/CC) are fabricated via topotactic phosphidation of Co3O4 NSs/CC. The synthesized CoP3 NSs/CC, as a novel non-precious-metal electrocatalyst with large specific surface area and high porosity, exhibits efficient bifunctional electrocatalytic performance in alkaline medium, with Tafel slopes of 66 mV dec(-1) and 72 mV dec(-1), and a current density of 10 mA cm(-2) at overpotentials of -121 and 291 mV for HER and OER, respectively, which are remarkably superior to those of transition metal phosphides (TMPs). In addition, it just needs a cell voltage of 1.54 V to acquire a current density of 10 mA cm(-2) for overall water splitting. The results of our work may shed light on the direction toward highly efficient bifunctional TMPs electrocatalysts with high phosphorous component. (C) 2017 Elsevier B.V. All rights reserved.