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

Abstract 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 CoP 3 nanospheres on carbon cloth (CoP 3 NSs/CC) are fabricated via topotactic phosphidation of Co 3 O 4 NSs/CC. The synthesized CoP 3 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.