Engineering inner-porous cobalt phosphide nanowire based on controllable phosphating for efficient hydrogen evolution in both acidic and alkaline conditions

Abstract Cobalt phosphide has been extensively studied as non-precious metal-based robust electrocatalyst for hydrogen evolution reaction. Innovation breakthrough is still highly desired to enhance its catalytic efficiency. In this work, through rational engineering strategy, a controlled inner-porous CoP nanowire array, which is vertical to the carbon fiber (ip-CoP/CF) was in-situ topotactically synthesized. The resulting ip-CoP/CF demonstrates improved hydrogen evolving efficiency in both acidic and alkaline conditions. At a current density of 10 mA∙cm−2, which with small Tafel slopes of 47 mV·dec−1 and 93 mV·dec−1 in acidic and alkaline solution, respectively. Such engineering strategy opens a diverting route to construct controllable inner-porous materials for high efficient electrocatalysts.