Precursor‐Transformation Strategy Preparation of CuP<i>_x</i> Nanodots–Decorated CoP₃ Nanowires Hybrid Catalysts for Boosting pH‐Universal Electrocatalytic Hydrogen Evolution

Abstract

Abstract The development of earth‐abundant, low cost, and versatile electrocatalysts for producing hydrogen from water electrolysis is still challenging. Herein, based on high hydrogen evolution reaction (HER) activity of transition metal phosphides, a CoP 3 nanowire decorated with copper phosphides (denoted as CuP x ) nanodots structures synthesized through a simple and easily scalable precursor‐transformation strategy is reported as a highly efficient HER catalyst. By decorating with CuP x nanodots, the optimized CoP 3 nanowires electrode exhibits excellent catalytic activity and long‐term durability for HER in alkaline conditions, achieving a low overpotential of 49.5 mV at a geometrical catalytic current density of 10 mA cm −2 with a small Tafel slope of 58.0 mV dec −1 , while also performing quite well in neutral and acidic media. Moreover, its overall performance exceeds most of the reported state‐of‐the‐art catalysts, especially under high current density of 100 mA cm −2 , demonstrating its potential as a promising versatile pH universal electrocatalyst for efficient water electrolysis. These results indicate that the incorporation of earth‐abundant stable element copper can significantly enhance catalytic activity, which widens the application range of copper and provides a new path for design and selection of HER catalysts.