Precursor-Transformation Strategy Preparation of CuPx Nanodots-Decorated CoP3 Nanowires Hybrid Catalysts for Boosting pH-Universal Electrocatalytic Hydrogen Evolution.

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 CoP3 nanowire decorated with copper phosphides (denoted as CuPx ) nanodots structures synthesized through a simple and easily scalable precursor-transformation strategy is reported as a highly efficient HER catalyst. By decorating with CuPx nanodots, the optimized CoP3 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.