Decorating cobalt phosphide and rhodium on reduced graphene oxide for high-efficiency hydrogen evolution reaction

Abstract Electrochemical reduction of water to hydrogen holds great promise for clean energy, while its widespread application relies on the development of efficient catalysts with large surface area, abundant exposed active sites and superior electron conductivity. Herein, we report a facile strategy to configure an electrocatalyst composed of cobalt phosphide and rhodium uniformly anchored on reduced graphene oxide for hydrogen generation. The hybrids effectively integrate the exposed active sites, electron conductivity and synergistic effect of the catalyst. Electrochemical tests exhibit that the catalyst shows superior hydrogen evolution reaction catalytic activity and stability, with a small Tafel slope of 43 mV dec −1 . Over-potentials as low as 29 and 72 mV are required to achieve current densities of 2 and 10 mA cm −2 in 0.5M H 2 SO 4 , respectively. The hybrid constitution with highly active sites on conductive substrate is a new strategy to synthesize extremely efficient electrocatalysts. Especially, the efficient synergistic effect among cobalt phosphide, rhodium and reduced graphene oxide provides a novel approach for configuring electrocatalysts with high electron efficiency.