Phosphorus-Doped CuCo2O4 Oxide with Partial Amorphous Phase as a Robust Electrocatalyst for the Oxygen Evolution Reaction

It is highly desirable to develop efficient and low-cost electrocatalysts for the oxygen evolution reaction (OER) to improve the efficiency of water electrolysis. Here, we report a strategy doping with a small amount of phosphorus to make inactive and low-cost spinel CuCo2O4 (CCO) turn into high-efficiency and superior to the noble metal catalyst RuO2. The spinel CuCo2O4-P-0.5 (CCP0.5) shows the best OER performance with a small overpotential of 290 mV at a current density of 10 mA cm(-2) and a low Tafel slope of 68 mV dec(-1) in an alkaline electrolyte. The phosphorus doping induces the production of an amorphous phase that provides a large number of active sites, and the synergistic effect of the crystalline phase and amorphous phase significantly improves the OER activity of CCO. It is also revealed that the conductivity of CCO is improved compared with pristine CCO. Our work highlights that non-metallic element doping is an effective strategy to greatly enhance the OER performance of spinel transition metal oxide electrocatalysts.