Al, Fe-codoped CoP nanoparticles anchored on reduced graphene oxide as bifunctional catalysts to enhance overall water splitting

Rational design of high-efficiency and low-cost catalysts for water splitting electrolysis plays an important role in clean energy conversion technology. Herein, density functional theory simulations indicate that the codoping of p-metal Al and d-metal Fe could reasonably regulate the electronic structure of CoP, resulting in an optimal H adsorption free energy. Based on this finding, we successfully prepared a bifunctional catalyst of Al, Fe-codoped CoP nanoparticles/reduced graphene oxide, which displays superior HER performance in a wide pH range and OER performance in the alkaline medium with high H2/O2 evolution rates and Faradaic efficiencies. For overall water splitting, such a catalyst exhibits excellent activity (a low cell voltage of 1.66 V at 10 mA cm−2) and durability. The strategy of synergistic modulation of electronic structure by introducing different-type dopants into a hybrid proposed in this work is beneficial for designing novel electrocatalysts for applications in energy-conversion devices.