Ce-Doped Ordered Mesoporous Cobalt Ferrite Phosphides as Robust Catalysts for Water Oxidation

Controllable synthesis and rational design of ordered nanostructures are crucial for their renewable energy applications. In this work, a mesoporous CoP/Fe₂P doped with 5 % Ce by a simple nanocasting method is designed as a superior electrocatalyst for the oxygen evolution reaction (OER). The well-designed composite delivers an efficient electrocatalytic activity with a low overpotential of 250 mV at 10 mA cm⁻² and excellent long-term stability with no degradation after 10 h of electrochemical OER test, superior to that of the state-of-the-art RuO₂ electrocatalyst in alkaline electrolyte. A comprehensive analysis demonstrates that the outstanding OER performance is due to the desirable combination of the highly exposed active centers in the Ce-doped bimetallic phosphides, efficient mass transfer, and effective electron conduction owing to the hierarchically mesoporous hybridization. Furthermore, the synergistic effect between Ce and CoP/Fe₂P accelerates the migration rate of electrons/ions and increases the electrochemical active area. This excellent OER performance observed by Ce doping of CoP/Fe₂P makes them possible candidates toward OER in alkaline electrolytes.