Phosphorus-doped CoFe2O4 nanoparticles decorated nitrogen-doped graphene for efficient and stable electrocatalytic water splitting

The development of bifunctional electrocatalysts from earth-abundant elements is crucial for sustainable energy modules to meet future energy demand. However, low activity and poor conductivity of bifunctional electrocatalysts are the main hindrances in the commercial-scale production of hydrogen. Here, we synthesized nitrogen-doped graphene and decorated with phosphorus-doped CoFe2O4 nanoparticles (P-CoFe2O4/NG) as a bifunctional electrocatalyst for OER and HER in alkaline media. The fabricated P-CoFe2O4/NG served as a superior catalyst and could work both as a cathode and anode to catalyze overall water splitting. Interestingly, the optimized catalyst required a voltage of -0.06 V (overpotential of 230 mV), 1.46 V (overpotential of 60 mV), and 1.52 V respectively to deliver a current density of 10 mA cm-2 for HER, OER, and total water splitting in alkaline medium making it as good as noble metal catalyst system (IrO2, Pt/C). The decoration of phosphorus doped CoFe2O4 nanoparticles not only improved the catalytic activity of the catalyst but the problem of poor conductivity was also resolved to accelerate the sulggish kinetics of the catalytic activity. We hope that this low cost and high activity electrocatalysts will serve as a potential electrocatalyst for the electrochemical water splitting and other applications.