Nitrogen-incorporated iron phosphosulfide nanosheets as efficient bifunctional electrocatalysts for energy-saving hydrogen evolution

Urea-assisted hydrogen evolution is a promising alternative to conventional water splitting for producing hydrogen with reduced energy consumption. Therefore, the development of bifunctional electrocatalysts to be used in urine-mediated electrolyzers for the hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) is required. In this work, nitrogen-doped iron phosphorus trisulfide (FePS3) nanosheets were prepared, which performance surpassed platinum on carbon electrocatalysts at large current densities above 140 mA cm(-2), exhibiting excellent HER performance. A low overpotential of 756 mV was observed for UOR to drive a current density of 10 mA cm(-2). When configured for hydrogen production, the urea electrolysis cell delivered a current density of 10 mA cm(-2) at a cell voltage of 1.26 V, which is about 0.28 V lower than in conventional water electrolysis. The development of FePS3-based materials as bifunctional electrocatalysts provides a new approach enabling energy-saving hydrogen production.