High-performance overall water splitting based on amorphous iron doped cobalt tungstate via facile co-precipitation

Abstract

Exploring high-performance and low-cost bifunctional electrocatalysts is crucial for developing highly efficient overall water splitting cells. In this work, a facile and cheap co-precipitation method, which is compatible with large-scale production, is applied to prepare amorphous Fe-doped CoWO₄ bifunctional electrocatalysts. Low overpotentials of 259 and 118 mV to reach a current density of 10 mA cm⁻² for the OER and HER in 1 M KOH are found, respectively. Moreover, no detectable potential decay is observed at 50 mA cm⁻² for at least 15 h, revealing its excellent long-term stability. Finally, a highly efficient overall water splitting cell is assembled with amorphous Fe-doped CoWO₄ as a bifunctional electrocatalyst. A low cell voltage of 1.55 V is required to achieve a current density of 10 mA cm⁻², which surpasses the benchmark IrO₂‖Pt/C cell.