Self-supporting FeCoMoP nanosheets for efficient overall water splitting

Abstract

The electrolysis of water is currently the most promising method for hydrogen production. Developing low-cost, highly active, and stable electrocatalysts is crucial for advancing large-scale industrial electrolysis of water for hydrogen production. Fe-CoMoP/NF electrocatalysts were fabricated on nickel foam (NF) by a simple cation exchange method. Benefiting from the synergistic effect of multiple metals and the ordered distribution of multi-level nanosheets, Fe-CoMoP/NF demonstrates outstanding bifunctional electrocatalytic performance for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) in 1 M KOH solution, with overpotentials of 205 mV and 94 mV at 10 mA cm⁻², respectively. Moreover, the electrolytic cell assembled with this catalyst as the cathode and anode can achieve a current density of 10 mA cm⁻² with a cell voltage of only 1.55 V and can operate stably for more than 115 h. The excellent performance of Fe-CoMoP/NF is attributed to the inherent HER activity and high conductivity of phosphide, as well as the slow introduction of Fe ions, which can regulate the charge density around Co and Mo, thus maintaining the integrity of the nanostructured Fe-CoMoP/NF and exposing a larger active surface area. This work offers an effective strategy for preparing high-efficiency, low-cost integrated water splitting reaction electrodes.