Abstract:Developing efficient, stable, and low-cost non-precious metal-based bifunctional electrocatalysts is crucial for hydrogen production through water electrolysis. Nanoarray structure electrocatalysts have attracted widespread attention due to their structural advantages. In this study, three-dimensional nano-sheet arrays of CoOx/CeO2 were in situ grown on nickel foam (NF) using a solution combustion method. The results showed that CoOx/CeO2 catalyst, in direct contact with the conductive nickel foam substrate, exhibited a positive synergistic effect between Ce and Co, an open three-dimensional nano-sheet structure, and excellent catalytic activity for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), with overpotentials of only 48 and 267 mV at 10 mA/cm2, respectively. Furthermore, the catalyst could operate stably in an electrolyte at 100 mA/cm2 for 100 h with almost no change in current density. This work not only demonstrated the enormous application potential of Co-based electrocatalysts in water electrolysis but also provided a feasible strategy for preparing efficient and stable Co-based catalysts.