Mo, V and M (M=Mn, Fe, Co, Cu) Co-modulated Ni oxides in-situ derived from nickel foam as efficient electrocatalysts for alkaline hydrogen evolution and oxygen evolution

The highly efficient catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are of great significance for electrochemical water splitting. Direct transforming nickel foam (NF) into nickel-based catalysts attracts extensive attention because of its excellent stability and high conductivity. However, the catalytic performances of this kind of catalyst are still far from expected. Herein, we report a series of Ni oxides co-modulated by Mo, V and M ( M =Mn, Fe, Co, Cu) as efficient catalysts for water splitting, which are directly prepared through a simple NF-transformation method. Especially, a MoVNi catalyst displays a low Tafel slope of 68 mV/dec and a small overpotential of 76 mV at 10 mA/cm 2 for HER in 1.0 M KOH solution. The OER performances of MoVNi can be greatly enhanced by M introduction. For example, Fe-MoVNi only requires 374 mV to achieve 100 mA/cm 2 and shows no declination in a-20 h stability test at 100 mA/cm 2 in 1.0 M KOH media. Such performances outperform the recently reported best-performing Ni oxides catalysts in an alkaline environment. The excellent catalytic performances suggest great promise in practical applications.