Controlled synthesis of X (X = Mo, Cr and W) doped NiCoP nanostructures as efficient and environmentally friendly urea electrolysis catalyst

Abstract

Urea electrolysis is an effective way to replace water splitting for H2 generation, which is expected to achieve carbon neutralization. However, problems such as high energy consumption and slow urea oxidation kinetics have hindered its rapid development. In this study, a series of foreign element modified NiCoP-based catalysts were in-situ grown on Ni foam through hydrothermal process, solvothermal method and low temperature phosphating method. The morphology of the electrode was regulated by changing the impregnation elements. It was found that Mo3P@NiCoP/NF has rich active sites and small impedance, which makes it have excellent urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) property. At a current density of 10 mA cm−2, the potential of UOR is 1.206 V, and the overpotential of HER is 90 mV. The assembled Mo3P@NiCoP/NF / / Mo3P@NiCoP/NF cell demands only a potential of 1.285 V to drive a current density of 10 mA cm−2, and presents good durability within 12 h, which is one of the best electrochemistry activity and stability reported to date. Density functional theory suggests that NiCoP improves the reaction rate of this Mo3P@NiCoP/NF catalyst, and Mo3P enhances the metallicity of this catalyst, thereby enhancing the catalytic performance of Mo3P@NiCoP/NF.