Novel MOF-Derived Nickel Nitride as High-Performance Bifunctional Electrocatalysts for Hydrogen Evolution and Urea Oxidation
Shengnan Hu, Shiquan Wang, Chuanqi Feng, Huimin Wu, Jiujun Zhang, He Mei
Abstract
Developing bifunctional catalysts toward urea oxidation and hydrogen evolution is a huge challenge. In this study, novel MOF-derived nickel nitride on nickel foam catalysts were successfully synthesized at different temperatures (300, 350, 400 °C) (denoted as C-T, T = 300, 350, 400). C-350 was demonstrated to be a highly active and durable 3D catalyst toward urea oxidation reaction (UOR), with a required potential of 1.337 V at 10 mA/cm2. At the same time, C-350 has higher catalytic performance toward hydrogen evolution reaction (HER) than other materials with a low overpotential of 47 mV at 10 mA/cm2. Furthermore, its two-electrode alkaline electrolyzer only needs a voltage of 1.503 V to obtain 100 mA/cm2, which is 0.160 V lower than that of pure water splitting. Also, the current density can be maintained for at least 24 h, showing its potential for practical applications.