CoNi alloy nanoparticles coated with carbon layer doped with P atom for efficient hydrogen evolution reaction

Abstract

Low cost, high activity and stability electrocatalysts for hydrogen evolution reaction (HER) have been extensively studied in recent years. We have successfully synthesized a transition metal phosphide electrocatalyst (CoNi@CP) with coating structure. The CoNi@CP was prepared with the mild conditions. An organophosphorus ligand was synthesized by simple organic reaction. It was synthesized by coordination with Co2+ and Ni2+ and then calcined. CoNi@CP has abundant and uniform phosphorus atom doping, no energy consumption in phosphating process, and avoids the generation of highly toxic gas PH3. Because of its special coating structure, the adsorption of H∗ on its surface was enhanced, and the active center of CoNi was protected, which contributed greatly to the improvement of catalytic performance. At 10 mA/cm2 current density, the overpotential of the catalyst only 74 mV, and the slope of Tafel was only 83 mVdec-1. The performance of the catalyst remained unchanged after 1000 stability tests. In addition, we had proved theoretically that the catalyst had high HER activity by DFT calculation. Therefore, it provides inspiration for us to better develop efficient transition metal phosphide electrocatalysts.