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

Low cost, high activity and stability electrocatalysts for hydrogen evolution reaction (HER) have been extensively studied in recent years. We have successfully synthesized a tran-sition 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 con-sumption 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/cm(2) 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. (c) 2021 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

The study successfully synthesized a CoNi@CP electrocatalyst with a special coating structure, which exhibited excellent catalytic performance and stability in the hydrogen evolution reaction. Through mechanisms such as enhanced H* adsorption on the surface and protection of the active center, the catalyst was able to reduce overpotential and increase Tafel slope, providing new insights for the development of efficient electrocatalysts.