Controllable tuning graphene composited PtCoYOx nanocomposites to promote electrocatalytic hydrogen evolution

Abstract

Water electrolysis powered by renewable energy is regarded as the feasible route for the production of hydrogen, which was obtained at the cathode side through electrochemical hydrogen evolution reaction (HER). Herein, we proposed a novel strategy to achieve high and stable HER catalytic performance by designing graphene coatings shaped like a flower trimetallic PtCoYOx @G nanoparticles with multiple petals and by adjusting the composition ratio of PtCoYOx @G (0.1:0.05:0.1). Compared with the bimetallic PtYO@G catalysts, the trimetallic PtCoYOx @G catalysts showed superior HER performance with an overpotential of 106 mV at 10 mA cm−2, a Tafel slope of 38.08 mV dec−1, and long-term stability of 25 h. Electron paramagnetic resonance (EPR) tests exhibited strong signal peaks and aerobic vacancies in PtCoYOx @G materials. Density functional theory (DFT) calculation revealed that Co doping increased the active site of the catalyst, resulting in excellent charge density with good conductivity. Therefore, the doping of Co in trimetallic PtCoYOx @G was the key to improve HER catalytic activity.