Unraveling the capacitive effect in the vacancy-heterostructure WTe₂/MoTe₂ for hydrogen evolution reaction by the grand canonical potential kinetics

Heterostructure shows superior catalytic performance since it inherits the catalytic properties of the components, and has the advantages of van der Waals interaction. Herein, we build a vacancy-van der Waals heterostructure with MoTe₂ and WTe₂ which forms a capacitor tuning performance, playing an important role in the energy barrier balance of the catalytic reaction. By using the grand canonical reaction kinetics (GCP-K) to explore the electrocatalytic, we predict the Tafel slope of the HER reaction is 81.31 mV/dec through changing applied potential.