High Alkaline Electrochemical Hydrogen Evolution on a Pt/GaN Heterostructure

Abstract The construction of suitable metal/substrate interfaces that can synergistically optimize the water dissociation, hydrogen transfer and hydrogen adsorption processes has proved to be a promising approach to boost the alkaline electrochemical hydrogen evolution reaction (HER) but remains challenging. Herein, a Pt/GaN heterostructure electrocatalyst is constructed using the electrochemical deposition technique and used for alkaline electrochemical HER. The as‐synthesized Pt/GaN catalyst exhibits competitive HER performance, including low overpotentials of 24 and 441 mV to reach current densities of 10 and 1000 mA cm⁻², respectively, and a superior mass activity (7.34 A mg_Pt⁻¹ at the overpotential of 100 mV), which is 25.7 and 5.0 times higher than commercial Pt/C and as‐synthesized Pt/CP, respectively. First‐principle calculations suggest that the Pt/GaN heterostructure can greatly reduce the energy barrier for H₂O dissociation, create a local acid‐like microenvironment through a H spillover process and optimize the value of ΔG_H, leading to a remarkable acceleration of the alkaline HER kinetics. This discovery provides new insights for the development of alkaline HER catalysts.