Asymmetrically coordinated nickel-based catalysts for enhanced hydrogen evolution reaction

Abstract

Developing non-noble metal hydrogen evolution reaction (HER) catalysts with high efficiency for water dissociation in alkaline environments is crucial for achieving cost-effective alkaline water electrolyzer. Surface engineering offers immense potential to design promising HER catalysts with enhanced performance, but it faces multiple challenges such as optimizing hydrogen adsorption energy. Herein, Ni-based hydroxide catalysts doped with heteroatoms are synthesized via electrodeposition, forming a Co-doped asymmetric S–Ni–F coordination structure, which requires the overpotential of only 20 mV to reach a current density of −10 mA cm⁻², and remains stable for over 100 h at −0.5 A cm⁻². DFT calculations reveal that sulfur and fluorine doping could effectively mitigate the energy associated with active hydrogen adsorption and facilitate water molecule dissociation. Furthermore, the electron coupling within the d-orbital of the Ni–O–Co structure further amplifies the catalytic efficacy. This asymmetric structure offering a pathway for designing high-efficiency and non-noble metal alkaline HER catalysts.