Doping-Modulated Water Dissociation for Energy-Efficient Hydrogen Production

Abstract

By modulating the electronic structure of NiMoN via electronegativity-guided doping to accelerate H2O dissociation, we develop a bifunctional catalyst with outstanding alkaline HER and MOR performance, resulting in energy-efficient hydrogen production.Hydrogen, a carbon-neutral fuel with high energy density, is widely regarded as a leading candidate for next-generation energy carriers. [1][2][3] The hydrogen evolution reaction (HER) offers a sustainable pathway for H2 production, facilitating the conversion and storage of intermittent renewable energy. Compared to acidic conditions, alkaline HER presents improved cost-effectiveness and operational stability, particularly under industrial high-current-density operation. Alkaline HER generally follows the water adsorption, dissociation, and hydrogen formation. 4,5 However, reaction kinetics are significantly compromised due to the high activation energy required for the additional water dissociation step. 6,7 Thus, high-performance alkaline HER catalysts must efficiently promote water dissociation to overcome this intrinsic kinetic limitation.Transition metal nitrides, particularly bimetallic NiMoN, have gained prominence as efficient alkaline HER electrocatalysts owing to their high electrical conductivity and favorable electronic structure. [8][9][10] To further enhance their catalytic performance, strategies such as heterointerface engineering and elemental doping are essential. [11][12][13][14] These approaches enable precise tuning of the electronic environment at active sites, optimizing the adsorption energetics of key reaction intermediates. For example, the construction of a Ni0.2Mo0.8N/F,N-C heterojunction has been demonstrated to effectively modulate the surface charge distribution, thereby