Interfacial Engineering of Oxyhydroxide/Sulfide Heterostructure Enables Efficient Charge/Mass Transfer for Industrial Hydrogen Production

Abstract

Developing highly efficient electrocatalysts to overcome charge/mass transfer limitations under industrial current densities is critical for enabling large-scale hydrogen production via alkaline water electrolysis (AWE). Herein, we constructed a heterostructured electrocatalyst featuring edge-exposed Ru-doped NiOOH nanosheets anchored on NiMoSx microspheres (RNHO/NMS-M) to achieve efficient hydrogen production under ampere-level current density. Experimental and theoretical analyses reveal that the Ni sites in the surface RuNiOOH layer of RNHO/NMS-M promote water adsorption and dissociation, and the charge redistribution-induced interface Ru sites trigger the H* spillover for optimal hydrogen desorption. Furthermore, the nanosheet/microsphere heterojunctions show superhydrophilic and superaerophobic surface with low adhesive force, which significantly enhances mass transport under high-current-density conditions. As a result, RNHO/NMS-M exhibits exceptional hydrogen evolution reaction performance, achieving an industrial-level current density of 1 A cm−2 at an ultra-low overpotential of 191.73 mV, and maintains stable operation for 500 h. Notably, the RNHO/NMS-M-based AWE displays a low cell voltage of 1.644 V under 1 A cm−2 (30 wt% KOH, 60 °C) with superior stability as long as 100 h. This work establishes a new paradigm for designing high-current-density-tolerant electrocatalysts via hierarchical heterointerface engineering.

Keywords: hydrogen evolution reaction, industrial current density, superhydrophilic, interface engineering, bubble transport, alkaline water electrolyzer