In-situ construction of RuS2 nanocrystal-decorated amorphous NiSx nanosheets for industrial-current-density water splitting

Developing enabling electrocatalysts for water splitting to operate at industrial-current-density is crucial for large-scale hydrogen production. Herein, a facile wet-chemistry strategy and scalable in-situ sulfidation technique are designed for formation of RuS nanocrystal-decorated amorphous NiS nanosheets vertically aligned on Ni foam (NF) (RuNiS/NF) as ultra-highly efficient electrocatalysts for electrochemical water splitting (EWS). The optimized electrocatalyst exhibits an excellent hydrogen evolution reaction (HER) performance, requiring overpotentials of only 15, 50, and 114 mV at 10, 100, and 1000 mA/cm, respectively, with robust stability at 10, 100, and 500 mA/cm for 120 h, ranking it one of the efficient electrocatalysts for industrial water electrolysis. The electron redistribution over heterointerfaces induces the modulatory electronic states of heterostructures, thus leading to the favorable adsorption behavior for reaction intermediates, enhancing intrinsic activity of active sites. Impressively, a RuNiS/NF||RuNiS/NF EWS device can afford industrial current densities of 10, 100, and 500 mA/cm at voltages of 1.55, 1.77, and 2.35 V, respectively, together with robust durability for over 50 h (@1000 mA/cm). This work provides an innovative approach to design unique heterostructures for industrial EWS via modulatory electronic states.