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

Developing enabling electrocatalysts for water splitting to operate at industrial-current-density is crucial for the large-scale hydrogen production. Herein, a facile wet-chemistry strategy and scalable in-situ sulfidation technique are designed for formation of RuS2 nanocrystal-decorated amorphous NiSx nanosheets vertically aligned on Ni foam (NF) (RuNiSx/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, 1000 mA cm−2, respectively, with robust stability at 10, 100, 500 mA cm−2 for 120 h, ranking it one of efficient electrocatalysts for industrial water electrolysis. The electron redistribution over heterointerfaces induce the modulatory electronic states of heterostructures, thus leading to the favorable adsorption behavior for reaction intermediates, enhancing intrinsic activity of active sites. Impressively, a RuNiSx/NF||RuNiSx/NF EWS device can afford industrial current densities of 10, 100 and 500 mA cm−2 at voltages of 1.55, 1.77 and 2.35 V, respectively, together with robust durability for over 50 h (@1000 mA cm−2). This work provides an innovative approach to design unique heterostructures for industrial EWS via modulatory electronic states.