Novel core–shell structure of Ni3S2@LiMoNiOx(OH)y nanorod arrays toward efficient high-current–density hydrogen evolution reaction

Abstract

A cost-effective, high-performance, and stable electrocatalyst at high current density is critical to an industrial hydrogen production system. Herein, the surface engineering was used to synthesize core–shell structured Ni3S2@LiMoNiOx(OH)y nanorod arrays on nickel foam by a single-step hydrothermal process. Systematic investigations confirm that the simultaneous incorporation of Li and Mo can change the morphology of pristine Ni3S2 from granules to nanorod, which facilitates electron and mass transport for electrochemical tests and provides more accessible active sites. Impressively, Ni3S2@LiMoNiOx(OH)y exhibits excellent catalytic activity for hydrogen evolution reaction (HER) with low overpotentials of −57 mV and −365 mV to achieve current densities of −10 mA/cm2 and −1000 mA/cm2, respectively. Additionally, the core–shell Ni3S2@LiMoNiOx(OH)y nanorods demonstrate a fast release of generated-H2 bubbles to favor for more than 100 h stability at a high current density of −1000 mA/cm2. The core–shell formation mechanism and the kinetic mechanism of excellent HER performance is elucidated.