Synergistic dual built-in electric fields in 1T-MoS/NiS/LDH for efficient electrocatalytic overall water splitting reactions.

Designing cost-effective electrocatalysts for water decomposition is crucial for achieving environmental-friendly hydrogen production. A transition metal sulfide/hydroxide electrocatalyst (1T-MoS/NiS/LDH) with double heterogeneous interfaces was developed through a two-step hydrothermal assisted electrodeposition method. The presence of the two built-in electric fields not only accelerated the charge transfer at the interface, but also enhanced the adsorption of the reactants and intermediate groups, and therefore improved the reaction rate and overall catalytic performance. The results suggest that the 1T-MoS/NiS/LDH catalysts display exceptional electrocatalytic reactivity. Under alkaline conditions, the overpotential of the electrocatalyst was 187 (η) mV for OER and 104 (η) mV for HER. Furthermore, the two-electrode system assembled by the electrocatalyst needs only a voltage of 1.55 V to deliver a current density of 10 mA cm. Our result provides a simple and effective methodical approach to the design of dual heterogeneous interfacial electrocatalysts.