Strong interfacial coupling of MoS₂/g-C₃N₄ van de Waals solids for highly active water reduction

Highlights: • An in-situ interfacial engineering method is used to obtain vdW hybrids for HER. • The strong interlayer coupling is present through out-of-plane Mo-N bonding. • The excellent performance originates from this strong interlayer coupling. • DFT shows the coupling enhances hydrogen adsorption/reduction kinetics for HER. The facile and sustainable production of hydrogen through water reduction requires high performance catalyst consisting of earth abundant elements for the hydrogen evolution reaction (HER). Here we report the synthesis of ultrathin molybdenum disulfide/g-carbon nitride (MoS₂/g-C₃N₄) vdW layers via an in situ interfacial engineering method. Such MoS₂/g-C₃N₄ vdW layers show outstanding HER activity with comparable potential and Tafel slope to commercial Pt catalysts. Our experimental data and density functional theory (DFT) based calculations revealed that the unpreceded electrocatalytic performances originate from the strong interfacial coupling of vdW layers through out-of-plane Mo-N bonding, which therefore enhances hydrogen adsorption/reduction kinetics for HER. These findings will shed light on the programmable catalysts for low cost and highly active water reduction.