Bimetal–Organic-Framework-Derived Nanohybrids Cu_0.9Co_2.1S₄@MoS₂ for High-Performance Visible-Light-Catalytic Hydrogen Evolution Reaction

Transition metal dichalcogenides (TMDs) are recognized as greatly promising substitutes for noble-metal-based catalysts for hydrogen evolution reaction (HER). The hybrids containing Co3S4@MoS2 components demonstrate excellent electrocatalytic activity of HER. However, the more sustainable photocatalytic HER of two-dimensional (2D) Co3S4@MoS2-based materials remain scarce. In this study, Cu0.9Co2.1S4@MoS2 composites were easily synthesized in situ by using bimetallic (Cu/Co) metal–organic frameworks (MOFs) as precursors through hydrothermal reaction; without extra precious metal and semiconductor as co-catalyst, the MoS2-content-optimized Cu0.9Co2.1S4@MoS2 efficiently catalyzed hydrogen production at a rate of 40156 μmol h–1 g–1 (with a TON of 109) in aqueous solution containing eosin Y under visible light. The developed strategy of homogeneously alloyed MOFs as precursors caused adequate hybridization of the object material with homogeneous Cu-doping in Co3S4 lattice, resulting in abundant interfaces and active sites as well as the low resistance of electron transfer, which thus considerably enhances photcatalytic HER performance, compared with undoped Co3S4@MoS2. HER mechanism was further elucidated by fluorescence spectroscopy, fluorescence lifetime test, impedance spectra, and photocurrent response measurements as well as control experiments.