Highly effective visible-photocatalytic hydrogen evolution and simultaneous organic pollutant degradation over an urchin-like oxygen-doped MoS2/ZnIn2S4 composite

Achieving hydrogen production and simultaneous decomposition of organic pollutants through dual-functional photocatalytic reactions has received increasing attention due to the environmentally friendly and cost-effective characteristics of this approach. In this work, an urchin-like oxygen-doped MoS2/ZnIn2S4 (OMS/ZIS) composite was fabricated for the first time using a simple solvothermal method. The unique microstructure with abundant active sites and fast charge transfer channels further shortened the charge migration distance and compressed carrier recombination. The obtained composite exhibited an efficient H-2 evolution reaction rate of 12.8 mmol/g/h under visible light, which was nearly times higher than pristine ZnIn2S4, and the apparent quantum efficiency was 14.9% (420 nm). The results of the simultaneous photocatalytic H-2 evolution and organic pollutant decomposition test were satisfactory, resulting in decomposition efficiencies of resorcinol, tetracycline, and bisphenol A that reached 41.5%, 63.5%, and 53.0% after 4 h, respectively, and the highest H-2 evolution rate was 672.7 mu mol/g/h for bisphenol A. Furthermore, natural organic matter (NOM) abundantly found in actual water was adopted as an electron donor for H production under simulated sunlight irradiation, indicating the promising practicability of simultaneous hydrogen evolution and NOM decomposition. Moreover, the mechanisms of the dual-purpose photocatalytic reactions, as well as the synergistic effect between the molecular structures of the organic pollutants and the corresponding adsorption behavior on the photocatalyst surface were illustrated in detail. These obtained results may serve as an inspiration for the rational design of highly efficient, dual-functional photocatalysts in the future. (C) Higher Education Press 2022

Automated summary

The fabrication of an urchin-like oxygen-doped MoS2/ZnIn2S4 (OMS/ZIS) composite using a solvothermal method is reported. The composite exhibits a unique microstructure with abundant active sites and fast charge transfer channels, enabling efficient hydrogen evolution and organic pollutant decomposition under visible light.