Preparation of a Coal-Based MoS2/SiO2/GO Composite Catalyst and Its Performance in the Photocatalytic Degradation of Wastewater and Hydrogen Production

Photocatalytic degradation of wastewater and the simultaneous production of hydrogen (H-2) is a green and efficient method to solve energy and environmental problems. In this paper, coal-based SiO2/GO with a stable structure was prepared by a modified Hummers oxidation method, and then, a lotus-shaped composite photocatalyst, MoS2/SiO2/GO, was prepared by in situ loading of flower cluster MoS2 from sodium molybdate reduction onto SiO2/GO. Its photocatalytic degradation of wastewater and H-2 production properties were investigated while characterizing the material structure. The results show that SiO2/GO as a carrier not only ensures adequate dispersion of MoS2 but also enhances the visible-light response of the composite catalyst. In addition, it can also hinder the recombination of photogenerated electrons and holes in MoS2 and act as an electron transport channel in composite catalysts. MoS2/SiO2/GO exhibits much higher photocatalytic degradation of wastewater and H-2 production capacity than MoS2 : after 180 min of reaction, the CODcr removal of wastewater increased from 45.6% for MoS2 to 84.2% for MoS2/SiO2/GO and the H-2 yield reached 233.4 mu mol. The goal of degrading wastewater while producing H-2 more economically has been tentatively achieved, although not to the extent required for industrialization.

Automated summary

Photocatalytic degradation of wastewater and simultaneous production of hydrogen is a green and efficient method. In this study, coal-based SiO2/GO and MoS2/SiO2/GO materials were prepared and their photocatalytic properties were investigated. The results showed that MoS2/SiO2/GO exhibited higher photocatalytic degradation and hydrogen production.