Preparation of a Coal-Based MoS/SiO/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) is a green and efficient method to solve energy and environmental problems. In this paper, coal-based SiO/GO with a stable structure was prepared by a modified Hummers oxidation method, and then, a lotus-shaped composite photocatalyst, MoS/SiO/GO, was prepared by in situ loading of flower cluster MoS from sodium molybdate reduction onto SiO/GO. Its photocatalytic degradation of wastewater and H production properties were investigated while characterizing the material structure. The results show that SiO/GO as a carrier not only ensures adequate dispersion of MoS 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 MoS and act as an electron transport channel in composite catalysts. MoS/SiO/GO exhibits much higher photocatalytic degradation of wastewater and H production capacity than MoS: after 180 min of reaction, the CODcr removal of wastewater increased from 45.6% for MoS to 84.2% for MoS/SiO/GO and the H yield reached 233.4 μmol. The goal of degrading wastewater while producing H more economically has been tentatively achieved, although not to the extent required for industrialization.