Fabrication of BiOI/MoS2 heterojunction photocatalyst with different treatment methods for enhancing photocatalytic performance under visible-light

The BiOI/MoS2 heterojunction photocatalysts were fabricated by the hydrothermal method and calcination method, and the photocatalytic oxidation performance of the samples was evaluated by the removal gas-phase Hg-0 under visible light irradiation. In this study, the BiOI/MoS2 heterojunction photocatalysts were adopted to explore the physical and chemical properties by characterization methods. The results show that BiOI/MoS2 with calcination method has an excellent photocatalytic performance for mercury removal reaching up to 58%. The enhanced photocatalytic performance can be due to the interfacial heterojunction between BiOI and MoS2, which inhibits the recombination of electrons and holes. Meanwhile, the Electron spin resonance (ESR) characterization indicated that the surface-active oxygen existed in BiOI/MoS2 heterojunction photocatalysts by calcination method. The synergistic effect of the above two factors makes BiOI/MoS2 be of higher activity under visible light. A plausible reaction mechanism and charge transfer were also proposed. In addition, this work provides a new prospect into hydrolysis of hydrogen production, CO2 reduction, degradation of organic pollutants and electrochemistry.