In-situ hydrothermal synthesis of MoS2 /TiO2 nanocomposites for enhanced and stable photocatalytic performance: Methylene blue degradation pathway and mechanism

Abstract

BackgroundIn recent years, nanocomposite photocatalytic has become more and more attractive and important since it has a great potential to contribute to such wastewater treatment and environmental problems. Pollutant dyes such as methylene blue (MB) have utilizations in manufacturing, paper, medicine and textiles. In addition, creating a Z-scheme nanocomposite illustrates a fitting approach for improving the photocatalytic performance of photocatalysts. Mott-Schottky curves demonstrate that MoS2 and TiO2 are combined to form Z-scheme nanocomposite. MethodsNovel MoS2/TiO2 nanocomposite photocatalysts were well synthesized by a simple hydrothermal process. The photodegradation intermediate products of MB dye are also identified by liquid chromatography-mass spectrometry (LC-MS) and the possible degradation pathway is proposed. Ultimately, the potential photocatalytic pathway mechanism of nanocomposites was verified according to the LC-MS analysis and trapping experiments. Significant findingsThe construction of a Z-scheme nanocomposite is a crucial factor in improving the photocatalytic activity of heterojunction photocatalysts. MoS2/TiO2 nanocomposites had photocatalytic activity within 120 min irradiation to visible light and achieved 98.5 % of MB. A stable heterostructure has been effort designed using MoS2/TiO2 with improved electron and hole migration. The photodegradation performance for MoS2/TiO2 is 3.8 folds that the bare photocatalysts. This nano-heterojunction significantly suppresses the recombination rate of photoexcited charge carriers and enhances the operation of solar energy. The Z-scheme nano-heterojunctions offer a potential strategy for promoting the utilization of photocatalysts in waste environmental purification and clean water.