Photocatalytic performance under visible light of WS2/TiO2/Au synthesized by hydrothermal method

In this study, transition metal dichalcogenide (TMD) material WS 2 and Au nanoparticles were combined with TiO 2 to enhance the photocatalytic performance under visible light. The WS 2 nanosheets were synthesized from bulk WS 2 via ultrasonic process, and the Au nanoparticles were prepared through the reduction reaction from HAuCl 4 . The composite photocatalysts of WS 2 /TiO 2 /Au, TiO 2 /Au, and WS 2 /TiO 2 were synthesized by a one-step hydrothermal process. The light absorption property of the composites was determined by ultraviolet-visible (UV-vis) photospectroscopy. Surface analysis of WS 2 nanosheet, TiO 2 nanoparticles, and Au nanoparticles was performed by scanning electron microscopy (SEM). The chemical structure of composites and thickness of WS 2 nanosheets were analyzed by Raman spectra. The photocatalytic activity was measured by methylene blue degradation reaction under visible light. These results revealed the photocatalytic behavior of WS 2 /TiO 2 /Au, TiO 2 /Au, and WS 2 /TiO 2 composites, as well as WS 2 nanosheets. The WS 2 /TiO 2 /Au composite showed improved photocatalytic behavior among all samples. It is believed that the WS 2 nanosheet and Au nanoparticle extend the light absorption range from UV region to the visible region, as well as the WS 2 /TiO 2 /Au composite reduces the recombination of electrons. This study shows that the enhanced photocatalytic behavior of WS 2 /TiO 2 /Au composite can be used as photocatalytic applications in the future.