Novel CsWO₃/TiO₂ Microspheres as Enhanced Visible Light Photocatalysts for Dye Pollutant Treatments.

CsxWO3/TiO2 composites with different contents of CsxWO3 were successfully synthesized in this study by a facile hydrothermal process. CsxWO3/TiO2 composites were characterized by XRD, Raman, UV-visible diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and SEM. TiO2 nanoparticles were distributed uniformly on the surface of the CsxWO3 microsphere in the prepared CsxWO3/TiO2 composites, and they formed heterojunctions with CsxWO3. The effect of CsxWO3 on the photoactivities of composites was investigated via DRS and PL. All CsxWO3/TiO2 catalysts showed enhanced photocatalytic activity for degrading rhodamine B under visible light irradiation. The 50% CsxWO3/TiO2 sample showed the best photocatalytic activity and its kinetic constant was 20 times larger than that of TiO2. The possible photocatalytic mechanism is also discussed from the trapping experiments of active species. The improved photocatalytic activity for the CsxWO3/TiO2 catalyst may be attributed to the synergetic effect between CsxWO3 microspheres and TiO2 nanoparticles. This novel photocatalyst can be used to degrade environmental pollutants in the future.