Synthesis of BiVO4/TiO2 composites and evaluation of their photocatalytic activity under indoor illumination.

BiVO4/TiO2 composites with different weight ratios have been prepared by coprecipitation-based reactions followed by either thermal or hydrothermal treatment with the aim of evaluating the TiO2 photosensitization by BiVO4. The obtained materials present in all cases the desired monoclinic phase of BiVO4 and anatase phase of TiO2. Visible light absorption increased with increasing amount of bismuth vanadate. XPS results reveal the surface enrichment of Ti with respect to the bulk composition in samples characterised by a higher content of BiVO4. The photocatalytic activity of the prepared materials was tested for the degradation of isopropanol in the gas phase under indoor illumination conditions. Although none of the composites was able to improve the activity of TiO2, the low BiVO4 containing samples appear as more suitable for further synthesis tuning.