Green synthesis of UV and visible light active TiO 2 /WO 3 powders and films for malachite green and ethylene photodegradation

Powder nanocomposites of TiO 2 /WO 3 are prepared by a simple solid-state thermal procedure from commercial oxide powders and cast thereafter as a film coating on TLC substrate. The WO 3 content in the powder composites is varied from 0.5 to 50%. The phase composition and morphology of titania/tungsten composites and films is characterized by SEM and X-ray analysis. The photocatalytic activity of TiO 2 /WO 3 powders is tested in the degradation of malachite green dye in aqueous solutions under UV and visible light irradiation. The effect of preparation temperature on the photocatalytic activity is also investigated. It is found out that the mixed powder of 5%WO 3 manifests the best photocatalytic performance. The prepared powder photocatalyst is deposited as a film coating on TLC sheet for gas-phase application. The as-obtained composite coated photocatalysts with 5%WO 3 are tested for air purification from ethylene contamination under UV and visible light illumination. The TiO 2 /WO 3 coated photocatalysts show always a higher efficiency in comparison to that of the pure TiO 2 .