Exploring the Photothermo-Catalytic Performance of Brookite TiO2-CeO2Composites

The thermocatalytic, photocatalytic and photothermo-catalytic oxidation of some volatile organic compounds (VOCs), 2-propanol, ethanol and toluene, was investigated over brookite TiO2-CeO(2)composites. The multi-catalytic approach based on the synergistic effect between solar photocatalysis and thermocatalysis led to the considerable decrease in the conversion temperatures of the organic compounds. In particular, in the photothermo-catalytic runs, for the most active samples (TiO2-3 wt% CeO(2)and TiO2-5 wt% CeO2), the temperature at which 90% of VOC conversion occurred was about 60 degrees C, 40 degrees C and 20 degrees C lower than in the thermocatalytic tests for 2-propanol, ethanol and toluene, respectively. Furthermore, the addition of cerium oxide to brookite TiO(2)favored the total oxidation to CO(2)already in the photocatalytic tests at room temperature. The presence of small amounts of cerium oxide allowed to obtain efficient brookite-based composites facilitating the space charge separation and increasing the lifetime of the photogenerated holes and electrons as confirmed by the characterization measurements. The possibility to concurrently utilize the photocatalytic properties of brookite and the redox properties of CeO2, both activated in the photothermal tests, is an attractive approach easily applicable to purify air from VOCs.