Decorating {0 0 1} TiO2 nanosheets on hydrophobic NaY zeolite: An efficient deactivation-resistant photocatalyst for gaseous toluene removal

Photocatalysis is regarded as a promising in situ air purification technology for the removal of volatile organic compounds. However, the deactivation of photocatalysts remains a serious issue that needs to be addressed. Herein, we report a novel dual-functional photocatalyst (TiO 2 @HYZ) with spatially separated catalytic sites and adsorption sites, which has been obtained by combining hydrophilic {0   0   1} TiO 2 nanosheets with hydrophobic NaY zeolite. TiO 2 @HYZ showed excellent photocatalytic activity for the degradation of gaseous toluene under UV irradiation in humid air. The optimized TiO 2 @HYZ-2 (containing 45.7 wt% TiO 2 ) achieved 96.6% toluene removal and 87.4% mineralization within 120 min. The specific reaction rate constant of TiO 2 @HYZ-2, pristine TiO 2 and P25 normalized by the unit amount of TiO 2 during the photocatalytic degradation process were calculated to be 0.481, 0.230 and 0.250 min −1 g −1 , respectively. Moreover, TiO 2 @HYZ-2 showed superior durability, maintaining stable performance over repeated toluene degradation processes, even at high toluene concentration, whereas pristine TiO 2 incurred severe deactivation with increasing number of photocatalysis cycles. The significantly enhanced activity and anti-deactivation property was attributed to a synergistic effect between HYZ and TiO 2 in the catalyst structure, which strengthened the adsorption of toluene on HYZ and facilitated effective separation of photoexcited charge carriers on TiO 2 , thus avoiding the deposition of degradation intermediates on the active sites and simultaneously improving mineralization. This work provided a new perspective for the design of efficient and deactivation-resistant photocatalysts for air pollution remediation.