Enhancement of toluene photocatalytic degradation using GO/S/TiO2

Backgrounds: Volatile organic compounds/VOCs (such as toluene) are the common indoor air pollutant that can be found in daily products. Photocatalytic degradation of toluene is a potential strategy with low-cost and eco-friendly characters. However, TiO₂, as the broadly applied photocatalyst, has the wide band gap and low absorption of visible light. Methods: In this study, TiO₂ photocatalyst was modified by doping of S element and various content of graphene oxide (GO) and applied in the photocatalytic degradation process of toluene. Findings: Compared to bare TiO₂, smaller crystal size was formed, utilization of visible light was improved, and the formation of Ti-O-S was presented. The 5wt%GO-S_0.05TiO₂ performed the best photocatalytic degradation for toluene. Moreover, higher temperature elevated the collision frequency and reduced adsorbed water on the active sites which led to enhancement of photocatalytic activity. Different trend in photocatalytic activity was shown by the various applied relative humidity. Furthermore, extended study about reaction kinetics was also carried out in this study.