Structure-activity relationship of TiO2 based trimetallic oxide towards 1,2-dichlorobenzene photodegradation: Influence of preparation method and its mechanism

Abstract

The influence of preparation method for hybrid trimetallic oxide consisting mixture of TiO2 with SnO2 and WO3 were investigated. The physicochemical characteristics of the photocatalyst prepared by sol-hydrothermal, sol-immobilization and mechanical mixed methods were compared based on XRD, FESEM, TEM, HRTEM, DRUV, NA and XPS. Among the samples prepared by different methods, photocatalyst prepared by sol-hydrothermal exhibits the maximum catalytic activity for degradation of 1,2-dichlorobenzene in aqueous, followed by mechanical mixed sample. On contrary, an apparent deactivation of the photocatalyst was observed for sample prepared using sol-immobilization method. The excellent catalytic activity of photocatalyst by sol-hydrothermal could be attributed to the large amount of surface defects such as Ti3+, W5+ and oxygen vacancies as well as the existence of facets or structural defects. Detailed characterization of the photocatalysts allowed correlation of the activity with structural properties, crystallinity, morphology, charge transfer and surface defects. In addition, thorough study on data obtained from GC–MS and ATR-FTIR leads to a new possible reaction pathway for degradation of 1,2-dichlorobenzene in aqueous.