Enhanced photocatalytic activity of hydrothermally synthesised SrTiO3/rGO for gaseous toluene degradation in the air: modelling and process optimisation using response surface methodology

Abstract

ABSTRACT In this study, the synthesised SrTiO3 was deposited on the graphene oxide (GO) by a simple hydrothermal method. Synthesised photocatalysts were used for photocatalytic degradation of gaseous toluene in a dynamic mode under UV irradiation. Characterisation of catalysts was performed by XRD, FE-SEM, UV-vis DRS, and FTIR. Results showed that the introduction of graphene increases the removal efficiency due to its high adsorption capacity and hydrophobic property. Process parameters’ (flow rate, toluene initial concentration, and relative humidity) effects on toluene removal efficiency and the interaction between them were investigated by Central composite design (CCD). Analysis of Variance (ANOVA) was used to evaluate the significance of the variables’ effects and the interaction between them. Maximum removal efficiency (RE) of 27.2 % and 32% were obtained by bare SrTiO3 and SrTiO3/rGO, respectively. The results revealed that the relative humidity and flow rate had significant negative effects on toluene RE over both catalysts, while concentration had a significant negative effect only on the RE over bare SrTiO3. Relative humidity was the most important factor that affects the RE on both photocatalysts.