Study on photocatalytic degradation of gaseous dichloromethane using pure and iron ion-doped TiO2 prepared by the sol–gel method

Abstract The synthesis of TiO 2 and Fe–TiO 2 by sol–gel method is demonstrated and characterized. The characterization of TiO 2 and Fe–TiO 2 is performed with instruments, including TGA/DTA, FTIR, UV–Vis, N 2 adsorption and SEM. Dichloromethane is used for the photocatalytic activity test. From the results of dichloromethane photocatalyitc degradation, the calcined temperature of TiO 2 and the presence of water vapor influence the photocatalytic activity. The optimum doping amount of iron ions is 0.005 mol%, and this can enhance the photocatalytic activity, while too great an amount will make the iron ions become recombination centers for the electron–hole pairs and reduce the photocatalytic activity. UV–Vis diffuse reflectance spectra of Fe–TiO 2 show an increase in absorbency in the visible light region with the increase in iron ions doping concentration The intermediate of dichloromethane photodegradation includes CHCl 3 , CCl 4 , CH 2 Cl 2 and COCl 2 . The presence of iron ions may reduce the adsorption of Cl element on the surface of the photocatalyst.