Microstructure of Nitrogen and Sulfur Co-doped Mesoporous TiO₂ Film and its Photocatalytic Activity

Using Ti(OBun)4 as the inorganic precursor,Pluronic F127 as the templating agent,and thiourea as the additive,mesoporous anatase TiO2 thin films were prepared through sol-gel method coupled with evaporation-induced self-assembly(EISA) process.Scanning electron microscope,X-ray photoelectron spectra,N2 adsorption-desorption,X-ray diffraction,and UV-Vis spectra were used to characterize the as-synthesized mesoporous TiO2 materials.It is found that,apart from doping N,S elements into the TiO2 lattice,the mesostructure of the TiO2 thin films is changed by adding thiourea into the reactive solution.When the mole ratio of thiourea to Ti(OBun)4 is 2.5%,the pore size of the synthesized mesostructured TiO2 reaches 12.4nm,and the mesoporous TiO2 sample shows the best UV photocatalytic activity in the degradation of the methyl organge(MO).When the mole ratio of thiourea to Ti(OBun)4 is 5%,the absorption edge of the as-synthesized sample can be extended from 380nm to 520nm,and the sample exhibits the best visible photo catalytic activity in decomposing the Rhodamine B(RhB).