Preparation of Lanthanum-doped TiO2 Film and Its Application for Gaseous Toluene Removal

Visible light response lanthanum-doped TiO2 film was prepared by Sol–Gel method using Ti(OBu)4 and La(NO)3·6H2O as raw materials. XPS, FTIR, XRD, N2(77K) adsorption, SEM and DRS were used for catalyst characterization. Gaseous toluene removal was used for photocatalytic activity test. The results show that La dopant can induce visible light activity. The sample of 2.8-La/TiO2-500 exhibites the highest activity, which can remove toluene of initial concentration 6110.18mg/m3 completely within 60min. La3+ disperses onto TiO2 as the form of La2O3 and partly as the form of Ti-O-La bond. La dopant can inhibit phase transformation, enhance phase transformation temperature and is also beneficial to gain smaller particle size and large surface area of TiO2. Compared with pure TiO2 film, La dopant can also inhibit the generation of air-pores and the surface of La/TiO2 film is more dense and smooth. Electrons transfer of f level of La and the destortion of TiO2 lattice is the main reason for the enhancement of visible-light activity.