Abstract:

Fe³⁺ doped TiO₂/attapulgite composite photocatalyst(Fe³⁺-TiO₂/ATP) was synthesized by acid-catalyzed sol-gel method, and the structure, morphology, light absorption properties and photocatalytic activity under visible light irradiation were investigated. XRD and TEM analyses reveal that the crystalline structure of ATP in the composite photocatalyst was found thermally stable after being treated at 450 ℃. TiO₂ nanoparticles with anatase form were uniformly dispersed on the surface of ATP without aggregation and the average crystallitesize of TiO₂ nanoparticles in the composite photocatalyst was smaller than that of the neat TiO₂. UV-Vis-DRS shows that the doping of Fe³⁺ could extend the light response of the composite photocatalyst from UV to visible light region. The Fe³⁺-TiO₂/ATP composite photocatalyst exhibited higher photocatalytic activity for the degradation of methyl blue(MB) and the determined apparent reaction rate constant were about 1.37 times that of TiO₂/ATP, 4.83 times that of P25 and 6.51 times that of neat TiO₂, respectively. Furthermore, the composite photocatalyst showed easy separation property compared with neat TiO₂ and P25.

Key words: Fe3+ doping, TiO2/attapulgite, composite photocatalyst, visible light, MB, photocatalytic degradation