TiO2/Kaolinite Photocatalytic Material of Fe3+ Chemical Doping and Fe2O3 Heat-Banding and its Mechanism Analysis
It is very prospective to prepare low-cost TiO2/nonmetallic minerals photocatalytic material, which utilizes sun as light source to treatment environmental problems. TiO2/kaolinite nanocomposite was prepared by sol-gel method, using layered kaolinite as substrate and Ti(OC4H9)4 as precursor. The optimum process conditions were achieved. In addition, photocatalytic material was modified by mean of Fe3+chemical doping and Fe2O3 heat-banding to enhance photocatalytic activity. AZO-dye wastewater containing Direct Blue and Direct Purple was treated by these two kinds of photocatalyst under UV-light and sunlight separately. The results showed that both methods improved material photocatalytic activity in some way and the photocatalytic efficiency was raised significantly in sunlight as well as in UV-light. The photocatalytic effect of Fe2O3 heat-banding was superior to Fe3+chemical doping. The characterization of SEM, TEM, AFM shown that the 1-10nm anatase TiO2 crystal grain was doped on surface of the kaolinite particles which is as like as ‘forest on the ground’. To further analyze the mechanism of the material, XPS was adopted to analyses the chemical composition, elements, valence state.
Jinsheng Liang and Lijuan Wang
C. H. Bai et al., "TiO2/Kaolinite Photocatalytic Material of Fe3+ Chemical Doping and Fe2O3 Heat-Banding and its Mechanism Analysis", Advanced Materials Research, Vol. 178, pp. 324-329, 2011