Photocatalytic Degradation of Organic Dyes by a High Efficient TiO 2 -Based Catalysts Under Solar Light Irradiation

In this work, the Er 3+ :YAlO 3 /Fe-doped TiO 2 composite, a high efficient TiO 2 -based photocatalyst, was synthesized by ultrasonic dispersion and liquid boil methods. Among which, the Er 3+ :YAlO 3 is a kind of upconversion luminescence agent, which was prepared by nitrate-citric acid method. It can emit ultraviolet light under visible light excitation. The Er 3+ :YAlO 3 /Fe-doped TiO 2 composite was characterized by X-ray diffraction and UV–vis spectral techniques. The degradation of Acid Red B dye was used to evaluate the photocatalytic activity of the Er 3+ :YAlO 3 /Fe-doped TiO 2 composite under solar light irradiation. It was found that the photocatalytic activity of Er 3+ :YAlO 3 /Fe-doped TiO 2 composite was much higher than that for the similar system with only Fe-doped TiO 2 . And the influencing factors, such as Er 3+ :YAlO 3 content, irradiation time, initial concentration of Acid Red B, addition amount of Er 3+ :YAlO 3 /Fe-doped TiO 2 and NaCl, on the photocatalytic degradation were also investigated. The Er 3+ :YAlO 3 as upconversion luminescence agent can elevate the photocatalytic activity of Fe-doped TiO 2 powder. Moreover, the Fe 2+ ion can restrain the recombination of photogenerated electrons and holes. Thus, this Er 3+ :YAlO 3 /Fe-doped TiO 2 composite is a useful material for the detoxification of wastewater because it can efficiently utilize solar light by converting visible light into ultraviolet light.