Enhancement of solar light photocatalytic activity of TiO2-CeO2 composite by Er3+:Y3Al5O12 in organic dye degradation

Abstract

The Er 3+ :Y 3 Al 5 O 12 , as an upconversion luminescence agent which is able to transform the visible part of the solar light to ultraviolet light, was prepared by nitrate citrate sol gel method. A novel solar light photocatalyst, Er 3+ :Y 3 Al 5 O 12 /TiO 2 -CeO 2 composite was synthesized using ultrasonic treatment. The X ray diffraction (XRD) and scanning election microscopy (SEM) were used to characterize the structural mor phology of the Er 3+ :Y 3 Al 5 O 12 /TiO 2 -CeO 2 composite. In order to evaluate the solar light photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /TiO 2 -CeO 2 composite, the Azo Fuchsine dye was used as a model organic pollut ant. The progress of the degradation reaction was monitored by UV-Vis spectroscopy and ion chromatogra phy. The key influences on the solar light photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /TiO 2 -CeO 2 were studied, such as Ti/Ce molar ratio, heat treatment temperature and heat treatment time. Otherwise, the effects of ini tial dye concentration, Er 3+ :Y 3 Al 5 O 12 /TiO 2 -CeO 2 amount, solar light irradiation time and the nature of the dye on the solar light photocatalytic degradation process were investigated. It was found that the solar light photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /TiO 2 -CeO 2 composite was superior to Er 3+ powder in the similar conditions.