Preparation of Er3+:Y3Al5O12/TiO2-ZnO composite and application of solar energy in photocatalytic degradation of organic dyes

The Er3+:Y3Al5O12, which is able to transform the visible light from solar light into ultraviolet light as an upconversion luminescence agent, was prepared by nitrate‐citrate acid and heat‐treated method. And then, a novel photocatalyst, Er3+:Y3Al5O12/TiO2‐ZnO composite, which could effectively utilize the solar energy, was synthesized by ultrasonic dispersion and liquids boil method. In succession, X‐ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the structural morphology of the Er3+:Y3Al5O12/TiO2‐ZnO composite. And the degradation performances were also tested by UV‐vis spectrum and Ion chromatograph. To inspect the photocatalytic activity of Er3+:Y3Al5O12/TiO2‐ZnO composite, the Azo Fuchsine dye as target organic pollutant was degraded under solar light irradiation. The key impact parameters on the photocatalytic activity of Er3+:Y3Al5O12/TiO2‐ZnO such as Ti/Zn molar ratio, heat‐treated temperature and heat‐treated time were studied. Otherwise, the effects of dye initial concentration, Er3+:Y3Al5O12/TiO2‐ZnO, solar light irradiation time and other organic dyes were also investigated. It was found that the photocatalytic activity of Er3+:Y3Al5O12/TiO2‐ZnO composite was superior to TiO2‐ZnO powder in the similar system. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 697–704, 2013