Synthesis of Er3+:Y3Al5O12 and its effects on the solar light photocatalytic activity of TiO2–ZrO2 composite

The Er 3+ :Y 3 Al 5 O 12 as an upconversion luminescence agent, which can transform visible light into ultraviolet light, was synthesized by nitrate–citrate acid and calcined method. Then, a novel photocatalyst, Er 3+ :Y 3 Al 5 O 12 /TiO 2 –ZrO 2 , was prepared using ultrasonic dispersion and liquid boiling method. The samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). In succession, the degradation process of organic dye was monitored by UV–Vis spectrum and ion chromatography for verifying the photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /TiO 2 –ZrO 2 . The influences on its photocatalytic activity such as Ti/Zr molar ratio, heat-treated temperature, and time were studied. In addition, the influences of initial concentration, Er 3+ :Y 3 Al 5 O 12 /TiO 2 –ZrO 2 amount, solar light irradiation time, and organic dye category on the photocatalytic degradation efficiency were also investigated. It was found the photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /TiO 2 –ZrO 2 was superior to Er 3+ :Y 3 Al 5 O 12 /TiO 2 and Er 3+ :Y 3 Al 5 O 12 /ZrO 2 . Therefore, the Er 3+ :Y 3 Al 5 O 12 /TiO 2 –ZrO 2 is a useful photocatalytic material for the wastewater treatment duo to efficient utilization of solar light.