Study on photocatalytic activity of Er3+:YAlO3/TiO2 composite films supported on electrically conductive glass (FTO) in visible-light photocatalytic degradation of organic dye

Abstract

Er3+:YAlO3/TiO2 composite films were prepared via a sol–gel dip-coating method by using electrically conductive glass as a supporter, which were used as photocatalyst in the degradation of dyes under simulated visible-light radiation. This improvement was attributed two sides, one side was due to the presence of Er3+:YAlO3 as up-conversion luminescence agent mixed with TiO2 to solve the problem of low activity of TiO2 to visible-light. On the other side, in virtue of reducing the recombination rate between photogenerated electron–hole pairs the conductive glass was used as electron transfer. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were performed to reveal the crystallinity, surface morphology and chemical composition of the prepared Er3+:YAlO3/TiO2 composite films. Its photocatalytic activity was examined through the degradation of some organic dyes under simulated visible-light irradiation. The degradation process of organic dyes was monitored by UV–vis spectrophotometer. Furthermore, some main influence factors on the photocatalytic activity of Er3+:YAlO3/TiO2 composite film such as Er3+:YAlO3/TiO2 mass ratio, layer number, heat-treated temperature and heat-treated time were studied. The recycling used times and organic dye kinds were also included in consideration. Finally, it can be predicted that the Er3+:YAlO3/TiO2 composite film plays a good and broad-spectrum photocatalytic activity to treat various organic dye wastewater on practical application.