Preparation of Yb, N, and F doped Er3+:Y3Al5O12/TiO2 composite films for visible-light photocatalytic degradation of organic dyes

摘要

Several up-conversion luminescent materials (Er3+:Y3Al5O12, Yb doped Er3+:Y3Al5O12, Yb and N co-doped Er3+:Y3Al5O12, Yb and F co-doped Er3+:Y3Al5O12, and Yb, N, and F co-doped Er3+:Y3Al5O12) were synthesized using sol-gel method. The corresponding TiO2 composite films (Er3+:Y3Al5O12/TiO2, Yb doped Er3+:Y3Al5O12/TiO2, Yb and N co-doped Er3+:Y3Al5O12/TiO2, Yb and F co-doped Er3+:Y3Al5O12/TiO2, and Yb, N, and F co-doped Er3+:Y3Al5O12/TiO2) were prepared by sol-gel dip-coating method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). The UV-Vis absorption and PL spectra of Er3+:Y3Al5O12 were also determined. The visible-light photocatalytic activity of the synthesized materials was evaluated in the degradation of Azo Fuchsine (AF) dye in aqueous solution. The concentration of the dye was monitored by UV-Vis spectroscopy. Some key factors, such as layer number, heat-treatment temperature and time on the photocatalytic activity of Yb, N, and F co-doped Er3+:Y3Al5O12/TiO2 composite films were studied. The doping of Yb, N, and F into Er3+:Y3Al5O12/TiO2 significantly enhanced the visible-light photocatalytic activity of Er3+:Y3Al5O12/TiO2 composite film in the degradation of organic dyes. The experiments also indicated that the Yb, N, and F co-doped Er3+:Y3Al5O12/TiO2 composite film has a good visible-light photocatalytic activity to degrade other organic dyes under visible-light irradiation.