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

Аннотация

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.