Fluorescence and room temperature activity of Y2O3:(Eu3+,Au3+)/palygorskite nanocomposite

Abstract

The fluorescence and room temperature activity of a palygorskite supported Y₂O₃:(Eu³⁺,Au³⁺) nanocomposite were investigated to design a fluorescence-indicated catalyst. The effects of Au³⁺ doping on the structure and surface properties of the host material were systematically characterized. The fluorescence intensity of Y₂O₃:Eu³⁺ was affected by Au³⁺ doping, which was related to the crystallinity of Y₂O₃. Excess Au³⁺ ions were segregated to the host surface and reduced to metallic Au. The local symmetry of Eu³⁺ was reduced by Au³⁺ doping, which benefited the energy transfer between Eu³⁺ and Au³⁺. Energy absorbed by Eu³⁺ was transferred from Au³⁺ to metallic Au, where electrons were produced. These electrons were absorbed by O₂ to change into O₂⁻, which acted as the oxidant for ortho-dichlorobenzene (o-DCB). The variation of fluorescence intensity during the catalytic reaction was observed. The room temperature catalytic activity of the nanocomposite under UV irradiation was revealed. The as-synthesized nanocomposite might have potential applications in environmental fields.