β-NaYF4:Yb,Tm@TiO2-Acac core-shell structure for efficient photocatalysis

Abstract

Novel hybrid core shell structure with extensive absorption was synthesized by a two-step wet chemical route. Up-converting β-NaYF4:Yb,Tm core was obtained through EDTA assisted hydrothermal process, while the shell of anatase TiO2-Acetylacetonate charge transfer complex (TiO2-Acac) was formed over these via sol-gel method. Tetracycline was used to investigate photocatalytic efficiency of obtained structure under irradiation of reduced power Vis and NIR spectra. Owing to the fact that 1D2→3F4 and 1G4→3H6 emission of Tm3+ matches well with the absorption edge of TiO2-Acac, radiation-reabsorption and FRET processes improve the overall generation of reactive oxygen species and degradation of tetracycline. Beside it, formation of tetracycline intermediates immediately after the addition of this novel hybrid core-shell structures, making them a promising material for water purification through the synergy of catalytic and photocatalytic processes.