Preparation of (CaY)F 2 :Tm 3+ ,Yb 3+ deposited porous TiO 2 matrix with highly near‐infrared light photocatalytic activity

Abstract

Porous titanium dioxide (TiO2) matrix deposited with upconversion luminescence agent (CaY)F2:Tm3+,Yb3+ was sol–gel prepared using polymethyl methacrylate (PMMA) microspheres as sacrificing template and tetrabutyl titanate as TiO2 precursors. The resulted photocatalysts were subsequently characterized by X-ray diffraction, scanning microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectra (PL) etc. The photocatalytic activity and biocompatibility of TiO2/(CaY)F2:Tm3+,Yb3+ were evaluated by photocatalytic degradation of methyl orange (MO) and fibroblast cytotoxicity analysis, respectively. The results revealed that (CaY)F2:Tm3+,Yb3+ nanoparticles were well dispersed onto the pore walls of porous TiO2 matrix to generate a biocompatible composite. In addition, TiO2/(CaY)F2:Tm3+,Yb3+ was found to show excellent photocatalytic activity in both UV and infrared spectra, highlighted with the fact that (CaY)F2:Tm3+,Yb3+ nanocrystals can be excited to release UV light under near infrared light source, which can in consequence active TiO2. When the mass ratio of TiO2 to (CaY)F2:Tm3+,Yb3+ nanocrystals is 2:1, the best photocatalytic efficiency can be achieved with most of UV light released by (CaY)F2:Tm3+,Yb3+ absorbed by TiO2 to induce photo-oxidation. The outstanding photocatalytic performance along with its biocompatibility, makes TiO2/(CaY)F2:Tm3+,Yb3+ a promising candidate in environmental and biomedical applications.