Preparation of nano-sized mixed crystal TiO₂-coated Er^3 +:YAlO₃ by sol–gel method for photocatalytic degradation of organic dyes under visible light irradiation

In this work, an upconversion luminescence agent, crystallized Er^3 +:YAlO₃, was synthesized and then coated by the nano-sized TiO₂ film through sol–gel technique. A novel TiO₂ photocatalyst, Er^3 +:YAlO₃/TiO₂, with high activity in visible light was subsequently prepared. The Er^3 +:YAlO₃ and Er^3 +:YAlO₃/TiO₂ were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The photocatalytic activity of Er^3 +:YAlO₃/TiO₂ photocatalyst was tested by the degradation of acid red B in aqueous solution as the primary model compound under visible light irradiation. The experimental results proved that the prepared TiO₂-coated crystallized Er^3 +:YAlO₃ was able to decompose the acid red B efficiently, and it is promising to use the idea to develop new TiO₂ photocatalyst with high activity for photocatalytic degradation under visible light.