Composite nano material and preparation method and application thereof

The invention provides a composite nano-material and a preparation method and application thereof, the composite nano-material comprises X-coated TiO2-Au nano-particles, and the X-coated TiO2-Au nano-particles are X-coated TiO2 mixed bodies coated with Au nano-particles; wherein the X-coated TiO2 mixed body is composed of water-soluble (X: Yb, Er, Tm) nano particles and TiO2 nano particles; and X is a visible light absorbing material and comprises CaF2 and NaYF4. Compared with the prior art, the composite nano material provided by the invention can degrade organic matters including rhodamine B (Rh B) under one or more of a near-infrared light irradiation condition, a visible light irradiation condition and an ultraviolet light irradiation condition; the growth of bacteria can also be inhibited. The preparation method is simple and easy to operate, and the prepared composite nano material is high in applicability. 本发明提供了一种复合纳米材料及其制备方法和应用，复合纳米材料包括X@TiO2-Au纳米颗粒，X@TiO2-Au纳米颗粒为包覆有Au纳米颗粒的X@TiO2杂糅体；其中，X@TiO2杂糅体由水溶性的