Study For Photocatalytic Degradation And Biocompatibility Of TiO₂ Coated Rare Earth Co-doped Flouride Nano Under Near Infrared Light

The increasing market demand for efficient sun sources motivates the research worldwide in phosphors activated with lanthanide ions.Generation of up-conversion luminescence?UCL?from NIR to ultraviolet?UV?proved to be of great interest in improving the photo-catalytic activity of some materials.For example,to utilize the photo-catalytic activity of the material in the visible region and near-infrared?NI?light of solar spectrum,great efforts have been done for expanding the TiO₂ optical absorption spectrum,by generating of UCL from NIR light to UV.Therefore,it is necessary to create more efficient NI-UV conversion materials to make good use of natural light.The rare erath co-doped fluoride nano called up-converting luminescence materials were prepared by solvothermal method.Using the four-factor three-level orthogonal table concluded the optimal conditions.When the doping amount of the luminescent ion Tm³⁺was 0.3%,the doping amount of the sensitized ion Yb³⁺was 20%,the solvothermal temperature was 310°C and the solvothermal reaction time was 3h,the up-conversion luminous efficiency of the?CaY?F₂:Tm³⁺and Yb³⁺was better,which can be excited by980 nm near infrared light and transfer to 360 nm UV.In this paper,TiO₂ and?CaY?F₂:Tm³⁺/Yb³⁺were prepared by three methods.The composites synthesized with TiO₂ and?CaY?F₂:Tm³⁺,Yb³⁺which prepared by solvothermal method;The composites synthesized with macroporous TiO₂ and?CaY?F₂:Tm³⁺,Yb³⁺which prepared by hydrothermal method;The composites synthesized with TiO₂ and?CaY?F₂:Tm³⁺,Yb³⁺which prepared by hydrothermal method.When the molar ratio of TiO₂:?CaY?F₂ was 2:1,the obtained composite powder was excellent in photocatalytic degradation under near infrared.The photocatalytic effect was better when the doped?CaY?F₂:Tm³⁺and Yb³⁺were prepared by solvothermal method.The results of in vitro cytotoxicity test showed that the composite materials synthesized by the three methods had no obvious cytotoxicity and good biocompatibility.Its MIC value is 125 ppm,which has certain antibacterial capacity.