Preparation Of Y₂O₃:Yb³⁺,Tm³⁺/SnO₂ Composite Material And Its Photocatalytic Performance

Solar energy is the cleanest and most environmentally friendly energy source,and people are paying more and more attention to the use of sunlight.Photocatalytic technology can use solar energy to solve problems such as energy shortage and environmental pollution.However,limited by specific factors in the energy process,most wide band gap semiconductor photocatalysts can only use ultraviolet light that accounts for less than 4%of sunlight,which greatly limits the utilization of solar energy.This paper adopts the method of combining up-conversion materials and wide band gap semiconductors to solve the problems of low solar energy utilization rate and poor photocatalytic activity of wide band gap semiconductors.The main tasks are as follows:1?The sol-gel method uses Y₂O₃as the host material and doped Yb³⁺and Tm³⁺ions to prepare Y₂O₃:Yb³⁺,Tm³⁺up-conversion luminescent powder.Through XRD,PL,SEM and other characterization methods,the crystal form,luminescence characteristics,and morphology of the material are studied.The results show that the calcination temperature,the concentration of nitric acid,and the aging time have an effect on the formation and luminescence properties of the up-conversion material.2?In order to further improve the up-conversion performance of the material,the up-conversion material prepared above was modified by Ag⁺doping.The effects of Ag⁺addition and calcination temperature on the up-conversion luminescence performance of the material were explored.Through characterization methods such as PL and XRD,the fluorescence properties and phases of the materials are analyzed.The results show that appropriate amount of Ag⁺doping can increase the upconversion fluorescence intensity of Y₂O₃:Yb³⁺,Tm³⁺,and Ag⁺doping can modify Y₂O₃:Yb³⁺,Tm³⁺.3?The Ag⁺-doped Y₂O₃:Yb³⁺,Tm³⁺/Sn O₂composite photocatalyst was prepared by sol-gel method,hydrothermal method and ultrasonic method,respectively.Through XRD,PL,SEM and other characterization methods,the Ag⁺doped Y₂O₃:Yb³⁺,Tm³⁺/Sn O₂catalyst was characterized by crystal type,fluorescence properties and morphology.The photocatalytic experiments were carried out with magenta,chrome blue and eosin as the target pollutants.The results show that under suitable experimental conditions,the Ag⁺-doped Y₂O₃:Yb³⁺,Tm³⁺and Sn O₂composite catalyst prepared by the sol-gel method has the best photocatalytic effect.The composite material is a spherical Sn O₂grown on the bulk upconversion material.The resulting composite structure.The dynamic analysis results of photo-generated carriers show that the semiconductor electron-hole recombination rate is significantly reduced after recombination.Under visible light conditions,the degradation rates of the three dyes at 120min are 100%,62%,and 73%,respectively.Compared with pure ultraviolet light,the degradation rates of the three dyes by semiconductor Sn O₂are 60%,36%,and 44%,respectively.Promote.Based on the experimental and characterization results,the photocatalytic mechanism of the composite material was analyzed.