Preparation Of Fluorin Oxide-Based Composites And Their Visible-Near-Infrared Photocatalytic Properties

In recent years,due to the rapid development of urban industry,the discharge of sewage has also increased.The increasing population and the gradually decreasing fresh water resources have seriously affected people’s normal life.Therefore,finding materials that can effectively degrade sewage has become the current research.Important topic.However,conventional photocatalyst materials,such as TiO₂,ZnO,etc.,mainly produce catalytic effects under visible light and ultraviolet light,have low utilization ratio of spectrum,and have unsatisfactory catalytic effects.The rare earth doped near-infrared photocatalytic material can extend the absorbable spectrum to near-infrared light,greatly improving the spectrum utilization.NaYF₄ is considered to be a better upconversion matrix material in its conventional sense with its lower photon energy.However,NaYF₄ is not a semiconductor material,and it does not have a catalytic effect by itself,and the photocatalytic efficiency of visible light does not increase.Therefore,it is particularly important to select the semiconductor heterojunction with lower photon energy for the full spectrum catalysis.Lanthanide catalytic materials have attracted much attention due to their unique outer electronic structure（6S²）.In this paper,rare earth doped BiOF is studied,which is modified with different lanthanide materials and degraded by rhodamine B.Explore its visible-near-infrared photocatalytic performance.The specific content of this article is as follows:1.The BiOF:Yb³⁺,Tm³⁺photocatalyst was prepared by solvothermal method.The XRD sample was completely consistent with the standard card（JCPDF73-1595）.There were no other peaks.The SEM showed that the sample had a smooth surface.The best luminescence of the sample when the doping amount of rare earth is 7.5%Yb³⁺:0.5%Tm³⁺.2.The Bi₂MoO₆/BiOF:Yb³⁺,Tm³⁺composite photocatalyst was prepared by two-step solvothermal method.When the mass of BiOF was 50%of the theoretical mass of Bi₂MoO₆,the photocatalytic effect was the best.Rhodamine B was used as a simulated pollutant,and the degradation rate reached 99.3%under visible light in50 minutes.The catalytic efficiency is improved by nearly 20%compared to a single catalyst.When irradiated by 980nm laser,the degradation rate reached 33.2%in 4h,and the degradation rate reached 45.85%in 5h,which was nearly 30%higher than that of single catalyst.XRD detection showed that the sample contained all the diffraction peaks of Bi₂MoO₆ and BiOF.The SEM showed that the morphology of the sample was a rough surface,indicating that the sample was a composite of Bi₂MoO₆ and BiOF.3.The carbon quantum dot modified CQDs/Bi₂MoO₆/BiOF:Yb³⁺,Tm³⁺ternary composite photocatalyst was prepared by two-step solvothermal method.When 2ml of CQDs were added,the photocatalytic effect was the best.Rhodamine B was used as the simulated pollutant.Under visible light,the degradation rate reached 97.6%in30 minutes.The catalytic effect of the complex was improved by 20 min compared to the pure Bi₂MoO₆/BiOF:Yb³⁺,Tm³⁺.Under the irradiation of 980 nm laser,the degradation rate reached 33.5%at 4 h.Compared with Bi₂MoO₆/BiOF:Yb³⁺,Tm³⁺the catalytic effect of complex did not change.4.The Bi₂S₃/BiOF:Yb³⁺,Tm³⁺,Er³⁺composite photocatalyst was prepared by two-step solvothermal method.When the mass of BiOF was 50%of the theoretical mass of Bi₂S₃,the photocatalytic effect was the best.Using Rhodamine B as a simulated pollutant,the degradation rate reached 39.6%in 100min under visible light,and the catalytic efficiency increased by nearly 30%compared to a single catalyst.When irradiated by a 980 nm laser,the degradation rate reached 12.8%at 4h,indicating that a heterojunction was formed between the two semiconductors.