Preparation Of Tin Dioxide Based Magnetic Composite Photocatalyst And Fenton-Like Photocatalysis Study

With the rapid development of industry,water pollution has become an environmental problem that cannot be ignored.The discharge of dyeing wasterwater has increased significantly.At present,various technologies have been developed to treat the wastewater.Amony them,photocatalysis,as an emeriging treatment technology,is environmentally friendly and has high degradation efficiency.LDHs?layered double hydroxides?have a typical characteristic,namely"memory effect",when LDHs are calcined at high temperature?>500°C?,they can be converted into cubic crystal oxides?LDO,layered double oxides?.However,the layered structure can be regenerated when the LDO is in aqueous solution.In this paper,bismuth or antimony doped tin oxide ternary composite materials were synthesized by solvent heat using Ni/Fe-LDH as precursor and Fe₃O₄ as carrier.The research on such composite materials is the mainstream trend in the field of photocatalytic degradation of pollutants,and the photocatalysis has important scientific significance and application value for energy conservation and environmental protection.The main research contents are as follows:1.We prepared BTO nanomaterials with various Bi doping amounts by solvothermal method to study the Fenton-like effect under visible light.Due to the presence of the Bi?has switchable valence state?in the BTO nanomaterials,the BTO presented efficient photocatalytic degradation of rhodamine B with a Fenton-like effect.The influencing factors of BTO photocatalysis were evaluated,such as the amount of Bi doping,the p H of the reaction solution,and the concentration of hydrogen peroxide.The switch of Bi valence was discussed.2.An Fe₃O₄@LDO@BTO as photocatalyst was synthesized.First,Ni/Fe-LDH was modified on the surface of Fe₃O₄ nanospheres by precipitation,and then BTO of different qualities was added to the surface of Fe₃O₄@LDH by ultrasound,hydrothermal method and calcined,the ternary composite can be successfully synthesized.The catalyst has a core-shell structure,and the photocatalytic degradation of methyl orange?MO?under visible light radiation,compared with Fe₃O₄,Ni/Fe-LDH,BTO,Fe₃O₄@LDO,Fe₃O₄@LDH,Fe₃O₄@LDH@BTO,the degradation efficiency of Fe₃O₄@LDO@BTO has been significantly improved.The excellent photocatalytic performance of Fe₃O₄@LDO@BTO is mainly due to the following aspect.Due to the memory effect of LDH in the photocatalytic reaction,the regenerated LDH in LDO accelerates the transfer of photogenerated carriers.3.ATO nanoparticles with different amounts of Sb doping were first synthesized by solvothermal method.Then a ternary core-shell structure composite photocatalyst Fe₃O₄@LDO@ATO was also successfully prepared by a simliar method in the previous project.The photocatalytic degradation efficiency of this material for malachite green has been greatly improved.The Nanocomposite formed by LDO/LDH/ATO inhibits the recombination of electrons and holes.Additionally,the magnetic properties of the materials demonstrated great potential for recycling in the photocatalytic degradation of dyeing wastewater.