Study On Preparation Of Two Kinds Of Modified Ag₃PO₄ Photocatalysts And Their Performance For Dye Degradation

With the accelerating process of industrialization,the problem of water pollution is becoming more and more serious.Organic dyestuffs discharged from textile and other industries are the main pollutants in wastewater,and how to remove and degrade these pollutants has always been a matter of concern.Focus.Among many pollutant treatment technologies,photocatalytic technology can use solar energy to degrade dyes,antibiotics,pesticides and other organic pollutants,with low energy consumption,less secondary pollution and other advantages,is regarded as one of the most promising methods of organic pollutant degradation,has received widespread attention from researchers.The research focus on photocatalytic degradation of organic pollutants is mainly on the design and construction of efficient photocatalysts.Among the many photocatalytic materials,Ag₃PO₄photocatalyst has a good visible light response（band width of about 2.4 e V）and a suitable oxidation capacity,which have received much attention from researchers.However,the catalysts have the disadvantages of easy complexation of photogenerated carriers and low quantum yields.Therefore,the development of novel photocatalysts with broad spectral response and high carrier separation efficiency based on Ag₃PO₄is of important scientific and application value.Among many catalyst modification strategies,the construction of Z-scheme heterojunction can effectively improve the semiconductor redox ability without reducing the carrier separation efficiency.Based on this,the ternary all-solids with Z-scheme heterojunction structure are constructed by compounding Ag₃PO₄with bismuth oxide or molybdenum oxide metal oxides in this paper.Photocatalyst with simultaneous introduction of Ag nanoparticles as electron mediators between different semiconductor materials to facilitate the rapid migration of photogenerated carriers The main research results obtained are as follows:1.Ag and Ag₃PO₄nanoparticles were prepared by depositing them on the surface of BiO_2-xnanosheets with Z-scheme heterojunction The Ag₃PO₄-Ag-BiO_2-xphotocatalyst is a combination of Ag₃PO₄,BiO_2-xand Ag/BiO_2-xcatalysts.Compared to pure Ag₃PO₄,BiO_2-xand Ag/BiO_2-x,the composite catalysts have a higher sensitivity to visible light than pure Ag₃PO_4,BiO_2-xand Ag/BiO_2-x.The Ag nanoparticles on the catalyst surface exhibit excellent photocatalytic activity and stability for the degradation of dyes（rhodamine B,methylene blue）.It is concluded that the Ag nanoparticles on the catalyst surface have a plasma resonance（SPR）effect,which can effectively improve the catalyst’s performance in the degradation of rhodamine B and methylene blue.light absorption capacity;at the same time,the formation of dense heterojunction between Ag₃PO₄-BiO_2-xand Ag particles can be effectively promote the separation of photogenerated electrons and holes to inhibit the photocorrosion of Ag₃PO₄materials.2.Ultrathin two-dimensional MoO_3-xnanosheets rich in oxygen vacancies were prepared using a fast phase change heating method,followed by Ag and Ag₃PO₄nanoparticles are progressively immobilized on the surface of MoO_3-xnanosheets to generate Ag₃PO₄-Ag-MoO_3-xternary Z-scheme heterojunction structure.Ag nanoparticles as an electron dielectric facilitate rapid separation and suppression of photogenic carriers.Photocorrosion of the material,the oxygen vacancies present on the MoO_3-xsurface enhanced the O₂adsorption and improved the oxidation properties of the material.Among all the complexes,the Ag₃PO₄content of 65 wt%of Ag₃PO₄-Ag-MoO_3-xhas the highest photocatalytic activity which was observed for the dyes（rhodamine B,methylene blue and its mixtures）and ciprofloxacin under visible light irradiation.The degradation exhibited excellent photocatalytic activity and stability.