Preparation And Inactivation Properties Of GO/AgI And AgI/BiVO₄ Photocatalysts

Recently,environmental contamination and food security have gradually become a focus in people's mind.The continuous growth of antibiotics in medical wastewater and pathogenic microorganisms in food has urged people to find good ways to stop the spread of the pollution.Among varieties of wastewater treatment methods,researchers found that the photocatalytic technology is one of the most prominent methods in view of many perspectives,such as high-efficient,durability,non-secondary pollution and low drug-fast.Therefore,we have synthesized AgI,GO and BiVO₄ based on silver nitrate,potassium iodide,graphite,ammonium metavanadate and bismuth nitrate pentahydrate,which were easy to obtain.Then the GO/AgI and AgI/BiVO₄ hybrids were fabricated via precipitation method.Whereafter,the crystal,morphology,element composition and optical properties of obtained samples were analyzed by XRD?SEM?TEM?HRTEM?EDX?XPS?DRS and PL technique.Finally,the obtained catalysts were employed to inactivate bacteria and degrade antibiotic to evaluate their photocatalytic properties and investigate the possible photocatalytic mechanisms.The details were listed below:1.Mainly talking about the fabrication method and photocatalytic performance of GO and GO/AgI.GO/AgI was prepared via two steps,Hummers method with some modification together with precipitation method.The photocatalytic property of GO/AgI was evaluated via antibacterial experiments under visible light irradiation;meanwhile,the ratio effects between GO and AgI,and the dosages of GO/AgI on antibacterial activities were also taken into discussion.Results turned out that the GA-2?GO occupied GO/AgI 50%?possesses the best photocatalytic performance,which could inactivate 3x10⁶ CFU/mL E.coli after 50 min irradiation with a dosage of 20 mg.Besides,we have also carried out the possible antibacterial mechanisms and recycle ability experiments for GO/AgI,results turned out that·O₂^-and h⁺play a crucial role in inactivation reactions,and GO/AgI possesses excellent photocatalytic property and recycle ability.2.Mainly talking about the fabrication method and photocatalytic performance of BiVO₄and AgI/BiVO₄.BiVO₄ was fabricated by hydrothermal method and AgI/BiVO₄ hybrids were then synthesized by precipitation method.The photocatalytic property of obtained catalysts was tested via the inactivation experiments on Escherichia coli?E.coli?and degradation experiments on antibiotic.To further investigate sample's catalytic performance under visible light,we have performed the inactivation experiments with different ratio obtained catalyst,with different initial concentration E.coli,with different anion solution.It reveals that BA3?AgI occupied AgI/BiVO₄ 9.09%?possesses the best photocatalytic performance,which could inactivate 7x10⁷ CFU/mL E.coli after 50 min irradiation and degrade 80%OTC-HCl after 60 min irradiation.In addition,we have discussed the possible photocatalytic mechanisms based on ion influence reactions,capturing experiments and bond gap structure analysis.·O₂^-and h⁺rather than Ag⁺are the key active speciecs in photocatalytic inactivation reactions,AgI/BiVO₄ owns a Z scheme heterojuction.At last,we summary the fruits of this paper and give the prospect of our future work.