| Water is the source of life; however, with the rapid development of industryespecially chemical industry, water pollution induced by organic pollutants isbecoming more and more serious. So, the pretreatment of waste water is necessary.Fortunately, photocatalytic technologies are very effective methods for treatingorganic pollutants, among which photocatalyst is key of the key. Up to now, there arestill two weaknesses in photocatalysts: low utilization rate of sunlight and easyrecombination of photogenerated electrons and holes. Studies have shown thatcomplexation of semiconductors is an effective way to solve these two problems.Based on the advantages of bismuth photocatalyst, we chose (BiO)2CO3as theresearch object, and prepared (BiO)2CO3based complex semiconductors, which canresponse to visible light. The main research contents include two aspects.(1) Byultrasonic assisted ion exchange method and hydrothermal method, we synthetizedBi2S3/(BiO)2CO3composite which can response to visible light; through manycharacterizations such as XRD, SEM, UV-Vis and PL, we investigated the structureand morphology of the composite photocatalyst; using the degradation of RhodamineB as a model reaction, we evaluated the performance of the photocatalyst; on the basisof all characterizations we proposed the photocatalytic degradation mechanism. Theresearch results show that the activity of the composite photocatalyst prepared byultrasonic assisted ion exchange method is superior to the hydrothermal method; ascompared with (BiO)2CO3, the composite photocatalyst exhibited much betterperformance for RhB degradation.(2) By using the method of sedimentprecipitation-illumination reduction we successfully prepared Ag/AgBr/(BiO)2CO3composite photocatalyst, which was characterized by XRD, XPS, UV-Vis, SEM andso on, and used for RhB degradation. It is found that this composite photocatalyst candegradate RhB very effectively due to the the synergy effect between the threecomponents in the system. |
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