Studies on Preparation of CdS/TiO2/Float Pearls Coupled Photocatalyst and Degradation of Beta-Cypermethrin
YAO Bing-hua1,ZHENG Huai-li2,YANG Li-qin1,TIAN Ping1,PANG Xiu-fen1
1. Department of Applied Chemistry, Xi’an University of Technology, Xi’an 710048，China 2. College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
Abstract：The coupled photocatalyst of CdS/TiO2/float pearls was prepared by sol-gel-dipping method, and its structure characterization was carried out with SEM and XRD analysis. As a model reaction, the photocatalytic degradation of beta-cypermethrin(BEC) was investigated in CdS/TiO2/float pearls powder suspension irradiated by different light sources. The effects of influence factors on the photocatalytic activity were discussed for the prepared photocatalyst. The results showed that under the following conditions: amount of photocatalyst 3 000 mg·L-1,initial concentration of BEC 45 mg·L-1,initial pH 6.5, and air flow rate 200 mL·min-1,the degradation rate of BEC reached 87.9%(125 W Hg lamp in 1 hour), 79.3%(5 W UV lamp in 1 hour) and 93.4% (solar light in 5 hours), respectively. The photocatalytic degradation of BEC was experimentally demonstrated to follow the Langmuir-Hinshelwood kinetic model, and the reaction rate constant (9.80 mg·(L·min)-1) and the adsorption constant (4.36×10-3L·mg-1 ) were determined, respectively.
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