CdS/TiO2/漂珠复合光催化剂制备及其降解高效氯氰菊酯研究

采用溶胶-凝胶-浸渍法制备了Cds/TiO2/漂珠复合光催化剂,通过SEM,XRD对其结构进行了表征.以高效氯氰菊酯(BEC)杀虫剂的光催化降解为模型反应,研究了CdS/TiO2/漂珠的光催化性能,探讨了影响催化剂活性的因素及采用太阳光作光源处理BEC的可行性.结果表明,CdS/TiO2/漂珠投加量为3 000mg·L-1,初始浓度为45 mg·L-1、初始pH为6.5,通气量为200 mL·min-1时间为60 min,BEC降解率分别为92.1%(125W高压汞灯)和79.3%(5 W紫外灯),采用太阳光照射300 min,BEC降解率可达93.4%.BEC的降解反应遵从L-H动力学模型,测得反应速率常数9.80 mg·(L·min)-1,吸附常数4.36×10-3 L·mg-1.

Studies on Preparation of CdS/TiO2/Float Pearls Coupled Photocatalyst and Degradation of Beta-Cypermethrin

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 3000 mg x L(-1), initial concentration of BEC 45 mg x L(-1), initial pH 6. 5, and air flow rate 200 mL x 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 x (L x min)(-1)) and the adsorption constant (4.36 x 10(-3) L x mg(-1)) were determined, respectively.