纳米Pd/TiO_2复合型农药的吸附和降解的QCM研究  

Study on the Adsorption and Photodegragation of Pesticide Complex With Nanocrystalline Pd/TiO_2 Photocatalyst by QCM

作　　者：刘国聪[1] 董辉[1] 杨政鹏[2] 李海斌[2] 

机构地区：[1]玉林师范学院化学与生物系,副教授博士生广西玉林537000 [2]中南大学化学化工学院,博士副教授湖南长沙410083

出　　处：《玉林师范学院学报》2006年第3期71-75,共5页Journal of Yulin Normal University

基　　金：国家863高技术计划项目(2001AA218041)

摘　　要：采用压电石英微天平(QCM)技术研究了有机农药甲基对硫磷在经钯(Palladium)掺杂和软脂酸(PalmicAcid)改性前后的纳米TiO2上的吸附和降解行为.研究表明Pd和PA均能提高纳米TiO2对非极性有机农药的吸附量,复合纳米TiO2和Pd/TiO2的最大吸附量Г∞分别为6.18×10-4mol/g和7.54×10-4mol/g,吸附常数k分别为5.72×103L/mol和1.79×103L/mol.光降解和毒力实验结果表明复合纳米TiO2和Pd/TiO2农药制剂可在太阳光照下自行降解,在农作物体内的残留期大大地缩短,且复合纳米TiO2和Pd/TiO2农药制剂的毒力有明显的提高,5%的纳米TiO2和Pd/TiO2乳液的毒力分别是95%原药毒力的1.68倍和2.19倍.A quartz crystal microbalance was used to investigate the adsorption photodegragation behaviors of methyl parathion on nanocrystalline TiO2 and Pd/TiO2 particles modified with and without palmic acid,respectively.The results show that the nanocrystalline TiO2 modified with palladium and palmic acid has better efficiency to adsorb non-polar organic pesticides than the original TiO2.lt is also found that amounts of the methyl parathion adsorbed on the surface of nanocrystalline TiO2 and Pd/TiO2 modified with pahnic acid are 6.18 ×10^-4mol/g and 7.54 ×10^-4mol/g, respectively,and constants of the adsorption are 5.72 × 10^3 L/mol and 1.79 × 10^3 L/mol, respectively. Nanosized TiO2-pesticide complex and Pd/TiO2--pesticide complex were prepared,and its photodegradation and biological toxicity were studied.Experimental results show that the nanosized Pd/TiO2-pesticide complex has obvious photodegradation.FZesidual times of TiO2 and Pd/TiO2-pesticide complex in the body of plant are significantly reduced and its biological toxicities are increased to 1.68 times and 2.19 times that of traditional pesticides,respectively.

关 键 词：纳米pd/TiO2 压电石英微天平 软脂酸 光降解 乳液毒力 

分 类 号：O62[理学—有机化学]