石英微天平定量分析纳米Pd/TiO_2对农药的吸附与降解  

Studies on the Adsorption and Photodegradation of Pesticide Complex with Nanocrystalline Pd/TiO_2 by Quartz Crystal Microbalance

作　　者：刘国聪[1] 董辉[1] 庞起[1] 梁达文[1] 曾楚杰[1] 韦庆敏[1] 

机构地区：[1]玉林师范学院化生系

出　　处：《分析测试学报》2007年第3期300-304,共5页Journal of Instrumental Analysis

基　　金：国家高新技术863项目(2001AA218041);广西教育厅项目(2005GX05075);玉林师范学院重点科研项目(2006YJZD017)

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,Pa)掺杂和软脂酸(palmic acid)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（QCM） was used to study the adsorption and photodegradation behaviors of methyl parathion on nanocrystalline（NC） TiO2 particles modified with palladium, with and without palmic acid, respectively. Compared with the unmodified NC TiO2, the NC TiO2 modified with palladium and palmic acid has higher adsorption capacity for non-polar organic pesticides. Experimental results showed that the amount of the methyl parathion adsorbed on the surface of NC TiO2 and Pd/ TiO2 modified with palmic acid were 6. 18 ×10 ^-4 mol/g and 7.54 ×10^ -4 mol/g, respectively, and the the adsorption constants were 5.72 ×10^3 L/mol and 1.79 ×10^3 L/mol, respectively. Nano-TiO2-pesticide complex and Pd/TiO2-pesticide complex were prepared, and their photodegradation and virulence were studied. The results showed that the nano-Pd/TiO2-pesticide complex was self-photodegradable in the sunlight. The residual times for TiO2 and Pd/TiO2-pesticide complex in the plant body were significantly shortened and their virulence were increased to 1.68 times and 2. 19 times that of the 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：S482.33[农业科学—农药学]