环保型甲基嘧啶磷纳米农药制剂的光催化降解

Photodegradation of Nonpolluting Pirimiphos-methyl Nano-pesticide Formulation

于甲基嘧啶磷农药中引入纳米TiO2、用十二烷基磺酸钠（SDS）改性的纳米TiO2和原位生成的纳米TiO2光催化剂,制成3种光降解源纳米农药制剂。它们在黑暗中能稳定存放,在紫外光和太阳光下3种纳米农药制剂的分解率显著提高。在太阳光下3 d,3种纳米农药制剂中甲基嘧啶磷分解率分别为69.00%、90.55%和51.90%,紫外光下3 h分解率分别是95.00%、99.5%和77.62%,而对照样纯农药在相同条件下分解率分别为9.1%和6.9%,改性纳米TiO2的制剂光催化活性最好。纳米农药制剂经粒度测试仪和扫描电镜分析,粒径～93nm,在黑暗中冷、热贮存7～14 d不分层,分解率小于1.4%。

Three types of photodegradable nano-pesticide formulations were prepared respectively by importing nano-TiO2, nano-TiO2 modified by sodium dodecyl sulfate and nano-TiO2 prepared in-situ in pirimiphos-methyl pesticide. These formulations could be steadily kept in the dark, and their degradation rates were markedly increased under UV-light and sunlight. The photodegradation rates of pirimiphos-methyl in three nano-pesticide formulations were 69.00%, 90.55% and 51.90% respectively under sunlight irradiation for 3 d, and 95.00% ,99.50% and 77.62% respectively under UV-light irradiation for 3 h ,while the pure pesticide degradated only 9. 1% and 6. 9% under the same conditions. The photocatalytic activity of modified TiO2 was the best. The grain sizes of nano-pesticide formulations analyzed by laser particle size analyzer and SEM were about 93 nm. These formulations were not bedded under cold or hot storage in the dark for 7 - 14 days and the decomposition rate was less than 1.4%.