太阳光TiO_2多孔纳米薄膜光催化降解有机磷农药的研究

STUDY ON PHOTOCATALYTIC DEGRADATION OF ORGANOP HOSPHOROUS INSECTICIDE USING POROUS TiO_2 NANOMETER THIN FILMS BY SUNLIGHT

锐钛矿型 Ti O2 多孔纳米薄膜可以从含聚乙二醇的钛醇盐溶胶前驱体中通过浸渍提拉法制备 ;涂层的形貌如孔的大小和孔的分布可以通过聚乙二醇的加入量来控制 ,当聚乙二醇的加入量为 0— 2 .0 g时 ,孔径大小在 0— 40 0 nm范围内变化。可见光透过光谱分析表明 :随着 Ti O2 薄膜中孔径增大 ,光的散射增强 ,透光率减小 ,该 Ti O2 镀膜玻璃对于紫外线具有吸收作用。有机磷农药水溶液的太阳光催化降解实验表明 :在 Ti O2 薄膜中引入气孔增强了光催化活性 ,孔的大小和薄膜厚度对光解率有显著的影响。当孔径大小为 1 0 0— 2 0 0 nm,镀膜次数为 1 0— 1 5次时 ,Ti O2 薄膜显示光催化效率高。

Porous anatase TiO 2 nanometer thin films were prepared from alkoxide solutions containing polyethylene glycol by a dip coating technique.The morphology of the coatings, such as pore size and pore distribution,could be controlled by the precursor solution containing the amount of polyethylene glycol.When the amount of polyethylene glycol is in the range 0-2.0g,the diameters of the pores in the TiO 2 thin films are in the range 0-400nm.The transparency of the glass with porous TiO 2 nanometer thin films in visible spectra shows:With the increase of the diameters of the pores in the TiO 2 thin films,the scattering of light was enhanced and its transmissivity was reduced,also it does not transmit ultraviolet light.Organophosphorous insecticides,dimethyl 2,2 dichlorovinyl phosphate(DDVP),were degraded in the presence of porous TiO 2 nanometer thin films by exposing the organophosphorous insecticide solution to sunlight.The photocatalytic degradation experiment of organophosphorous insecticide indicated that the pores in the TiO 2 thin films enhance its photocatalytic activity,the size of the pores and the thickness of thin films obviously affect the photodegradation rate of organophosphorous insecticide.