ZnO纳米粒子光催化降解失效农药草甘膦的研究

采用Zn（NO3）2.6H2O和CF3COONa为原料制备ZnO纳米材料,运用扫描电子显微镜（SEM）、X射线衍射仪（XRD）和紫外-可见漫反射光谱（UV-VisDRS）测定等技术对其进行表征。ZnO纳米粒子在波长为200～400nm的紫外光范围内具有强吸收,以高压汞灯为光源,利用ZnO纳米催化剂对失效农药草甘膦（FGP）进行光降解实验。研究表明,在经900℃煅烧的ZnO纳米粒子浓度为0.5g.L-1,FGP试液初始pH=2.2的条件下,光催化降解90min后FGP去除率达91.8%;光催化体系中,引入Fe3＋有利于提升ZnO纳米粒子催化活性。光谱分析显示,经ZnO纳米粒子光催化,失效农药草甘膦基本降解。

Study on the Photocatalytic Degradation of Failure Glyphosate Pesticide by ZnO Nanoparticle

The glyphosate is a destructive organophosphorous herbicide which is hazardous to the crops at certain level.Moreover,the large amount of failure glyphosate pesticides（FGP） has a substantial threat to both the plants and the environment.The treatment of FGP has been attracted much attention.ZnO nanomaterials（photocatalysts） were prepared with Zn（NO3）2·6H2O,and CF3COONa and then were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD） and UV-vis diffuse reflection spectroscopy（UV-vis DRS）.The XRD observation suggested that as the calcining temperature increased,the high crystallinity of ZnO nanoparticles was obtained.SEM analysis found that the morphology of ZnO photocatalyst greatly depended on the calcining temperature.The DRS analysis of ZnO nanoparticles showed that strong absorption was appeared between the 200~400 nm wavelength.The photodegradation experiments on FGP were conducted by high pressure Hg lamp as light source and ZnO as nano-catalyst.The results indicated that 91.8% FGP in the testing solution could be removed under UV light irradiation for 90 min when the initial pH in FGP testing solution was 2.2,and the concentration of ZnO nanoparticles（calcined at 900 ℃）was 0.5 g·L-1.It was found that introduction of Fe3＋ was helpful to enhance the catalytic activity of ZnO nanoparticles in the photocatalytic system.The spectral analysis indicated that FGP had been almost degraded by the photocatalysis of ZnO nanoparticles.