title: Photosensitizing effects of nanometer TiO2 on chlorothalonil photodegradation in aqueous solution and on the surface of pepper.
abstract: The present study examined the effects of anatase nanometer TiO2 on photochemical degradation of chlorothalonil in aqueous solution and on the plant surface. Results showed that nanometer TiO2 exhibited a strong photosensitizing effect on the degradation of chlorothalonil both in aqueous solution and on the surface of green pepper. The photosensitization rate was the highest in the sunlight compared to illumination under high-pressure mercury and UV lamps. Use of distinct hydroxyl radical scavengers indicated that nanometer TiO2 acted by producing hydroxyl radicals with strong oxidizing capacity. Notably, nanometer TiO2 facilitated complete photodegradation of chlorothalonil with no detectable accumulation of the intermediate chlorothalonil-4-hydroxy. Nanometer TiO2 was also active on the surface of green pepper under natural sunlight both inside and outside of plastic greenhouse. These results together suggest that nanometer TiO2 can be used as a photosensitizer to accelerate degradation of the pesticides under greenhouse conditions.
authors: Provincial Key Laboratory for Agri-Food Safety, School of Resource & Environment, Anhui Agricultural University, Hefei, Anhui 230036, China.
authors: Yong Qiang
authors: YQ
authors: Tan
authors: Hai Xia
authors: HX
authors: Xiong
authors: Tao Zhong
authors: TZ
authors: Shi
authors: Ri Mao
authors: RM
authors: Hua
authors: Xiang Wei
authors: XW
authors: Wu
authors: Hai Qun
authors: HQ
authors: Cao
authors: Xue De
authors: XD
authors: Li
authors: Jun
authors: J
authors: Tang
mesh_terms: D002212:Capsicum / Q000737:chemistry / Q000187:drug effects* / Q000592:standards; D008027:Light; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D009570:Nitriles / Q000737:chemistry*; D010575:Pesticides / Q000737:chemistry*; D010782:Photolysis / Q000528:radiation effects; D017319:Photosensitizing Agents / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D009570:Nitriles; D010575:Pesticides; D017319:Photosensitizing Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium; C005806:tetrachloroisophthalonitrile