title: TiO(2)/BaTiO(3)-assisted photocatalytic mineralization of diclofop-methyl on UV-light irradiation in the presence of oxidizing agents.
abstract: Gas chromatograph-mass spectroscopic identification of intermediate products in the degradation of diclofop-methyl and the kinetics of the reaction has been investigated. Formation of 4-[(2,4-dichlorophenoxy) phenoxy] ethane and (2,4-dichlorophenoxy) phenol was investigated. The other intermediate products are 2,4-dichlorophenol, 2,4-dichlorobenzene, phenol and acetic acid have been ascertained. The decrease in the concentration of the parent/intermediate compounds is followed by UV-vis spectral study and the supportive information on the functional groups in the intermediates has been obtained from IR-spectroscopy. Degradation process proceeds with oxidation-reduction reaction by the attack of OH*, H*, O(2)*(-) free radicals, which are photogenerated on the UV-light illuminated TiO(2)/BaTiO(3) photocatalysts particles in aqueous medium. In this presentation another wide band gap semiconductor BaTiO(3) is shown to have comparable photocatalytic efficiency. The oxidizing agents are added to accelerate the rate of the reaction by enhancing the formation of free radicals. Based on the intermediates formed in the process of degradation, a suitable mechanism has been proposed.
authors.affiliation: Department of Post Graduate Studies in Chemistry, Central College Campus, Dr. B.R. Ambedkar Veedi, Bangalore University, Bangalore 560001, India. gomatidevi_naik@yahoo.co.in
authors.forename: L
authors.initials: L
authors.lastname: Gomathi Devi
authors.forename: G
authors.initials: G
authors.lastname: Krishnamurthy
mesh_terms: D017609:Barium Compounds / Q000737:chemistry*; D002384:Catalysis; D008401:Gas Chromatography-Mass Spectrometry; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry*; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D017609:Barium Compounds; D055768:Halogenated Diphenyl Ethers; D016877:Oxidants; C024547:barium titanate(IV); C009495:titanium dioxide; C012891:dichlorfop-methyl; D014025:Titanium