title: Photocatalytic degradation of methyl orange in aqueous suspension of mesoporous titania nanoparticles.
abstract: The photodegradation of methyl orange (MO) was investigated in aqueous suspension containing titania nanoparticles with mesostructures (m-TiO(2)) under UV irradiation. The experimental results show that 98% MO can be mineralized in the 1.0 g l(-1) m-TiO(2) suspension (pH 2.0) after 45 min illumination. Particular attention was devoted to the identification and the transformation of the fragments retaining the chromophoric group. The photodegradation mechanism of the quinonoid MO mainly involves three intermedial processes: demethylation, methylation and hydroxylation. Among those processes, demethylation is more favorable than the hydroxylation, but the hydroxylation results in the largest number of intermediates. The degradation pathway of quinonoid MO under the optimal conditions is also proposed.
authors.affiliation: College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Ke
authors.initials: K
authors.lastname: Dai
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.forename: Tianyou
authors.initials: T
authors.lastname: Peng
authors.forename: Dingning
authors.initials: D
authors.lastname: Ke
authors.forename: Huabing
authors.initials: H
authors.lastname: Yi
mesh_terms: D001391:Azo Compounds / Q000032:analysis* / Q000528:radiation effects; D002384:Catalysis; D053758:Nanoparticles; D010777:Photochemistry; D016062:Porosity; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods*
chemical_list: D001391:Azo Compounds; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; C100258:methyl orange; D014025:Titanium