title: Photodegradation of methyl green using visible irradiation in ZnO suspensions: determination of the reaction pathway and identification of intermediates by a high-performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry method.
abstract: Heterogeneous photocatalytic treatment of a dye called methyl green (MG), which was simulating textile wastewater from associated auxiliary chemicals, was investigated using ZnO. A detailed investigation of the photodegradation of MG has been carried out in the ZnO suspension irradiated with visible light. The effects of various factors - viz. pH values, amount of catalyst, initial dye concentration, and the presence of NaCl, Na(2)CO(3), H(2)O(2), and Na(2)S(2)O(8) - on the degradation efficiency were studied. Thirty-two intermediates were separated, identified, and characterized by high-performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry (HPLC-ESI-DAD-MS) technology, giving us insight into the pathways of the degradation process.
authors.affiliation: Department of Biochemistry, School of Medicine, Taipei Medical University, Taipei 110, Taiwan.
authors.forename: F D
authors.initials: FD
authors.lastname: Mai
authors.forename: C C
authors.initials: CC
authors.lastname: Chen
authors.forename: J L
authors.initials: JL
authors.lastname: Chen
authors.forename: S C
authors.initials: SC
authors.lastname: Liu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry; D008739:Methyl Green / Q000737:chemistry*; D015394:Molecular Structure; D010777:Photochemistry; D010782:Photolysis / Q000528:radiation effects; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014466:Ultraviolet Rays; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D008739:Methyl Green; D006861:Hydrogen Peroxide; D015034:Zinc Oxide