title: Template free synthesis of ZnO/Ag2O nanocomposites as a highly efficient visible active photocatalyst for detoxification of methyl orange.
abstract: A simple and effective route for the synthesis of ZnO/Ag2O nanocomposites with different weight ratios (4:1 to 4:4) have been successfully obtained by combination of thermal decomposition and precipitation technique. The structure, composition, morphology and optical properties of the as-prepared ZnO/Ag2O composites were characterized by XRD, FT-IR, EDS, SEM, TEM, UV-Vis DRS and PL, respectively. The photocatalytic performance of the photocatalysts was evaluated towards the degradation of a methyl orange (MO) under UV and visible light. More specifically, the results showed that the photocatalytic activity with highest rate constant of MO degradation over ZnO/Ag2O (4:2) nanocomposites is more than 22 and 4 times than those of pure ZnO and Ag2O under visible light irradiation, respectively. An improved photocatalytic activity was attributed to the formation of heterostructure between Ag2O and ZnO, the strong visible light absorption and more separation efficiency of photoinduced electron-hole pairs. Moreover, the ZnO/Ag2O (4:2) nanocomposite showed excellent stability towards the photodegradation of MO under visible light. Finally, a possible mechanism for enhanced charge separation and photodegrdation is proposed. Genotoxicity of MO before and after photodegradation was also evaluated by simple comet assay technique.
authors.affiliation: Nanomaterials Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416004, India.
authors.forename: Abhijit
authors.initials: A
authors.lastname: Kadam
authors.affiliation: Nanomaterials Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416004, India.
authors.forename: Rohant
authors.initials: R
authors.lastname: Dhabbe
authors.affiliation: Department of Zoology, Shivaji University, Kolhapur 416004, India.
authors.forename: Anna
authors.initials: A
authors.lastname: Gophane
authors.affiliation: Department of Zoology, Shivaji University, Kolhapur 416004, India.
authors.forename: Tukaram
authors.initials: T
authors.lastname: Sathe
authors.affiliation: Nanomaterials Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416004, India. Electronic address: kmg_chem@unishivaji.ac.in.
authors.forename: Kalyanrao
authors.initials: K
authors.lastname: Garadkar
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000737:chemistry* / Q000633:toxicity; D002347:Carps / Q000235:genetics; D002384:Catalysis; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects / Q000528:radiation effects; D007700:Kinetics; D008027:Light; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry*; D010782:Photolysis / Q000187:drug effects / Q000528:radiation effects*; D018030:Silver Compounds / Q000737:chemistry*; D014466:Ultraviolet Rays; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D010087:Oxides; D018030:Silver Compounds; C100258:methyl orange; C040225:disilver oxide; D015034:Zinc Oxide
keywords: Comet assay; Nanocomposites; Optical properties; Visible photocatalysis