title: Microwave-assisted preparation, characterization and photocatalytic properties of a dumbbell-shaped ZnO photocatalyst.
abstract: A novel dumbbell-shaped ZnO photocatalyst was successfully synthesized by microwave heating in the present study. The prepared ZnO photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis absorption spectrum (UV-Vis). The results indicated that the prepared ZnO photocatalyst shows a united dumbbell shape with 2 microm diameter and 5 microm length. The photocatalytic activity of the prepared dumbbell-shaped ZnO photocatalyst was evaluated by the degradation of Methylene Blue (MB) in aqueous solution. The effects of pH, catalyst dosage ([ZnO]) and initial concentration of MB ([MB]) on the photocatalytic degradation efficiency of MB were investigated. An optimum condition was determined as pH 7-8, [ZnO]=1.0 g-ZnO L(-1) and [MB]=15 mg-MB L(-1). Under the optimum condition, the decolorization and TOC removal efficiencies of MB at 75 min reaction time were achieved 99.6% and 74.3%, respectively, which were higher than that by the commercial ZnO powder. In addition, the photocatalytic degradation kinetics of MB was also investigated. The results showed that the photocatalytic degradation kinetics of MB fitted the pseudo-first-order kinetics and the Langmuir-Hinshelwood model.
authors.affiliation: Henan Key Laboratory for Environmental Pollution Control, College of Chemistry and Environmental Sciences, Henan Normal University, Xinxiang, Henan 453007, PR China.
authors.forename: Li-Yun
authors.initials: LY
authors.lastname: Yang
authors.forename: Shu-Ying
authors.initials: SY
authors.lastname: Dong
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Sun
authors.forename: Jing-Lan
authors.initials: JL
authors.lastname: Feng
authors.forename: Qiu-Hua
authors.initials: QH
authors.lastname: Wu
authors.forename: Sheng-Peng
authors.initials: SP
authors.lastname: Sun
mesh_terms: D000465:Algorithms; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008872:Microwaves; D015233:Models, Statistical; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D004396:Coloring Agents; D007202:Indicators and Reagents; D015034:Zinc Oxide; D008751:Methylene Blue