Henan Key Laboratory for Environmental Pollution Control, College of Chemistry and Environmental Sciences, Henan Normal University, Xinxiang, Henan 453007, PR China.
J Hazard Mater. 2010 Jul 15;179(1-3):438-43. doi: 10.1016/j.jhazmat.2010.03.023. Epub 2010 Mar 12.
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.
本研究采用微波加热法成功合成了一种新型哑铃状 ZnO 光催化剂。通过 X 射线衍射（XRD）、扫描电子显微镜（SEM）和紫外-可见吸收光谱（UV-Vis）对所制备的 ZnO 光催化剂进行了表征。结果表明，所制备的 ZnO 光催化剂呈现出统一的哑铃形状，直径为 2 微米，长度为 5 微米。通过在水溶液中降解亚甲基蓝（MB）来评价所制备的哑铃状 ZnO 光催化剂的光催化活性。考察了 pH 值、催化剂用量（[ZnO]）和 MB 的初始浓度（[MB]）对 MB 光催化降解效率的影响。确定了最佳条件为 pH 7-8、[ZnO]=1.0 g-ZnO L(-1)和[MB]=15 mg-MB L(-1)。在最佳条件下，反应 75 min 后 MB 的脱色率和 TOC 去除率分别达到 99.6%和 74.3%，高于商用 ZnO 粉末的去除率。此外，还研究了 MB 的光催化降解动力学。结果表明，MB 的光催化降解动力学符合准一级动力学和 Langmuir-Hinshelwood 模型。
