Preparation and photocatalytic property of a novel dumbbell-shaped ZnO microcrystal photocatalyst

A novel dumbbell-shaped ZnO microcrystal photocatalyst was successfully synthesized by hydrothermal method in the present study. The prepared ZnO photocatalyst was systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG-DTA), photoluminescence spectrum (PL) and UV-vis absorption spectrum (UV-vis). The characterizations of dumbbell-shaped ZnO were also compared with the commercial ZnO. The results show that the prepared ZnO photocatalyst has a unique dumbbell shape and it belongs to the hexagonal wurtzite family. In addition, the photocatalytic activity of the prepared dumbbell-shaped ZnO microcrystal photocatalyst was evaluated by the degradation of three different kinds of dyes wastewater (Crystal Violet, Methyl Violet and Methylene Blue). After 75 min reaction, the decolourization efficiencies of the three kinds of dyes wastewater achieved 68.0%, 99.0% and 98.5%, the TOC removal efficiencies achieved 43.2%, 59.4% and 70.6%, respectively. Compared to commercial ZnO, 16-22% higher TOC removal efficiency was obtained by the dumbbell-shaped ZnO. The results indicated that the prepared dumbbell-shaped ZnO microcrystal photocatalyst showed good photocatalytic activity and it could be considered as a promising photocatalyst for dyes wastewater treatment. (C) 2009 Elsevier B.V. All rights reserved.