Synthesis, characterization and photocatalytic properties of hierarchical fan-shaped ZnOHF and ZnO microcrystals

Employing NH4BF4 as the fluoride source, large scale fan-shaped ZnOHF hierarchical structures have been synthesized successfully with a template-free hydrothermal approach. The purity, crystalline phase, thermal stability and morphologies of the as-prepared ZnOHF were characterized by XRD, TG-DSC and SEM. Time-dependent experiments indicate that the hierarchical ZnOHF microfans are self-assembled by numerous nanotubes with diameter of 100 nm. A possible chemical mechanism is proposed. The as-prepared ZnOHF can be transformed into hexagonal phased netlike ZnO by calcination in air at 600 degrees C. Furthermore, the as-prepared ZnOHF and ZnO were investigated by the decomposition of methylene orange under UV light irradiation and the results show that they have good photocatalytic activities. (C) 2012 Elsevier B.V. All rights reserved.