Synthesis and enhanced photocatalytic activity of hierarchical ZnO nanostructures.

In this report, hierarchical ZnO nanostructures were successfully synthesized by a simple chemical method at room temperature. The scanning electron microscopy and transmission electron microscope result indicated that this unique structure was assembled by nanoneedles which of the needle tips and roots were about 5 nm and 20 nm, respectively. The photocatalytic activity of the ZnO nanostructures was evaluated by photodegradation reaction of methylene blue (MB). The as-prepared hierarchical ZnO nanostructures exhibited a significantly enhanced photocatalytic activity than commercial ZnO and TiO2. This was mainly attributed to the larger specific surface area and stability against aggregation.