Morphology-controlled synthesis of flowerlike ZnO nano/microstructures and their photocatalytic property.

Flowerlike ZnO nano/microstructures (FZNM) have been synthesized on glass substrates by a simple hydrothermal method. The as-prepared samples are composed of many radially oriented nano/submicron rods, which are single crystalline with a hexagonal structure and grow along the [001] direction. The diameter of ZnO nano/submicron rods ranges from 20 nm to 1 microm. With prolonged reaction time, the number of the nano/submicron rods of each ZnO flowerlike will decrease, while further prolonged reaction time, the amount increase actually. The reaction time is one key factor to control the sizes of the rods and the morphology of flowerlike structures. The possible growth mechanism has been discussed and proposed. A preliminary study on photocatalytic property of as-synthesized flowerlike structure reveals that morphology and size significantly influenced the photocatalytic activity for a solution of methylene blue (MB). Moreover, it is found that the annealed product exhibited higher photocatalytic performance.