Controllably hierarchical growth of large-scale ZnO microrods

Hierarchical ZnO microrods were successfully grown on the upward surface of a Si substrate by a low-temperature hydrothermal method. The morphology and size can be easily controlled by adjusting reaction temperature and reactant concentration. The photocatalytic activities were evaluated by the degradation of Rhodamine B (RB) dye under UV and visible irradiation. The resultant hierarchical ZnO microrods show better photocatalytic activities for the photodegradation of RB than traditional nanoparticles and aligned nanorods.