Growth of flower-like ZnO on ZnO nanorod arrays created on zinc substrate through low-temperature hydrothermal synthesis

► Flower-like ZnO on ZnO nanorod arrays were fabricated on zinc substrate. ► Dense ZnO nanorod arrays and flower-like ZnO were created when the time is 30 min. ► In situ nucleation and growth caused the generation of dense ZnO nanorod arrays. ► Growth mechanism of flower-like ZnO on ZnO nanorod arrays was proposed.