Single-crystal star-like zinc oxide: synthesis, characterization and growth mechanism

A novel star-like single-crystal ZnO structure was synthesized by a simple solvothermal method. The as-prepared products were characterized by XRD, SEM and TEM. The star-like ZnO, which shows sixfold symmetry, was constructed by six uniform arms distributing symmetrically around the [0001] zone axis. It is also found that the arms are not perpendicular to the [0001] zone axis and each arm is grown at a certain angle with the [0001] direction. CBED pattern and corresponding simulation demonstrate that the convex part of the star-like ZnO is O-terminated (000-1) plane and the concave part is Zn-terminated (0001) plane. H2S plays a crucial role in the synthesis process. The anisotropic growth habit along [0001] and [000-1] results in the formation of star-like structure.