Engineering of Nanotips in ZnO Submicrorods and Patterned Arrays

Unusual nanotips have been selectively achieved in the synthesis of hexagonal-faceted ZnO submicrorods along with two types of its patterned arrays based on a mild precursor-hydrothermolysis reaction. In the synthesis, ethylenediamine (En) with two anchor atoms was introduced not only as a ligand and an alkali medium but also as a crystal-growth modifier for studying the crystal growth kinetics. It has been demonstrated that as-fabricated arrays are composed of ZnO submicrorods with exotic nanotips; the morphology of the nanotips, as well as the preferred spatial orientation and alignment of the rods, strongly depends on the adopted substrates. The growth mechanisms for the ZnO submicrorods and the patterned arrays have been discussed, respectively, on the basis of the growth model for the polar ZnO crystals.