Triangle-shape ZnO prepared by thermal decomposition

Using oleic acid as surfactant, triangle-shape ZnO with an average diameter of 250 nm can be synthesized by thermal decomposition of precursor zinc acetate (Zn(CH3CH2COO)2) in the high boil-point solvent trioctylamine (TOA). Fundamental characterizations including transmission electron microscopy, X-ray diffraction, high-resolution transmission electron microscopy, scanning electron microscopy and photoluminescence were conducted for the as-synthesized ZnO particles. The effects of refluxing time and the content of surfactant on size and morphology of ZnO particles were studied. It is found that the shape of ZnO particles changes from round-shape, disk-shape to triangle-shape. Based on experimental observations and surface and attachment energies simulation for various crystallographic planes, a possible growth mechanism was put forward to explain the formation of triangle-shape ZnO particles.