Nanotripods of Zinc Oxide

Abstract

We report the discovery of two-dimensional (2-D) nanotripods of ZnO, a new member of the ZnO nanostructure family. These planar nanotripods are synthesized via a novel approach known as catalyst-free combust-oxidized mesh (CFCOM) process that we developed using a ZnO factory furnace. At about 1200 °C, high velocity zinc vapor is instantly oxidized and captured in a steel mesh for 20s and then air-quenched. From this subminute synthesis process, three types of polycrystalline 2-D tripodal nanostructures are discovered. The ZnO tripods are composed of three planar arms that appear as rectangular nanoplates. We propose two growth routes for these planar tripods, namely base-arm and tripodal-core routes. For the former route, growth begins with the base arm in [[unk] [unk] 20 ] direction. During quenching, the other two arms grow from newly formed tapered facets, ([unk]110) and (1[unk]10). The tripodal-core growth route involves the formation of a hexagonal disc with ±( 0002 ) larger surfaces. From this core, three arms grow simultaneously in [ 11[unk]0 ], [ [unk]10 ] and [ 1[unk]10 ] directions, while the core transforms into a Y-shaped configuration with ±( 10[unk]0), ±( 01[unk]0 ) and ±( [unk]100 ) planes. Morphological analyses are performed using FESEM, EDS, TEM and XRD. Photoluminescence test detects the presence of structural defects associated with green and red peak emissions.