Morphology Evolution of One-Dimensional-Based ZnO Nanostructures Synthesized via Electrochemical Corrosion

Abstract

Various morphologies of ZnO nanostructures can be obtained through a novel method, incorporating electrochemical corrosion with three modes: liquid membrane and above and below the water line in partial immersion. X-ray diffraction (XRD) patterns, high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) are employed to characterize their structure. The mechanism of the growth of NRs is proposed as electrochemical corrosion and oriented attachment, which occur in a liquid membrane or partial immersion in a vapor membrane. The evolution of ZnO nanostructures such as nanorods, nanowires, nanopins, and nanodentrites is observed, and the influence of concentration, reaction time, additives, state of substrate, membrane thickness, and solvent on the morphology of ZnO is investigated. Optical properties of ZnO nanostructures are studied by using UV−visible absorption spectra and photoluminescence (PL). Their optical gaps vary from different morphologies. Among the studied samples, short nanorods show the largest optical gap, while big nanorods present the smallest value of optical gap. PL properties demonstrate that peaks of near-band emission and defect-related luminescence are basically in the same position. However, intensities for different morphologies are of different values, and short nanorods exhibit the best near-band emissions.