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.

Control of Interfacial Structure with Precursor Chemistry in Radial Core/Shell Nanowires of Zinc Oxide, Optically-Active Erbium, and Germanium

“…The HRTEM image of Figure c exhibits the presence of zinc germanate ( d = ∼0.716 nm (±0.005) corresponding to the (110) plane, which is parallel to the longitudinal direction of GeNWs) . In addition to a zinc germanate phase, a d -spacing of 0.272 nm (±0.004), shown in Figure d, is assigned to the ZnO(002) plane, a value expanded slightly by the presence of Er and Ge atoms in the ZnO lattice. , Thus, we conclude that the annealed ZnO/Er/GeNWs consist of a majority of zinc germanate and a minor ZnO component in the given annealing conditions. Such a conclusion is also supported by X-ray powder diffraction measurements (Supporting Information), where an absence of crystalline reflections is detected in the annealed nanowire product.…”

Sun-light-driven photocatalytic activity by ZnO/Ag heteronanostructures synthesized via a facile thermal decomposition approach

“…The distance between the two consecutive spots in the SAED pattern of pure ZnO was found to be 0.263 nm which is attributed to (002) plane of hexagonal ZnO which suggests the preferential growth of ZnO nanorods along (001) direction. 51 The SAED patterns of ZnO/Ag heteronanostructures show spot patterns due to ZnO and ring patterns due to cubic silver.…”

Erbium-Doped Mixed Oxide Nanowires of Zinc and Germanium: Role of Host Structure on Near Infrared Emission

“…Further information is provided by HREM imaging (Figure b), where the lattice spacing associated with the ⟨110⟩ plane of zinc germanate (∼0.713 nm) is readily observed. The presence of excess zinc in the system results in the formation of separate ZnO domains (hexagonal phase), as noted by d -spacings of 0.269 nm associated with the ⟨0002⟩ index (Figure c). , …”

“…The presence of excess zinc in the system results in the formation of separate ZnO domains (hexagonal phase), as noted by d-spacings of 0.269 nm associated with the ⟨0002⟩ index (Figure 4c). 10,11 Spectroscopically, the impact of increasing Zn 2+ concentration on the 1540 nm Er 3+ PL is presented in Figure 5 for a series of nanowire films containing Er 3+ at a concentration of 2 at. %.…”