Precursor‐controlled synthesis of different ZnO nanostructures by the hydrothermal method

Abstract

Versatile ZnO nanostructures have been fabricated by a two‐step hydrothermal method. Controllable growth of ZnO is feasible by using different kinds of zinc sources. It is revealed by scanning electron microscopy that ZnO nanorods with average diameter 155 nm were synthesized by using Zn(CH3COO)2 as the zinc source. As for the situation when Zn(NO3)2 was used, taper‐like ZnO nanostructure with large aspect ratio was formed. In particular, two‐dimensional ZnO nanosheets can be fabricated when ZnCl2 was introduced and the distinctive X‐ray diffraction spectrum indicates that the anisotropic growth of ZnO along its <0001> direction was hindered, which was caused by the attraction of Cl− ions onto the ZnO polar face instead of growth units. Consequently, the anisotropic growth of ZnO along this direction was hindered, while the other two samples were vertically aligned against the substrates, which can be deduced from their sharp and strong ZnO (002) diffractions. Additionally, their optical properties including the absorptions of ultraviolet light and the corresponding optical bandgaps were also measured by an ultraviolet–visible spectrometer, which changed with the structural transformations. All these properties make them feasible for applications in the fields of both solar cells and biosensors.

Enhanced photocatalytic activity of Co doped ZnO nanodisks and nanorods prepared by a facile wet chemical method

“…Thus growth along (0001) is suppressed and crystal growth then proceeds along sideways leading to the formation of ZnO nanodisks. 59 Li et al 60 have also reported that when Cl À anions are adsorbed on the polar facet of ZnO, nanosheets can be fabricated by suppressing the crystal growth along its h0001i direction. Schematic diagrams depicting the underlying mechanisms of growth for ZnO nanorods and nanodisks are shown in Fig.…”

p-GaN/n-ZnO Nanorod/CsPbBr3 Quantum Dots Decorated with ZnO Nanoseeds for Light-Emitting Diodes

“…As an important semiconductor material, zinc oxide (ZnO) possesses a broad band gap, and its band gap and lattice spacing are very close to those of GaN. − ZnO is also an intrinsic n-type material, so it can be employed as the n-type layer in an LED. In the last decades, many efforts have been made to realize ZnO-based thin-film LED devices, and most scientists studied the n-ZnO/p-GaN heterojunction LEDs. , Except for the traditional thin-film LED devices, ZnO can present many kinds of novel nanostructures, such as nanowires, − nanorods, , nanopins, and nanotubes, , and the ZnO nanodevices can demonstrate better light extraction and higher electroluminescent intensity. − Recently, Yang et al constructed blue-violet LEDs by covering solution-treated ZnO QDs with p-GaN/Mg . In the production of p-GaN/n-ZnO nanostructure LEDs, a ZnO nanoseed is usually necessary for ZnO nanorod growth.…”

Growth Mechanism and Optical Properties of Phosphorus‐Doped ZnO Nanorods Synthesized by Hydrothermal Method

“…A ZnO seed layer was grown on the ITO substrate by a sol–gel‐based dip‐coating method . Phosphorus‐doped ZnO nanorods were grown on the ITO substrate coated with a ZnO seed layer by hydrothermal system.…”