Growth of Oriented Zinc Oxide Nanowire Array into Novel Hierarchical Structures in Aqueous Solutions

Abstract

The strategy to manipulate nanoscale building blocks into well-regulated hierarchical architectures is of great interest and valuable to both material synthesis and advanced nanodevices. Novel ZnO hierarchical structures with nanowire arrays connected on both faces of parallel ZnO hexagonal disks were produced in a facile temperature-dependent multi-step hydrothermal route within an open vessel, in which lamellar zinc hydroxide (LHS-Zn) disks were firstly formed as intermediate basic floor, whose surface may be roughened at elevated temperature; the resultant ZnO nanowires were then assembled into a highly ordered array on the top/bottom surfaces of disks in the presence of dense ammonia. Higher [Zn 2+ ] at the beginning lead to multicell sandwiches or nanowire-disk-nanowire-disk-nanowire-like superlattice. Ammonia molecules in the vessel play a key role in controlling architecture evolution. Room-temperature Raman-scattering and photoluminescence measurements indicated the optical properties of single as-prepared ZnO structure.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…As the growth proceeded, growth nutrient was consumed, and the precursor concentration became dilute, which induced secondary growth and a decrease in the nanowire diameter and eventually the formation of bilayered structures [207]. [208]. The ZnO nanowire arrays were connected between parallel ZnO hexagonal disks.…”

“…During dehydration, many regular nanosized ZnO islands were left on the disk surface, which seeded the secondary growth of ZnO nanowires, resulting in multicell sandwiches or nanowire-disk-nanowire-disk superlattices, as shown in Fig. 20(c) [208]. Most recently, Xu et al demonstrated a novel technique for multilayer ZnO nanowire assemblies [209].…”

Controllable synthesis and formation mechanism of bow-tie-like Sb2O3 nanostructures via a surfactant-free solvothermal route

“…In recent years, semiconductor materials with different sizes and morphologies have received much attention due to their potential applications as active components or interconnect in nanoscaled electronic, optical, optoelectronic, electrochemical, and electromechanical devices [1][2][3][4][5][6]. The properties of the semiconductor nanomaterials were controlled by their chemical composition, their shape and size.…”

Growth of novel ZnO nanostructures by soft chemical routes

“…Normally, ZnO nanostructures exhibit UV emission and visible emission. The UV emission is attributed to the near-band edge emission of ZnO due to the annihilation of excitons [24], while the visible luminescence mainly originates from the surface defect states such as Zn interstitials and oxygen vacancies [25]. One of the key issues on ZnO photoluminescence is the suppression of defect emission either by varying the preparation conditions or post-fabrication treatments [26].…”