Zhi Peng

Synthesis and Growth Mechanism of Ni Nanotubes and Nanowires

Highly ordered Ni nanotube and nanowire arrays were fabricated via electrodeposition. The Ni microstructures and the process of the formation were investigated using conventional and high-resolution transmission electron microscope. Herein, we demonstrated the systematic fabrication of Ni nanotube and nanowire arrays and proposed an original growth mechanism. With the different deposition time, nanotubes or nanowires can be obtained. Tubular nanostructures can be obtained at short time, while nanowires take longer time to form. This formation mechanism is applicable to design and synthesize other metal nanostructures and even compound nanostuctures via template-based electrodeposition.

Fabrication of Patterned Polystyrene Nanotube Arrays in an Anodic Aluminum Oxide Template by Photolithography and the Multiwetting Mechanism

Patterned polystyrene (PS) nanotube arrays were successfully fabricated using photolithography via the polymer solution-wetting method. The microstructure of these nanotubes was investigated using conventional and high-resolution transmission electron microscopy (HRTEM). Two major types of morphology were observed for these PS nanotubes, one being bamboo-like and the other being barrel-shaped. The multiwetting mechanism was proposed to explain the different morphologies. X-ray diffraction (XRD) showed that the PS nanotubes have a higher degree of crystallinity than bulk PS. In addition, crystalline lattice fringes were observed in some regions of the PS nanotubes using HRTEM. Patterned polymer nanotube arrays could be used for nanocable coating to protect from oxidation and corrosion in nanodevices.

Assembly of one-dimensional polymer nanostructure arrays by photolithographic approaches

In this work, large area polymer nanostructure arrays with different patterns were successfully obtained by photolithographic approach and wetting anodic aluminum oxide (AAO) templates. First of all, the AAO templates with patterns were produced by photolithographic approach. Then the AAO/pattern membrane was used as a secondary template to fabricate polymer nanostructure arrays by solution-wetting and melt-wetting methods. The morphology of the polymer nanostructures has been characterized using scanning electron microscopy and transmission electron microscopy. The different factors have been discussed in the process of experiments.

Effect of Each Layer on Anisotropic Magnetic Properties of Nd/Fe/Polyamide 66 Three-Layer Coaxial Nanocables

One-dimensional (1D) Nd/Fe/polyamide 66 (Nd/Fe/PA66) three-layer coaxial nanocable arrays with high aspect ratio and highly anisotropic magnetization were successfully prepared via layer-by-layer deposition in the anodic aluminum oxide template. The morphology, chemical composition, and magnetic properties of Nd/Fe/PA66 nanocables were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometry . The effects of 1D nanocables on the magnetic properties of the assembled ordered arrays have been systematically investigated. The structural properties of these nanostructures are investigated as a function of the geometrical parameters. The magnetic anisotropy of Nd/Fe/PA66 nanocables has been significantly enhanced owing to the doped Nd that possesses a larger spin-orbital coupling and leads to a synergistic effect with Fe to enhance anisotropy energy.

Preparation and Magnetic Properties of Nd/FM (FM=Fe, Co, Ni)/PA66 Three-Layer Coaxial Nanocables

A new preparation method of three-layer coaxial nanocables has been developed in this work. Nd/FM (FM=Fe, Co, Ni)/PA66 three-layer coaxial nanocables were assembled successfully from outer to inner layer by layer. PA66 nanotubes which served as the outer shell were prepared by polymer solution wetting AAO template. Ferromagnetic metals and Nd were deposited into pre-prepared PA66 nanotubes to be served as the middle layer and inner core, respectively. The results show that the structure has effects on the magnetic properties, and the nanocable preparation allows each layer, length, and thickness of the nanocables to be tuned.

Enhanced photocatalytic degradation rate of 2,4-dichlorophenol by P25 in Na2CO3/NaHCO3 buffer solution

ABSTRACT The degradation of 2,4-dichlorophenol (2,4-DCP) in wastewater is widely concerned in recent years because of its toxicity, carcinogenic and mutagenic properties. Generally, the pH values vary during the process of photocatalytic degradation, effecting UV-Vis absorbance spectral of 2,4-DCP. In this paper, we utilized the Na2CO3-NaHCO3 buffer solution to eliminate the impact of pH changes caused by the acidic intermediates. As a result, the removal efficiency of 2,4-DCP and the reaction rate are significantly elevated. It can be concluded that the buffer solution can promote the photocatalytic degradation of 2,4-DCP effectively.