Synthesis Of Diverse One-dimensional Nano-materials By High Frequency Induction Furnace

The one-dimensional nanomaterials because of their unique structure and diversification, excellent physical and chemical properties as well as a wide range of application prospects, attracted the attention of the majority of researchers. This thesis, on the background of the semiconductor nanomaterials, use self-designed high frequency induction heating system to prepared a variety of one-dimensional semiconductor materials, characterized by SEM, TEM, XRD, SAED analysis and so on. The main research work is following:1. Preparation and characterization of silicon nanowires and its derivative morphologyA. Using SiO as a raw material, at first, passing into appropriate reaction gas to prepare a large number of yellow-brown silicon nanowires, the preparation process without any substrate material, and deposited directly on the inner wall of the quartz tube, to study the very shape of the silicon nanowires with temperature, pressure, gas environment are closely related. B. According to grasp the relationship, use step-by-step heating method further to prepare the silicon nanowire having a three-dimensional hybrid structure, the structure consists of two parts:the silicon nanowires coarse criss-cross structures into the framework of the large number of voids, very fine silicon nanowires filled with a large number of gaps. The structure has a very high specific surface area and a more stable structure, having some application prospects. C. Try to use the waste silicon debris to prepare silicon nanowires, combined with a typical CVD reactor stepwise heating, we get a small amount of silicon nanowires in silicon without catalyst, interesting to note that each wafer edge can be arranged in an orderly, dense growth of silicon nanowires, the silicon surface is still only a very small amount of silicon nanowires. Guess defective silicon surface is easier to grow silicon nanowires, in order to verify this conjecture, human silicon surface with sandpaper and then wipe experiment conjecture was confirmed. This discovery is conducive to the selective growth of silicon nanowires.D. Try to use a metal catalyst to prepare silicon nanowires, different from the common sputtering catalyst, the paper in a simple principle directly to the same group of researchers used magnetic primer obtained Ni nanowires as a catalyst. The results show that silicon nanowires easier to grow, in the case of the presence of a nickel catalyst, and having a good morphology.2. Preparation and characterization of silicon carbide nanowires and nano-needleSilicon carbide material has a wide band gap, high critical breakdown voltage, high thermal conductivity, carrier migration velocity, small dielectric constant and strong radiation, good mechanical properties and other characteristics, and become popular third generation of wide band gap semiconductor, become an ideal material for the production of high-temperature, high-frequency, high-power, optoelectronics, anti-radiation, high-speed devices. But the preparation of the SiC material is more difficult compared to silicon nanowires.A. This thesis uses electromagnetic induction rapid heating, and the system have a advantage of high temperature at the end point. Using of silicon material (SiO2, Si, SiO) and carbon material (graphite powder, carbon black) to prepare a high-quality silicon carbide nanowires, and references in the ultrasonic welding SiC devices.B. Attempt to use carbon fiber as a carbon source and the deposition substrate, growing of silicon carbide prepared inverted nanoneedles and to study its growth mechanism. The nano-needle grown carbon fiber base on the bottom, with an inverted growth characteristics, the tip is on the substrate, the crude end outwardly. The nanoneedle the growth morphology different from the general understanding of the growth mechanism has a positive effect.3. Preparation and characterization of zinc oxide one-dimensional nanomaterialsZinc oxide is a direct band gap semiconductor, the band gap of 3.37eV, has a high exciton binding energy and thermal stability, and preparation methods varied range of nano-morphology. Therefore, in the past few decades has been a research focus. In this thesis, a simple electromagnetic induction equipment, research and zinc oxide nanomaterials prepared in three forms, namely,A. Direct using of a zinc oxide powder and coke powder mixed and heated, without using any catalyst and an additional gas, directly using air as the reaction gas, to prepare a large amount of zinc oxide nano band.B. appropriately adjust the gas atmosphere to prepare a zinc oxide nano-material having a tetrapod-like nanomaterialsC. in the course of the study, preparation of samples have a small amount of comb-like nanomaterials, the mechanism of its formation process4. Preparation and characterization of carbon nanotubes and graphene derivative morphology.The paper will not go into the preparation of carbon nanotubes, focusing on the following carbonaceous material preparation and characterization of:A. The case of the first, prepare octopus-like carbonaceous nanomaterials with a lot of iron catalyst on wafer surface, the specific morphology of a nanoscale iron particles catalyze the growth of the number of pieces (2-15) linear carbonaceous material, shaped like an octopus. The study found that the morphology of the carbonaceous material and the density of the catalyst particle size is closely related to the content of hydrogen in the growth environment.B. Reduce the density and particle size of the catalyst particles to increase the hydrogen content, prepared by CVD for the first time the graphene nanoribbons single, the course of the study informed that the graphene nanoribbons as a single carbon nanotube in the presence of iron catalystC. Silicon Nanowires method for preparing silicon nanowire prepared for the first time-a core-shell structure of graphene nanomaterials.