The Preparation And Properties' Research Of Graphene

Graphene has attracted considerable attentions owing to its unique properties, including excellent Chemical stability, large surface area, high electron mobility, high conductivity, mechanical properties, etc. So that it is widely used in sensors, energy storage devices, hydrophobic materials, field effect transistors and carrier materials, etc. In this paper we prepared Desert Rose stone-like graphene(DRG) by the pyrolysis of oligomer-Polysilane(o-PS), which grown vertically. This article is mainly to research the hydrophobic property of DRG, sensing property of DRG, chemical property of Graphene. And we preliminary explored the application of DRG. Products are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman dispersive spectrum. The work in this thesis as follows:We found that DRG is composed of silicon carbide and graphene. DRG has different contact angle(CA) with multilayer graphene. Multilayer graphene has hydrophilic property, but DRG is hydrophobic material. The time of ultrasonic and base material can effect the value of CA. When time of ultrasonic is longer, CA value is first increased then the value is decreased. When time of ultrasonic was 30 min and nylon fiber as base material, the CA of DRG film has the maximum value 146.1?.The results demonstrate that lots of SnO2 nanoparticles are loaded on the surface of DRG. It found DRG and SnO2/DRG composite had good selectivity of ammonia, and they had response of ammonia. When temperature is high, SnO2/DRG composite had worse response of ammonia. Because DRG is p-type semiconductor and SnO2 is n-type semiconductor. They have antagonism on the response of ammonia. When temperature is 49.1 ?, the DRG has a highest response value 2.8% of ammonia.In order to research graphene's chemical stability, graphene as raw material to prepared silicon carbide nanowires in this thesis. The average diameters of the nanowires are about 50 nm and tens of micrometers in length. The vapor-solid(VS) mechanism was employed to interpret the silicon carbide nanowires growth. Since the surface of silicon powder is easily oxidized into SiO2. Therefore, raw material silicon powder was coated with SiO2 membrane. The SiO vapor would be released by Si reacted with SiO2 at high temperature. Subsequently, the produced SiO vapor encountered and further reacted with the solid graphene, so the SiC crystal nuclei came into being and CO to be released. The SiC crystal nuclei acted as an active site for further growing, Released gaseous SiO and CO constantly reacting on the nuclei, and SiC nanowires can grow longer.