Low Temperature Synthesis Of High-quality Graphene And Its Application In Water Pollution Treatment

Focusing on in situ synthesis of graphene in the thesis, low-temperature synthetic methods of high-qualified graphene and their mechanism have been explored comprehensively. Hexachlorobenzene was used as the carbon source of graphene for the first time. Copper foils and silicon slices were employed as the substrates for the growth of graphene in chemical vapor deposition (CVD) process. Through modification of CVD procedure and experimental parameters, mono-layer and mutli-layer graphene films were successfully synthesized, respectively. The mechanism of the formation of graphene and the controllability of the layer number of graphene were also investigated. The main results and innovations of the research work are as follows:1. For first time, the copper was used to make HCB dechlorinate to prepare graphene on the surface. And copper foils was not only as sedimentary basement in preparation process of graphene, but also played as catalyst to promote dechlorination efficiency of hexachlorobenzene, which achieved preparation of graphene at low temperature (360℃).2. Pyrolysis of HCB was deposited on siliconand and copper foils to prepare multi-layers graphene in situ. At sometime, the deposition temperature greatly reduced because of the use of a new type carbon source-hexachlorobenzene.3. We found that copper foils played a decisive role in the preparation mechanism of graphene at low temperature. Owing to the presence of Cu not only greatly reduced the temperature of HCB dechlorination and also increased efficiency and completeness of dechlorination of HCB. So monolayer graphene could be prepared on Copper foils at relatively low temperature.4. We regulated the temperature to control layers of graphene films. when the temperature of Pyrolysis of HCB is below 400℃without catalyst, the efficiency of dechlorination is low, so graphene prepared at low temperature is monolayer. Along with increased deposition temperature, double and multi-layer graphene were got at 460℃and 560℃respectively.The result of this paper provides a new principle and method to prepare graphene at the low-temperature, and a new way to synthesize the controllable layers of graphene films.