| Graphene has attracted tremendous research interest in recent years, owing to its unique two-dimensional (2D) structure and exceptional physical and chemical properties. Unfortunately, aggregation of graphene sheets is very easy to occur. This constitutes a major obstacle for exploiting the proposed applications. In order to solve the aggregation problem, we make the silica grow around the surface of graphene by electrostatic interactions to form a2D sandwichlike graphene/mesopurous silica nanocomposite material. This material has two advantages:1) Independent sheet which is not easy to aggregate;2) Combine the pore structure of silica and the unique properties of graphene in ion storage, heat and electric conduction to exploit the applications of silica in adsorption and energy storage fields. In this paper we mainly studied:1) Using sol-gel method to synthesize "silica-graphene-silica" sandwichlike graphene/silica nanocomposites;2) Using hydrothermal method to synthesize graphene/silica nanocomposites with hexagonally regular pores. The mainly conclusions are as follows:1) Graphene(2-5layers) was prepared by microwave irradiation method. It had a silklike structure and its BET surface area, pore volume, average pore size and C/O ratio were485m2/g,1.51cm3/g,6.23nm and4.52, respectively.2) The sandwichlike graphene/silica nanocomposites were synthesized by the sol-gel method. The silica grew evenly on both sides of the graphene, using the two-dimensinal structure as the template. The BET surface area, pore volume and average pore size of the optimal product were1550m2/g,1.47cm3/g and1.90nm, respectively.3) The graphene/silica nanocomposites with hexagonally regular mesopores were synthesized by the hydrothermal method. The hexagonal vertically aligned mesopores in the silica were perpendicular to the graphene sheet. The BET surface area, pore volume, average pore size and cell parameter were743m2/g,1.13cm3/g,3.04nm and5.45nm, respectively. |
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