| Graphene,as a novel two-dimensional material,can not only act as basic structural unit to assemble carbon-based materials with various structure and special properties,but also build advanced functional graphene-based materials.Graphene-based materials show much easier operability and applicability than graphene sheets.However,finely structure control for these graphene-based materials is still hard to achieve.In this dissertation,focusing on the controllable preparation of materials,we proposed the concept of graphene-based materials acting as versatile templates.At first,we studied the template effect of graphene oxide sheet and interlayer nanospace in graphene membrane for the structure control of graphene/metal oxide or graphene/metal hybrid material.Then,we developed a water removal promoted strategy for the construction of graphene membrane with an open and grade structure,and further analyzed the size effect of graphene sheet on the assemble behavior as well as the structure and performance of their assemblies,which provided a foundation for further application of graphene-based templates.Finally,we also designed and fabricated sheet-like porous carbon based on self-template techonology,and explored the potential applications in energy storage.The controllable preparation of Fe2O3 nanoparticles and their secondary particles is realized with graphene oxide（GO）sheet as the soft template.It is shown that small amounts of GO could alter the structure and morphology of Fe2O3 and microspheres with compact structure can be obtained.The obtained Fe2O3 microspheres/graphene hybrid shows high volumetric capacity of 1200 mAh cm-3 at a current density of 0.1 A g-1 when used as anode for lithium ion battery.The interlayer nanospace formed in the graphene membrane is proposed to use as a shaping template to prepare the noncarbon nanosheets.The graphene oxide sheets loaded Sn4+ on their surface were filtered into a membrane with layer structure,and then,the Sn nanosheets were prepared from the directed growth of Sn by thermal reduction of the pre-seeded Sn4+ in the interlayer nanospace.The formed graphene/Sn hybrid has sandwich structure which can provide efficient “face to face” contact and greatly buffer the volume expansion during the charging and discharging process,and shows excellent capacity and cyclic performance when used as anode for lithium ion battery.According to the phase diagram of water,the strategy of water removal promoted structure control is realized for graphene membrane.And the obtained graphene membrane with an open and grade structure shows high surface utilization and possesses high adsorption capability and provides fast ion diffusion channels and high surface utilization which shows excellent performance in adsorption,supercapacitor and lithium sulfur battery.Size control of GO sheets is realized by simply controlling the exfoliation procedure.And we further study the size effect of graphene sheet on the assemble behavior and the structure and performance of their assemblies.The strategy to prepare carbon sheets based on biomass self-template method is proposed by selecting precursor with specific structure.Sheet-like porous carbons（SPC）with abundant pore structures were obtained after one-step carbonization.SPC-1000 shows excellent rate performance with a high capacitance retention of 75.0%.A high energy density of 14 Wh kg-1 for SPC-1000 can be achieved at a power density of 1.6 kW kg-1 in 1M Li2SO4 electrolyte. |
