Catalyst-free graphene nano-sheets without substrates have been synthesized using fullerene and a high direct current (dc) pulse in the spark plasma sintering (SPS) process. Graphene nano-sheets were synthesized directly in the gas phase of carbon atoms which are generated from fullerene at a temperature of 600 o C. Characterization has been carried out by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD).

Phosphate has been removed in waste water by chemically synthesized graphene oxide. Removing efficiency of phosphate was investigated using phosphate dispersion aqueous solution, and 70 % of phosphate was removed in phosphate dispersion solution by chemically synthesized graphene oxide solution. Removing efficiency of phosphate was increased from 70 % to 80 % with assistant of iron nano-particle in chemically synthesized graphene oxide solution. Phosphate removing capacity was up to 89.37 mg/g at initial phosphate concentration of 100 mg/l and temperature of 303 K. The Freundlich was applied to describe the equilibrium isotherms and the isotherm constants were determined.

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Concerning application of graphene, a lot of efforts have been made to improve performance of nanomaterials in many fields, such as electric and electronic devices. Some examples are preparation of 3-dimension structured nanomaterials like nanoballs by CVD process and hybridizing with silicon. These graphene-based materials are proven to be available for secondary battery, EMI and ACF in electronics. Especially, some research has shown that they were very effective to enhance safety and volumetric capacity when they were used as anode materials of secondary battery. Although graphite and its compound with metal have been used as an anode material due to their high stability and reversibility, it still has lower charge capacity. On the contrary, silicon is known as a material which increases the charge capacity up to four times, compared with carbon-based materials, but it has lower stability and reversibility. For that reason, a few researchers just started to improve the charge capacity by hybridization of carbon-based material with silicon. In this paper, we prepared nanocarbon based material which has a new structure of graphene encapsulated silicon nanoball as an anode material which is applicable to high-capacity secondary battery. In order to form a graphene encapsulated silicon nanoballs, the polystyrene encapsulated silicon nanoballs were prepared by emulsion polymerization of styrene monomer with silicon nanoparticles. The resulting nanoballs were immersed in iron chloride solution and then dried. Finally they were treated in high temperature through CVD and etched by hydrogen chloride. Morphology of the graphene encapsulated silicon nanoballs was observed by the field emission scanning electron microscope (FESEM) and the field emission transmission electron microscope (FETEM) to search for core-shell structured nanoball. Spherical structure of graphene encapsulated silicon nanoball was investigated by the Raman, the X-ray Photoelectron Spectroscopy to identify graphene layers on the surface of the inner silicon core.