▎ 摘　　要

NOVELTY - Preparation of graphene includes taking microcrystalline graphite, adding solid sodium nitrate into clean dry reaction container, adding concentrated sulfuric acid, placing in ice bath, and stirring; adding potassium permanganate and dissolving; adjusting temperature of water bath to obtain first solution; adding deionized water and heating to obtain second solution; and cooling to room temperature, adding deionized water, stirring, adding hydrogen peroxide solution until color changes from brown to yellow to obtain graphite oxide solution; carrying out suction filtration and pumping. USE - Method for preparing graphene (claimed) used as ultra-light material, efficient energy conversion and storage of material, oil absorbing material, photoelectric material, photocatalytic material, and magnetic absorbing material. ADVANTAGE - The method is simple and has controllable operation, stable product quality, wide raw material sources and low cost. The graphene is small, fluffy and light weight and has high purity and large surface area. DETAILED DESCRIPTION - Preparation of graphene comprises: (A) taking 3 pts. wt. microcrystalline graphite, adding 3 pts. wt. solid sodium nitrate into clean dry reaction container, adding 98% concentrated sulfuric acid, placing in ice bath, and stirring; adding 9 pts. wt. potassium permanganate and dissolving at 0.5 g/minute; adjusting temperature of water bath to 35-40 degrees C to obtain first solution; adding deionized water and heating to 70-100 degrees C for 10 minutes-1 hour to obtain second solution; and cooling to room temperature, adding deionized water, stirring, adding hydrogen peroxide solution until color changes from brown to yellow to obtain graphite oxide solution; (B) carrying out suction filtration, pumping, washing with 10 wt.% diluted hydrochloric acid solution, and carrying out suction filtration; and washing with deionized water and carrying out suction filtration for 3-5 days to obtain graphite oxide crude product; (C) adding deionized water, uniformly mixing, centrifuging at 3000-5000 revolutions/minute (rpm), collecting upper gum solution, centrifuging at 8000-11000 rpm, and collecting lower layer solution to obtain third solution; (D) carrying out molecular weight cut-off dialysis at 8000-14000 into dialysis bag until neutral and collecting solution to obtain fourth solution; (E) adding ethylene glycol, uniformly mixing, adjusting alkalinity, adding into reaction kettle, and performing reduction reaction at 180 degrees C for 6-12 hours to obtain gel-like block; and (F) washing with deionized water until neutral.