▎ 摘　　要

NOVELTY - Preparing graphene aerogel with different micro-size comprises (i) diluting the graphene oxide solution with solvent, (ii) centrifuging the upper layer of the graphite oxide dispersion liquid, collecting the deposition portion, (iii) centrifuging the upper layer liquid, collecting the deposition portion as medium-sized graphene oxide, (iv) centrifuging the upper liquid, collecting the deposition portion is smaller size graphene oxide and the upper liquid is a small-sized graphene oxide, (v) ultrasonically processing the small size of graphene oxide, (vi) adding ascorbic acid to the different size graphene oxide solutions, stirring, mixing and (vii) adding mixed solution quantitatively into the mold, placing the mold into a water bath, heating and (viii) freezing and drying the grapheme hydrogel to remove the water content. USE - The method is useful for preparing graphene aerogel with different micro-size. ADVANTAGE - The method is simple and easy, the reaction condition is mild, the product is no toxicity and environmentally friendly and is easy to realize mass production. DETAILED DESCRIPTION - Preparing graphene aerogel with different micro-size comprises (i) diluting the graphene oxide solution with solvent so that the concentration of the graphene oxide solution is 0.01-20 mg/ml, (ii) centrifuging the upper layer of the graphite oxide dispersion liquid 1000-5000 revolutions/minutes at room temperature for 10-600 minutes, collecting the deposition portion to obtain the large-size graphene oxide, (iii) centrifuging the upper layer liquid obtained in the step (i) at room temperature to 5000-8000 revolutions/minutes for 10-600 minutes, collecting the deposition portion as medium-sized graphene oxide, (iv) centrifuging the upper liquid at 8000-15000 revolutions/minutes for 10-600 minutes, collecting the deposition portion is smaller size graphene oxide and the upper liquid is a small-sized graphene oxide, (v) ultrasonically processing the small size of graphene oxide, where the ultrasonic power is 10-10000 W, the ultrasonic time is 10-600 minutes to obtain ratio of smaller size and more uniform graphene oxide, (vi) adding ascorbic acid to the different size graphene oxide solutions obtained in the step (ii), (iii), (iv) and (v) according to the ratio oxidized graphene and ascorbic acid is 1:1-1:1000, stirring for 1-360 minutes or ultrasonic 1-360 minutes, uniformly mixing the mixture and (vii) adding mixed solution quantitatively into the mold, placing the mold into a water bath, heating temperature to 60-100 degrees C and maintain the temperature for 1-24 hours to obtain graphene hydrogel and (viii) freezing and drying the grapheme hydrogel to remove the water content to obtain the porous graphene aerogel.