▎ 摘　　要

NOVELTY - Preparing graphene powder, comprises adding 1 pts. wt. of graphite into 2-100 pts. wt. of pure acid solution, heating at 10-100 degrees C and uniformly stirring for 10-20 hours, filtering and washing with water, then drying at 50 degrees C for 10 hours to obtain acid treated graphite material, then adding active solution, ultrasonically treating the material at 0-100 degrees C for 5-20 minutes to obtain the graphene dispersion liquid, filtering ultrasonic graphene dispersion liquid, then washing with distilled water, and drying at 50 degrees C for 10 hours. USE - The method is useful for preparing graphene powder (claimed). ADVANTAGE - The simple method is capable of preparing graphene powder with mild reaction condition, high quality and high yield at low cost in large scale. DETAILED DESCRIPTION - Preparing graphene powder, comprises adding 1 pts. wt. of graphite into 2-100 pts. wt. of pure acid solution, heating at 10-100 degrees C and uniformly stirring for 10-20 hours, filtering and washing with water, then drying at 50 degrees C for 10 hours to obtain acid treated graphite material, then adding active solution, ultrasonically treating the material at 0-100 degrees C for 5-20 minutes to obtain the graphene dispersion liquid, filtering ultrasonic graphene dispersion liquid, then washing with distilled water, and drying at 50 degrees C for 10 hours. The pure acidic solution is potassium permanganate, sulfuric acid or nitric acid. The amount of potassium permanganate is 0.01-0.2 times of sulfuric acid. The amount of nitric acid is 0.1-1 times of sulfuric acid. The active solution is water or organic solvent. The amount of graphite material in active solution is 2-100 times. The active component is sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate and/or aqueous ammonia. The amount of graphite material in active ingredient is 0.1-50 times. The organic solvent is ethanol, N-methylpyrrolidone, methanol, isopropyl alcohol, dimethyl sulfoxide, and/or N,N- dimethylformamide amine and/or N,N-dimethylacetamide. The ultrasonic treatment is ultrasonic bath or ultrasonic probe. The ultrasonic bath power is 20-4000 W and the working frequency is 20-120 KHz. The ultrasonic probe power is 50-3000 W and the working frequency is 20-120 KHz.