▎ 摘　　要

NOVELTY - Preparing reduced graphene comprises e.g. (i) adding 50-120 ml concentrated sulfuric acid in a beaker, adding 1-10 g graphite powder and 1-10 g sodium nitrate, magnetically stirring for 10-80 minutes in a ice bath, slowly adding 1-20 g potassium permanganate, reacting for 30-120 minutes, placing in a constant temperature water bath of 20-50 degrees C for 30-120 minutes, adding the 100-150 ml distilled water, reacting in a constant temperature water bath at 50-100 degrees C for 5-30 minutes, adding 10-30 ml hydrogen peroxide, when the color of the solution changes from brown to bright yellow, and filtering while hot, and washing with hydrochloric acid and distilled water for 5-10 times to obtain graphene oxide solution, (ii) adding 1-5 g green tea and 50-150 mldeionized water into the beaker, boiling at 50-100 degrees C for 10-60 minutes, and filtering to obtain tea solution, taking the tea solution and the graphene oxide solution according to a volume ratio of 2-4:1. USE - The method is useful for preparing reduced graphene. ADVANTAGE - The method: has low cost; is environmentally friendly; produces product has excellent dispersing properties. DETAILED DESCRIPTION - Preparing reduced graphene comprises (i) preparing graphene oxide in a beaker, adding 50-120 ml concentrated sulfuric acid, adding 1-10 g graphite powder and 1-10 g sodium nitrate, magnetically stirring for 10-80 minutes in a ice bath, slowly adding 1-20 g potassium permanganate, reacting for 30-120 minutes, placing in a constant temperature water bath of 20-50 degrees C for 30-120 minutes, adding the 100-150 ml distilled water, reacting in a constant temperature water bath at 50-100 degrees C for 5-30 minutes, adding 10-30 ml hydrogen peroxide, when the color of the solution changes from brown to bright yellow, and filtering while hot, and washing with hydrochloric acid and distilled water for 5-10 times to obtain graphene oxide solution, (ii) adding 1-5 g green tea and 50-150 mldeionized water into the beaker, boiling at 50-100 degrees C for 10-60 minutes, and filtering to obtain tea solution, taking the tea solution and the graphene oxide solution obtained in the step (i) according to a volume ratio of 2-4:1, subjecting ultrasonic treatment for 30-90 minutes, stirring, and reacting in a magnetic stirrer at 50-100 degrees C for 1-3 hours to obtain reduced graphene solution, freezing the reduced graphene solution in the refrigerator for 12-48 hours, drying in a freeze dryer for 3-100 hours, and finally grinding into a powder by agate mortar to obtain reduced graphene.