▎ 摘　　要

NOVELTY - A graphene and manganese dioxide nano composite material preparing method involves stir-mixing graphene, potassium nitrate and concentrated sulfuric acid in an ice water bath. Manganese dioxide is added to the reaction mixture and reacted, followed by addition of deionized water. Hydrogen peroxide is then added, and teh obtained reaction mixture is filtered, and washed to prepare graphite oxide. The graphite oxide is dispersed in water and reacted with hydrazine hydrate. The obtained product is washed and ultrasonically dispersed in saturated potassium permanganate solution. USE - Method for preparing nano composite material of graphene and manganese dioxide. Uses include but are not limited to a catalyst, biosensing material, electrode material of lithium ion battery and electrode material of super capacitor. ADVANTAGE - The method enables simplifying reaction and process, facilitating control, and improving operating convenience. The obtained composite material has wide application range. DETAILED DESCRIPTION - A graphene and manganese dioxide nano composite material preparing method involves stir-mixing graphene, potassium nitrate and concentrated sulfuric acid in an ice water bath. Manganese dioxide is added to the reaction mixture (rate of manganese dioxide with respect to graphene is 1-5:1) and reacted at 30-40 degrees C for 20-40 minutes. Deionized water (rate of addition of water is 100-200 ml with respect to graphene 1 g) is added and reacted for 15-30 minutes. Hydrogen peroxide (rate of addition of hydrogen peroxide 10-30 ml with respect to graphene 1 g) is pumped into the reaction mixture, filtered, and washed to prepare graphite oxide, where the volume quality rate of manganese dioxide is 20-50 g with respect to concentrated sulfuric acid (1 L). The graphite oxide is dispersed in water, and hydrazine hydrate having volume quality rate with graphite oxide of 1-3 ml to 1 g is added and reacted at 95 degrees C for 1-24 hours. The product is washed and the graphene is ultrasonically dispersed in saturated potassium permanganate solution according to the quality rate of 10-30 to 1. Acid (mol ratio of acid with respect to potassium permanganate is 2-5:1) is added, and ultrasonically reacted at 60-80 degrees C for 1-5 hours. The product is filtered and washed to prepare nano composite material of graphene and manganese dioxide.