▎ 摘　　要

NOVELTY - Preparing high-conductivity graphene comprises (i) adding mixed oxidant into concentrated sulfuric acid, stirring until it is dissolved completely, then reducing the temperature to 40-160 degrees C, adding graphite powder and reacting; (ii) washing the reaction mixture with water until the filtrate is neutral, then acidifying, washing and drying to obtain the pre-oxidized graphite powder; and (iii) mixing the pre-oxidized graphite powder and bis-azo dye, mechanical grinding for 1-10 hours, and washing the mixture with water until the filtrate is colorless. USE - The high-conductivity graphene and graphene conductive film are useful in electronic materials (claimed) including lithium ion battery, solar cell, super capacitor, electromagnetic shielding, antistatic device, biosensor and low cost optical transmission electrode. ADVANTAGE - The method is simple, ensures mild reaction conditions, is easy to control, produces high yield, and is economical. The high-conductivity graphene can be dispersed in solvent, has stripping efficiency and film-forming property. The graphene conductive film has low resistance, good mechanical property and biocompatibility. DETAILED DESCRIPTION - Preparing high-conductivity graphene comprises (i) adding 1-10 g mixed oxidant into 10-200 ml concentrated sulfuric acid of 60-180 degrees C, stirring until it is dissolved completely, then reducing the temperature to 40-160 degrees C, adding 1-10 pts. wt. graphite powder, and reacting for 1-10 hours, where the mixed oxidant is mixture of strong oxidant and phosphorus pentoxide; (ii) washing the reaction mixture with water until the filtrate is neutral, then acidifying, washing and drying to obtain the pre-oxidized graphite powder; and (iii) mixing the pre-oxidized graphite powder and bis-azo dye according to mass ratio of 10:1-1:10, mechanical grinding for 1-10 hours, and washing the mixture with water until the filtrate is colorless. INDEPENDENT CLAIMS are also included for: (1) high-conductivity graphene prepared by the above method; (2) preparing graphene conductive film, comprising ultrasonically dispersing high-conductivity graphene in a solvent to obtain the graphene solution, depositing the graphene solution on surface of a substrate by film-forming method and surface processing to form graphene conductive film; and (3) graphene conductive film prepared by the above method.