▎ 摘　　要

NOVELTY - Graphene is prepared by treating graphite oxide with volatile acid aqueous solution to obtain acidized graphite oxide; heating the acidized graphite oxide to 100-200 degrees C under normal pressure, and keeping the temperature constant for 1 minute-12 hours to expand the acidized graphite oxide and obtain graphene. USE - Method for preparing graphene (claimed) used in, e.g. electronic device and conductive plastic. ADVANTAGE - The method is carried out at normal pressure and low temperature, thus overcoming the prior art's limitation on graphene preparation under vacuum or low pressure condition. It is simple and easy to perform, and can provide graphene with high specific surface area (500-1000 m2/g) and wide market application prospect, thus making it suitable for large-scale production. DETAILED DESCRIPTION - Graphene is prepared by (1) treating graphite oxide with volatile acid aqueous solution to obtain acidized graphite oxide; (2) heating the acidized graphite oxide to 100-200 degrees C under normal pressure, and keeping the temperature constant for 1 minute-12 hours to expand the acidized graphite oxide and obtain graphene. Step (1) can be performed by (a) soaking the graphite oxide in the volatile acid aqueous solution with pH 0-6.8 to absorb the volatile acid molecule between sheets of graphite oxide, taking the graphite oxide out, and drying to obtain the acidized graphite oxide; or (b) adding neutral solution comprising graphite oxide into the volatile acid aqueous solution to adjust the pH of the mixed solution to 0-6.8 and absorb the volatile acid molecule between sheets of graphite oxide, washing with deionized water, filtering, and drying to obtain the acidized graphite oxide.