▎ 摘　　要

NOVELTY - Mass preparation of large-size graphene comprises weak oxidizing large-size graphite by modified Hummers method; dispersing graphite oxide in water; stripping by weak ultrasonic-assisted or oscillating method; removing graphite oxide, which is not stripped completely, and small-size graphene oxide to obtain uniform large-size graphene oxide; reducing large-size graphene oxide using hydrazine or hydrazine hydrate; removing oxygen-containing functional group; and restoring performance. USE - Mass preparation of large-size graphene (claimed) used for flexible optoelectronic thin film field. Uses include but are not limited to transparent conductive film, display, solar cell electrode, gas sensor, optical-electrical converter, and thin film electron component. ADVANTAGE - The method provides high-quality large-size graphene having maximum area of 3x 104 mu m2. DETAILED DESCRIPTION - Mass preparation of large-size graphene comprises: (A) weak oxidizing large-size graphite by modified Hummers method; (B) dispersing graphite oxide in water; and stripping graphite oxide by weak ultrasonic-assisted or oscillating method; (C) separating graphene oxide by removing graphite oxide, which is not stripped completely, and small-size graphene oxide to obtain uniform large-size graphene oxide; (D) reducing the large-size graphene oxide by depositing graphene oxide dispersing liquid on base; reducing the liquid by hydrazine or hydrazine hydrate; removing oxygen-containing functional group; and restoring the performance.