▎ 摘　　要

NOVELTY - Producing reduced graphene oxide sheet, comprises (a) preparing graphite oxide by mixing graphite powder and solution containing strong acid and oxidizing agent, and oxidizing, (b) producing graphene oxide by delaminating obtained graphite oxide, (c) preparing graphene oxide sheet having predetermined area by processing graphene oxide into a sheet shape, and (d) producing reduced graphene oxide sheet by reducing the graphene oxide sheet. USE - The sheet is useful in film for electromagnetic shielding (claimed). ADVANTAGE - The sheet has large area and high heat radiation, electromagnetic shielding efficiency of greater than or equal to 20 dB at a frequency band of 0.1-10 GHz, thermal conductivity of greater than or equal to 1000 W/mk and electrical conductivity of greater than or equal to 200 S/cm (claimed), excellent workability and mechanical strength. The method is simple and economical, and enables mass production. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for reduced graphene oxide sheet prepared by the above method.