▎ 摘　　要

NOVELTY - The method for preparing single crystal graphene sheet from papermaking black liquor involves performing hydrothermal carbonization of papermaking black liquor, and adjusting the reaction conditions. USE - The method for preparing single crystal graphene sheet from papermaking black liquor, which is used in transparent conductive materials such as transparent conductive electrodes (claimed), batteries, supercapacitors and catalysis and adsorption applications. ADVANTAGE - The method enables simple and economical preparation of single crystal graphene sheet from papermaking black liquor with maximum average size of 2.5 mu m and high quality in an environmentally-friendly manner.