▎ 摘　　要

NOVELTY - Preparation of carboxyl functionalized graphene comprises adding ball milling balls into ball-milling tank; taking natural crystalline flake graphite powder into ball-milling tank, introducing carbon dioxide gas, and sealing ball grinding tank; fixing in planetary ball milling pot, air blasting to obtain sample, grinding, separating, and transferring into sieve-like beaker; adding deionized water, diluting, adding hydrochloric acid, milling, washing until neutral, and centrifuging to remove impurities; and lyophilizing samples for 6 hours, and freezing at - 30-20 degrees C. USE - Method for preparing carboxyl functionalized graphene (claimed). ADVANTAGE - The method has excellent performance, better dispersibility in solvent, simple operation, and low operation temperature. DETAILED DESCRIPTION - Preparation of carboxyl functionalized graphene comprises adding ball milling balls into ball-milling tank up to 2/5 of the volume; taking natural crystalline flake graphite powder into ball-milling tan, introducing carbon dioxide gas at natural crystalline flake graphite powder and carbon dioxide gas mass to volume ratio of 1 g:20-60 mL, and sealing ball grinding tank; fixing in planetary ball milling pot, air blasting at room temperature at 600-1200 revolutions/minute to obtain sample, grinding, separating, and transferring into sieve-like beaker; adding deionized water, diluting, adding hydrochloric acid, milling, washing until neutral, and centrifuging to remove impurities; and lyophilizing samples for 6 hours, and freezing at - 30-20 degrees C.