▎ 摘　　要

NOVELTY - A biopolymer-based three-dimensional graphene is obtained by absorbing cobalt ions by biopolymer, performing high-temperature carbonization, and washing with concentrated nitric acid to obtain final product with specific surface area of 300-400 m2/g. USE - Biopolymer-based three-dimensional graphene. ADVANTAGE - The biopolymer-based three-dimensional graphene has stable product performance, and is prepared by simple and industrial process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation method of biopolymer-based three-dimensional graphene, which involves (1) weighing persimmon tannin and chitosan according to a certain mass ratio, dissolving in water, and reacting under certain condition to obtain solidified persimmon tannin powder, (2) adding solidified persimmon tannin powder obtained in the step (1) to the mixed solution of cobalt nitrate according to a certain mass ratio, reacting for 1-2 hours, filtering, washing and drying to obtain product as a precursor for preparing three-dimensional graphene, and (3) calcining the precursor obtained in the step (2) under certain condition, washing and refluxing with concentrated nitric acid, filtering, drying and washing.