▎ 摘　　要

NOVELTY - A composite electrode preparing method involves pretreating graphite plate by immersing plate in acid, soaking in alkali and washing in water. Graphene is prepared by taking two graphite plates as cathode and anode, respectively, and performing electrolysis in ammonium sulfate solution to obtain graphite plates with graphene on the surface. Modification of graphene is performed followed by immersing graphite plates with carboxyl-modified graphene on the surface into dimethylformamide to react fully to obtain a composite electrode. USE - Method for preparing composite electrode that is utilized as the anode of bio-electrochemical system. ADVANTAGE - The electrode has large specific surface area, low electrical resistance, stable structure, and good performance. DETAILED DESCRIPTION - A composite electrode preparing method involves pretreating graphite plate by immersing plate in acid, soaking in alkali and washing in water. Graphene is prepared by taking two graphite plates as cathode and anode, respectively, and performing electrolysis in ammonium sulfate solution to obtain graphite plates with graphene on the surface. Modification of graphene is performed by immersing graphite sheet containing graphene on the surface in an aqueous solution of sodium hydroxide and chloroacetic acid to fully react to obtain a graphite sheet containing a carboxyl-modified graphene followed by preparing metal-organic framework by immersing graphite plates with carboxyl-modified graphene on the surface of modified graphene into dimethylformamide of ferric nitrate and terephthalic acid to react fully to obtain a composite electrode. An INDEPENDENT CLAIM is also included for a composite electrode prepared by the method.