▎ 摘　　要

NOVELTY - Preparing copper oxide/graphene composite nano material, comprises preparing copper oxide nano-particle solution by mixing hexadecyl trimethyl ammonium chloride solution, copper nitrate solution and sodium citrate solution, transferring to 80-100 degrees C, stirring while dropping alkali solution into mixed solution, centrifuging, collecting precipitate and dispersing into ultra-pure water to obtain copper oxide nano-particle solution, preparing copper oxide/graphene composite nano material by mixing graphene nano-sheet dispersion liquid with copper oxide nano-particle solution, and ultrasonically processing for 3-10 hours to obtain copper oxide/graphene composite nano material, where the molar ratio of hexadecyl trimethyl ammonium chloride, copper nitrate solution and sodium citrate solution is 25-100:1-4:1-4, the volume ratio of the graphene nano-sheet dispersion liquid and copper oxide nano-particle solution is 2-4:1-2. USE - The nano material is useful for bifunctional electrode for chemical oxygen demand detection and removal. ADVANTAGE - The method recurs to multi-layer stack structure of graphene nano sheet, and convenient for copper oxide nano-particle doped into the graphene nano sheet. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) copper oxide/graphene composite nano material, prepared as mentioned above; and (2) bifunctional electrode for chemical oxygen demand detection and removal, comprising a glassy carbon electrode and copper oxide/graphene composite nano material, the copper oxide/graphene composite nano material is coated on the surface of the glassy carbon electrode, and naphthol ethanol solution is coated on the surface of the glassy carbon electrode after drying.