▎ 摘　　要

NOVELTY - Preparing graphene/polyaniline modified carbon-based electrode, involves (a) diluting the graphene oxide solution to 0.3-0.8 g/L by using a citric acid buffer solution with pH of 6 as a first-step electrolyte, where the buffer solution is citric acid buffer solution, (b) diluting 0.1 mol/L aniline solution with 0.1 mol/L protonic acid to 0.1-0.3mol/L, as second-step electrolyte, where the protonic acid is sulfuric acid or hydrochloric acid, (c) using carbon-based electrode as a working electrode, comprises a carbon fiber brush, a carbon felt or a carbon cloth, followed by cleaning and pretreating by using acetone soaking and acid soaking before use, and (d) constructing a three-electrode system by taking the first-step electrolyte as an electrolyte, a platinum mesh as a counter electrode and silver/silver chloride (Ag/AgCl) as a reference electrode. USE - Method for preparing graphene/polyaniline modified carbon-based electrode, used for treating wastewater of azo dyes by using bioelectrochemical device (claimed). ADVANTAGE - The modified graphene/polyaniline electrode is used as the cathode of the bioelectrochemical system to construct a bipolar chamber bioelectrochemical system, and also used to enhance the decolorization of azo dyes in water. DETAILED DESCRIPTION - Preparing graphene/polyaniline modified carbon-based electrode, involves (a) diluting the graphene oxide solution to 0.3-0.8 g/L by using a citric acid buffer solution with pH of 6 as a first-step electrolyte, where the buffer solution is citric acid buffer solution, (b) diluting 0.1 mol/L aniline solution with 0.1 mol/L protonic acid to 0.1-0.3mol/L, as second-step electrolyte, where the protonic acid is sulfuric acid or hydrochloric acid, (c) using carbon-based electrode as a working electrode, comprises a carbon fiber brush, a carbon felt or a carbon cloth, followed by cleaning and pretreating by using acetone soaking and acid soaking before use, (d) constructing a three-electrode system by taking the first-step electrolyte as an electrolyte, a platinum mesh as a counter electrode and silver/silver chloride (Ag/AgCl) as a reference electrode, using cyclic voltammetry to scan 30-50 circles under the conditions of a scanning range of (-)1.6-0.6 volt vs Ag/AgCl and a scanning rate of 50 mV/s, and depositing the in-situ generated graphene on the surface of the carbon-based electrode, (e) taking the electrolyte obtained in the second step as the electrolyte, taking the working electrode as a working electrode, taking a platinum mesh as a counter electrode and taking Ag/AgCl as a reference electrode, and constructing a three-electrode system, and (f) using a cyclic voltammetry to generate polyaniline in situ to be modified on the surface of the graphene electrode under the conditions of a scanning range of (-)0.2-1 volt vs Ag/AgCl, a scanning speed of 50 mV/s and scanning cycles of 10-20 to prepare the graphene/polyaniline modified carbon-based electrode. INDEPENDENT CLAIMS are included for: A graphene/polyaniline modified carbon-based electrode prepared by the method. A method for treating wastewater of azo dyes by using bio-electrochemical device, which involves: (a) using graphene/polyaniline modified carbon-based electrode as cathode, and unmodified carbon-based electrode as anode, (b) inoculating anode with microorganisms, and cathode with or without microorganisms, to form electroactive bio-membrane on the surface of the electrode, and further inoculating microorganisms refers to inoculating anaerobic activated sludge of a secondary sedimentation tank on the surface of an electrode, (c) feeding water respectively and discharging from the anode chamber and the cathode chamber, where anode chamber is wastewater containing organic pollutants, and the cathode is wastewater containing azo dyes. The wastewater containing the organic pollutants is easily degradable organic pollutants without containing azo dyes. (d) The resistor of 5-20 omega is connected between the anode and the cathode. (e) The anode chamber and the cathode chamber are separated by a diaphragm, e.g. proton exchange membrane or a cation exchange membrane. (f) The voltage ≤1 volt is applied between the anode and the cathode.