▎ 摘　　要

NOVELTY - Preparing carbon-based composite material comprises (i) adding N,N-dimethylacetamide and riboflavin to the reactor, and heating the reactor to obtain reaction solution, (ii) adding carboxylated carbon nanotubes, carboxylated graphene and hydrochloric acid in the reaction solution obtained in the step (i) to obtain first mixture after heating, (iii) placing the first mixture obtained in the step (ii) into a microwave reactor, and performing microwave catalytic reaction to obtain second mixture, and(iv) washing and vacuum drying the second mixture obtained in the step (iii). USE - The material is useful for decolorization of azo dyes (claimed). ADVANTAGE - The method: improves the conductivity and biocompatibility of a single carbon material; achieves the fixation of riboflavin; has excellent electron transfer properties and biological safety, and good dispersibility; can be recycles; and decolorizes the azo dye. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for method of using carbon-based composite material for decolorizing the azo dyes, comprising using the carbon-based composite material for decolorizing the azo dye wastewater.