▎ 摘　　要

NOVELTY - Composite material comprises three-dimensional graphene foam matrix, where hole diameter of matrix is 50-500 micron and has porosity of not less than 95%, and gold nano particle that is uniformly dispersed on substrate. USE - Composite material used for degradation of organic pollutant that contains nitrophenol and used in sewage disposing agent (all claimed). ADVANTAGE - The composite material is prepared in simple and cost-effective manner, maintains three-dimensional porous structure, improves the dispersion of gold nano particle to avoid agglomeration of its occurrence, good stability, rapid adsorption, active degradation, and has broad application prospect in field of chemical catalysis and waste water treatment. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a method for preparing composite material, which involves carrying out oxidation treatment by an oxidation agent, and reacting obtained graphene in organic polymer solution, and nano gold particle solution to obtain composite material; and (2) a sewage disposing agent comprises the composite material.