▎ 摘　　要

NOVELTY - Preparing cigarette butt based graphene composite material, comprises (i) cleaning the waste cigarette butt, adding into dilute sulfuric acid, stirring for 1-1.5 hours, washing multiple times using ultra-pure water and drying in an oven to obtain primary purified solid sample, (ii) placing the solid sample on the nickel foam, then calcining under inert gas atmosphere, naturally cooling, washing multiple times with sulfuric acid and ultra-pure water, and drying to obtain initial carbon material, (iii) taking certain amount of initial carbon material in ethanol solution, and carrying out ultrasonic oscillation for 1-1.5 hours, then adding methacrylic acid, manganese(II) chloride hydrate and iron(III) nitrate nonahydrate, and stirring uniformly to obtain mixed solution, and (iv) transferring the mixed solution into muffle furnace for calcining, naturally cooling, washing multiple times with ultra-pure water and ethanol, and drying to obtain graphene composite material. USE - The cigarette butt based graphene composite material is useful for catalytic degradation of herbicide penoxsulam by peroxodisulfate (claimed). ADVANTAGE - The method produces graphene composite material having magnetic three-dimensional structure.