▎ 摘　　要

NOVELTY - A composite material preparation method involves mixing graphene, ethylene glycol and deionized water to obtain uniformly dispersed mixed solution A, dissolving cerium nitrate hexahydrate, sodium hydroxide and polyvinylpyrrolidone in the solution A and magnetically stirring to obtain uniformly dispersed mixed solution B. The mixed solution is transferred to an autoclave followed by reacting to obtain cubic form cerium dioxide nanoparticles and graphene composite material. The composite material is cleaned and dried to obtain composite structural powder of cerium dioxide and graphene. USE - Method for preparing composite material that is utilized for highly sensitive gas sensor. ADVANTAGE - The method enables preparing composite material in a simple and clear manner by completely exerting synergistic effect between active crystal face and heterojunction, significantly improving sensitivity of nitrogen dioxide gas at room temperature and achieving detection of gas in a rapid manner. DETAILED DESCRIPTION - A composite material preparation method involves thoroughly mixing 10-30 mg graphene, 10-25 ml ethylene glycol and 10-25 ml deionized water to obtain uniformly dispersed mixed solution A, dissolving 150-450 mg cerium nitrate hexahydrate, 41.47-124.41 mg sodium hydroxide and 300 mg polyvinylpyrrolidone in the solution A and magnetically stirring for 3 hours to obtain uniformly dispersed mixed solution B. The mixed solution is transferred to an autoclave followed by reacting at 160-220 degrees C for 24 hours to obtain cubic form cerium dioxide nanoparticles and graphene composite material. The composite material is cleaned and dried to obtain composite structural powder of cerium dioxide and graphene, where volume ratio of ethylene glycol and deionized water is 1:1 and mass ratio of cerium nitrate hexahydrate and sodium hydroxide is 1:3.