▎ 摘　　要

NOVELTY - Preparing a ternary composite gas-sensitive material involves preparing polypeptide self-assembled nanotube materials by dissolving phenylalanine dipeptide in dimethyl sulfoxide, adding deionized water and allowing to stand to obtain nanotube materials, adding the polypeptide self-assembled nanotube material to a mixed solution and performing hydrothermal reaction after stirring to assemble the nanotube/tin dioxide (SnO2) composite material. The solutes in the mixed solution are tin tetrachloride pentahydrate, sodium hydroxide and polyvinylpyrrolidone-K30 and the solvent in the mixed solution is deionized water or anhydrous ethanol. Graphene is added into ethanol for ultrasonic treatment and the composite material is added to continue ultrasonic treatment to obtain a suspension, followed by drying the suspension and annealing the obtained dried material to obtain polypeptide self-assembled nanotubes/SnO2/graphene composite. USE - Method for preparing a ternary composite gas-sensitive material for carbon monoxide gas sensor (claimed). ADVANTAGE - The method enables to prepare ternary composite gas sensitive material using easily obtainable raw materials, low equipment investment and simple process and to realize effective detection of carbon monoxide gas with high sensitivity at room temperature.