▎ 摘　　要

NOVELTY - A palladium/tin dioxide/graphene composite material preparing method involves dissolving a tin salt in deionized water to form a tin salt solution, stirring and adjusting the pH of the tin salt solution to 7-9 to form a white precipitate, washing and drying to obtain white crystals, grinding the white crystals into powder, and roasting to obtain tin dioxide nanoparticles. The tin dioxide nanoparticles are added to the graphene solution, and the mixture is uniformly dispersed by ultrasonic to obtain a mixed solution, and the tin dioxide/graphene composite material is obtained by centrifugal separation, drying and baking. The tin dioxide/graphene composite material is added to a palladium chloride solution, and the mixture is uniformly dispersed by ultrasonic to obtain a mixed solution, and performing centrifugal separation, drying, and baking to obtain the finished product. USE - Method for preparing a palladium/tin dioxide/graphene composite material for detecting carbon monoxide (claimed). ADVANTAGE - The method enables preparing a palladium/tin dioxide/graphene composite material with high gas-sensitive sensing performance for carbon monoxide gas under lower working temperature conditions. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a gas sensor, comprising a gas-sensitive layer.