▎ 摘　　要

NOVELTY - Preparing tin dioxide/graphene composite material, comprises (i) carrying out hydrothermal process by carrying out ultrasonic dispersion of graphite oxide in water; (ii) dissolving tin salt in deionized water, placing three-dimensional columnar reduced graphene oxide in the above solution, soaking, transferring solution and three-dimensional reductive graphene oxide into a hydrothermal reactor, carrying out reaction, to obtain a precursor; and (iii) calcining precursor at 280-550 degrees C for 1-6 hours, preferably 300-450 degrees C for 1.5-3 hours, and naturally cooling to room temperature. USE - The composite material is useful for resistance-type gas sensor (claimed). ADVANTAGE - The method produces product having good selectivity, high sensitivity, good stability and rapid response performance. DETAILED DESCRIPTION - Preparing tin dioxide/graphene composite material, comprises (i) carrying out hydrothermal process by carrying out ultrasonic dispersion of graphite oxide in water to obtain graphene oxide solution, adding sulfuric acid into the solution, and carrying out ultrasonic dispersion, to obtain uniform mixture, transferring the mixture into a reaction kettle, allowing to react at 160-260 degrees C for 18-30 hours, washing, to obtain three-dimensional columnar reduced graphene oxide, and reacting at 190-220 degrees C for 20-24 hours; (ii) dissolving tin salt in deionized water, to obtain solution, placing three-dimensional columnar reduced graphene oxide in the above solution, soaking at 3-50 degrees C for 1 day or more, preferably 10-30 degrees C for 1-2 days, transferring the solution and three-dimensional reductive graphene oxide into a hydrothermal reactor, carrying out reaction at 160-260 degrees C for 18-48 hours, preferably 180 -220 degrees C for 20-28 hours, washing and drying the product, to obtain a precursor; and (iii) calcining precursor at 280-550 degrees C for 1-6 hours, preferably 300-450 degrees C for 1.5-3 hours, and naturally cooling to room temperature. An INDEPENDENT CLAIM is also included for a resistance-type gas sensor comprising a sensitive layer of tin dioxide/graphene composite material.