▎ 摘　　要

NOVELTY - A gas sensing material preparation method involves adding 0.05-0.5 mol/l indium salt to reactor, adding deionized water, stirring at room temperature, controlling temperature to 35 degrees C, introducing ammonia gas, adjusting pH to 10, reacting for 3-5 hours to obtain indium(III) hydroxide colloid and terminating introduction of ammonia gas. The colloid is washed with distilled water, added with 0.01-0.2 mol/l chloroauric acid solution, stirred at room temperature and adjusted to pH of 10 using ammonia water to obtain colloidal solution followed by obtaining indium(III) oxide/gold/manganese dioxide composite metal oxide particles and obtaining graphene oxide colloidal solution. The metal oxide particles are added to graphene oxide colloidal solution and calcined in presence of inert gas. USE - Method for preparing gas sensing material that is utilized for detecting flammable gas e.g. formaldehyde (claimed). ADVANTAGE - The method enables preparing gas sensing material with rapid response and improved detection sensitivity for formaldehyde at large scale in a simple manner under mild conditions. DETAILED DESCRIPTION - A gas sensing material preparation method involves adding 0.05-0.5 mol/l indium salt to reactor, adding deionized water, stirring at room temperature, controlling temperature to 35 degrees C, introducing ammonia gas, adjusting pH to 10, reacting for 3-5 hours to obtain indium(III) hydroxide colloid and terminating introduction of ammonia gas. The colloid is washed with distilled water, added with 0.01-0.2 mol/l chloroauric acid solution, stirred at room temperature and adjusted to pH of 10 using ammonia water to obtain colloidal solution. The colloidal solution is added with manganocene, in dropwise manner at 10-20 degrees C and added with sodium borohydride followed by raising temperature to 40-50 degrees C, stirring for 6-10 hours to obtain precipitate, centrifuging, washing with deionized water, reacting obtained product in reaction vessel at 120-140 degrees C for 2-6 hours, washing and drying obtained product, calcining obtained product in presence of inert gas at 200-400 degrees C for 3-6 hours, obtaining indium(III) oxide/gold/manganese dioxide composite metal oxide particles, grinding and crushing, dispersing graphene oxide in deionized water and ultrasonically dispersing to obtain graphene oxide colloidal solution. The crushed metal oxide particles are added to graphene oxide colloidal solution and calcined in presence of inert gas at 200-400 degrees C for 3-6 hours, where surface of the gas sensing material is modified by graphene oxide. An INDEPENDENT CLAIM is also included for a gas sensing material prepared by the method.