▎ 摘　　要

NOVELTY - Sensitive material is stannic oxide nanosheet loaded with reduced reduced graphene oxide having mesoporous structure on surface. USE - Sensitive material for detecting formaldehyde. ADVANTAGE - The sensitive material has high sensitivity and good selectivity, strong gas/recoveryability, stable performance, it is effectively improves sensitivity and selectivity of formaldehyde gas sensor, and it is used for detecting outer in door formaldehyde concentration to evaluate quality of air to ensures health of human body. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for following: (1) a method for preparing sensitive material, which involves adding reduced graphene oxide to anhydrous ethanol, controlling power of 400 watt, and frequency of 32 kilo hertz for ultrasonic treatment for 30 minutes to uniformly disperse the graphene oxide in anhydrous ethanol to obtain a graphene oxide dispersion, where amount of above reduced graphene oxide and absolute ethanol is 10-200 milligram: 20-200 milliliter graphene oxide; (2) adding a tin source to obtained graphene oxide dispersion, controlling the temperature to 10-50 degrees C, and rotating at 1000 revolution per minute for 12-18 hours to obtain a mixed solution, where tin source is tin tetrachloride, dibutyltin dilaurate or tetra-n-butyl stannate, and amount of tin source added is calculated by volume ratio of reduced graphene oxide dispersion and tin source is 1:4-16; (3) centrifuging mixed solution at a speed of 10000 revolution per minute for 15 minutes, and washing resulting precipitate with absolute ethanol until tin source is effluent; (4) controlling rotation speed at 10,000 revolution per minute for 15 minutes, and again centrifuging; (5) drying at 60 degrees C, collecting dried product, placing dried product in a muffle furnace and heating at 450-500 degrees C at a rate of 1-5 degrees C per minute for 2-12 hours to obtain sensitive material; (6) a method for using sensitive material for formaldehyde detection, which involves alculating amount of reduced graphene oxide andanhydrous ethanol, reduced graphene oxide, absolute ethylalcohol according to the ratio of 100 milligram: 200 milliliter at 25 degrees C with stirring speed of 1000 revolution per minute for 16 hours, using dibutyltin dilaurate as tin source by adding tin source and graphene oxide dipersion liquid in ratio of 1:16, drying at 60 degrees C with 2 degrees C per minute, performing calcining treatment for 2 hours by controlling coating thickness of 1 millimeter; and (7) a method for preparing gas sensor for detecting formaldehyde, which involves using CGS-8 gas sensor system test, where gas concentration is 0.25-100 parts per million, working temperature is 40-90 degrees C, and sensitivity of 100-2200 parts per million, and response recovery time is less than 90 second.