▎ 摘　　要

NOVELTY - Preparation of graphene-loaded tin dioxide quantum dots involves (1) dissolving 2-5 mmol tin salt and 0.1-0.5 mmol zinc salt in 10 mL deionized water, (2) taking 10 mL deionized water, formulating with an aqueous solution of triblock polymer with a molar concentration of 0.8-1.2 M, slowly dripping the solution obtained in step (1) into triblock polymer aqueous solution, stirring for 30-50 minutes, adding 1-3 mL of hydrochloric acid, stirring for 30-50 minutes, (3) adding 5-10 mL of graphene oxide with a concentration of 1 mg/mL to the solution obtained in step (2), stirring for 1-2 hours, performing hydrothermal reaction at 180-200 degrees C, cooling to room temperature, centrifuging to collect the precipitate, drying at 60-80 degrees C, obtaining powder, (4) adding the powder into an aqueous solution of nitric acid with a concentration of 1-2 M, and performing hydrothermal reaction at 160-180 degrees C for 12-14 hours. USE - Preparation of graphene-loaded tin dioxide quantum dots for detection of formaldehyde and nitrogen dioxide gas (all claimed). ADVANTAGE - The method uses combination of metal oxide and graphene, which can improve its electrical conductivity and realize the catalytic reaction of the target gas at room temperature, thereby realizing the detection of nitrogen dioxide at room temperature.