▎ 摘　　要

NOVELTY - An in-situ assembled polypyrrole-coupled tungsten oxide nanowire/nitrogen-doped graphene aerogel gas sensor preparing method involves weighing the tungsten carbide powder, dissolving powder in ethanol, stirring, adding polyvinylpyrrolidone and stirring. The prepared solution is transferred into a kettle and the nanowires are washed with ethanol and water. Piranha solution is prepared and the device is placed in piranha solution, rinsed and dried to obtain a clean surface. The nanowires are mixed with the graphene oxide aqueous solution, dispersed, pyrrole monomer is added and dispersed. The mixed solution is transferred to the hydroxylated device surface to obtain polypyrrole-coupled nanowires/graphene on the device surface hydrogel. The device containing the obtained hydrogel is placed into an aging solution, frozen, placed into freeze-drying equipment, dried to obtain polypyrrole-coupled nanowire/graphene aerogel and placed in a tube furnace to obtain the desired product. USE - Method for preparing an in-situ assembled polypyrrole-coupled tungsten oxide nanowire/nitrogen-doped graphene aerogel gas sensor (claimed). ADVANTAGE - The method enables preparing graphene aerogel gas sensor in simple manner, maximizing the gas sensing performance of graphene aerogel and ensuring excellent response performance to low concentrations of nitrogen dioxide. DETAILED DESCRIPTION - An in-situ assembled polypyrrole-coupled tungsten oxide (W18O49) nanowire/nitrogen-doped graphene aerogel gas sensor preparing method involves weighing and dissolving tungsten carbide (WC16) powder in absolute ethanol and stirring for 10-30 minutes to form a light yellow solution. Polyvinylpyrrolidone is added and stirred for 10-30 minutes, the prepared solution is transferred into a reaction kettle for solvothermal reaction, where the reaction temperature is 160-200 degrees C and the reaction time is 12-48 hours. The nanowires are repeatedly washed with anhydrous ethanol and deionized water for later use. Piranha solution is prepared, the device is placed in piranha solution and treated at 90 degrees C for 30 minutes, thoroughly rinsed with ultrapure water and dried with flowing nitrogen to obtain a clean surface. The nanowires are mixed with the graphene oxide aqueous solution according to a certain mass ratio, ultrasonically dispersed for 15-60 minutes, pyrrole monomer is added and dispersed for 15-60 minutes. The mixed solution is transferred dropwise to the hydroxylated device surface for in-situ assembly, where the reaction temperature is 20-40 degrees C and the reaction time is 12-36 hours to obtain polypyrrole-coupled nanowires/graphene on the device surface hydrogel. The device containing polypyrrole-coupled nanowire/graphene hydrogel is placed into an aging solution for aging for 24-72 hours, frozen at -20 to -80 degrees C for 12-24 hours, placed into freeze-drying equipment and dried for 12-72 hours to obtain polypyrrole-coupled nanowire/graphene aerogel. The obtained polypyrrole-coupled nanowire/graphene aerogel is placed in a tube furnace under the protection of the atmosphere, the temperature is raised to 200-300 degrees C for 1-3 hours at a temperature increase rate of 1-5 degrees C/minute, and the temperature is naturally reduced to obtain the polypyrrole-coupled nanowire/nitrogen-doped graphene aerogel.