▎ 摘　　要

NOVELTY - A room temperature-nitrogen oxide sensor consists of a composite prepared by dissolving 0.6-0.9 g cobalt nitrate hexahydrate and 0.4-0.6 g urea in 20-40 ml water, stirring, hydrothermally reacting at 150-180 degrees C for 14-18 hours, cooling, centrifuging, washing the precipitate with deionized water and absolute ethanol, freezing at -50 degrees C to -30 degrees C, drying for 12-18 hours, calcining at 500-700 degrees C for 1-3 hours to obtain black cobalt oxide powder, adding 15-20 mg freeze-dried graphene oxide powder to 15-20 ml water, ultrasonically processing for 30-60 minutes to obtain graphene oxide solution, adding 10-30 mg cobalt oxide powder to 10-30 ml water, adding 100-1000 mu L graphene oxide solution, stirring, adding 70-90 %mass aqueous solution of hydrazine monohydrate, stirring for 30-60 minutes, reacting in a water bath at 70-90 degrees C for 3-6 hours, cooling, centrifuging, washing with water and absolute ethanol, freeze-drying at -50 degrees C to -30 degrees C, and calcining at 400-600 degrees C for 1-3 hours. USE - Room temperature-nitrogen oxide sensor. ADVANTAGE - The nitrogen oxide sensor has excellent sensitivity and small volume, and can be fabricated by simple method. The sensor enables detection of nitrogen oxide accurately. The cobalt oxide-graphene oxide composite has high specific surface area, gas adsorption capacity, fast carrier mobility and excellent electrical conductivity. DETAILED DESCRIPTION - The sensor consists of an aluminum oxide ceramic tube with two separate ring-shaped gold electrodes, a film of sensitive material uniformly coated on the outer surface of the gold electrode and ceramic tube, and a nickel-cadmium alloy coil inside the ceramic tube. The sensitive material is cobalt oxide-graphene oxide composite.