▎ 摘　　要

NOVELTY - The air pollutant detector has a light filter (2) arranged on a surface of an infrared emission unit. The infrared emission unit is provided with a polysialate layer, a graphene electric heating layer, a silicon carbide layer and a graphitizable macromolecule layer. The graphene microspheres are inserted into the silicon carbide layer and graphitizable macromolecule layer in a penetrating mode. The infrared emission unit is configured to convert electric energy into thermal energy and radiate heat outwards in an infrared mode. The infrared light filter is configured to filter radiated infrared light so as to allow infrared light of a specific wave band to pass through. The detection unit is configured to detect the infrared light, where the intensity is weakened due to the fact that infrared light of a corresponding wave band is absorbed by the pollution gas, when pollution gas is contained, and detection for the pollution gas is realized. USE - Air pollutant detector for detecting toxic gas such as sulfur dioxide and nitric oxide generated from atmospheric pollution, based on a graphene infrared emission unit. ADVANTAGE - The number of low-frequency phonons in a vertical direction sharply increases with respect to graphite, so that thermal conduction of the graphene microspheres is greatly enhanced. The graphene microspheres can rapidly conduct heat at a bottom layer to the entire graphene microspheres, and the heat rapidly acts with air in a vertical direction to enhance efficiency of thermal radiation and thermal conduction. DETAILED DESCRIPTION - The detector has a cavity configured to collect to-be-detected gas, where the infrared light corresponding to the wave band allowed to pass through the light filter is at least filtered out from the cavity. The infrared emission unit and the detection unit are separately arranged at two opposite sides of the cavity. The detector portion is configured to detect a content of carbon monoxide in the gas when a light filter wave band is 4.5-4.7 μ m, and a transmissivity of the light filter for 4.5-4.7 μ m at least is 50% or higher, and a cut-off rate for the other wave bands is 90% or higher. The detector portion is configured to detect a content of nitric oxide in the gas when a light filter wave band is 5.2-5.3 μ m, and a transmissivity of the light filter for 5.2-5.3 μ m at least is 50% or higher, and a cut-off rate for the other wave 30 bands is 90% or higher. The sizes of the graphene microspheres are 2-5 μ m, a total thickness of the silicon carbide layer and the graphitizable macromolecule layer does not exceed 1/4 of the sizes of the graphene microspheres. The wall thicknesses of the microspheres are less than 5 atomic layers. DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the air pollutant detector. 1Multi-infrared emission coating 2Light filter 3Gas chamber 4Infrared receiver 5Data processing module