33results about How to "Good gas response" patented technology

The invention provides a novel ammonia gas sensor based on a reduced graphene oxide-tungsten disulfide composite and a preparation technology thereof and belongs to the technical field of sensors. The novel ammonia gas sensor comprises a gas-sensitive composite and a sensor substrate, wherein the gas-sensitive composite is a nano material obtained through one-step hydrothermal synthesis, the gas-sensitive composite is uniformly coated on a gold interdigitated electrode on the sensor substrate, transient heating temperature of a heating plate on the back of the sensor substrate is 140 DEG C, and heating recovery time is linearly varied along with concentration of detected gas. The reduced graphene oxide-tungsten disulfide composite disclosed by the invention shows good response performance on ammonia gas in a room temperature environment and has good selectivity, stability and repeatability. In a recovery stage of the gas sensor provided by the invention, transient heating is used, time required for reduction is effectively shortened without influencing performance of a gas-sensitive material, and concrete transient heating time can be set according to the gas concentration obtained through detection.

The invention proposes a gas-liquid interface processing method for a semiconductor gas sensor comprising the following steps: preparing a precursor solution; irradiating the precursor solution with ultraviolet light to prepare a film on the surface of the solution; picking up the surface film with a clean glass sheet and transferring it to Wash the film on the surface of deionized water; pick up the film cleaned by deionized water with a ceramic tube; weld the ceramic tube with the film on the special base of the gas sensor, and there is a heating resistance wire in the ceramic tube; insert the base into the On the gas-sensing test system, apply a voltage to the resistance wire, and obtain a gas sensor after obtaining a film with stable composition. The invention achieves the attachment of gas-sensitive materials on the sensor substrate, improves the defects of multi-step operation, high-temperature processing, stability, repeated processing and batch processing in the current gas sensor processing process, and has the advantages of easy-to-obtain raw materials, simple process, It is characterized by easy operation and mass production, good gas response and recovery performance and excellent stability.

The invention provides a rare-earth doped modified graphene composite material gas sensitive element for detecting NOx and a preparation method of the gas sensitive element, and relates to a gas sensitive element for detecting the NOx and the preparation method of the gas sensitive element, solving the problems that an existing gas sensitive material is low in sensitivity, slow in response, and poor in resistance to factors except gas concentration. The rare-earth doped modified graphene composite material gas sensitive element for detecting the NOx is prepared from graphene, distilled water, a cupric acetate solution, a ceric nitrate solution, a sodium hydroxide solution and a glucose solution; an obtained rare-earth doped modified graphene composite material is mixed with a dispersant and a dispersion solution is dropwise added to the surface of a gold interdigital electrode to prepare the rare-earth doped modified graphene composite material gas sensitive element. The preparation method comprises the following steps: 1, preparation of the rare-earth doped modified graphene composite material; and 2, assembling of the composite material gas sensitive element.

A based on ZnO microspheres and CsPbBr 3 Room temperature NO of quantum dot heterostructure composites 2 A sensor and a preparation method thereof belong to the technical field of semiconductor oxide gas sensors. A ceramic substrate with metal interdigitated electrodes and ZnO microspheres and CsPbBr coated on the metal interdigitated electrodes 3 Composition of sensitive layer of quantum dot heterostructure composite material. The morphology of zinc oxide is a sphere structure, which has a large specific surface area and can provide more attachment sites, so that it can be combined with the smaller perovskite CsPbBr 3 The quantum dots are in full contact, so that a gas sensor with better gas sensor response and faster response recovery speed can be obtained. In addition, CsPbBr 3 As an excellent photoelectric material, quantum dots can absorb visible light, thereby providing more photogenerated carriers. The sensor of the present invention adopts a planar structure, has simple process, short production period, and is suitable for mass production.

The present invention relates to the use of g-C for detecting VOCs 3 N 4 A method for synthesizing a modified porous zinc oxide nanosheet composite gas-sensing material, comprising the following steps: (1) preparing basic zinc carbonate and recrystallized commercialized melamine respectively, and grinding and mixing the two evenly according to a certain mass ratio; (2) The mixture obtained in step (1) is calcined under the protection of nitrogen to obtain a composite gas-sensitive material. In this method, the chemical synthesis method of precursors is used to synthesize g-C, which has a special interaction with gas molecules containing benzene rings. 3 N 4 Composite on porous zinc oxide nanosheets, with the help of the synergistic effect between the two porous two-dimensional semiconductor materials, the gas-sensing performance of zinc oxide is effectively improved. The material can be used for the gas-sensing detection of benzene-containing volatile organic pollutants and chlorobenzene-like gases. The gas-sensing response is good, the material synthesis method is green and simple, and the repeatability is good. It is easy to realize large-scale production and gas sensing detection applications. .

The invention discloses a boron-doped titanium dioxide photo-assisted gas-sensitive element, a preparation method and application. According to the method, a boron doping mode is adopted for modifyingTiO2 and used for preparing the photo-assisted gas-sensitive element, the method is mild in condition and easy to operate, and the prepared B / TiO2 gas-sensitive element shows excellent H2 and CO response performance under the action of ultraviolet light, shows high stability and repeatability, and helps to provide convenience for practical application of semiconductor photo-assisted gas-sensitivesensors.

The invention belongs to the technical field of gas sensors, and relates to a gas sensor based on a metal molybdate nanocomposite material and a preparation method thereof; the ring-shaped gold electrode of the sensor is coated with a metal molybdate nanocomposite film, and the metal The specific preparation process of molybdate nanocomposites is as follows: first, ammonium molybdate, thiourea and ammonium fluoride are prepared by hydrothermal synthesis of MoS 2 At the same time, the semiconducting metal oxide suspension is prepared by hydrothermal synthesis of the semiconducting metal salt; then the molybdenum sulfide powder and the semiconducting metal oxide suspension are hydrothermally synthesized into the molybdenum sulfide nanocomposite precursor, and the prepared molybdenum sulfide The metal molybdate nanocomposite material is obtained by calcining the precursor of the nanocomposite material in an atmosphere; the ethanol gas sensor has high selectivity to ethanol, high sensitivity, good stability, long service life, and short response time and recovery time to ethanol gas , excellent performance, quick and timely alarm for ethanol gas.

The invention belongs to the technical field of preparation of gas sensors, and provides a LaFeO3-based ethanol gas sensor with high gas-sensitive property and a preparation method thereof. La2 / 3Ba1 / 3Fe2 / 3Ti1 / 3O3 nano-powder prepared with a sol-gel method is taken as a working mediumsubstance for preparing a nindirectly-heated heater-type ceramic tube constructed gas sensor element. In a LaFeO3 lattice, an equivalent quantity of Ba elements and Ti elements with an equivalent quantity are introduced at a La bit and an Fe bit, so that the surface oxygen adsorption performance of the nano-powderis improved, the ethanol gas sensor element is lower in working temperature under the condition of not adding heavy metals or rare earth precious metals, and is higher in gas response and selectivity.The high gas-sensitive property LaFeO3-based ethanol gas sensor with high gas-sensitive property is 128 DEG C in best working temperature specific to the ethanol, is 48.1 in gas response specific to100ppm ethanol at the best working temperature, is below 22.4 and below in gas response specific to 100ppm acetone, DMF (Dimethyl Fformamide), dichloromethane, n-hexane, carbon dioxide and hydrogen gas response, and is up to 15.1 in gas response specific to 20ppm ethanol.

The invention belongs to the technical field of gas sensors, and provides a high gas response and selective LaFeO3-based ethanol gas sensor element and a preparation method thereof. LaFeO3 and BaTiO3nano powder are prepared by a sol-gel method and mixed at a molar ratio of 2:1; the mixture is sintered for 2 h at 190-210 DEG C, a nano gas-sensitive material is obtained, and a side-heating ceramictube structure gas sensor element is obtained. The oxygen adsorption capability of the surface of the nano-gas sensitive material is enhanced, and the gas response and selectivity are significant improved at lower operating temperatures. The optimum operating temperature of the gas sensor element for ethanol is 128 DEG C; the gas response to 100 ppm ethanol at the optimum operating temperature is102.9, and good stability is achieved; for 100 ppm acetone, dichloromethane, n-hexane, carbon dioxide and hydrogen and the like, the gas response is 38 or below, and good selectivity is achieved; andthe gas sensor element has a very high gas response to low concentration ethanol gas.