11results about How to "Improve gas sensing performance" patented technology

This invention discloses a chemiluminescence gas sensor based on polyoxometalates (POMs), and relates to its fabrication method and application. The sensor is suitable for detecting ammonia at room temperature. The gas sensor includes an adapter base and a sensing element, wherein the sensing element consists of interdigitated electrodes and a sensitive material loaded on the electrode surface. This sensitive material is a composite material of POMs and SnO2. POMs, as excellent electron acceptors, possess good redox properties, thermal stability, and photosensitivity. When combined with SnO2, they can effectively suppress electron-hole recombination, thereby significantly improving the gas-sensing performance of the semiconductor material. Compared with existing technologies, the sensor provided by this invention exhibits high response characteristics to ammonia at room temperature, while also demonstrating excellent selectivity and repeatability.

The invention provides a Sn-MOF (at) SnO2 / Fe2O3 multilevel structure nano composite material, a preparation method thereof and an n-butyl alcohol gas sensor, belongs to the technical field of material synthesis, and aims to solve the technical problem of poor gas sensitivity of a Sn-MOF induced metal oxide nano composite material. The preparation method of the Sn-MOF (at) SnO2 / Fe2O3 multilevel structure nano composite material comprises the following steps: adding a tin source, a ligand and alkali into a solvent I to prepare a mixed solution I, and then reacting to prepare Sn-MOF; adding the Sn-MOF, an iron source and an alkali precipitator into a solvent II to prepare a mixed solution II, and reacting under the microwave-assisted condition to prepare an Sn-MOF (at) SnO2 / Fe2O3 precursor; and calcining the Sn-MOF (at) SnO2 / Fe2O3 precursor to prepare the Sn-MOF (at) SnO2 / Fe2O3 nano composite material with the multilevel structure. According to the invention, the n-butanol gas sensor prepared by using the Sn-MOF-coated SnO2 / Fe2O3 multilevel structure composite material as the sensitive layer has good gas sensing performance. The optimal detection working temperature of the sensor on n-butyl alcohol gas is 200 DEG C, and meanwhile, the sensor has the advantages of high response speed, large response value, good long-term stability and the like.

The invention discloses an Ag monatomic modified In2O3 single crystal film prepared based on pulse voltage discharge, a method thereof and a gas sensitive sensor, and the method comprises the following steps: 1) placing a substrate in a vacuum cavity of magnetron sputtering equipment, taking an indium oxide target as an In source, and growing on the substrate through a magnetron sputtering technology to obtain an indium oxide single crystal film; the substrate is yttrium oxide stabilized zirconia (YSZ); (2) placing the indium oxide single crystal thin film obtained in the step (1) on a vacuum chamber sample table which is internally provided with a pulse voltage discharge electrode and an Ag target material, evaporating Ag particles based on a pulse voltage discharge process, and depositing the Ag particles on the surface of the indium oxide single crystal thin film material to form dispersed clusters; and annealing to obtain the Ag single atom modified In2O3 single crystal thin film. The synthesis of a sensitive material with a high atom utilization rate and a stable structure is realized, and an advanced NO2 gas sensing device with high sensitivity and high selectivity is obtained.

The invention discloses an NO2 gas sensing material, an NO2 gas sensor and a preparation method and application of the NO2 gas sensing material and the NO2 gas sensor. The NO2 gas sensing material is a semiconductor substrate material doped with variable-valence metal elements; the material of the semiconductor substrate is BiOX, and the element X is at least one of Cl, Br and I; the variable-valence metal element is a variable-valence transition metal element. The invention provides a design and preparation method of a gas sensor capable of rapidly detecting NO2 at room temperature. The method can realize reversible detection of NO2 at room temperature.

The application discloses a nano-needle self-assembled flower-shaped microsphere metastable indium oxide gas-sensitive material, a gas-sensitive element and a preparation method and application. The nano-needle self-assembled flower-shaped microsphere metastable indium oxide gas-sensitive material has a three-dimensional flower-shaped microsphere formed by nano-needle self-assembly, the diameter of the nano-needle is about 8 nm, the diameter of the flower-shaped microsphere is about 2-3 microns, the main exposed crystal face of the material is (104), and the crystal structure is a metastable rhombohedral corundum phase. The prepared nano-needle self-assembled flower-shaped microsphere metastable indium oxide successfully realizes preparation of pure metastable indium oxide material under mild conditions and realizes application in the field of gas-sensitive detection, especially in the detection of H2S, and has the advantages of low working temperature, high sensitivity, high selectivity and low detection limit. Meanwhile, the synthesis preparation method is simple in synthesis, low in cost and has good industrial production prospects.

The application discloses alkali metal doped MOF-74, a gas sensitive material, a gas sensitive sensor and a preparation method and application thereof, and belongs to the technical field of gas sensitive sensors. The application takes magnesium nitrate hexahydrate and 2,5-dihydroxyterephthalic acid as raw materials, in-situ adds alkali metal salt doping, takes triethylamine (TEA) as a deprotonating agent, optimizes a reaction process, rapidly performs synthesis of the alkali metal doped MOF-74 at room temperature, realizes miniaturization of the MOF-74 without losing crystallinity and high porosity, and is favorable for improving the gas sensitive performance of the material. The alkali metal doped MOF-74 is used for the gas sensitive sensor, has excellent selectivity and high sensing response to CO2 gas, and can meet the demand of CO2 gas detection. Moreover, the preparation period is short, heating is not needed, and the method is favorable for large-scale production.

The application discloses a kind of PdO-SnO2-SiO2 / SiO2 Self-supporting flexible gas-permeable nanofiber membrane gas sensor and preparation method thereof.Si electrospinning fiber is prepared by single needle head electrospinning method first, then Si electrospinning fiber and Pd-Sn electrospinning fiber interwoven fiber membrane is prepared on it by double needle head electrospinning method, then PdO-SnO2-SiO2 / SiO2 Flexible gas-permeable nanofiber membrane is obtained by heat treatment, finally electrode is prepared on its surface to obtain gas sensor.SiO2 Nanofiber in the sensor of the application has good flexibility, as a framework material to ensure the flexibility of the fiber membrane;Interwoven fiber membrane can effectively prevent SiO2 Nanofiber and PdO-SnO2 Nanofiber from separating, and has good gas permeability;At the same time, the fiber membrane is all inorganic material, which can maintain the original shape at high temperature, has good high temperature resistance and gas sensitivity.The sensor of the application has simple preparation process, stable performance, wide range of use, low cost, and has broad application prospect.

This invention discloses a method and application for in-situ growth of Ti3C2Tx-titanium dioxide heterostructure material, belonging to the field of two-dimensional composite materials and gas sensor technology. The invention uses a hydrochloric acid solution containing fluorine compounds as the etching solvent and employs a hydrothermal method to etch Ti3AlC2 to prepare Ti3C2Tx material (Tx = -F, -OH, and -O). The Ti3C2Tx material is then subjected to oxygen microwave plasma treatment at low power, while controlling the oxygen volume fraction to 10-30%. This partially oxidizes the Ti3C2Tx material into two-dimensional sheet-like TiO2 oxides. These two-dimensional sheet-like TiO2 oxides tightly coat the surface of Ti3C2Tx, forming a Ti3C2Tx-TiO2 heterostructure material. Gas sensors prepared using this Ti3C2Tx-TiO2 heterostructure material exhibit excellent responsiveness and selectivity to hydrogen.

The application relates to a ZnO / Bi2S3 photosensitization synergistic photothermal sensitization NO2 gas sensing material and a preparation method thereof, and belongs to the technical fields of nanomaterial preparation, atmospheric environment detection and gas sensors, and has a good application prospect. The characteristic is that porous ZnO precursors are prepared first, and then are combined with Bi2S3 to prepare ZnO / Bi2S3, porous ZnO particles are distributed on the outer wall of the flower-like Bi2S3, the recombination rate of electrons and holes is reduced by means of a type II heterojunction, and the gas sensing performance is improved. Under 365 nm light activation, the response value of the ZnO / Bi2S3 sensor to 100 ppm NO2 at room temperature is 1.73 times that under thermal activation (dark, 60 DEG C); 810 nm near-infrared light provides light activation and photothermal synergistic effect, the surface temperature of the gas sensor is increased to 47 DEG C, and the response value to 100 ppm NO2 is increased to 21.77.

The application discloses an indium trioxide nanotube loaded cobalt oxyhydroxide composite material and application of the composite material in detection of nitrogen oxide, and the composite material is obtained by uniformly mixing indium trioxide nanotubes and Co / MOF in an aqueous solution, adding an etchant to fully react, washing the reaction product to neutral, and then drying to obtain the composite material; the organic skeleton raw material in the Co / MOF is dimethyl imidazole; and the etchant is sodium hydroxide or potassium hydroxide. The method has the advantages of simple process, low cost and no pollution to the environment; the indium trioxide nanotube has the advantages of excellent conductivity, large surface area and chemical stability, and the synthesized low-cost sensing material has high response value at room temperature, rapid detection and good stability, and has excellent selectivity to nitrogen oxide; the composite material has excellent gas sensing performance, and has excellent long-term stability and cycle stability, and has wide application prospect in the field of detection of nitrogen oxide.

This invention belongs to the field of gas sensor technology, specifically relating to an antimonate composite material based on heterogeneous isomorphism, its preparation, and its application. It utilizes bimetallic antimonate Ni... x Mg 1‑x Sb₂O₆ or antimonate / titanium dioxide composite Ni x Mg 1‑x A n-propanol gas sensor was fabricated using Sb₂O₆ / TiO₂ as the sensitive material. At the optimal operating temperature, it achieved a response value of over 35 for 20 ppm n-propanol, with a detection limit as low as 20 ppb and excellent selectivity. It shows great potential in environmental monitoring, industrial production, and early disease screening through breath analysis.