11results about How to "High response" patented technology

This invention relates to a tungsten-doped tin dioxide nanopowder, its preparation method, and its application in semiconductor-type gas-sensitive elements. The method for preparing the tungsten-doped tin dioxide nanopowder includes the following steps: dissolving a soluble tungsten compound and a soluble tin compound in an aqueous solution containing a surfactant, and adding a complexing agent to obtain a homogeneous metal ion mixed solution; adding a precipitant to the mixed solution under stirring conditions to adjust the pH to 2-6, causing a metal hydroxide precursor to precipitate; aging, solid-liquid separation, washing, and drying the precipitate to obtain a precursor powder; adding a dispersant to the precursor powder and mixing evenly; and calcining to obtain the tungsten-doped tin dioxide nanopowder. The tungsten-doped tin dioxide nanopowder of this invention can be used in the preparation of semiconductor-type gas-sensitive sensors, ultraviolet detectors, lithium-ion battery anode materials, catalysts, or transparent conductive films.

The invention provides a gas chromatographic analysis method of maleic anhydride, and belongs to the technical field of maleic anhydride analysis methods. As a maleic anhydride sample to be detected contains acidic substances and has a low response value on an FID (Flame Ionization Detector), according to the method provided by the invention, the BSTFA reagent is adopted for esterification treatment, the response value of the acidic substances in the sample to be detected is increased, a weak-polarity chromatographic column is adopted for gas chromatographic analysis, a hydrogen flame detector is used for detection, and an external standard method is used for quantitative calculation. The method provided by the invention has the advantages of high accuracy of the obtained detection result, good data repeatability and high sensitivity, can accurately analyze the maleic anhydride component concentration, has important guiding significance for quality control of maleic anhydride products produced by a device, and has good popularization and application values.

The invention is suitable for the field of gas sensor detection, and provides a mixed potential type ammonia gas sensor and a preparation method thereof. The mixed potential type ammonia gas sensor comprises a layered nickel silicate sensitive electrode, a reference electrode and a solid electrolyte, the layered nickel silicate sensitive electrode and the reference electrode are positioned on the surface of the solid electrolyte; the layered nickel silicate sensitive electrode is prepared from three kinds of layered nickel silicate electrode slurry with different morphologies. According to the invention, the layered nickel silicate is used as the sensitive electrode, so that the response value to ammonia gas is obviously improved at room temperature; compared with an existing most advanced mixed potential type ammonia gas sensor, the high-temperature mixed potential type ammonia gas sensor has the advantage that the low-concentration response to ammonia gas can be remarkably improved at room temperature compared with other high-temperature mixed potential type ammonia gas sensors.

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 application discloses a kind of Ni doped nano SnO2 semiconductor HCHO sensing materials and preparation method and application thereof, and the preparation method of sensing material includes the following steps: step one, Sn salt-Ni salt solution is configured;Step two, using supercritical hydrothermal synthesis (CSHS) reaction device, Sn salt-Ni salt solution is contacted with supercritical water and crystallization is generated nano doped oxide, and reaction liquid is discharged and collected after cooling, and the crystalline material is separated, i.e. the Ni doped nano SnO2 semiconductor HCHO sensing material of the application.The Ni doped nano SnO2 semiconductor HCHO sensing material prepared by the method of the application has good structural consistency and excellent sensing performance.

This invention belongs to the technical field of bactericide residue analysis and determination in plant-derived foods, specifically relating to a method for detecting isobutylethoxyquinoline and its metabolites in plant-derived foods. The method includes extraction with acetonitrile under citrate conditions, followed by purification with C18 (25 mg), PAX (25 mg), and XFM64 (nitrogen-doped multi-walled carbon nanotubes, 10 mg) adsorbents. Chromatographic separation is performed using a C18 column with methanol-2 mmol / L ammonium acetate (containing 0.1% formic acid) as the mobile phase, isocratic elution at a flow rate of 0.40 mL / min, electrospray ionization (ESI+), and detection in multiple reaction monitoring (MRM) mode. This invention is simple to operate, has high pretreatment efficiency, and its precision and recovery rate meet the regulatory residue limit monitoring requirements. It is suitable for the simultaneous determination of isobutylethoxyquinoline and its metabolites in plant-derived foods.

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 invention provides a micro-flower WO3 nano material and a preparation method and application thereof, and relates to the technical field of gas sensitive materials.The preparation method of the micro-flower WO3 nano material comprises the following steps that WCl6 is dissolved in absolute ethyl alcohol and stirred in a water bath; putting the washed and dried loofah sponge LO into the precursor solution, and standing at room temperature; the impregnated LO is taken out and put into a drying oven to be dried; and finally, calcining the dried LO in a muffle furnace to obtain the micro-flower WO3 nano material. The material can be used for gas detection, and due to the characteristic of the micro-flower structure, more detected gas is allowed to pass through, so that the gas contact surface is increased, the specific surface area is larger, the detection effect is better, and the detection efficiency is higher; meanwhile, the material can be used as a gas-sensitive semiconductor material; experiments prove that a triethylamine gas sensor prepared from the micro-flower WO3 nano material prepared by the method has a relatively high response value to triethylamine gas, and has relatively good selectivity and a relatively good detection effect.

The invention discloses a preparation method and application of a Co3O4 / In2O3 heterostructure, and the preparation method at least comprises the following steps: grinding and mixing Co3O4 and In2O3 powder, and calcining to obtain the Co3O4 / In2O3 heterostructure. The preparation method comprises the following steps: firstly, physically mixing Co3O4 and In2O3 by adopting a mechanical grinding method, further calcining the mixed Co3O4 / In2O3 at a high temperature, and enabling Co3O4 and In2O3 to interact under the induction of heat to form a heterostructure. The Co3O4 / In2O3 heterostructure based hydrogen sensor is prepared by taking the Co3O4 / In2O3 heterostructure as a gas sensing film. In hydrogen sensing detection, the response value of the Co3O4 / In2O3 heterostructure-based hydrogen sensor to 10 ppm hydrogen at 200 DEG C can reach 100, and the defect of poor hydrogen sensing performance is overcome.

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.