CN-117985760-B - Composite material assembled by indium-poor tungsten bronze phase mosaic blocks and preparation method thereof

Abstract

The invention relates to a composite material assembled by indium-poor tungsten bronze phase mosaic blocks and a preparation method thereof, wherein the composite material assembled by the indium-poor tungsten bronze phase mosaic blocks is formed by compounding In 0.02 WO 3 and WO 3 , a plurality of tunnels consisting of gaps between tungsten and oxygen atoms exist In the composite material assembled by the indium-poor tungsten bronze phase mosaic blocks, and indium ions are randomly distributed at two sides of the center position of the tunnels. The method comprises the steps of firstly, creating a supersaturated sodium sulfate solution environment, secondly, adding indium nitrate into the supersaturated sodium sulfate solution environment obtained in the first step, adding NH 4 Cl for hydrothermal reaction, thirdly, centrifuging, thirdly, sequentially adding sodium tungstate, oxalic acid and ammonium chloride into deionized water, dripping HCL into the deionized water, adding a product of the third step for hydrothermal reaction, centrifuging and washing to finally obtain the composite material assembled by the indium-poor tungsten bronze mosaic blocks. The material has high sensitivity to acetone gas and low working temperature.

Inventors

• LI MINGCHUN
• MOU HANLIN
• QU XIAOHAN
• WANG RUIYANG
• JIAN LIANG
• WU YUSHENG

Assignees

• 沈阳工业大学

Dates

Publication Date

20260508

Application Date

20231231

Claims (2)

1. 1. A composite material assembled by indium-poor tungsten bronze phase mosaic blocks is characterized In that the composite material assembled by the indium-poor tungsten bronze phase mosaic blocks is formed by compounding In 0.02 WO 3 and WO 3 , a plurality of tunnels formed by gaps between tungsten and oxygen atoms exist In the composite material assembled by the indium-poor tungsten bronze phase mosaic blocks, indium ions are randomly distributed on two sides of the central position of the tunnels, the structure of the composite material assembled by the indium-poor tungsten bronze phase mosaic blocks is formed by innumerable hollow spheres, the hollow spheres of a single indium-poor tungsten bronze phase structure have good dispersibility, the diameter of the microspheres is 2-3 mu m, the thickness is 450-520 nm, micropores with diameters being more than 1nm and less than or equal to 2nm, mesopores with diameters being more than 2nm and less than or equal to 50nm, the diameters being more than or equal to 100nm, the hollow spheres of a single indium-poor bronze phase structure are hollow sphere structure assembled by mosaic block battens, and the lengths of the mosaic block battens are 50-250nm, and the heights of the mosaic battens are 20-100nm.
2. 2. A method for preparing a composite material assembled by the indium-poor tungsten bronze phase mosaic blocks according to claim 1, which is characterized by comprising the following steps: Firstly, adding sodium sulfate into a container filled with deionized water under the water bath condition of 50-80 ℃ to ensure that the concentration of the sodium sulfate is 5.8-8.2g/100mL, stirring for 0.5-1.5h at the rotating speed of 500-800rpm, rapidly placing the container filled with deionized water into a 0 ℃ ice-water mixture, reducing the rotating speed to 100-300rpm within 1s, and continuously stirring for 10-20min to create a supersaturated sodium sulfate solution environment; Adding indium nitrate In the supersaturated sodium sulfate solution environment obtained In the step one, wherein the mass ratio of sodium sulfate to indium nitrate is (3.8-4.2): 1, simultaneously adding NH 4 Cl as an activity auxiliary agent and a pH value regulator, stirring for 0.5-1.5h at the speed of 700-1200 rpm In the NH 4 Cl and In (NO 3 ) 3 mass ratio is (0.5-2): 1), transferring the container from the ice-water mixture at the temperature of zero ℃ to a hydrothermal reaction kettle, and carrying out hydrothermal reaction for 3-4h at the constant pressure of 35-40MPa with the filling ratio of (3.5-4.2): 5 at the temperature of 160-180 ℃, naturally cooling to 130-160 ℃ and then carrying out the reaction for 6-10h; Centrifuging the product obtained in the step II, transferring the centrifuged solid into a freeze dryer, drying for 20-40 hours at the temperature of minus 30 to minus 60 ℃, obtaining an indium oxide precursor, and placing the indium oxide precursor into a vacuum tank for vacuumizing and preserving the activity of the indium oxide precursor; Sequentially adding sodium tungstate, oxalic acid and ammonium chloride into deionized water, wherein the molar ratio of the sodium tungstate to the oxalic acid to the ammonium chloride is (0.3-1.2), the molar ratio of the sodium tungstate to the oxalic acid to the ammonium chloride is (1-1.2), the solid-liquid mass ratio of the sodium tungstate to the ammonium chloride is (0.30-0.31), stirring the sodium tungstate and the oxalic acid at room temperature for 1-2h under the condition of 1000-1300rpm, adding HCL with the concentration of 6-10mol/L into the deionized water at the speed of 2-7 drops/s, continuously stirring the HCL with the deionized water for 1-1.5h, adding the product of the third step, heating the product at the temperature of 1-3 ℃ for 50-70min, continuously stirring the product of 1-3h, transferring the product into a hydrothermal reaction kettle, performing hydrothermal reaction at the filling ratio of (3.5-4.2), naturally cooling the product to room temperature to obtain a yellow suspension mixed solution, centrifuging the yellow suspension solution at the temperature of 150-220 ℃ and the pressure of 35-40 MPa, centrifuging the yellow suspension mixed solution, and carrying out centrifugation at 3000-4500rpm, and washing the solid-phase of the tungsten-poor composite block by ethanol, and preparing the indium-phase, and washing the composite material, and assembling the indium-poor composite material.

Description

Composite material assembled by indium-poor tungsten bronze phase mosaic blocks and preparation method thereof Technical Field The invention belongs to the technical field of metal oxide semiconductor nano materials, and relates to a composite material assembled by indium-poor tungsten bronze phase mosaic blocks and a preparation method thereof. Background Common toxic gases in the atmosphere are CO, SO 2、NO2, H 2 S and the like. The above gas concentration is too high, which can cause acute poisoning of human body and even cause serious consequences such as physiological dysfunction. In addition, long-term exposure to Volatile Organic Compounds (VOCs) from building materials, automobile exhaust, fuel combustion, and industrial production can cause chronic poisoning even at low concentrations, causing serious damage to the human nervous system, blood system, and even brain development in children. Therefore, research and development of tungsten oxide-based gas sensors with fast response to harmful gases, good selectivity and stability, low optimal working temperature and excellent gas sensitivity are one of the current research hotspots. The most widely used sensing mechanism of tungsten-based semiconductor gas sensors is the adsorption-desorption model. The model refers to the change of the electrical property of the material caused by the adsorption or desorption reaction of the monitored gas on the surface of the gas-sensitive material, so that the purpose of detecting the gas is achieved. Thus, the gas-sensitive performance of the material is closely related to the effective specific surface area, the inherent structure, the defects and the number of active sites, and the gas-sensitive performance can be confirmed in a plurality of reports. In order to solve the problem of high working temperature of the tungsten-based gas-sensitive material and combine the sensing mechanism of the tungsten-based gas-sensitive sensor, the design and development of the nanostructure gas-sensitive material have become one of important research directions. A large number of experimental researches show that the multi-dimensional nano-structure gas sensor with good gas sensitivity can be obtained in various different modes at present. The nano-structure can be mainly divided into a zero-dimensional nano-structure (nano particles and the like), a one-dimensional nano-structure (nano wires, nano tubes and the like), a two-dimensional nano-structure (nano films, nano sheets and the like), a three-dimensional nano-structure (sea urchin-like, flower-like, hollow microspheres and the like) and a multi-dimensional nano-structure assembled by the low-dimensional nano-structure according to the dimension classification. These nanostructures can have high activity in gas-sensitive reactions due to their unique properties such as large specific surface area, good pore structure, and small size effects. This greatly improves the gas sensitive material in terms of a number of properties such as sensitivity, selectivity, response recovery time, operating temperature, etc. In addition, people can further improve the gas-sensitive performance of the tungsten oxide by controlling the morphology crystal form or compounding with other materials and the like. In view of the many special electrical properties of tungsten bronze structured materials, the multidimensional nanostructured tungsten oxide based gas sensitive materials containing tungsten bronze phases have great potential for gas detection. Up to now, there is little research on preparing a three-dimensional self-assembled In 0.02WO3/WO3 material by a two-step hydrothermal method, but the three-dimensional self-assembled In 0.02WO3/WO3 material has great operability on the regulation and modification of the structure of tungsten oxide, and the detection temperature of a few metal semiconductor oxide sensors is controlled to be 100 ℃ or below, so that it is necessary to develop a preparation method of an In 0.02WO3/WO3 material capable of combining the phase composition of a composite material and the advantages of a nano composite structure so as to realize the control of the detection temperature of acetone waiting for measuring gas to be about 100 ℃. Disclosure of Invention Object of the Invention The invention provides a composite material assembled by indium-poor tungsten bronze phase mosaic blocks and a preparation method thereof, and aims to solve the problems of complex preparation process, unstable thermodynamics, single composite microstructure, higher agglomeration degree, small specific surface area and the like In the preparation process of an In 0.02WO3 material In the prior art. Technical proposal The composite material assembled by the indium-poor tungsten bronze phase mosaic blocks is formed by compounding In 0.02WO3 and WO 3, a plurality of tunnels consisting of gaps between tungsten and oxygen atoms exist In the composite material assembled by the indium-poor tungst