CN-121974386-A - Tungsten doped tin oxide nano powder and preparation method thereof

CN121974386ACN 121974386 ACN121974386 ACN 121974386ACN-121974386-A

Abstract

The invention relates to the technical field of functional oxide materials, and particularly discloses tungsten doped tin oxide nano powder and a preparation method thereof, wherein the molecular level uniform mixing and complexing of tin and tungsten ions are realized under the action of an ultrasonic field through a compound complexing agent system with a specific proportion, and then tungsten atom uniformly doped tin dioxide nano crystals are directly formed by crystallization under a mild hydrothermal condition, so that the necessary high-temperature calcination step in the traditional process is omitted, and the problems of complex process flow, non-ideal doping uniformity, high-temperature post-treatment requirement, grain aggregation or high equipment cost in the traditional tungsten doped tin oxide nano powder preparation technology are solved, and the preparation method has the advantages of simplified process upset, improved doping uniformity, precise and controllable morphology and structure, environmental friendliness, excellent product performance and the like.

Inventors

LONG HUIWU
CHAI KE
ZENG WEN
LI HUANGXU
LI YANQIONG
YANG QIANGBIN
LI TIANMING
WANG CHENXI
YANG LIN
WEN CHENGLIN
ZHENG TIANXU

Assignees

重庆文理学院

Dates

Publication Date: 20260505
Application Date: 20260206

Claims (10)

1. The preparation method of the tungsten doped tin oxide nano powder is characterized by comprising the following steps of: Step S1, preparing a precursor solution, namely dissolving a tin source and a tungsten source in deionized water, adding a composite complexing agent and a surfactant, and adjusting the pH to 2.5-3.5 to obtain a transparent solution; The compound complexing agent comprises sodium citrate, sodium phytate and beta-cyclodextrin sodium phosphate, wherein the mass ratio of the sodium citrate to the sodium phytate to the beta-cyclodextrin sodium phosphate is 10 (4-6) to 2-3; the tin source is stannic chloride pentahydrate, the tungsten source is ammonium metatungstate, and the molar ratio of tungsten to tin is 1:4-1:8; S2, carrying out ultrasonic pre-mixing treatment, namely carrying out ultrasonic treatment on the solution obtained in the step S1 at 60-80 ℃ for 30-60min; s3, carrying out hydrothermal reaction, namely transferring the solution subjected to ultrasonic treatment into a hydrothermal reaction kettle, reacting at 180-220 ℃ for 6-12 h, adopting a step heating program in the reaction process, and utilizing ammonia water to self-regulate the pH value to be 4-6; And S4, after the reaction is finished, centrifuging, washing and vacuum drying to obtain the tungsten doped tin dioxide nano powder.
2. The method for preparing the tungsten doped tin oxide nano powder according to claim 1, wherein the surfactant is sodium dodecyl benzene sulfonate, and the addition amount is 0.5-1.0g/L.
3. The method for preparing the tungsten doped tin oxide nano powder according to claim 1, wherein the tin source is tin tetrachloride pentahydrate; The tungsten source is ammonium metatungstate.
4. The method of preparing tungsten doped tin oxide nano powder according to claim 3, wherein in the step S1, the pH value is adjusted by dropping ammonia water.
5. The method for preparing the tungsten-doped tin oxide nano powder according to claim 1, wherein in the step S2, the ultrasonic frequency is 40kHz, and the power is 200-500W.
6. The method for preparing the tungsten doped tin oxide nano powder according to claim 1, wherein step heating is adopted in the step S3, and the method comprises the following steps: The first stage of heating, namely heating the solution from room temperature to 100 ℃; maintaining the temperature, and maintaining 60 min after 100 ℃; The second stage is warmed and then the solution is warmed from 100 ℃ to 180-220 ℃.
7. The method for preparing the tungsten doped tin oxide nano powder according to claim 6, wherein in the step heating, the heating rate of the first-stage heating is 3 ℃ per min; The temperature rising speed of the second stage is 2 ℃ per minute.
8. The method for preparing the tungsten doped tin oxide nano powder according to claim 1, wherein in the step S4, the method comprises: s401, solid-liquid separation, namely after the reaction is finished, naturally cooling to room temperature, and centrifuging at 8000 rpm for 10 min; step S402, washing, namely washing 3 times by deionized water, washing 2 times by absolute ethyl alcohol, and centrifuging after each washing; step S403, drying, namely drying 12 h under the conditions of 80 ℃ and vacuum degree of-0.09 MPa to obtain pale yellow or off-white loose powder.
9. The method for preparing tungsten doped tin oxide nano powder according to claim 8, wherein the step S4 further comprises light grinding, wherein the obtained pale yellow or gray loose powder is slightly ground by using an agate mortar for 5-10 min.
10. A tungsten doped tin oxide nanopowder, characterized in that it is produced by the method of any one of claims 1-9.

Description

Tungsten doped tin oxide nano powder and preparation method thereof Technical Field The application relates to the technical field of functional oxide materials, and particularly discloses tungsten doped tin oxide nano powder and a preparation method thereof. Background Tin oxide (tin dioxide) is an important wide-bandgap n-type semiconductor material, and has wide application in the fields of gas sensors, transparent conductive films, lithium ion battery cathode materials, photocatalysis and the like due to excellent optical, electrical and chemical stability. In order to further regulate and improve the electrical properties, metal ion doping is an effective means. Among them, tungsten ions are regarded as a highly efficient n-type dopant due to their high charge and suitable ionic radius, and can significantly improve the conductivity of SnO 2. At present, various methods for preparing tungsten doped tin dioxide nano powder have been reported, and mainly comprise a coprecipitation method, a hydrothermal method, an ultrasonic chemical method, a spray pyrolysis method and the like. Coprecipitation method, which generally requires a plurality of complicated processes of mixing soluble salts of tin source and tungsten source in a solution, coprecipitating them by adding a precipitant, followed by long aging, repeated washing to remove impurity ions, drying, and high temperature calcination at more than 500 ℃. The process steps are complicated, and the production period is long. Although the uniformity of mixing can be improved by adding complexing agents, it is still difficult to avoid localized segregation of tungsten element during precipitation, drying and subsequent high temperature calcination. In addition, the abnormal growth of SnO 2 crystal grains and hard agglomeration among the grains are extremely easy to occur in the high-temperature calcination process, so that the specific surface area and sintering activity of the powder are reduced, and the performance of a device prepared from the powder is finally affected. The traditional hydrothermal method has the advantage of controlling the morphology of the nano material, but the hydrothermal method reported at present is mostly used for preparing the WO 3/SnO2 heterojunction composite oxide, and the product is a two-phase mixture rather than an evenly doped W-SnO 2 solid solution on an atomic scale. There is insufficient research to achieve uniform substitutional doping of tungsten atoms in the SnO 2 lattice. In addition, many precursors obtained by the hydrothermal method are still amorphous or substances with poor crystallinity, and a subsequent high-temperature heat treatment is required to obtain a SnO 2 phase with good crystallization, which also causes the problems of grain growth and agglomeration, and the advantages of one-step crystallization of the hydrothermal method cannot be fully exerted. The ultrasonic chemistry method utilizes the local extreme high temperature and high pressure environment generated by the ultrasonic cavitation effect to promote the mixing and reaction of the precursor. While helping to obtain fine particles, the process typically needs to be conducted under inert gas protection to prevent oxidation, and process control is complex. In addition, the product obtained by the ultrasonic chemistry method often needs to be subjected to subsequent high-temperature calcination steps to complete crystallization, low-temperature one-step synthesis cannot be realized, and the equipment requirement is high. Spraying pyrolysis method, in which the precursor solution is sprayed into a high-temperature reaction zone after being atomized, and the liquid drops undergo the processes of solvent evaporation, solute precipitation, thermal decomposition, sintering and the like instantaneously to directly obtain powder. Although the flow is short, the equipment is expensive, the energy consumption is extremely high, the particle size distribution of the product is wider, and the uniformity control difficulty is high. The characteristics make the method more suitable for large-scale industrial production, and are not beneficial to laboratory research and development or small-batch and multi-variety functional material preparation. In summary, the existing technology for preparing the tungsten doped tin dioxide nano powder generally has the problems of complex process flow, non-ideal doping uniformity, high-temperature post-treatment required to cause grain aggregation, high equipment cost and the like, so the invention provides the tungsten doped tin oxide nano powder and the preparation method thereof, so as to solve the problems. Disclosure of Invention The invention aims to solve the problems of complex process flow, non-ideal doping uniformity, grain aggregation caused by high-temperature post-treatment or high equipment cost in the traditional preparation technology of tungsten doped tin dioxide nano powder. In order to achieve the abo