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CN-121972152-A - Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material and preparation method and application thereof

CN121972152ACN 121972152 ACN121972152 ACN 121972152ACN-121972152-A

Abstract

The invention relates to the technical field of composite material preparation, in particular to a Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material, and a preparation method and application thereof. ZIF-8 in the ternary composite film gas-sensitive material provides a high specific surface area and a regular microporous skeleton for preliminary adsorption and enrichment of VOCs molecules, pd nano particles are uniformly distributed inside and outside a ZIF-8 pore canal, high catalytic active sites are provided for accelerating activation and reaction of toluene molecules, CQDs construct a rapid electron transport network for remarkably improving interface conductivity, feHCF is used as Prussian blue analogues for enhancing mechanical stability and moisture resistance of the film and providing a multiphase interface. The Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material adopts an adsorption-catalysis-conduction three-in-one multiphase composite strategy, breaks through the bottleneck of the traditional sensor gas-sensitive material between specific surface area, conductivity and stability, provides a brand new implementation path for quick detection of VOCs represented by toluene at ppb level, and has good expansibility and industrialization potential.

Inventors

  • DING BAISUO
  • WANG QIANYOU
  • LIU HUALI
  • BAI LEI

Assignees

  • 理工清科(重庆)先进材料研究院有限公司

Dates

Publication Date
20260505
Application Date
20260114

Claims (10)

  1. The preparation method of the Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material is characterized by comprising the following steps of: Preparing Pd@ZIF-8, mixing Pd NPs ethanol dispersion liquid with 2-methylimidazole, then adding the mixture into methanol, carrying out ultrasonic dissolution for 8-13 min to obtain a solution A, adding zinc nitrate hexahydrate into the methanol to dissolve the solution A to obtain a solution B, pouring the solution B into the solution A under stirring, reacting at 25-80 ℃ for 6-12 h, centrifuging the obtained first reaction solution, collecting precipitate, washing the precipitate to obtain a Pd@ZIF-8 core-shell structure, dispersing the Pd@ZIF-8 core-shell structure into the methanol, and obtaining Pd@ZIF-8 methanol dispersion liquid; Preparing FeHCF/N-CQDs composite carrier, dispersing FeHCF precipitate in absolute ethyl alcohol, adding N-CQDs ethanol solution, stirring at room temperature for reacting for 2.0-3.0 h, centrifugally washing the obtained second reaction solution, dispersing the obtained precipitate in absolute ethyl alcohol again, and carrying out vortex and ultrasonic treatment to obtain FeHCF/N-CQDs ethanol dispersion; the method comprises the steps of constructing a film, dropwise adding Pd@ZIF-8 methanol dispersion liquid into FeHCF/N-CQDs ethanol dispersion liquid, carrying out ultrasonic treatment for 10-20 min, centrifuging and purifying the obtained mixed liquid, dispersing the obtained precipitate in absolute methanol to obtain ternary dispersion liquid, washing and drying an interdigital electrode, taking ternary dispersion liquid to drop at the center of the interdigital electrode, carrying out spin coating according to the following procedures, firstly, carrying out spin coating at a low speed of 700-900 rpm for 5-10 s, spreading the ternary dispersion liquid to cover the whole interdigital electrode, secondly, carrying out spin coating at a medium speed of 1500-2500 rpm for 20-40 s, carrying out preliminary film forming, thirdly, carrying out spin coating at a high speed of 2500-3500 rpm for 10-20 s, and carrying out vacuum drying at 60-80 ℃ for 2-5 h on the obtained coated electrode to obtain the Pd@ZIF-8/CQDs/FeHCF ternary composite film.
  2. 2. The method for preparing the Pd@ZIF-8/CQDs/FeHCF ternary composite film gas sensitive material according to claim 1, wherein the method for preparing the Pd NPs ethanol dispersion liquid is as follows: Adding sodium citrate into ultrapure water, stirring and dissolving to obtain sodium citrate solution, adding sodium chloropalladate into the ultrapure water, and uniformly mixing to obtain sodium chloropalladate solution; Heating the sodium citrate solution to 60-80 ℃ in a water bath, connecting a reflux condenser pipe, introducing cooling water, dropwise adding the sodium chloropalladate solution at the rate of 0.2-0.8 mL/min under stirring, continuing stirring after the dropwise adding, and after carrying out reflux reaction for 0.5-2 h at 60-80 ℃, keeping the stirring and reflux state, and naturally cooling to room temperature to obtain a third reaction solution; Centrifuging the third reaction solution at 6000-12000 rpm for 10-20 min, discarding the supernatant, dispersing the precipitate with absolute ethyl alcohol, centrifuging at 6000-12000 rpm for 10-20 min again, repeating for 3 times, and adding the final precipitate into absolute ethyl alcohol for ultrasonic dispersion to obtain Pd NPs ethanol dispersion.
  3. 3. The method for preparing the Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material according to claim 2, wherein the molar ratio of sodium citrate to sodium chloropalladate is (0.34-1.00) (0.025-0.05).
  4. 4. The method for preparing a Pd@ZIF-8/CQDs/FeHCF ternary composite film gas sensitive material according to claim 3, wherein the molar ratio of palladium to 2-methylimidazole in the Pd NPs ethanol dispersion liquid is 1:10.
  5. 5. The method for preparing the Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material according to claim 4, wherein the molar ratio of the 2-methylimidazole to the zinc nitrate hexahydrate is (7-8): 1.
  6. 6. The preparation method of the Pd@ZIF-8/CQDs/FeHCF ternary composite film gas sensitive material according to claim 1, wherein the preparation method of the N-CQDs is as follows: and (3) adding citric acid and ethylenediamine into the inner lining of the reaction kettle, adding ultrapure water, stirring until the citric acid and ethylenediamine are completely dissolved, sealing the reaction kettle, putting the reaction kettle into a blast drying oven preheated to 200-240 ℃, reacting for 2-6 hours, taking out and naturally cooling to room temperature, diluting the obtained solid product with the ultrapure water, filtering with a 0.22 mu m filter membrane, centrifuging at 8000-12000 rpm for 10-20 minutes, collecting supernatant, and finally drying at 80-120 ℃ to obtain N-CQDs.
  7. 7. The method for preparing the Pd@ZIF-8/CQDs/FeHCF ternary composite film gas sensitive material according to claim 1, wherein the preparation method of the FeHCF precipitate is as follows: Preparing FeCl 2 aqueous solution with concentration of 0.05-0.15 mol/L and K 3 [Fe(CN) 6 aqueous solution with concentration of 0.05-0.15 mol/L respectively, simultaneously injecting FeCl 2 aqueous solution and K 3 [Fe(CN) 6 aqueous solution into an ice bath according to a molar ratio of 3:2 of FeCl 2 to K 3 [Fe(CN) 6 , stirring and reacting for 0.5-2 h, centrifuging the obtained reaction solution, and collecting FeHCF precipitate.
  8. 8. The method for preparing the Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material according to claim 1, wherein the step of constructing the film is characterized in that centrifugal purification is carried out by centrifuging the mixed solution at 8000-12000 rpm for 5-15 min, dispersing the precipitate by using anhydrous methanol in a vortex manner, centrifuging at 8000-12000 rpm for 5-15 min, and repeating methanol washing for 5 times.
  9. 9. The Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material is characterized in that the ternary composite film gas-sensitive material is prepared by adopting the preparation method of any one of embodiments 1-8.
  10. 10. The use of the pd@zif-8/CQDs/FeHCF ternary composite film gas-sensitive material according to claim 9 in the preparation of toluene concentration detection material.

Description

Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material and preparation method and application thereof Technical Field The invention relates to the technical field of composite material preparation, in particular to a Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material, and a preparation method and application thereof. Background With the rapid development of ultra large scale integrated circuits (ULSI), high-end displays, new energy sources, medical electronics and other industries, clean rooms and critical process environments have increasingly stringent requirements for the on-line detection and control of trace Volatile Organic Compounds (VOCs). VOCs represented by toluene are easy to adsorb or condense on optical and semiconductor surfaces in the processes of extreme ultraviolet lithography, chemical vapor deposition, lithography development, cleaning and the like due to the high volatility and nonpolar molecular characteristics, and the specular reflectivity is attenuated, the optical distortion, the electrical performance drift and the breakdown voltage are reduced. Along with the gradual advance of the process nodes to 3nm or even below 2nm, industry provides ppb level harsh requirements for the detection sensitivity and response speed of VOCs represented by toluene, and meanwhile, the sensor is required to be kept stable under the long-time operation condition of a complex environment. However, the traditional detection means depend on large-scale instruments such as chromatography, mass spectrum and ion mobility spectrometry or single-function chemical sensors, and have the problems of high cost, slow response, huge equipment, difficulty in online continuous monitoring and the like. Therefore, the online detection of VOCs at home and abroad focuses on the development of novel gas-sensitive materials such as Metal Oxide Semiconductors (MOS), carbon-based materials, metal Organic Frameworks (MOFs), and the like, and as patent CN113512062A discloses a CuIP 2 S-type complex VOC fluorescence sensing material. MOS materials such as SnO 2、In2O3、ZnO、WO3 and the like are simple to prepare and low in cost, but have weak response signals at trace concentrations (as shown in document "An, DongminWang, QiongTong, XiaoqiangLian, XiaoxueZou, YunlingLi, Yan.ZnO-enhanced In2O3-based sensors for n-butanol gas[J].CERAMICS INTERNATIONAL, 2019, 45(6)."). Carbon-based materials such as graphene, carbon nanotubes, carbon Quantum Dots (CQDs) have high electron mobility, which can accelerate electron conduction, but lack sufficient adsorption sites and catalytic activity, resulting in limited response to nonpolar VOCs. MOFs material has adjustable aperture and high specific surface area, can realize pre-concentration of target molecules, but has poor conductivity, limited mechanical strength, easy structural collapse under damp and hot conditions and insufficient sensing stability. Therefore, the development of a gas-sensitive material with high sensitivity, rapid response, good selectivity and environmental stability is a key technical direction for the breakthrough of the current urgent need. Disclosure of Invention In view of the above, the invention aims to provide Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material, a preparation method and application thereof, and solves the problems of low sensitivity, slow response and insufficient sensing stability in the prior art by adopting an adsorption-catalysis-conduction three-in-one multiphase composite strategy. The invention solves the technical problems by the following technical means: in a first aspect, the invention provides a preparation method of Pd@ZIF-8/CQDs/FeHCF ternary composite film gas-sensitive material, which comprises the following steps: Preparing Pd@ZIF-8, mixing Pd NPs ethanol dispersion liquid with 2-methylimidazole, then adding the mixture into methanol, carrying out ultrasonic dissolution for 8-13 min to obtain a solution A, adding zinc nitrate hexahydrate into the methanol to dissolve the solution A to obtain a solution B, pouring the solution B into the solution A under stirring, reacting at 25-80 ℃ for 6-12 h, centrifuging the obtained first reaction solution, collecting precipitate, washing the precipitate to obtain a Pd@ZIF-8 core-shell structure, dispersing the Pd@ZIF-8 core-shell structure into the methanol, and obtaining Pd@ZIF-8 methanol dispersion liquid; Preparing FeHCF/N-CQDs composite carrier, dispersing FeHCF precipitate in absolute ethyl alcohol, adding N-CQDs ethanol solution, stirring at room temperature for reacting for 2.0-3.0 h, centrifugally washing the obtained second reaction solution, dispersing the obtained precipitate in absolute ethyl alcohol again, and carrying out vortex and ultrasonic treatment to obtain FeHCF/N-CQDs ethanol dispersion; The method comprises the steps of constructing a film, dropwise adding Pd@ZIF-8 methanol dispersion liquid into FeHCF/N-CQDs ethanol dispersion liq