Two-dimensional carbon-based conductive polymer nanosheet array composite, preparation method and application

Abstract

The application belongs to the field of nanomaterials, and particularly relates to a two-dimensional carbon-based conductive polymer nanosheet array composite material, a preparation method and application. The preparation method of the two-dimensional carbon-based conductive polymer nanosheet array composite material comprises the following steps: dispersing a two-dimensional carbon-based material into an aqueous hydrochloric acid solution; adding potassium permanganate to perform a hydrothermal reaction; centrifuging and drying; dispersing into an aqueous hydrochloric acid solution, adding a conductive polymer monomer, and performing an oxidative polymerization reaction; centrifuging and drying. The application utilizes MnO2 to construct a two-dimensional array structure on the surface of a carbon-based material in situ, and guides the ordered growth of a conductive polymer, while realizing oxidative polymerization and doping, so as to obtain high structural controllability and conductivity. The prepared composite material has excellent specific surface area and electron transport performance, significantly improves the gas response value and stability, and has a simple process and is suitable for large-scale application.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of nanomaterials, and particularly relates to a two-dimensional carbon-based conductive polymer nanosheet array composite material, a preparation method and applications. BACKGROUND

[0002] Two-dimensional carbon-based materials, such as graphene, graphene oxide and MXene, have wide application prospects in heterogeneous catalysis, energy storage, sensing and antibacterial applications due to their excellent specific surface area, high electron mobility and good surface modifiability. In the field of gas sensing, such materials provide abundant gas adsorption sites and fast electron transport paths, which help to achieve high sensitivity and low detection limit response.

[0003] Conductive polymers are a class of functional polymer materials with π-conjugated structure, and representative examples include polypyrrole, polyaniline and polyindole. The chemical properties of conductive polymers can be dynamically regulated through the doping / dedoping process, and they have good responsiveness and processing adaptability. By combining conductive polymers with two-dimensional carbon-based materials, the heterojunction interface can be constructed to improve the carrier migration efficiency, and molecular recognition and functional group selectivity can be introduced to improve the sensitivity and selectivity of gas response.

[0004] However, in the prior art, conductive polymers are usually combined with carbon-based materials by physical mixing, simple deposition or disordered polymerization, and the resulting composite materials lack regular nanostructures. The conductive polymers often cover the surface of the carbon-based material in bulk or amorphous form, which leads to shielding of active sites and difficulty in effectively utilizing the interface synergistic effect. In addition, due to the lack of structure guiding and reaction control means, the controllable assembly and batch stability of the materials are poor, making it difficult to meet the application requirements of high performance and high consistency in sensing.

[0005] Therefore, there is an urgent need to develop a method for constructing a two-dimensional carbon-based conductive polymer nanosheet array composite material with controllable structure, ordered interface and excellent response performance, in order to break through the bottleneck of existing preparation methods in performance improvement. SUMMARY

[0006] In view of the poor controllability of conductive polymer structure and insufficient sensitivity of the composite material in the prior art, the technical problem to be solved by the present application is to provide a two-dimensional carbon-based conductive polymer nanosheet array composite material with ordered structure and adjustable performance, and a preparation method thereof. The method generates a cross-shaped manganese dioxide nanosheet array on the surface of the carbon-based material in situ by using potassium permanganate, and uses manganese dioxide as a structure directing agent and an oxidation initiator in the oxidation polymerization process to guide the in-situ polymerization and growth of conductive polymer monomers on its surface. By adjusting the types of monomers used, two-dimensional array composite materials with different electronic structures and response characteristics can be flexibly prepared, which significantly improves the performance of the materials in gas sensing applications.

[0007] In order to achieve the above object, the present application adopts the following technical solutions:

[0008] A preparation method of a two-dimensional carbon-based conductive polymer nanosheet array composite material, comprising the following steps:

[0009] Dispersing a two-dimensional carbon-based material into an aqueous hydrochloric acid solution;

[0010] Adding potassium permanganate to perform a hydrothermal reaction;

[0011] Centrifuging and drying;

[0012] Dispersing into an aqueous hydrochloric acid solution, adding a conductive polymer monomer, and performing an oxidative polymerization reaction;

[0013] Centrifuging and drying.

[0014] Preferably, a preparation method of a two-dimensional carbon-based conductive polymer nanosheet array composite material, comprising the following steps:

[0015] Dispersing a two-dimensional carbon-based material into an aqueous hydrochloric acid solution with a concentration of 0.1-0.5 wt.%, to form a uniform suspension;

[0016] Adding potassium permanganate to the suspension, and allowing the potassium permanganate to react with the two-dimensional carbon-based material at 120-160°C for 4-8 hours to generate a carbon-based composite material with a cross two-dimensional manganese dioxide nanosheet structure loaded on the surface;

[0017] Centrifuging, washing, and drying to obtain a two-dimensional manganese dioxide carbon-based composite material;

[0018] Dispersing the two-dimensional manganese dioxide carbon-based composite material into an aqueous hydrochloric acid solution with a concentration of 0.3-1.8 wt.%, adding a conductive polymer monomer, and allowing the manganese dioxide to induce the monomer to perform an oxidative polymerization reaction at 25-60°C for 2-8 hours;

[0019] Centrifuging, washing, and drying to obtain the two-dimensional carbon-based conductive polymer nanosheet array composite material.

[0020] Preferably, a preparation method of a two-dimensional carbon-based conductive polymer nanosheet array composite material, comprising the following steps:

[0021] Step A: dispersing a two-dimensional carbon-based material into an aqueous hydrochloric acid solution and mixing uniformly, stirring at room temperature for 10-30 min, to prepare a suspension containing the two-dimensional carbon-based material;

[0022] Step B: adding potassium permanganate to the suspension containing the two-dimensional carbon-based material, stirring at room temperature for 10-30 min, to prepare a mixed solution, and placing the mixed solution in a reactor at 120-160°C for 4-8 h to obtain a product X;

[0023] Step C: centrifuging the product X and washing with deionized water, and then vacuum drying at 35-55°C to obtain the two-dimensional manganese dioxide carbon-based composite material;

[0024] Step D: dispersing the two-dimensional manganese dioxide carbon-based composite material into an aqueous hydrochloric acid solution to obtain a dispersion containing the two-dimensional manganese dioxide carbon-based composite material;

[0025] Step E: adding a conductive polymer monomer into the dispersion containing the two-dimensional manganese dioxide carbon-based composite material and reacting at 25-60°C for 2-8h to obtain product Y;

[0026] Step F: centrifuging the product Y and washing with deionized water, and then vacuum drying at 35-55°C to obtain the two-dimensional carbon-based conductive polymer nanosheet array composite material.

[0027] Further preferably, in the step A, the two-dimensional carbon-based material is one or more of graphene oxide, reduced graphene oxide, Ti3C2T x MXene, Ti2CT x MXene, Ti3CN MXene, Nb4C3T x MXene, Nb2CT x MXene; the concentration of the aqueous hydrochloric acid solution is 0.15-0.37 wt.%; and the mass ratio of the two-dimensional carbon-based material to the aqueous hydrochloric acid solution is 1: (1-5).

[0028] Further preferably, in the step B, the mass ratio of the potassium permanganate to the two-dimensional carbon-based material is (0.05-0.1):1.

[0029] Further preferably, in the step D, the concentration of the aqueous hydrochloric acid solution is 0.3-1.8 wt.%; and the mass ratio of the two-dimensional manganese dioxide carbon-based composite material to the aqueous hydrochloric acid solution is 1: (100-250).

[0030] Further preferably, in the step E, the mass ratio of the conductive polymer monomer to the dispersion containing the two-dimensional manganese dioxide carbon-based composite material is 1: (200-600); and the conductive polymer monomer is one or more of pyrrole, aniline, indole and p-phenylenediamine. More preferably, the conductive polymer monomer is a mixture of pyrrole and indole. More preferably, the mass ratio of pyrrole to indole is 1: (0.2-5); and most preferably, the mass ratio of pyrrole to indole is 1: (0.5-2).

[0031] Further preferably, step E can also be: adding a conductive polymer monomer and phenyl guanidine (CAS No.: 2002-16-6) into the dispersion liquid containing the two-dimensional manganese dioxide carbon-based composite material, and reacting at 25-60 DEG C for 2-8 h to obtain product Y. The mass ratio of the conductive polymer monomer and phenyl guanidine is 1: (0.05-0.15). The phenyl guanidine stabilizes free radicals, promotes polymerization, the benzene ring enhances the template π-π interaction, and cooperatively improves the array order and response performance.

[0032] The application further discloses a two-dimensional carbon-based conductive polymer nanosheet array composite material prepared by the method.

[0033] The application further discloses application of the two-dimensional carbon-based conductive polymer nanosheet array composite material in an organic gas sensor.

[0034] The application constructs two-dimensional cross array MnO2 nanosheets on the surface of the two-dimensional carbon-based material in situ through a hydrothermal reaction, and the MnO2 acts as an oxidation initiator and a structure directing template for the conductive polymer monomer in subsequent oxidative polymerization, so that the conductive polymer grows in an array on the surface in situ. The structure can accurately copy the two-dimensional sheet morphology of the MnO2, and significantly improves the structure controllability and purity of the composite material.

[0035] The polymerization process is synchronized with doping under an acidic condition, and the intrinsic conductivity of the conductive polymer is improved. The prepared composite material has high specific surface area, excellent interface electron transmission capacity and molecular recognition capacity, and exhibits significantly improved response performance and long-term stability in a gas sensing test. The composite material has comprehensive advantages such as simple process, easily available raw materials and suitability for scale-up, and is suitable for the field of high-performance sensors and other nanofunctional devices. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0037] Figure 1 The scanning electron microscope image of the polypyrrole nanosheet array / Ti3C2T MXene composite material provided in Embodiment 1 of the application is shown in Figure 1. x The scanning electron microscope image of the polypyrrole nanosheet array / Ti3C2T MXene composite material provided in Embodiment 1 of the application is shown in Figure 1.

[0038] Figure 2 The scanning electron microscope image of the polypyrrole nanosheet array / Ti3C2T MXene composite material provided in Embodiment 1 of the application is shown in Figure 1. x The scanning electron microscope image of the polypyrrole nanosheet array / Ti3C2T MXene composite material provided in Embodiment 1 of the application is shown in Figure 1.

[0039] Figure 3 A scanning electron microscope image of the polypyrrole nanosheet array / graphene oxide composite material provided in Embodiment 3 of the present application;

[0040] Figure 4 A scanning electron microscope image of the polypyrrole nanosheet array / graphene oxide composite material provided in Embodiment 3 of the present application;

[0041] Figure 5 A scanning electron microscope image of the polypyrrole nanosheet array / graphene oxide composite material provided in Embodiment 3 of the present application;

[0042] Figure 6 A scanning electron microscope image of the polypyrrole nanosheet array / graphene oxide composite material provided in Embodiment 3 of the present application;

[0043] Figure 7 A concentration response curve of the polypyrrole nanosheet array / graphene oxide composite material provided in Embodiment 3 of the present application to dibutyl phthalate;

[0044] Figure 8 A concentration response curve of the polypyrrole nanosheet array / graphene oxide composite material provided in Embodiment 3 of the present application to dibutyl phthalate. DETAILED DESCRIPTION

[0045] The technical problems, technical solutions and advantages of the present application will be described in detail below with reference to exemplary embodiments. The exemplary embodiments described below are only used to explain the present application and cannot be explained as a limitation of the present application. Those skilled in the art can understand that unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as that generally understood by those skilled in the art in the field to which the present application belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have meanings consistent with those in the context of the prior art, and unless defined herein, should not be interpreted to have an idealized or overly formal meaning.

[0046] A method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material, comprising the following steps:

[0047] Step A: dispersing a two-dimensional carbon-based material into an aqueous hydrochloric acid solution and mixing uniformly, stirring at room temperature for 10-30 min, to obtain a suspension containing the two-dimensional carbon-based material; the two-dimensional carbon-based material is graphene oxide, reduced graphene oxide, Ti3C2T x MXene, Ti2CT x MXene, Ti3CN MXene, Nb4C3T x MXene, Nb2CT xone or more of MXenes; the concentration of the aqueous hydrochloric acid solution is 0.15-0.37wt.%; the mass ratio of the two-dimensional carbon-based material to the aqueous hydrochloric acid solution is 1:(1-5); the main role of this step is to obtain a stable reaction solution, so as to provide a uniform next product in the subsequent chemical reaction.

[0048] Step B: potassium permanganate is added to the suspension containing the two-dimensional carbon-based material, stirred at room temperature for 10-30 min, a mixed solution is prepared, and placed in a 120-160°C reaction for 4-8 h to obtain the product; the mass ratio of the potassium permanganate to the two-dimensional carbon-based material is (0.05-0.1):1; the purpose of this step is to generate a two-dimensional manganese dioxide carbon-based composite material by reaction, and the adjustment of the reaction temperature and time can directly affect the growth of the two-dimensional manganese dioxide nanosheet array.

[0049] Step C: the product is centrifuged and washed with deionized water, and then vacuum dried at 35-55°C to obtain a two-dimensional manganese dioxide carbon-based composite material; in this step, the product generated after the reaction in step B is subjected to solid-liquid separation by centrifugation to remove the reaction residue. Subsequently, the separated product is washed with deionized water to remove the surface residual impurities. Then, the washed product is dried in a vacuum environment to finally obtain a pure two-dimensional manganese dioxide carbon-based composite material.

[0050] Step D: the two-dimensional manganese dioxide carbon-based composite material is dispersed in 0.3-1.8wt.% aqueous hydrochloric acid solution to obtain a dispersion liquid containing the two-dimensional manganese dioxide carbon-based composite material; the mass ratio of the two-dimensional manganese dioxide carbon-based composite material to the aqueous hydrochloric acid solution is 1:(100-250); the main role of this step is to ensure that the two-dimensional manganese dioxide carbon-based composite material is uniformly dispersed in the acidic solvent, thereby providing a stable reaction environment for the subsequent polymerization reaction.

[0051] Step E: a conductive polymer monomer is added to the dispersion liquid containing the two-dimensional manganese dioxide carbon-based composite material to prepare a reaction solution, and the reaction solution is subjected to reaction at 25-60°C for 2-8h to obtain a two-dimensional carbon-based conductive polymer nanosheet array composite material; the mass ratio of the conductive polymer monomer to the dispersion liquid containing the two-dimensional manganese dioxide carbon-based composite material is 1:(200-600); the conductive polymer monomer is one or more of pyrrole, aniline, indole and p-phenylenediamine. Under the guidance of the two-dimensional MnO2 cross array template adopted in the present application, the electronic structure and polymerization behavior of the conductive polymer monomer will directly affect its replication ability to the template structure, and then determine the array regularity and gas sensitive response performance of the composite material. It is found that the pyrrole and indole copolymerization system exhibits good electronic synergistic properties in the template structure: the pyrrole molecule has high charge density and strong polymerization activity, which can provide an efficient conductive skeleton; the indole molecule has large conjugated area and strong π-π stacking ability, which helps to enhance the adsorption on the template surface and the two-dimensional direction expansion. The copolymerization of the two can realize the synergistic matching of the free radical initiation efficiency and the molecular stacking ability, and more easily replicate the nanosheet array structure under the guidance of MnO2, to construct a conductive network with high specific surface area and high regularity, thereby significantly improving the gas response performance. In comparison, the aniline molecule is difficult to effectively participate in the free radical induced polymerization reaction due to the stable resonance structure and high oxidation polymerization potential, and its rigid molecular structure and limited π stacking ability cannot be cooperatively assembled with pyrrole or indole to form a regular structure. Under the guidance of the MnO2 template, the aniline related copolymerization system often appears monomer dispersion polymerization, interface fracture or array replication failure, forming a dense or disordered structure, resulting in a decrease in response performance instead of an increase.

[0052] Step F: the product is centrifuged and washed with deionized water, and then vacuum dried at 35-55°C to obtain a two-dimensional carbon-based conductive polymer nanosheet array composite material. In this step, the product generated after the reaction in step E is subjected to solid-liquid separation by centrifugation to remove the reaction residue liquid. Subsequently, the separated product is washed with deionized water to remove the surface residual impurities. Then, the washed product is dried in a vacuum environment to obtain a pure two-dimensional carbon-based conductive polymer nanosheet array composite material. The obtained two-dimensional carbon-based conductive polymer nanosheet array composite material has a two-dimensional structure, and the polymer nanosheets grow on the surface of the two-dimensional carbon-based material to form an array containing a porous structure, which significantly improves the specific surface area and practicability of the material, exposes more active sites, facilitates the adsorption and desorption of guest molecules, and exhibits better performance in application.

[0053] The present application provides a new method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material, which utilizes a two-dimensional carbon-based material as a substrate to induce the growth of manganese dioxide on the surface thereof during a hydrothermal reaction to form two-dimensional cross nanosheets, and then uses the obtained two-dimensional manganese dioxide carbon-based composite material as an oxidizing agent to initiate monomer polymerization to obtain a two-dimensional carbon-based conductive polymer nanosheet array composite material. Specifically, first, the two-dimensional carbon-based material is dispersed in an aqueous hydrochloric acid solution to form a stable solution environment. Then, potassium permanganate is added to the solution to ensure that it is fully dissolved to form a uniform reaction solution. During the reaction stage, the potassium permanganate is adsorbed on the surface of the two-dimensional carbon-based material and gradually decomposes to generate manganese dioxide crystals. By controlling the reaction temperature and time, the generated manganese dioxide crystals aggregate and crystallize in a specific direction due to surface energy, and finally form manganese dioxide cross nanosheets on the surface of the two-dimensional carbon-based material. Then, the reaction residues are removed by centrifugal separation and deionized water washing, and vacuum drying is performed to obtain a two-dimensional manganese dioxide carbon-based composite material. After the two-dimensional manganese dioxide carbon-based composite material is dispersed in an aqueous hydrochloric acid solution to form a stable solution environment, a conductive polymer monomer is added and fully dissolved to form a uniform reaction solution. During the subsequent polymerization reaction stage, due to the strong oxidizing property of manganese dioxide, it can act as an oxidizing agent for the polymerization of the conductive polymer monomer, and the monomer molecules are adsorbed on the manganese dioxide interface and oxidized and polymerized, while the manganese dioxide is reduced to generate water-soluble manganese ions and is continuously etched and removed. Therefore, the conductive polymer generated on the surface of the two-dimensional carbon-based material can completely reproduce the two-dimensional nanosheet structure of the manganese dioxide, thereby generating a two-dimensional carbon-based conductive polymer nanosheet array composite material. The preparation method of the present application is simple and efficient, and the two-dimensional carbon-based conductive polymer nanosheet array composite material obtained has excellent two-dimensional structure and nanocomposite properties.

[0054] Graphene oxide, catalog number: G139803, purchased from Aladdin;

[0055] Ti3C2T x MXene, catalog number: T463267, purchased from Aladdin;

[0056] Example 1:

[0057] A polypyrrole nanosheet array / Ti3C2T x The preparation method of the MXene composite material comprises the following steps:

[0058] Step A: 20 mg of Ti3C2T x Mxene was added to 60 mL of 0.25wt.% aqueous hydrochloric acid solution and stirred at room temperature for 20 min to obtain a suspension containing Ti3C2T x Mxene.

[0059] Step B: 400 mg of potassium permanganate was added to the above suspension containing Ti3C2T x The mixed solution was prepared by stirring for 10 min and then transferred to a hydrothermal kettle and reacted at 150°C for 4 h to obtain the product.

[0060] Step C: The product was centrifuged and washed with deionized water, and then vacuum dried at 40°C to obtain a two-dimensional manganese dioxide / Ti3C2T x MXene composite material.

[0061] Step D: 100 mg of the two-dimensional manganese dioxide / Ti3C2T x MXene composite material obtained in step C was added to 20 mL of 0.4 wt.% hydrochloric acid aqueous solution to prepare a dispersion liquid containing the two-dimensional manganese dioxide / Ti3C2T x MXene composite material.

[0062] Step E: 50 mg of pyrrole monomer was added to the above dispersion liquid containing the two-dimensional manganese dioxide / Ti3C2T x MXene composite material to prepare a reaction solution; and the above reaction solution was stirred at 25°C for 2 h to perform an oxidative polymerization reaction.

[0063] Step F: The product obtained by the reaction in step E was centrifuged and washed with deionized water, and then vacuum dried at 35°C to obtain a polypyrrole nanosheet array / Ti3C2T x MXene composite material.

[0064] Referring to Figure 1 , the polypyrrole nanosheet array / Ti3C2T x MXene composite material has a two-dimensional structure, and the polypyrrole nanosheet is arranged on the surface of the Ti3C2T x MXene to form an array and a channel.

[0065] Example 2:

[0066] A polyaniline nanosheet array / Ti3C2T x MXene composite material, comprising the following steps:

[0067] Step A: 20 mg of Ti3C2T x MXene was added to 60 mL of 0.25 wt.% hydrochloric acid aqueous solution, stirred at room temperature for 20 min to prepare a suspension containing Ti3C2T x MXene.

[0068] Step B: 400 mg of potassium permanganate was added to the above suspension containing Ti3C2T xThe mixture solution was prepared by stirring the suspension of Mxene for 10 min and was transferred to a hydrothermal kettle, which was placed at 150°C for 4 h to obtain the product.

[0069] Step C: The product was centrifuged and washed with deionized water, and then vacuum dried at 40°C to obtain two-dimensional manganese dioxide / Ti3C2T x Mxene composite material.

[0070] Step D: The two-dimensional manganese dioxide / Ti3C2T x Mxene composite material 100 mg was added to 20 mL of 0.4 wt.% hydrochloric acid aqueous solution to prepare a suspension containing two-dimensional manganese dioxide / Ti3C2T x Dispersion of Mxene composite material.

[0071] Step E: 50 mg of aniline monomer was added to the above suspension containing two-dimensional manganese dioxide / Ti3C2T x Mxene composite material to prepare a reaction solution; and the above reaction solution was stirred at 25°C for 2 h to perform an oxidative polymerization reaction.

[0072] Step F: The product obtained by the reaction in Step E was centrifuged and washed with deionized water, and then vacuum dried at 35°C to obtain a polypyrrole nanosheet array / Ti3C2T x MXene composite material.

[0073] Referring to Figure 2 , the obtained polypyrrole nanosheet array / Ti3C2T x MXene composite material has a two-dimensional structure, and polypyrrole nanosheets are arranged on Ti3C2T x The Mxene surfaces cross to form an array and a channel.

[0074] Example 3:

[0075] A method for preparing a polypyrrole nanosheet array / graphene oxide composite material, comprising the following steps:

[0076] Step A: 20 mg of graphene oxide was added to 60 mL of 0.25 wt.% hydrochloric acid aqueous solution, and stirred at room temperature for 20 min to prepare a suspension containing graphene oxide.

[0077] Step B: 400 mg of potassium permanganate was added to the above suspension containing graphene oxide material, and a mixture solution was prepared by stirring for 10 min, which was transferred to a hydrothermal kettle, which was placed at 150°C for 4 h to obtain the product.

[0078] Step C: The product was centrifuged and washed with deionized water, and then vacuum dried at 40°C to obtain the two-dimensional manganese dioxide / graphene oxide composite material.

[0079] Step D: 100 mg of the two-dimensional manganese dioxide / graphene oxide composite material obtained in Step C was added to 20 mL of 0.4 wt.% aqueous hydrochloric acid solution to prepare a dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material.

[0080] Step E: 50 mg of pyrrole monomer was added to the above dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material to prepare a reaction solution; and the above reaction solution was stirred at 25°C for 2 h to perform an oxidative polymerization reaction.

[0081] Step F: The product obtained in Step E was centrifuged and washed with deionized water, and then vacuum dried at 35°C to obtain a polypyrrole nanosheet array / graphene oxide composite material.

[0082] Referring to Figure 3 The obtained polypyrrole nanosheet array / graphene oxide composite material has a two-dimensional structure, and polypyrrole nanosheets cross on the surface of graphene oxide to form an array and a channel.

[0083] Example 4:

[0084] A method for preparing a polypyrrole-indole copolymer nanosheet array / graphene oxide composite material, comprising the following steps:

[0085] Step A: 20 mg of graphene oxide was added to 60 mL of 0.25 wt.% aqueous hydrochloric acid solution, and stirred at room temperature for 20 min to prepare a suspension liquid containing graphene oxide.

[0086] Step B: 400 mg of potassium permanganate was added to the above suspension liquid containing graphene oxide material, and stirred for 10 min to prepare a mixed solution, which was transferred to an autoclave and reacted at 150°C for 4 h to obtain a product.

[0087] Step C: The product was centrifuged and washed with deionized water, and then vacuum dried at 40°C to obtain a two-dimensional manganese dioxide / graphene oxide composite material.

[0088] Step D: 100 mg of the two-dimensional manganese dioxide / graphene oxide composite material obtained in Step C was added to 20 mL of 0.4 wt.% aqueous hydrochloric acid solution to prepare a dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material.

[0089] Step E: 25 mg of pyrrole and 25 mg of indole monomer were added into the dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material to prepare a reaction solution; and the reaction solution was stirred at 25 °C for 2 h to perform an oxidative polymerization reaction.

[0090] Step F: The product obtained in Step E was centrifuged, washed with deionized water, and then vacuum dried at 35 °C to obtain a pyrrole-indole copolymer nanosheet array / graphene oxide composite material.

[0091] Referring to Figure 4 The pyrrole-indole copolymer nanosheet array / graphene oxide composite material obtained has a two-dimensional structure, and the pyrrole-indole copolymer nanosheets cross on the surface of the graphene oxide to form an array and a channel.

[0092] Example 5:

[0093] A method for preparing a polyindole nanosheet array / graphene oxide composite material, comprising the following steps:

[0094] Step A: 20 mg of graphene oxide was added into 60 mL of a 0.25 wt.% hydrochloric acid aqueous solution, stirred at room temperature for 20 min, and a suspension liquid containing graphene oxide was prepared.

[0095] Step B: 400 mg of potassium permanganate was added into the suspension liquid containing the graphene oxide material, stirred for 10 min to prepare a mixed solution, and then transferred into an autoclave, which was placed at 150 °C for 4 h to obtain a product.

[0096] Step C: The product was centrifuged, washed with deionized water, and then vacuum dried at 40 °C to obtain a two-dimensional manganese dioxide / graphene oxide composite material.

[0097] Step D: 100 mg of the two-dimensional manganese dioxide / graphene oxide composite material obtained in Step C was added into 20 mL of a 0.4 wt.% hydrochloric acid aqueous solution to prepare a dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material.

[0098] Step E: 50 mg of an indole monomer was added into the dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material to prepare a reaction solution; and the reaction solution was stirred at 25 °C for 2 h to perform an oxidative polymerization reaction.

[0099] Step F: The product obtained in Step E was centrifuged, washed with deionized water, and then vacuum dried at 35 °C to obtain a polyindole nanosheet array / graphene oxide composite material.

[0100] Referring to Figure 5, the obtained polyaniline nanosheet array / oxidized graphene composite material has a two-dimensional structure, and the polyaniline nanosheets cross on the surface of the oxidized graphene to form an array and a channel.

[0101] Example 6:

[0102] A preparation method of a polyaniline nanosheet array / oxidized graphene composite material, comprising the following steps:

[0103] Step A: 20 mg of oxidized graphene is added to 60 mL of 0.25 wt.% hydrochloric acid aqueous solution, stirred at room temperature for 20 min, and a suspension containing oxidized graphene is prepared.

[0104] Step B: 400 mg of potassium permanganate is added to the suspension containing the oxidized graphene material, stirred for 10 min to prepare a mixed solution, and then transferred to an autoclave, and reacted at 150°C for 4 h to obtain a product.

[0105] Step C: The product is centrifuged, washed with deionized water, and then vacuum dried at 40°C to obtain a two-dimensional manganese dioxide / oxidized graphene composite material.

[0106] Step D: 100 mg of the two-dimensional manganese dioxide / oxidized graphene composite material obtained in Step C is added to 20 mL of 0.4 wt.% hydrochloric acid aqueous solution to prepare a dispersion containing the two-dimensional manganese dioxide / oxidized graphene composite material.

[0107] Step E: 50 mg of aniline monomer is added to the dispersion containing the two-dimensional manganese dioxide / oxidized graphene composite material to prepare a reaction solution; and the reaction solution is stirred at 25°C for 2 h to perform an oxidative polymerization reaction.

[0108] Step F: The product obtained in Step E is centrifuged, washed with deionized water, and then vacuum dried at 35°C to obtain a polyaniline nanosheet array / oxidized graphene composite material.

[0109] Reference Figure 6 , the obtained polyaniline nanosheet array / oxidized graphene composite material has a two-dimensional structure, and the polyaniline nanosheets cross on the surface of the oxidized graphene to form an array and a channel.

[0110] Example 7:

[0111] A preparation method of an aniline-pyrrole copolymer nanosheet array / oxidized graphene composite material, comprising the following steps:

[0112] Step A: 20 mg of oxidized graphene is added to 60 mL of 0.25 wt.% hydrochloric acid aqueous solution, stirred at room temperature for 20 min, and a suspension containing oxidized graphene is prepared.

[0113] Step B: 400 mg of potassium permanganate was added to the above suspension containing graphene oxide material, stirred for 10 min to prepare a mixed solution, which was transferred to an autoclave and reacted at 150°C for 4 h to obtain a product;

[0114] Step C: The product was centrifuged and washed with deionized water, and then vacuum dried at 40°C to obtain a two-dimensional manganese dioxide / graphene oxide composite material.

[0115] Step D: 100 mg of the two-dimensional manganese dioxide / graphene oxide composite material obtained in Step C was added to 20 mL of 0.4 wt.% hydrochloric acid aqueous solution to prepare a dispersion containing the two-dimensional manganese dioxide / graphene oxide composite material.

[0116] Step E: 25 mg of aniline and 25 mg of pyrrole monomer were added to the above dispersion containing the two-dimensional manganese dioxide / graphene oxide composite material to prepare a reaction solution; and the above reaction solution was stirred at 25°C for 2 h to perform an oxidative polymerization reaction.

[0117] Step F: The product obtained by reaction in Step E was centrifuged and washed with deionized water, and then vacuum dried at 35°C to obtain an aniline-pyrrole copolymer nanosheet array / graphene oxide composite material.

[0118] Example 8:

[0119] A method for preparing an aniline-indole copolymer nanosheet array / graphene oxide composite material, comprising the following steps:

[0120] Step A: 20 mg of graphene oxide was added to 60 mL of 0.25 wt.% hydrochloric acid aqueous solution, stirred at room temperature for 20 min to prepare a suspension containing graphene oxide.

[0121] Step B: 400 mg of potassium permanganate was added to the above suspension containing graphene oxide material, stirred for 10 min to prepare a mixed solution, which was transferred to an autoclave and reacted at 150°C for 4 h to obtain a product;

[0122] Step C: The product was centrifuged and washed with deionized water, and then vacuum dried at 40°C to obtain a two-dimensional manganese dioxide / graphene oxide composite material.

[0123] Step D: 100 mg of the two-dimensional manganese dioxide / graphene oxide composite material obtained in Step C was added to 20 mL of 0.4 wt.% hydrochloric acid aqueous solution to prepare a dispersion containing the two-dimensional manganese dioxide / graphene oxide composite material.

[0124] Step E: 25 mg of aniline and 25 mg of indole monomer were added to the dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material to prepare a reaction solution; and the reaction solution was stirred at 25 °C for 2 h to perform an oxidative polymerization reaction.

[0125] Step F: The product obtained from the reaction of Step E was centrifuged, washed with deionized water, and then vacuum dried at 35 °C to obtain aniline-indole copolymer nanosheet array / graphene oxide composite material.

[0126] Example 9:

[0127] A method for preparing a pyrrole-indole copolymer nanosheet array / graphene oxide composite material, comprising the following steps:

[0128] Step A: 20 mg of graphene oxide was added to 60 mL of 0.25 wt.% hydrochloric acid aqueous solution, stirred at room temperature for 20 min to prepare a suspension liquid containing graphene oxide.

[0129] Step B: 400 mg of potassium permanganate was added to the hydrochloric acid aqueous solution containing the graphene oxide material, stirred for 10 min to prepare a mixed solution, and then transferred to an autoclave, which was placed at 150 °C for 4 h to obtain a product.

[0130] Step C: The product was centrifuged, washed with deionized water, and then vacuum dried at 40 °C to obtain a two-dimensional manganese dioxide / graphene oxide composite material.

[0131] Step D: 100 mg of the two-dimensional manganese dioxide / graphene oxide composite material obtained from Step C was added to 20 mL of 0.4 wt.% hydrochloric acid aqueous solution to prepare a dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material.

[0132] Step E: 25 mg of pyrrole and 25 mg of indole monomer and 5 mg of phenyl guanidine were added to the dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material to prepare a reaction solution; and the reaction solution was stirred at 25 °C for 2 h to perform an oxidative polymerization reaction.

[0133] Step F: The product obtained from the reaction of Step E was centrifuged, washed with deionized water, and then vacuum dried at 35 °C to obtain a pyrrole-indole copolymer nanosheet array / graphene oxide composite material.

[0134] Example 10:

[0135] A method for preparing a pyrrole-indole copolymer nanosheet array / graphene oxide composite material, comprising the following steps:

[0136] Step A: 20 mg of graphene oxide was added to 60 mL of 0.25 wt.% aqueous hydrochloric acid solution, stirred at room temperature for 20 min to prepare a graphene oxide-containing suspension.

[0137] Step B: 400 mg of potassium permanganate was added to the graphene oxide-containing aqueous hydrochloric acid solution described above, stirred for 10 min to prepare a mixed solution, and transferred to an autoclave, which was placed in a 150°C reaction for 4 h to obtain a product;

[0138] Step C: The product was centrifuged and washed with deionized water, and then vacuum dried at 40°C to obtain a two-dimensional manganese dioxide / graphene oxide composite material.

[0139] Step D: 100 mg of the two-dimensional manganese dioxide / graphene oxide composite material obtained in Step C was added to 20 mL of 0.4 wt.% aqueous hydrochloric acid solution to prepare a dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material.

[0140] Step E: 25 mg of pyrrole and 25 mg of indole monomer, 5 mg of phenyl guanidine, and 1 mg of phytic acid were added to the dispersion liquid containing the two-dimensional manganese dioxide / graphene oxide composite material described above to prepare a reaction solution; and the reaction solution was placed in a 25°C stirring for 2 h to perform an oxidative polymerization reaction. In particular, the phytic acid was used as a crosslinking agent, and the conductive polymer was added to the two-dimensional manganese dioxide / carbon-based composite material to form a porous structure, which not only provided a larger specific surface area, but also improved electron transport.

[0141] Step F: The product obtained by the reaction in Step E was centrifuged and washed with deionized water, and then vacuum dried at 35°C to obtain a pyrrole-indole copolymer nanosheet array / graphene oxide composite material.

[0142] Application Example 1:

[0143] This application example provides a polypyrrone nanosheet array / Ti3C2T x MXene composite material for detecting the concentration of dibutyl phthalate at 35°C.

[0144] The specific test method includes the following steps:

[0145] Step A, the polypyrrone nanosheet array / Ti3C2T x MXene composite material prepared in Example 1 was dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polypyrrone nanosheet array / Ti3C2T x MXene composite material to anhydrous ethanol was 1:10;

[0146] Step B, 1 μL of the slurry-like material was uniformly coated on the substrate (1 × 1 mm2 ) and air dry;

[0147] Step C, the poly-pyrrole nanosheet array / Ti3C2T x The test element of MXene composite material is heated to 50℃ and aged for 48h;

[0148] Step D, the poly-pyrrole nanosheet array / Ti3C2T x The test element of MXene composite material is placed in the Nanrei MA1.0 gas sensitive test system, the temperature is adjusted to 35℃, the dibutyl phthalate concentration of 300 ppb is injected, and the response value is recorded;

[0149] The response value of the material of example 1 to 300 ppb of dibutyl phthalate is 35.5%.

[0150] Application Example 2:

[0151] The application example provides a poly-pyrrole nanosheet array / Ti3C2T x The test results of MXene composite material for detecting dibutyl phthalate concentration at 35℃.

[0152] The specific test method includes the following steps:

[0153] Step A, respectively, the poly-pyrrole nanosheet array / Ti3C2T x MXene composite material is dispersed in anhydrous ethanol and grinded into a slurry, the poly-pyrrole nanosheet array / Ti3C2T x The mass ratio of MXene composite material to anhydrous ethanol is 1:10;

[0154] Step B, 1 μL of the slurry material is uniformly coated on the substrate (1×1 mm 2 ) of the MEMS test element, and air dry;

[0155] Step C, the poly-pyrrole nanosheet array / Ti3C2T x The test element of MXene composite material is heated to 50℃ and aged for 48h;

[0156] Step D, the poly-pyrrole nanosheet array / Ti3C2T x The test element of MXene composite material is placed in the Nanrei MA1.0 gas sensitive test system, the temperature is adjusted to 35℃, the dibutyl phthalate concentration of 300 ppb is injected, and the response value is recorded;

[0157] The response value of the material of example 2 to 300 ppb of dibutyl phthalate is 16.7%.

[0158] Application Example 3

[0159] The application example provides test results of the polypyrrole nanosheet array / graphene oxide composite material of the application for detecting dibutyl phthalate concentration at 35°C.

[0160] The specific test method comprises the following steps:

[0161] Step A, respectively, the polypyrrole nanosheet array / graphene oxide composite material prepared in Example 3 is dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polypyrrole nanosheet array / graphene oxide composite material to anhydrous ethanol is 1:10;

[0162] Step B, 1 μL of the slurry-like material is uniformly coated on the substrate (1×1 mm 2 ) of the MEMS test element, and is air-dried;

[0163] Step C, the test element coated with the polypyrrole nanosheet array / graphene oxide composite material is heated to 50°C and aged for 48 h;

[0164] Step D, the test element coated with the polypyrrole nanosheet array / graphene oxide composite material is placed in the Nanrui MA1.0 gas sensitive test system, the temperature is adjusted to 35°C, 300 ppb of dibutyl phthalate concentration is injected, and the response value is recorded;

[0165] As shown in Figure 7 , the response value of the material of Example 3 to 300 ppb of dibutyl phthalate is 31.3%.

[0166] Application Example 4

[0167] The application example provides test results of the polypyrrole nanosheet array / graphene oxide composite material of the application for detecting dibutyl phthalate concentration at 35°C.

[0168] The specific test method comprises the following steps:

[0169] Step A, respectively, the polypyrrole nanosheet array / graphene oxide composite material prepared in Example 3 is dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polypyrrole nanosheet array / graphene oxide composite material to anhydrous ethanol is 1:10;

[0170] Step B, 1 μL of the slurry-like material is uniformly coated on the substrate (1×1 mm 2 ) of the MEMS test element, and is air-dried;

[0171] Step C, the test element coated with the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material was heated to 50°C and aged for 48h;

[0172] Step D, the test element coated with the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material was placed in the Nanjing MA1.0 gas sensitive test system, the temperature was adjusted to 35°C, 300 ppb of dibutyl phthalate was injected, and the response value was recorded;

[0173] As shown in Figure 8 , the response value of the material of Example 4 to 300 ppb of dibutyl phthalate was 106.2%.

[0174] Application Example 5:

[0175] The application example provides test results of the polyindole nanosheet array / oxidized graphene composite material of the application for detecting the concentration of dibutyl phthalate at 35°C.

[0176] The specific test method comprises the following steps:

[0177] Step A, the polyindole nanosheet array / oxidized graphene composite material prepared in Example 5 was respectively dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polyindole nanosheet array / oxidized graphene composite material to anhydrous ethanol was 1:10;

[0178] Step B, 1 μL of the slurry-like material was uniformly coated on the substrate (1×1 mm 2 ) of the MEMS test element, and was air-dried;

[0179] Step C, the test element coated with the polyindole nanosheet array / oxidized graphene was heated to 50°C and aged for 48h;

[0180] Step D, the test element coated with the polyindole nanosheet array / oxidized graphene composite material was placed in the Nanjing MA1.0 gas sensitive test system, the temperature was adjusted to 35°C, 300 ppb of dibutyl phthalate was injected, and the response value was recorded;

[0181] The response value of the material of Example 5 to 300 ppb of dibutyl phthalate was 37.1%.

[0182] Application Example 6:

[0183] The application example provides test results of the polyaniline nanosheet array / oxidized graphene composite material of the application for detecting the concentration of dibutyl phthalate at 35°C.

[0184] The specific test method comprises the following steps:

[0185] Step A, respectively, the polyaniline nanosheet array / graphene oxide composite material prepared in Example 6 was dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polyaniline nanosheet array / graphene oxide composite material to anhydrous ethanol was 1:10;

[0186] Step B, 1 μL of the slurry-like material was uniformly coated on the substrate (1 × 1 mm 2 ) of a MEMS test element, and was air-dried;

[0187] Step C, the test element coated with the polyaniline nanosheet array / graphene oxide was heated to 50℃ and aged for 48 h;

[0188] Step D, the test element coated with the polyaniline nanosheet array / graphene oxide composite material was placed in a Nanjing MA1.0 gas sensitive test system, the temperature was adjusted to 35℃, a dibutyl phthalate concentration of 300 ppb was injected, and the response value was recorded;

[0189] The response value of the material of Example 6 to 300 ppb of dibutyl phthalate was 26.8%.

[0190] Application Example 7

[0191] The application example provides test results of the polyaniline-pyrrole copolymer nanosheet array / graphene oxide composite material of the application for detecting a dibutyl phthalate concentration at 35℃.

[0192] The specific test method comprises the following steps:

[0193] Step A, respectively, the polyaniline nanosheet array / graphene oxide composite material prepared in Example 6 was dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polyaniline nanosheet array / graphene oxide composite material to anhydrous ethanol was 1:10;

[0194] Step B, 1 μL of the slurry-like material was uniformly coated on the substrate (1 × 1 mm 2 ) of a MEMS test element, and was air-dried;

[0195] Step C, the test element coated with the polyaniline nanosheet array / graphene oxide was heated to 50℃ and aged for 48 h;

[0196] Step D, the test element coated with the polyaniline nanosheet array / graphene oxide composite material was placed in a Nanjing MA1.0 gas sensitive test system, the temperature was adjusted to 35℃, a dibutyl phthalate concentration of 300 ppb was injected, and the response value was recorded;

[0197] The response value of the material of Example 6 to 300 ppb of dibutyl phthalate was 26.8%.

[0190] Application Example 7

[0191] The application example provides test results of the polyaniline-pyrrole copolymer nanosheet array / graphene oxide composite material of the application for detecting a dibutyl phthalate concentration at 35℃.

[0192] The specific test method comprises the following steps:

[0193] Step A, respectively, the polyaniline nanosheet array / graphene oxide composite material prepared in Example 6 was dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polyaniline nanosheet array / graphene oxide composite material to anhydrous ethanol was 1:10;

[0194] Step B, 1 μL of the slurry-like material was uniformly coated on the substrate (1 × 1 mm 2 ) of a MEMS test element, and was air-dried;

[0195] Step C, the test element coated with the polyaniline nanosheet array / graphene oxide was heated to 50℃ and aged for 48 h;

[0196] Step D, the test element coated with the polyaniline nanosheet array / graphene oxide composite material was placed in a Nanjing MA1.0 gas sensitive test system, the temperature was adjusted to 35℃, a dibutyl phthalate concentration of 300 ppb was injected, and the response value was recorded;

[0197] The response value of the material of Example 6 to 300 ppb of dibutyl phthalate was 26.8%.

[0190] Application Example 7

[0191] The application example provides test results of the polyaniline-pyrrole copolymer nanosheet array / graphene oxide composite material of the application for detecting a dibutyl phthalate concentration at 35℃.

[0192] The specific test method comprises the following steps:

[0193] Step A, respectively, the polyaniline nanosheet array / graphene oxide composite material prepared in Example 6 was dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the polyaniline nanosheet array / graphene oxide composite material to anhydrous ethanol was 1:10;

[0194] Step B, 1 μL of the slurry-like material was uniformly coated on the substrate (1 × 1 mm 2 ) of a MEMS test element, and was air-dried;

[0195] Step C, the test element coated with the polyaniline nanosheet array / graphene oxide was heated to 50℃ and aged for 48 h;

[0196] Step D, the test element coated with the polyaniline nanosheet array / graphene oxide composite material was placed in a Nanjing MA1.0 gas sensitive test system, the temperature was adjusted to 35℃, a dibutyl phthalate concentration of 300 ppb was injected, and the response value was recorded;

[0197] The response value of the material of Example 6 to 300 ppb of dibutyl phthalate was 26.8%.

[0198] Application Example 8

[0199] The application example provides test results of the aniline-indole copolymer nanosheet array / graphene oxide composite material of the application for detecting dibutyl phthalate concentration at 35°C.

[0200] The specific test method comprises the following steps:

[0201] Step A, respectively, the aniline-indole copolymer nanosheet array / graphene oxide composite material prepared in Example 8 is dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the aniline-indole copolymer nanosheet array / graphene oxide composite material to anhydrous ethanol is 1:10;

[0202] Step B, 1 μL of the slurry-like material is uniformly coated on the substrate (1×1 mm 2 ) of the MEMS test element, and is air-dried;

[0203] Step C, the test element coated with the aniline-indole copolymer nanosheet array / graphene oxide is heated to 50°C and aged for 48 h;

[0204] Step D, the test element coated with the aniline-indole copolymer nanosheet array / graphene oxide composite material is placed in the Nanrei MA1.0 gas sensitive test system, the temperature is adjusted to 35°C, 300 ppb of dibutyl phthalate concentration is injected, and the response value is recorded;

[0205] The response value of the material of Example 8 to 300 ppb of dibutyl phthalate is 26.1%.

[0206] Application Example 9

[0207] The application example provides test results of the pyrrole-indole copolymer nanosheet array / graphene oxide composite material of the application for detecting dibutyl phthalate concentration at 35°C.

[0208] The specific test method comprises the following steps:

[0209] Step A, respectively, the pyrrole-indole copolymer nanosheet array / graphene oxide composite material prepared in Example 9 is dispersed in anhydrous ethanol and ground into a slurry, and the mass ratio of the pyrrole-indole copolymer nanosheet array / graphene oxide composite material to anhydrous ethanol is 1:10;

[0210] Step B, 1 μL of the slurry-like material is uniformly coated on the substrate (1×1 mm 2 ) of the MEMS test element, and is air-dried;

[0211] Step C, heat the test element coated with the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material to 50°C and age for 48 h;

[0212] Step D, place the test element coated with the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material in the Nanjing MA1.0 gas sensitive test system, adjust the temperature to 35°C, inject 300 ppb of dibutyl phthalate, and record the response value;

[0213] The response value of the material of Example 9 to 300 ppb of dibutyl phthalate is 124.6%.

[0214] Application Example 10:

[0215] The application example provides test results of the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material of the application for detecting the concentration of dibutyl phthalate at 35°C.

[0216] The specific test method comprises the following steps:

[0217] Step A, respectively disperse the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material prepared in Example 10 in anhydrous ethanol and grind into a slurry, and the mass ratio of the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material to anhydrous ethanol is 1:10;

[0218] Step B, uniformly coat 1 μL of the slurry-like material on the substrate (1×1 mm 2 ) of the MEMS test element, and air dry;

[0219] Step C, heat the test element coated with the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material to 50°C and age for 48 h;

[0220] Step D, place the test element coated with the pyrrole-indole copolymer nanosheet array / oxidized graphene composite material in the Nanjing MA1.0 gas sensitive test system, adjust the temperature to 35°C, inject 300 ppb of dibutyl phthalate, and record the response value;

[0221] The response value of the material of Example 10 to 300 ppb of dibutyl phthalate is 131.2%.

[0222] In the present application, the two-dimensional cross-MnO2 array structure constructed in situ guides the polymerization of conductive polymer monomers. The molecular structure and electronic properties of the conductive polymer significantly affect its replication ability to the template structure, and further determine the regularity of the nanometer array and the gas response performance of the composite material. Through systematic comparison, it is found that only the copolymerization of pyrrole and indole exhibits a significant synergistic enhancement effect. The reason is that: the pyrrole molecule has a high charge density and free radical polymerization activity, and can construct a high-quality conductive skeleton; while the indole molecule has a large conjugated area and excellent π-π stacking ability, which is beneficial to stable adsorption and expansion on the surface of the two-dimensional template. The copolymerization of the two can be cooperatively arranged and polymerized under the guidance of the MnO2 cross-template, forming a highly regular copolymer nanosheet array.

[0223] Experiments have proved that the response value of the composite material prepared by the pyrrole-indole copolymerization system (Example 4) to 300 ppb dibutyl phthalate is as high as 106.2%, which is much higher than that of pyrrole (31.3%) and indole (37.1%) alone, showing a typical synergistic effect. In contrast, aniline is difficult to form a regular copolymer structure under the guidance of the template due to its high oxidation polymerization potential, high rigidity and weak π stacking ability, and the response value decreases when copolymerized with pyrrole or indole (Examples 7 and 8, 28.9% and 26.1% respectively). Therefore, the pyrrole-indole combination has a unique advantage in terms of molecular electronic structure matching and template adaptability.

[0224] Example 9 adds 5 mg of phenyl guanidine in step E based on Example 4, to improve the response value. The reason is that phenyl guanidine stabilizes free radicals and promotes polymerization, and the benzene ring enhances the π-π interaction of the template, thereby synergistically improving the array order and response performance.

[0225] The above is the preferred embodiment of the present application. It should be noted that the present application is not limited to the above disclosed exemplary embodiments. The essence of the specification is only to help relevant technical personnel comprehensively understand the specific details of the present application. For ordinary technical personnel in the technical field, several improvements and refinements, easily thought changes or replacements within the technical scope disclosed by the present application without departing from the principles of the present application should be covered within the protection scope of the present application.

Claims

1. A method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material, characterized in that, Includes the following steps: Step A: Disperse the two-dimensional carbon-based material in a 0.1-0.5 wt.% hydrochloric acid aqueous solution, mix thoroughly, and stir at room temperature for 10-30 min to obtain a uniform suspension containing the two-dimensional carbon-based material; Step B: Add potassium permanganate to the suspension containing the two-dimensional carbon-based material, stir at room temperature for 10-30 min to obtain a mixed solution, and place it in a hydrothermal reaction at 120-160℃ for 4-8 h to obtain a carbon-based composite material with a surface-loaded cross-shaped two-dimensional manganese dioxide nanosheet structure. Step C: Centrifuge the carbon-based composite material with surface-loaded cross-shaped manganese dioxide nanosheets, wash with deionized water, and then vacuum dry at 35-55℃ to obtain the two-dimensional manganese dioxide carbon-based composite material; Step D: Disperse the two-dimensional manganese dioxide carbon-based composite material in a 0.3-1.8 wt.% hydrochloric acid aqueous solution to obtain a dispersion containing the two-dimensional manganese dioxide carbon-based composite material; Step E: Add the conductive polymer monomer to the dispersion containing the two-dimensional manganese dioxide carbon-based composite material, and react at 25-60℃ for 2-8 hours to induce the monomer to undergo an oxidative polymerization reaction, thereby obtaining product Y. Step F: Centrifuge the product Y, wash it with deionized water, and then vacuum dry it at 35-55℃ to obtain the two-dimensional carbon-based conductive polymer nanosheet array composite material.

2. The method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material as described in claim 1, characterized in that, In step A, the two-dimensional carbon-based material is graphene oxide, reduced graphene oxide, or Ti3C2T. x MXene, Ti2CT x MXene, Ti3CN, MXene, Nb4C3T x MXene, Nb2CT x One or more of MXene; the concentration of the hydrochloric acid aqueous solution is 0.15-0.37 wt.%; the mass ratio of the two-dimensional carbon-based material to the hydrochloric acid aqueous solution is 1:(1-5).

3. The method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material as described in claim 1, characterized in that, In step B, the mass ratio of potassium permanganate to the two-dimensional carbon-based material is (0.05-0.1):

1.

4. The method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material as described in claim 1, characterized in that, In step D, the concentration of the hydrochloric acid aqueous solution is 0.3-1.8 wt.%; the mass ratio of the two-dimensional manganese dioxide carbon-based composite material to the hydrochloric acid aqueous solution is 1:(100-250).

5. The method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material as described in claim 1, characterized in that, In step E, the mass ratio of the conductive polymer monomer to the dispersion containing the two-dimensional manganese dioxide carbon-based composite material is 1:(200-600).

6. The method for preparing a two-dimensional carbon-based conductive polymer nanosheet array composite material as described in claim 1, characterized in that, The conductive polymer monomer is one or more of pyrrole, aniline, indole, and p-phenylenediamine.

7. A two-dimensional carbon-based conductive polymer nanosheet array composite material, characterized in that, It is prepared by the method described in any one of claims 1-6.

8. The application of the two-dimensional carbon-based conductive polymer nanosheet array composite material as described in claim 7 in organic gas sensors.

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