Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material and preparation method thereof

Abstract

The application belongs to the technical field of microwave absorbing materials, and relates to Fe3O4@C magnetic modification MXene-based aerogel microwave absorbing material and a preparation method thereof. The microwave absorbing material has a porous structure, and the inner wall is attached with magnetic double-layer structure Fe3O4@C particles. The outer shell is spindle-shaped amorphous carbon, and the inner core is Fe3O4 magnetic particles. The preparation method comprises the following steps: preparation of nano spindle-shaped Fe2O3 precursor, preparation of magnetic double-layer structure Fe3O4@C particles, preparation of single-layer MXene nanosheet, and preparation of Fe3O4@C magnetic modification MXene-based aerogel. The Fe2O3 precursor is generated by using a hydrothermal method. The Fe2O3 precursor can not only be used as a template of a polydopamine shell, but also can be partially reduced to generate magnetic Fe3O4, so that the wave absorbing performance is enhanced. The polydopamine shell is carbonized at high temperature, and the internal Fe2O3 precursor is reduced to Fe3O4. The magnetic particles are positively charged and naturally adsorbed with the single-layer MXene nanosheet by using polydiallyldimethylammonium chloride treatment. Gelatin is used as a cementing agent in the application, so that the strength of the aerogel is ensured while the economy is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microwave absorption materials, and relates to a Fe3O4@C magnetic modification MXene-based aerogel microwave absorption material and a preparation method thereof. BACKGROUND

[0002] With the development of science and technology, electromagnetic wave technology is widely used in different fields such as communication, medical treatment, military affairs and the like, and brings various conveniences to people, but a large number of electronic devices may generate electromagnetic radiation, especially radio frequency electromagnetic radiation, which often affects the normal operation of surrounding electronic devices. However, the existing wave absorption materials are difficult to meet the demand of light weight and high efficiency. Therefore, the demand for light weight and high performance wave absorption materials and preparation methods thereof is increasingly strong. SUMMARY

[0003] In order to solve the above technical problems, the application is realized through the following technical scheme.

[0004] A Fe3O4@C magnetic modification MXene-based aerogel microwave absorption material, the aerogel microwave absorption material has a porous structure, and the inner wall of the aerogel microwave absorption material is attached with magnetic double-layer structure Fe3O4@C particles, and the double-layer structure is represented as shell-spindle-shaped amorphous carbon, and core-Fe3O4 magnetic particles.

[0005] The application further discloses a preparation method of the Fe3O4@C magnetic modification MXene-based aerogel microwave absorption material, which is used for preparing the Fe3O4@C magnetic modification MXene-based aerogel microwave absorption material, and comprises the following steps:

[0006] Step S1, preparation of nano-spindle-shaped Fe2O3 precursor: iron trichloride hexahydrate is reacted with sodium hydroxide to generate iron hydroxide colloid, and the iron hydroxide colloid is subjected to hydrothermal reaction to generate nano-spindle-shaped Fe2O3 precursor;

[0007] Step S2, preparation of magnetic double-layer structure Fe3O4@C particles: dopamine hydrochloride is used to generate Fe2O3@PDA in a tris aqueous solution, the Fe2O3@PDA is placed in a tube furnace for annealing treatment to obtain black magnetic nano-spindle-shaped Fe3O4@C, part of the Fe3O4 template is removed by using hydrochloric acid, and the magnetic double-layer structure Fe3O4@C particles are obtained by again placing in a tube furnace for annealing;

[0008] Step S3, preparation of single-layer MXene nanosheet: HF etching is used to etch MAX powder to obtain a single-layer MXene nanosheet;

[0009] Step S4, preparation of Fe3O4@C magnetic modified MXene-based aerogel: using polydiallyldimethylammonium chloride (PDDA) to modify the magnetic double-layer structure Fe3O4@C particles, and composite with MXene nanosheets, introduce gelatin as a colloid, freeze-drying to form Fe3O4@C magnetic modified MXene-based aerogel.

[0010] Preferably, in the step S1, the mass ratio of ferric chloride hexahydrate and sodium hydroxide is 0.95-1.05:0.3-0.45.

[0011] Preferably, in the step S1, the ferric chloride hexahydrate and sodium hydroxide are stirred in an oil bath at 20-90℃ for 10-30min; the hydrothermal reaction conditions are 70-120℃, and the reaction time is 1-5 days.

[0012] Preferably, in the step S2, the mass ratio of dopamine hydrochloride, tris-hydroxymethyl aminomethane, and nano-spatula Fe2O3 precursor is 0.9-1.1:1.5-1.8:0.85-1.05; the dopamine hydrochloride is added to the tris-hydroxymethyl aminomethane aqueous solution containing nano-spatula Fe2O3 precursor, stirred for 2-5h, centrifuged and washed, and dried overnight.

[0013] Preferably, in the step S2, the first annealing treatment conditions are 450-550℃ for 2-4h under Ar atmosphere, and the heating rate is 5℃ / min; the second annealing treatment conditions are 700-850℃ for 2-4h under Ar atmosphere, and the heating rate is 5℃ / min; the mass-volume concentration of nano-spatula Fe3O4@C is 1.5-1.7mg / mL, the molar concentration of hydrochloric acid is 3-4.5mol / L, and the mixture is magnetically stirred at 60-75℃ for 5-25min, and the product is collected by centrifugation.

[0014] Preferably, in the step S3, HF is generated from HCl and LiF, the mass-volume concentrations of LiF and MAX powder are 80-95mg / mL and 45-50mg / mL respectively, and the molar concentration of hydrochloric acid is 7-9mol / L.

[0015] More preferably, in the step S3, the MAX powder is slowly added to the HCl solution of LiF, and the reaction is carried out at 30-50℃ in an oil bath for 12-60h to obtain the product, which is washed with water several times, the supernatant is collected and freeze-dried to obtain single-layer MXene powder.

[0016] Preferably, in the step S4, the mass-volume concentrations of the magnetic double-layer structure Fe3O4@C particles and polydiallyldimethylammonium chloride are 0.9-1.05mg / mL and 0.35-0.5mg / mL respectively.

[0017] Preferably, in the step S4, the magnetic double-layer structure Fe3O4@C particles are dispersed in a 0.35-0.5 mg / mL polydiallyldimethylammonium chloride aqueous solution, and mechanically stirred for 10-35 min; the single-layer MXene powder is dispersed in water to form an aqueous solution with a mass-volume fraction of 9-10 mg / mL; the two are mixed in a volume ratio of 0.9-1.05:0.95-1.1, shaken for 5-10 min, and the precipitate is collected by centrifugation to obtain a composite product; the composite product is added to a 10-20 mg / mL gelatin aqueous solution, shaken for 60-120 min, and then placed in a freeze dryer after freezing, and freeze-dried for 20-48 h to obtain the Fe3O4 magnetic particle modified MXene-based aerogel.

[0018] The beneficial effects of the present application are:

[0019] The present application uses a hydrothermal method to generate Fe2O3 precursors with uniform texture and size. The Fe2O3 precursors not only serve as templates for polydopamine shells, but also can be partially reduced to generate magnetic Fe3O4, enhancing the wave absorption performance; in an Ar environment, high-temperature heat treatment is used for reduction treatment, the polydopamine shell is carbonized, and the internal Fe2O3 precursor is reduced to Fe3O4; polydiallyldimethylammonium chloride is used for treatment, so that the magnetic particles are positively charged and naturally adsorbed with single-layer MXene nanosheets; finally, the present application uses gelatin as a cementing agent, which is economical while ensuring the strength of the aerogel. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 Figure 6 is an XRD pattern of the nanometer shuttle-shaped Fe2O3 precursor, the magnetic double-layer structure Fe3O4@C particles, and the Fe3O4@C magnetic modified MXene-based aerogel prepared in the examples of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorbing material and the preparation method thereof of the present application;

[0021] Figure 2 Figure 7 is a SEM image of the nanometer shuttle-shaped Fe2O3 precursor with a magnification of 30000;

[0022] Figure 3 Figure 8 is a TEM image of the nanometer shuttle-shaped Fe2O3 precursor;

[0023] Figure 4 Figure 9 is a SEM image of the magnetic double-layer structure Fe3O4@C particles with a magnification of 20000;

[0024] Figure 5 Figure 10 is a TEM image of the magnetic double-layer structure Fe3O4@C particles;

[0025] Figure 6This is a 100x SEM image of the Fe3O4@C magnetically modified MXene-based aerogel of the present invention.

[0026] Figure 7 This is a SEM image of the Fe3O4@C magnetically modified MXene-based aerogel of the present invention, magnified at 10000.

[0027] Figure 8 This is a schematic diagram of the reflection loss of the Fe3O4@C magnetically modified MXene-based aerogel of the present invention;

[0028] Figure 9 This is another schematic diagram of the reflection loss of the Fe3O4@C magnetically modified MXene-based aerogel of the present invention;

[0029] Figure 10 This is a distribution diagram of the electromagnetic parameters of the Fe3O4@C magnetically modified MXene-based aerogel of the present invention;

[0030] Figure 11 The image shows the RCS diagram of the Fe3O4@C magnetically modified MXene-based aerogel of the present invention. Detailed Implementation

[0031] The related technologies of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] The following components were used in this embodiment: ferric chloride hexahydrate (F419646-500g), sodium hydroxide (S140903-500g), dopamine hydrochloride (XW016231702), tris(hydroxymethyl)aminomethane (30188336), hydrochloric acid (10011018), LiF (L104226-50g), polydiallyldimethylammonium chloride solution (P109719-100ml), and gelatin (G108398-100g).

[0033] The MAX (Ti3AlC2) powder was purchased from Jilin Yiyi Technology Co., Ltd., product number YY201702.

[0034] The preparation method of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material of the embodiment comprises the following steps:

[0035] 1. Preparation of nano-fusiform Fe2O3 precursor: The nano-fusiform Fe2O3 precursor is prepared by using a hydrothermal reaction of iron hydroxide colloid. First, ferric chloride hexahydrate and sodium hydroxide are dissolved in deionized water, and the mixture is heated and stirred in an oil bath for a certain time. Then, the colloid is poured into a 50 mL hydrothermal kettle and placed in a high-temperature oven for reaction for a certain time. Finally, the hydrothermal product is washed with water and alcohol, centrifuged, dried overnight, and the nano-fusiform Fe2O3 precursor is obtained.

[0036] In this step, the molar volume fraction of ferric chloride hexahydrate and sodium hydroxide is (1.8-2.1) mol / L and (5.1-5.4) mol / L, respectively.

[0037] In this step, the oil bath heating condition is (50-90) ℃, and the reaction time is (10-30) min.

[0038] In this step, the hydrothermal heating condition is (70-120) ℃, and the reaction time is (1-5) days.

[0039] The SEM and TEM images of the nano-fusiform Fe2O3 precursor prepared in the first step are shown in Figure 2 、 Figure 3 It can be seen that the particles are fusiform, uniform in size, about 500-600 nm in diameter, and smooth in surface. Figure 3 This is further proved by the TEM image.

[0040] 2. Preparation of magnetic double-layer structure Fe3O4@C particles: First, a polydopamine shell is formed on the surface of the nano-fusiform Fe2O3 precursor after treatment with hydrochloric acid dopamine and tris; then, Fe2O3@PDA is placed in a tube furnace for annealing, and the internal Fe2O3 is reduced to Fe3O4; then, part of the Fe3O4 template is removed using hydrochloric acid; and finally, the magnetic double-layer structure Fe3O4@C particles are annealed again in a tube furnace.

[0041] In this step, the mass ratio of hydrochloric acid dopamine, tris, and nano-fusiform Fe2O3 precursor is (0.9-1.1):(1.5-1.8):(0.85-1.05).

[0042] In this step, the annealing treatment in the tube furnace is carried out under Ar atmosphere at (450-550) ℃ for (2-4) h, and the heating rate is 5 ℃ / min.

[0043] In this step, Fe3O4@C particles with a mass-volume concentration of (1.5-1.7) g / L are dispersed in (3-4.5) mol / L hydrochloric acid, magnetically stirred at (60-75) °C for (5-25) min, the precipitate is collected by centrifugation, and washed alternately with deionized water and ethanol.

[0044] In this step, the double-layer structured particles are annealed in a tube furnace under Ar atmosphere at (700-850)℃ for (2-4) hours with a heating rate of 5℃ / min.

[0045] The SEM and TEM images of the magnetic bilayer Fe3O4@C particles prepared in the second step are shown below. Figure 4 , Figure 5 As shown, by Figure 4 It can be seen that the Fe3O4@C particles have a double-layer structure, with an outer spindle-shaped shell and an inner core of irregular, slightly spherical particles. Figure 5 The TEM images further confirm this, and it can be clearly seen that the internal core diameter is about 200-300 nm, accounting for about 15% of the volume of the overall magnetic bilayer structure Fe3O4@C particles.

[0046] 3. Preparation of monolayer MXene nanosheets: MAX powder was obtained by etching with HF.

[0047] In this step, HF is generated from HCl and LiF, with mass-volume concentrations of LiF and MAX powder of (80-95) mg / mL and (45-50) mg / mL, respectively, and the molar concentration of hydrochloric acid of (7-9) mol / L.

[0048] In this step, MAX powder is slowly added to a LiF HCl solution and reacted in an oil bath at 30-50°C for (12-60) hours.

[0049] In this step, the oil bath reaction product is centrifuged and washed with water multiple times, the supernatant is collected, and freeze-dried to obtain monolayer MXene powder.

[0050] 4. Preparation of Fe3O4@C magnetically modified MXene-based aerogel: First, Fe3O4@C particles with a magnetic bilayer structure were modified with polydiallyldimethylammonium chloride (PDDA); then, MXene nanosheets and Fe3O4@C particles with a magnetic bilayer structure were composited by potentiometric adsorption; gelatin was used as a binder, and the composite product was freeze-dried to form an aerogel.

[0051] In this step, the mass-volume concentrations of the magnetic bilayer Fe3O4@C particles and polydiallyldimethylammonium chloride are (0.9-1.05) mg / mL and (0.35-0.5) mg / mL, respectively.

[0052] In this step, the magnetic double-layer structure Fe3O4@C particles are dispersed in 20 mL of a polydiallyldimethylammonium chloride aqueous solution, and the suspension is mechanically stirred for 10-35 min to obtain a PDDA-modified double-layer structure Fe3O4@C particle suspension.

[0053] In this step, the single-layer MXene nanosheet is dispersed in 10 mL of deionized water, and the PDDA-modified double-layer structure Fe3O4@C particle suspension is added in a volume ratio of (0.9-1.05):(0.95-1.1), and shaken for 5-10 min, and the precipitate is collected by centrifugation to obtain a composite product.

[0054] In this step, the composite product is dispersed in 10 mL of a gelatin aqueous solution with a mass-volume concentration of (10-20) mg / mL, and shaken for 60-120 min.

[0055] In this step, the shaken product is placed in a freeze dryer and freeze-dried for 20-48 h to obtain Fe3O4@C magnetic modification MXene-based aerogel.

[0056] The SEM image of the Fe3O4@C magnetic modification MXene-based aerogel prepared in the fourth step is shown in Figure 6 、 Figure 7 As can be seen from Figure 6 , the aerogel has a porous structure as a whole; Figure 7 For further magnification, it can be seen that the magnetic double-layer structure Fe3O4@C particles are uniformly distributed therein, the overall morphology is retained intact, the collapse is less, and the surface is wrapped with a layer of gelatin-MXene mixture, which has good mechanical properties and ensures the microwave absorption performance.

[0057] LiF lithium chloride PDDA polydiallyldimethylammonium chloride Tris tris(hydroxymethyl)aminomethane PDA polydopamine RCS radar cross section

[0058] To sum up, the Fe2O3 precursor with uniform texture and size is generated by the hydrothermal method, the Fe2O3 precursor can not only serve as a template for the polydopamine shell, but also can be partially reduced to generate magnetic Fe3O4 to enhance the wave absorption performance; in an Ar environment, the polydopamine shell is carbonized and the internal Fe2O3 precursor is reduced to Fe3O4 by high-temperature holding and reduction treatment; the magnetic particles are positively charged by using polydiallyldimethylammonium chloride treatment and naturally adsorbed with single-layer MXene nanosheets; the gelatin is used as a cementing agent in the present application, which is economical and ensures the strength of the aerogel, so the present application has a broad application prospect.

[0059] It should be pointed out that the above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application still belongs to the scope of the technical solution of the present application.

Claims

1. A method for preparing Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material, characterized in that, The aerogel microwave absorption material has a porous structure, and the inner wall of the aerogel microwave absorption material is attached with magnetic double-layer structure Fe3O4@C particles, and the double-layer structure is represented as shell-spindle amorphous carbon, and core-Fe3O4 magnetic particles; The preparation method comprises the following steps: Step S1, preparation of nano-spindle Fe2O3 precursor: using ferric chloride hexahydrate and sodium hydroxide to react to generate ferric hydroxide colloid, and the ferric hydroxide colloid is generated into nano-spindle Fe2O3 precursor through hydrothermal reaction; Step S2, preparation of magnetic double-layer structure Fe3O4@C particles: using hydrochloric acid dopamine in a tris-hydroxymethyl aminomethane aqueous solution to generate Fe2O3@PDA, annealing Fe2O3@PDA to obtain black magnetic nano-spindle Fe3O4@C, using hydrochloric acid to remove part of Fe3O4 template, and annealing again to obtain magnetic double-layer structure Fe3O4@C particles; Step S3, preparation of single-layer MXene nanosheet: using HF etching MAX powder to obtain single-layer MXene nanosheet; Step S4, preparation of Fe3O4@C magnetic modification MXene-based aerogel: using polydiallyldimethylammonium chloride to modify the magnetic double-layer structure Fe3O4@C particles, and compounding with MXene nanosheet, introducing gelatin as glue, and freeze-drying to form Fe3O4@C magnetic modification MXene-based aerogel; In the step S2, the mass ratio of hydrochloric acid dopamine, tris-hydroxymethyl aminomethane and nano-spindle Fe2O3 precursor is 0.9-1.1:1.5-1.8:0.85-1.05; the hydrochloric acid dopamine is added into the tris-hydroxymethyl aminomethane aqueous solution with nano-spindle Fe2O3 precursor dispersed therein, stirring for 2-5 h, centrifugal cleaning and drying overnight; In the step S2, the first annealing treatment condition is 450-550 DEG C for 2-4 h under Ar atmosphere, and the heating rate is 5 DEG C / min; the second annealing treatment condition is 700-850 DEG C for 2-4 h under Ar atmosphere, and the heating rate is 5 DEG C / min; the mass-volume concentration of the nano-spindle Fe3O4@C is 1.5-1.7 mg / mL, the molar concentration of hydrochloric acid is 3-4.5 mol / L, and the mixture is magnetically stirred at 60-75 DEG C for 5-25 min, and the product is collected by centrifugation.

2. The preparation method of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material according to claim 1, characterized in that, In the step S1, the mass ratio of ferric chloride hexahydrate and sodium hydroxide is 0.95-1.05:0.3-0.

45.

3. The preparation method of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material according to claim 1, characterized in that, In the step S1, the ferric chloride hexahydrate and sodium hydroxide are reacted under oil bath stirring at 20-90 DEG C for 10-30 min; and the hydrothermal reaction condition is 70-120 DEG C, and the reaction time is 1-5 days.

4. The preparation method of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material according to claim 1, characterized in that, In the step S3, the HF is generated from HCl and LiF, the mass-volume concentrations of LiF and MAX powder are 80-95 mg / mL and 45-50 mg / mL respectively, and the molar concentration of hydrochloric acid is 7-9 mol / L.

5. The preparation method of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material according to claim 4, characterized in that, In the step S3, MAX powder is slowly added into the LiF-HCl solution, and the reaction is carried out in an oil bath at 30-50℃ for 12-60h to obtain the product. The product is centrifuged and washed with water for several times, the supernatant is collected and freeze-dried to obtain the single-layer MXene powder.

6. The preparation method of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material according to claim 1, characterized in that, In the step S4, the mass-volume concentration of the magnetic double-layer structure Fe3O4@C particles and the polydiallyldimethylammonium chloride is 0.9-1.05mg / mL and 0.35-0.5mg / mL respectively.

7. The preparation method of the Fe3O4@C magnetic modified MXene-based aerogel microwave absorption material according to claim 1, characterized in that, In the step S4, the magnetic double-layer structure Fe3O4@C particles are dispersed in the 0.35-0.5mg / mL polydiallyldimethylammonium chloride aqueous solution, and mechanically stirred for 10-35min. The single-layer MXene powder is dispersed in water to form an aqueous solution with a mass-volume fraction of 9-10mg / mL. The two are mixed in a volume ratio of 0.9-1.05:0.95-1.1, shaken for 5-10min, and the precipitate is collected by centrifugation to obtain the composite product. The composite product is added into the 10-20mg / mL gelatin aqueous solution, shaken for 60-120min, and then placed in a freeze dryer after freezing, and freeze-dried for 20-48h to obtain the Fe3O4 magnetic particle modified MXene-based aerogel.

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