A self-powered moisture generator made of MXene / CNF composite aerogel and its preparation method
By preparing a composite aerogel of MWCNT and MXene/CNF, the problems of insufficient conductivity and hydrophilicity of existing wet gas generator materials are solved, achieving high efficiency of self-powered capability and structural stability, which is suitable for wearable electronic devices and Internet of Things technology.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG UNIV OF SCI & TECH
- Filing Date
- 2024-05-16
- Publication Date
- 2026-07-17
AI Technical Summary
Existing materials for wet gas generators suffer from poor conductivity, insufficient hydrophilicity, or complex preparation processes, resulting in low efficiency and stability of wet gas power generation. Furthermore, the aerogel structure prepared using MXene alone lacks sufficient strength.
By combining multi-walled carbon nanotubes (MWCNTs) with MXene/CNF, and using a combination of ultrasonic and centrifugal filtration processes to achieve uniform dispersion of MWCNTs, combined with vacuum drying and directional freezing processes, an MXene/CNF/MWCNT composite aerogel with good electrical conductivity and hydrophilicity was prepared.
The conductivity and hydrophilicity of the aerogel were improved, the structural stability was enhanced, and a highly efficient self-powered capability was achieved, making it suitable for applications in various environments.
Smart Images
Figure CN118561270B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power generation equipment, and in particular to an MXene / CNF composite aerogel self-powered moisture generator and its preparation method. Background Technology
[0002] With the rapid development of wearable electronic devices and IoT technology, the demand for new energy materials capable of harvesting energy from the environment is increasing. Among them, wet generators, as devices that can convert the chemical energy of water molecules into electrical energy, have attracted much attention due to their environmentally friendly, renewable, and readily available characteristics. However, most existing wet generators rely on external power sources, which limits their application range and portability.
[0003] In existing technologies, wet gas generators typically employ a combination of conductive and hydrophilic materials to achieve the adsorption of water molecules and the conversion of electrical energy. Despite some progress, these materials often suffer from problems such as poor conductivity, insufficient hydrophilicity, or complex preparation processes, resulting in low efficiency and stability of wet gas power generation.
[0004] To address these issues, researchers have been exploring novel materials with superior conductivity and hydrophilicity. MXene, as a novel two-dimensional transition metal carbide or nitride material, has attracted considerable attention due to its excellent conductivity and hydrophilicity. However, aerogels prepared using MXene alone often lack structural strength and have limited performance in wet gas power generation processes.
[0005] Furthermore, multi-walled carbon nanotubes (MWCNTs) are considered ideal for improving the performance of composite materials due to their high electrical conductivity and mechanical strength. However, effectively doping MWCNTs into aerogels while maintaining their structural integrity, and simultaneously improving their hydrophilicity and power generation efficiency, remains a technical challenge. Therefore, there is an urgent need for an MXene / CNF composite aerogel self-powered wet gas generator and its preparation method that can effectively dope MWCNTs into aerogels while maintaining their structural integrity, and simultaneously improving their hydrophilicity and power generation efficiency. Summary of the Invention
[0006] This invention provides a self-powered humid gas generator made of MXene / CNF composite aerogel and its preparation method, which can effectively dope MWCNT into the aerogel while maintaining its structural integrity, and at the same time improve its hydrophilicity and power generation efficiency.
[0007] To solve the above-mentioned technical problems, this application provides the following technical solution:
[0008] A method for preparing an MXene / CNF composite aerogel self-powered moisture generator includes:
[0009] Preparation of S1 multi-walled carbon nanotube dispersion: Dissolve the dispersant TNWDIS in deionized water, then add carbon nanotubes and stir thoroughly to wet the carbon nanotubes with the dispersant solution. Sonicate the mixture using an ultrasonic cell disruptor. After sonication, remove the mixture and place it in ice water to cool and defoam, then continue sonicating. Use a glass rod to pick up a small amount of the dispersion and drop it into clean water. The well-dispersed carbon nanotubes quickly and evenly diffuse in the water without obvious particles. After sonication, centrifuge the dispersion to remove undispersed aggregated particles. After centrifugation, filter the supernatant to obtain the final carbon nanotube dispersion.
[0010] Preparation of S2 MXene / CNF / MWCNT composite aerogel: Different volumes of monolayer -Ti3C2T x MXene dispersion was added to CNF suspension and magnetically stirred to disperse evenly. The homogeneous mixture was transferred to a mold, which was then transferred to a vacuum drying oven for degassing until no bubbles were generated. After pre-cooling a copper block by immersing it in liquid nitrogen, the mold containing the homogeneous MXene / CNF mixture was placed on top of the copper block for directional freezing. Subsequently, the sample was transferred to a freeze dryer for freeze drying to obtain a directional monolayer MXene / CNF composite aerogel.
[0011] S3 MXene / CNF composite aerogel cutting: Cut the MXene / CNF composite aerogel into cubes of the required size for later use. Control the spray gun flow rate and obtain MXene / TOCNF / MWCNT composite aerogels with different MWCNT mass loads by changing the number of sprays.
[0012] S4 generator fabrication: A piece of MXene / CNF / MWCNT composite aerogel is sandwiched between two copper tapes to complete the generator fabrication.
[0013] Furthermore, the preparation of the S1 multi-walled carbon nanotube dispersion specifically includes: dissolving 0.40g of dispersant TNWDIS in 97.60g of deionized water, then adding 2.00g of carbon nanotubes, stirring thoroughly to wet the carbon nanotubes with the dispersant aqueous solution, and then sonicating the mixture using an ultrasonic cell disruptor.
[0014] Furthermore, the preparation of the S1 multi-walled carbon nanotube dispersion specifically includes: after sonication for 5 minutes, the mixture is removed and placed in ice water to cool and defoam, followed by further sonication. A small amount of the dispersion is added dropwise to clean water using a glass rod. The well-dispersed carbon nanotubes rapidly and uniformly diffuse in the water without obvious particles. After sonication, the dispersion is centrifuged at a speed of 2000 r / min for 30 minutes to remove undispersed aggregated particles. After centrifugation, the upper layer of liquid is filtered through a 300-mesh filter cloth.
[0015] Furthermore, in the preparation of the S2 MXene / CNF / MWCNT composite aerogel, CNF can be mechanical CNF, TEMPO oxidized CNF, or enzymatic CNF.
[0016] Furthermore, the preparation of the S2 MXene / CNF / MWCNT composite aerogel also includes: preparing different volumes of 4 mg / mL monolayer -Ti3C2T x The MXene dispersion was added to a CNF suspension with a concentration of 2.06 wt% and magnetically stirred for 5 hours to disperse it evenly.
[0017] Furthermore, the preparation of the S2 MXene / CNF / MWCNT composite aerogel also includes: transferring the sample to a freeze dryer and freeze-drying for 72 hours to obtain a directional monolayer MXene / CNF composite aerogel.
[0018] Furthermore, the preparation of the S2 MXene / CNF / MWCNT composite aerogel also includes: cutting the MXene / CNF composite aerogel with an MXene content of 10wt% into 20mm×10mm×2mm cubes for later use; controlling the spray gun flow rate; and obtaining MXene / CNF / MWCNT composite aerogels with different MWCNT mass loads by changing the number of sprays (10, 20, 30, 40, and 50 times).
[0019] Furthermore, in the cutting of the S3 MXene / CNF composite aerogel, the size of one MXene / CNF / MWCNT composite aerogel is 20mm×10mm×2mm.
[0020] Furthermore, in the preparation of the S4 generator, three holes with a diameter of 5mm are made on one side of the copper tape, and the copper tape with holes is attached to the bottom surface of the aerogel that has not been coated with MWCNT.
[0021] The basic principles and beneficial effects of the scheme are as follows:
[0022] MWCNTs were thoroughly wetted and dispersed using a mixture of dispersant TNWDIS and deionized water, and the dispersion was enhanced by ultrasonic treatment. After defoaming by ice water cooling, the MWCNTs were ultrasonically treated again to ensure uniform dispersion. Undispersed agglomerated particles were removed by centrifugation, and a pure MWCNT dispersion was obtained by filtration, providing a uniform nanotube dispersion medium for the subsequent preparation of composite aerogels.
[0023] Single-layer Ti3C2T xMXene dispersion and CNF (cellulose nanofiber) suspension were mixed and uniformly dispersed using magnetic stirring, ensuring a good interfacial bond between MXene and CNF. Degassing was performed in a vacuum drying oven to ensure the mixture was bubble-free, resulting in a uniform aerogel structure. Directional freezing of a copper block pre-cooled with liquid nitrogen promoted the formation of an ordered microstructure in the MXene / CNF mixture, enhancing the mechanical properties and structural stability of the aerogel. Finally, freeze-drying removed the solvent and solidified the MXene / CNF structure, yielding a directional monolayer MXene / CNF composite aerogel.
[0024] The prepared MXene / CNF composite aerogel was cut into cubes of specific sizes to meet different application requirements. By controlling the spray gun flow rate and varying the number of spray coats, MXene / CNF / MWCNT composite aerogels with different MWCNT mass loads were prepared, optimizing the aerogel's conductivity and sensitivity. The cut MXene / CNF / MWCNT composite aerogels were sandwiched between two copper tapes to form a complete moisture-powered structure. The copper tapes not only served as electrodes but also helped to fix the aerogel. Spraying MWCNTs increased the hydrophilicity of the aerogel surface. When the perforated copper tape was attached to the unsprayed aerogel bottom surface, water molecules could quickly migrate within the aerogel due to the higher hydrophilicity of the MWCNT-sprayed surface, thus rapidly generating electricity.
[0025] A combined process of ultrasonication and centrifugal filtration was used to achieve uniform dispersion of MWCNTs in solution, providing a foundation for the preparation of high-performance composite aerogels. Through the synergistic effect of MXene and CNF, and the doping of MWCNTs, the prepared composite aerogel exhibits good conductivity and high sensitivity to humidity changes, resulting in a composite aerogel with high conductivity and high sensitivity.
[0026] The directional freezing process enhances the microstructural order of the aerogel, improving its structural stability and mechanical properties, which is beneficial for its application in various environments. The entire preparation process is clear, simple to operate, and easy to scale up, which helps reduce costs and promotes its application. The prepared MXene / CNF / MWCNT composite aerogel has self-powering capabilities and can generate electricity under the influence of moisture, providing a possibility for the development of new environmentally friendly energy sources.
[0027] By changing the number of spraying passes, the mass load of MWCNTs in the aerogel can be easily adjusted, thereby optimizing sensor performance and meeting the needs of different application scenarios. Through the description of the invention's principles and technical effects above, it can be seen that this invention provides a method for preparing a structurally stable and high-performance MXene / CNF / MWCNT composite aerogel self-powered moisture generator, which has broad application prospects. Attached Figure Description
[0028] Figure 1a SEM image of pure MWCNT dispersion;
[0029] Figure 1b SEM images of MXene / CNF / MWCNT composite aerogel after 10 coats of MWCNT;
[0030] Figure 1c SEM images of MXene / CNF / MWCNT composite aerogel after 20 coats of MWCNT;
[0031] Figure 2 FT-IR spectrum of MXene / TOCNF / MWCNT composite aerogel;
[0032] Figure 3a The static contact angle of the MXene / CNF composite aerogel;
[0033] Figure 3b The static contact angle of the MXene / CNF / MWCNT composite aerogel;
[0034] Figure 4 This is a top view of Example 2 of an MXene / CNF composite aerogel self-powered moisture generator and its preparation method. Detailed Implementation
[0035] The following detailed description illustrates the specific implementation method:
[0036] A method for preparing an MXene / CNF composite aerogel self-powered moisture generator includes:
[0037] Preparation of multi-walled carbon nanotube (MWCNT) dispersions:
[0038] 0.40 g of dispersant TNWDIS was dissolved in 97.60 g of deionized water, followed by the addition of 2.00 g of carbon nanotubes. The mixture was stirred thoroughly to wet the carbon nanotubes with the dispersant solution. The mixture was then sonicated using an ultrasonic cell disruptor. After sonication for 5 minutes, the mixture was removed and placed in ice water to cool and defoam, followed by further sonication. A small amount of the dispersion was added dropwise to clean water using a glass rod. The well-dispersed carbon nanotubes quickly and uniformly diffused in the water without any noticeable particles. After sonication, the dispersion was centrifuged at 2000 r / min for 30 minutes to remove undispersed agglomerates. After centrifugation, the supernatant was filtered through a 300-mesh filter cloth (to remove a small amount of poorly dispersed agglomerates) to obtain the final carbon nanotube dispersion. The final actual carbon nanotube content in the dispersion was 1.4 wt%.
[0039] Preparation of MXene / CNF / MWCNT composite aerogel:
[0040] CNF can be mechanical CNF, TEMPO oxidative CNF, or enzymatic CNF.
[0041] Different volumes of 4 mg / mL Ti3C2T monolayers were used. x MXene dispersion was added to a 2.06 wt% CNF suspension and magnetically stirred for 5 hours to achieve uniform dispersion. The homogeneous mixture was transferred to a mold, which was then transferred to a vacuum drying oven for degassing until no bubbles were generated. After pre-cooling a copper block by immersing it in liquid nitrogen, the mold containing the homogeneous MXene / CNF mixture was placed on top of the copper block for directional freezing. Subsequently, the sample was transferred to a freeze dryer and freeze-dried for 72 hours to obtain a directional monolayer MXene / CNF composite aerogel.
[0042] The specific procedure for preparing the above-mentioned monolayer MXene is as follows: 1g of LiF powder and 20mL of 9mol / L HCl were magnetically stirred in a polytetrafluoroethylene container for 10min to ensure the dissolution of LiF. Then, 1g of Ti3AlC2 powder was gradually added to the above LiF / HCl etching solution. The mixture was stirred continuously at 35℃ for 24h to obtain a stable suspension. The etched Ti3C2T was washed with deionized water. x The suspension was repeatedly centrifuged at 4000 rpm for 8 minutes until the pH of the upper layer in the centrifuge tube was adjusted to 7. Deionized water was added to the bottom precipitate to obtain multilayer Ti3C2T. x Dispersion (m-Ti3C2T) x MXene); multilayer Ti3C2T x The dispersion was ultrasonically treated for 30 minutes to create a monolayer of Ti3C2T. x Peeling (d-Ti3C2T) xMXene, which is a single-layer Ti3C2T x MXene). Finally, the dispersion was centrifuged at 4000 rpm for 1 h, and the supernatant was collected as a monolayer of two-dimensional Ti3C2T. x MXene.
[0043] MXene / CNF composite aerogel with a 10wt% MXene content was cut into 20mm×10mm×2mm cubes for later use. By controlling the spray gun flow rate and varying the number of sprays (10, 20, 30, 40, 50), MXene / CNF / MWCNT composite aerogels with different MWCNT mass loads were obtained. The mass content at different MWCNT spraying times was calculated using a plastic mold. The obtained mass contents at different MWCNT spraying times were 0.021mg (10 times), 0.042mg (20 times), 0.063mg (30 times), 0.084mg (40 times), and 0.105mg (50 times).
[0044] A self-charging moisture generator was constructed by sandwiching a piece of MXene / CNF / MWCNT composite aerogel (20mm×10mm×2mm) between two copper strips and further connecting them using a digital multimeter. Three 5mm diameter holes were drilled in one of the copper strips, which were then attached to the uncoated aerogel surface to ensure effective moisture diffusion into the composite aerogel. The voltage change on the digital multimeter was observed by bringing a finger close to the composite aerogel.
[0045] SEM of MWCNT ( Figure 1a The composite aerogel exhibits a highly interwoven configuration, likely a result of MWCNT functionalization, with MWCNTs approximately 50 nm in length. When the MWCNTs were sprayed 10 times, no significant changes were observed on the surface of the composite aerogel. Figure 1b , Figure 1c As the number of sprayings increases, the surface of the composite aerogel is covered by MWCNT.
[0046] like Figure 2 The FT-IR spectrum is shown at 1560 cm⁻¹. -1 The spectral band at the location and the sp in MWCNT 2 The graphitic structure of hybrid carbon corresponds to that of 1398 cm⁻¹ -1 The band at 1072 cm⁻¹ is attributed to the curvature of CH. -1The characteristic peak at the point of curvature corresponds to the C-OH group, further confirming the presence of hydrophilic hydroxyl groups on MWCNTs. It can be observed that the spectrum of the MXene / TOCNF / MWCNT composite aerogel possesses almost all the important characteristic peaks of MWCNTs and MXene / TOCNFs, with very little variation. These results indicate that MWCNTs were successfully coated onto the MXene / TOCNF composite aerogel.
[0047] The water contact angle of the prepared composite aerogel was tested at room temperature, and the results are shown in Figure 3. Figure 3a It can be seen that the time from water contacting the surface of the MXene / CNF composite aerogel to complete absorption is 65ms. However, for the MXene / CNF / MWCNT composite aerogel after MWCNT coating, the time from water contacting the surface to complete absorption is extremely short, only 0.333ms. Figure 3b This further illustrates that the MXene / TOCNF / MWCNT composite aerogel exhibits significantly enhanced hydrophilicity. The addition of MWCNTs further strengthens the hydrophilic properties of the composite aerogel.
[0048] The MXene / CNF / MWCNT composite aerogel has the ability to generate moisture without an external power source. When the digital multimeter is exposed to air, no voltage is observed. Subsequently, when a finger touches the surface of the porous copper tape, the multimeter immediately detects a significant output voltage. With continued finger contact, the output voltage rapidly increases; however, when the finger is removed, the output voltage gradually and automatically drops to zero after continuous discharge, completing a full cycle.
[0049] The above are merely embodiments of the present invention. The invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are able to access all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel, characterized in that: include: Preparation of S1 multi-walled carbon nanotube dispersion: Dissolve the dispersant TNWDIS in deionized water, then add carbon nanotubes and stir thoroughly to wet the carbon nanotubes with the dispersant solution. Sonicate the mixture using an ultrasonic cell disruptor. After sonication, remove the mixture and place it in ice water to cool and defoam, then continue sonicating. Use a glass rod to pick up a small amount of the dispersion and drop it into clean water. The well-dispersed carbon nanotubes quickly and evenly diffuse in the water without obvious particles. After sonication, centrifuge the dispersion to remove undispersed aggregated particles. After centrifugation, filter the supernatant to obtain the final carbon nanotube dispersion. Preparation of S2 MXene / CNF composite aerogel: Different volumes of monolayer -Ti3C2T x MXene dispersion was added to CNF suspension and magnetically stirred to disperse evenly. The homogeneous mixture was transferred to a mold, which was then transferred to a vacuum drying oven for degassing until no bubbles were generated. After pre-cooling a copper block by immersing it in liquid nitrogen, the mold containing the homogeneous MXene / CNF mixture was placed on top of the copper block for directional freezing. Subsequently, the sample was transferred to a freeze dryer for freeze drying to obtain a directional monolayer MXene / CNF composite aerogel. Preparation of S3 MXene / CNF / MWCNT composite aerogel: Cut the MXene / CNF composite aerogel into cubes of the required size for later use. Control the spray gun flow rate and obtain MXene / CNF / MWCNT composite aerogels with different MWCNT mass loads by changing the number of spraying times, namely 10 times, 20 times, 30 times, 40 times, and 50 times. S4 generator fabrication: A piece of MXene / CNF / MWCNT composite aerogel is sandwiched between two copper tapes to complete the generator fabrication.
2. The method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel according to claim 1, characterized in that: The preparation of the S1 multi-walled carbon nanotube dispersion further includes: dissolving 0.40 g of dispersant TNWDIS in 97.60 g of deionized water, then adding 2.00 g of carbon nanotubes, stirring thoroughly to wet the carbon nanotubes with the dispersant aqueous solution, and then sonicating the mixture using an ultrasonic cell disruptor.
3. The method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel according to claim 2, characterized in that: The preparation of the S1 multi-walled carbon nanotube dispersion specifically includes: after sonication for 5 min, the mixture is taken out and placed in ice water to cool and defoam, and then sonication is continued.
4. The method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel according to claim 3, characterized in that: The MXene / CNF composite aerogel is prepared by means of mechanical CNF, TEMPO oxidized CNF, or enzymatic CNF.
5. A method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel according to claim 4, characterized in that: The preparation of the MXene / CNF composite aerogel also includes: preparing monolayers of Ti3C2T with different volumes of 4 mg / mL. x The MXene dispersion was added to a CNF suspension with a concentration of 2.06 wt% and magnetically stirred for 5 h to disperse it evenly.
6. A method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel according to claim 5, characterized in that: The preparation of the MXene / CNF composite aerogel also includes: transferring the sample to a freeze dryer and freeze-drying for 72 h to obtain a directional monolayer MXene / CNF composite aerogel.
7. A method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel according to claim 6, characterized in that: In the cutting of the S3 MXene / CNF composite aerogel, the size of one MXene / CNF composite aerogel is 20 mm × 10 mm × 2 mm.
8. A method for preparing a self-powered moisture generator using MXene / CNF / MWCNT composite aerogel according to claim 7, characterized in that: In the fabrication of the S4 generator, three holes with a diameter of 5 mm are made on one side of the copper tape, and the copper tape with holes is attached to the aerogel bottom surface that has not been coated with MWCNT.
9. A self-powered moisture generator based on MXene / CNF / MWCNT composite aerogel, characterized in that, Prepared according to any one of claims 1-8.