A Janus C@CMCs / CNF aerogel composite material, its preparation method, and its application in wet gas power generation.

Abstract

The application belongs to the technical field of functional materials and energy devices, and discloses a Janus C@CMCs / CNF aerogel composite material, a preparation method thereof and application thereof in moisture power generation. The preparation method comprises the following steps: uniformly dispersing cellulose nanofiber and carboxymethyl chitosan, and adding an activator to obtain a suspension; transferring the suspension into a mold with a copper sheet at the bottom, and obtaining an aerogel with a vertical pore structure through gelation, directional freezing in liquid nitrogen and freeze drying; immersing one side of the aerogel into the suspension, and obtaining an aerogel / hydrogel composite material after vacuum impregnation; and finally, performing one-sided carbonization treatment on the unimpregnated side to obtain a Janus structure composite material. The material can spontaneously generate an electric potential in a moisture environment, and the open-circuit voltage reaches 0.689 V and the short-circuit current reaches 3.72 mu A under a humidity of 85% RH, and can be used in a moisture power generation device.

Description

Technical Field

[0001] This invention belongs to the field of functional materials and energy devices, and specifically relates to a Janus C@CMCs / CNF aerogel composite material, its preparation method, and its application in wet gas power generation. Background Technology

[0002] Cellulose nanofibers (CNFs), as a widely available and renewable natural polymer material, are rich in active functional groups such as hydroxyl groups on their surface, making them easy to assemble into aerogels with a three-dimensional porous structure. CNF-based aerogels, due to their high specific surface area, good mechanical properties, and tunable surface chemistry, have shown application potential in the fields of moisture adsorption and ion transport, and are considered an ideal substrate for ion carriers in moisture power generation.

[0003] Janus-structured materials, due to their differentiated physicochemical properties (such as hydrophilicity and hydrophobicity) on both sides, can spontaneously construct stable humidity and ion concentration gradients in humid environments, and have been explored for application in the field of humid power generation in recent years. Theoretically, combining the Janus structure with CNF-based aerogels and constructing an asymmetric structure through unilateral modification can both utilize the porous structure of CNF-based aerogels to adsorb moisture and maintain the driving force for directional ion migration through the Janus structure, thereby potentially improving the power generation performance of the material.

[0004] However, the Janus CNF-based aerogels disclosed in the prior art still have the following technical defects in practical applications: First, their internal channels are mostly disordered porous network structures. This structure has a weak ability to directionally transport moisture, resulting in greater diffusion resistance of water molecules inside the material, low ion migration efficiency, and difficulty in building a stable ion concentration gradient in a short time, which in turn affects the stability and response speed of the electrical signal output; Second, the moisture absorption capacity of a single CNF aerogel is limited, and its ability to supply ions as charge carriers is insufficient, which limits the upper limit of the material's power generation performance and makes it difficult to meet the demand for high power output in practical applications. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a Janus C@CMCs / CNF aerogel composite material, its preparation method and its application in wet gas power generation, to overcome the shortcomings of synthetic materials such as energy consumption, lack of functionality and the influence of resistance caused by material structure on self-generated potential, and to explore the structural composition of Janus CNF-based composite aerogel under the optimal self-generated potential.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing Janus C@CMCs / CNF aerogel composite material includes the following steps: S1. Cellulose nanofibers (CNF) and carboxymethyl chitosan (CMCs) were uniformly dispersed in deionized water and magnetically stirred for 30 min; then 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride (DMTMM) was added as an activator, and magnetic stirring was continued until the mixture was uniform to obtain a CMCs / CNF suspension; S2. The CMCs / CNF suspension was transferred to a polytetrafluoroethylene cylindrical mold with a copper sheet at the bottom, gelled at a constant temperature of 45 ℃ for 3 h, and then placed in liquid nitrogen for rapid directional freezing, followed by freeze drying for 72 h to obtain V-CMCs / CNF aerogel with a vertical pore structure. S3. Immerse one side of the V-CMCs / CNF aerogel in the CMCs / CNF suspension, place it under vacuum for 10-40 min to impregnate and fill, and then let it stand at 45 ℃ for 3 h to obtain the V-CMCs / CNF aerogel / hydrogel composite material. S4. The unimpregnated side was carbonized using a one-sided carbonization process to finally prepare V-JanusC@CMCs / CNF aerogel / hydrogel composite material, abbreviated as VC@CCAH.

[0007] Preferably, in step S1, the mass ratio of the cellulose nanofibers, carboxymethyl chitosan and 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride is 1:2:2, and the concentration of the cellulose nanofibers is 0.4 wt%.

[0008] Preferably, in step 3, the impregnation and filling time is 30 minutes.

[0009] Preferably, in step 4, the carbonization treatment conditions are 350 °C and carbonization for 300 s.

[0010] Janus C@CMCs / CNF aerogel composite material prepared based on any of the above preparation methods.

[0011] Preferably, the Janus C@CMCs / CNF aerogel composite material has the following layer structure from top to bottom: carbonized layer (V-CCA-C), uncarbonized layer (V-CCA), and composite hydrogel layer (V-CCA-H).

[0012] The above-mentioned Janus C@CMCs / CNF aerogel composite material is used in wet gas power generation. Beneficial effects

[0013] Compared with existing technologies, this invention presents a Janus C@CMCs / CNF aerogel composite material, its preparation method, and its application in moisture-powered electricity generation. This material uses cellulose nanofibers (CNF) and carboxymethyl chitosan (CMCs) as main raw materials, prepared through directional freezing, vacuum impregnation, and freeze-drying processes combined with unilateral carbonization. Due to the ion concentration gradient driven by the Janus structure, which drives the directional migration of ionized protons, this aerogel can generate a self-generating potential under humidity changes. Experimental results show that among the three aerogel structures RC@CCA, VC@CCA, and VC@CCAH, VC@CCAH exhibits the best electrical signal response. Specifically, this invention has the following beneficial effects: (1) This invention uses a single-sided carbonization process to treat CMCs / CNF aerogels, creating a difference in oxygen content on both sides. EDS and XPS analysis results show that the oxygen content of the carbonized layer is significantly reduced and the proportion of CC bonds is increased, while the uncarbonized layer retains abundant oxygen-containing functional groups. This oxygen gradient can spontaneously form a stable ion concentration gradient in a humid environment, providing a driving force for the directional migration of protons, thereby enabling the material to generate its own potential. (2) This invention employs directional freeze-drying technology to construct a vertically oriented pore structure within the aerogel. Water droplets can be completely wetted on the V-CCA surface in just 30 ms, while on the R-CCA surface it takes 60 ms, demonstrating that the vertical pores effectively reduce moisture transport resistance. Simultaneously, the introduction of vertical pores enhances the material's moisture absorption rate and electrical signal output. Based on the vertically oriented aerogel, this invention further composites a CMCs / CNF hydrogel layer on one side. V-CCA-H, by increasing the density of hydrophilic groups and moisture absorption capacity, forms a synergistic effect with the directional transport effect of the vertical pores, achieving further improvement in power generation performance. At 85% RH humidity, the open-circuit voltage of VC@CCAH reaches 0.689 V and the short-circuit current reaches 3.72 μA, both higher than the 0.603 V and 3.32 μA of VC@CCA. Attached Figure Description

[0014] Figure 1For Comparative Examples 1-2, scanning electron microscope (SEM) images of the CMCs / CNF composite materials obtained in Example 1 are shown. Among them, (a) is a transverse cross-sectional view of R-CCA obtained in Comparative Example 1; (b) and (c) are low-magnification and high-magnification images of R-CCA obtained in Comparative Example 1 in the longitudinal cross-section, respectively; (d) is a transverse cross-sectional view of V-CCA obtained in Comparative Example 2 / Example 1; (e) and (f) are low-magnification and high-magnification images of V-CCA obtained in Comparative Example 2 / Example 1 in the longitudinal cross-section, respectively; (g) is a transverse cross-sectional view of V-CCA-H obtained in Example 1; (h) and (i) are low-magnification and high-magnification images of V-CCA-H obtained in Example 1 in the longitudinal cross-section, respectively; (j) is a transverse cross-sectional view of V-CCA-C obtained in Comparative Example 2 / Example 1; (k) and (l) are low-magnification and high-magnification images of V-CCA-C obtained in Comparative Example 2 / Example 1 in the longitudinal cross-section, respectively.

[0015] Figure 2 For Comparative Examples 1-2, the contact angle test diagrams of the VC@CCAH-30 mins composite material obtained in Example 1 are shown; where (a) is the droplet contact angle of R-CCA obtained in Comparative Example 1; (b) is the droplet contact angle of V-CCA obtained in Comparative Example 2 / Example 1; (c) is the droplet contact angle of V-CCA-H obtained in Example 1; (d) is the droplet contact angle of R-CCA-C obtained in Comparative Example 1; and (e) is the droplet contact angle of V-CCA-C obtained in Comparative Example 2 / Example 1.

[0016] Figure 3 The following are the EDS spectra of VC@CCA obtained in Comparative Example 2 / Example 1; where (a) is the total EDS spectrum of V-CCA; and (b) is the total EDS spectrum of V-CCA-C.

[0017] Figure 4 The X-ray photoelectron spectra of VC@CCAH obtained in Example 1 are shown below. Among them, (a) is a comparison of the full XPS spectra of the three-layer structures of V-CCA-C, V-CCA, and V-CCA-H; (b) is the C 1s spectrum of V-CCA-C; (c) is the C 1s spectrum of V-CCA; and (d) is the C 1s spectrum of V-CCA-H.

[0018] Figure 5 The Fourier transform infrared spectrum of VC@CCAH is shown below; (a) is the FTIR spectrum of CMCs, CNF and V-CCA obtained in Example 1; (b) is the FTIR spectrum of the three-layer structure of V-CCA-C, V-CCA and V-CCA-H in VC@CCAH obtained in Example 1.

[0019] Figure 6The X-ray diffraction and Raman spectra of VC@CCAH obtained in Example 1 are shown below; (a) is the XRD spectrum of the three-layer structure of V-CCA-C, V-CCA and V-CCA-H obtained in Example 1; (b) is the Raman spectrum of the three-layer structure of V-CCA-C, V-CCA and V-CCA-H obtained in Example 1.

[0020] Figure 7 The image shows the zeta potential test results for the three-layer structure of VC@CCAH obtained in Example 1, consisting of V-CCA-C, V-CCA, and V-CCA-H layers.

[0021] Figure 8 For Comparative Examples 1-2, the moisture absorption kinetic curves of the CMCs / CNF composite material obtained in Example 1 are shown. Among them, (a) is the moisture absorption kinetic curve of RC@CCA-300s obtained in Comparative Example 1 under different ambient humidity; (b) is the moisture absorption kinetic curve of VC@CCA-300s obtained in Comparative Example 2 under different ambient humidity; (c) is the moisture absorption kinetic curve of VC@CCAH-30 mins obtained in Example 1 under different ambient humidity; (d) is a comparison diagram of the moisture absorption kinetic curves of RC@CCA-300s, VC@CCA-300s and VC@CCAH-30 mins obtained in Example 1 under 85% RH conditions for Comparative Examples 1-2; (e) is a comparison diagram of the moisture absorption kinetic curves of the three-layer VC@CCAH material obtained in Example 1 under 85% RH conditions.

[0022] Figure 9 The graphs show the power generation performance of the RC@CCA obtained in Comparative Example 1 at different carbonization times; where (a) is a comparison graph of open-circuit voltage; (b) is a comparison graph of short-circuit current; (c) is a comparison graph of power density; and (d) is a comparison graph of current density.

[0023] Figure 10 The graphs show the power generation performance of the RC@CCA-300s obtained in Comparative Example 1 under different ambient humidity conditions; where (a) is a comparison graph of open circuit voltage; (b) is a comparison graph of short circuit current; (c) is a comparison graph of power density; and (d) is a comparison graph of current density.

[0024] Figure 11 The graphs show the power generation performance of the RC@CCA-300s obtained in Comparative Example 1 under different ambient temperatures; where (a) is a comparison graph of open-circuit voltage; (b) is a comparison graph of short-circuit current; (c) is a comparison graph of power density; and (d) is a comparison graph of current density.

[0025] Figure 12 The graph shows the relationship between the open-circuit voltage and the number of cycles for the RC@CCA-300s obtained in Comparative Example 1 under conditions of 85% RH and 25℃.

[0026] Figure 13 The graphs show the power generation performance of VC@CCA obtained in Comparative Example 2 at different carbonization times; where (a) is a comparison graph of open-circuit voltage; (b) is a comparison graph of short-circuit current; and (c) is a comparison graph of power density. (d) is a comparison chart of current densities.

[0027] Figure 14 The graphs show the power generation performance of VC@CCA-300 s under different ambient humidity conditions obtained in Comparative Example 2; where (a) is a comparison graph of open circuit voltage; (b) is a comparison graph of short circuit current; and (c) is a comparison graph of power density. (d) is a comparison chart of current densities.

[0028] Figure 15 The graphs show the power generation performance of VC@CCA-300 s obtained in Comparative Example 2 under different ambient temperatures; where (a) is a comparison graph of open-circuit voltage; (b) is a comparison graph of short-circuit current; (c) is a comparison graph of power density; and (d) is a comparison graph of current density.

[0029] Figure 16 The graph shows the relationship between the open-circuit voltage and the number of cycles for the VC@CCA-300 s obtained in Comparative Example 2 under conditions of 85% RH and 25℃.

[0030] Figure 17 The graphs show the power generation performance of VC@CCAH obtained in Example 1 under different negative pressure immersion times; where (a) is a comparison graph of open circuit voltage; (b) is a comparison graph of short circuit current; (c) is a comparison graph of power density; and (d) is a comparison graph of current density.

[0031] Figure 18 The graphs show the power generation performance of VC@CCAH-30 mins obtained in Example 1 under different ambient humidity conditions; where (a) is a comparison graph of open circuit voltage; (b) is a comparison graph of short circuit current; (c) is a comparison graph of power density; and (d) is a comparison graph of current density.

[0032] Figure 19 The graphs show the power generation performance of VC@CCAH-30 mins obtained in Example 1 under different ambient temperatures; where (a) is a comparison graph of open circuit voltage; (b) is a comparison graph of short circuit current; (c) is a comparison graph of power density; and (d) is a comparison graph of current density.

[0033] Figure 20 The following are performance test graphs of VC@CCAH-30 mins obtained in Example 1 under conditions of 85% RH and 25℃; where (a) is the polarity test graph; (b) is the graph showing the relationship between open circuit voltage and number of cycles; and (c) is the graph showing the voltage change when the humidity is turned on and off.

[0034] Figure 21 The graphs show the power generation performance of VC@CCAH-30 mins obtained in Example 1 under different external loads at 85% RH and 25℃; where (a) is the relationship between voltage and load resistance; and (b) is the relationship between current and load resistance.

[0035] Figure 22 The voltage output diagram is for charging the capacitor by VC@CCAH-30 mins, obtained from 5 series-connected capacitors in Example 1.

[0036] Figure 23 The diagram shows the series and parallel electrical signal output and application of the VC@CCAH-30 mins obtained in Example 1 under the conditions of 85% RH and 25℃; where (a) is the series data diagram; (b) is the series physical diagram; (c) is the parallel data diagram; (d) is the parallel physical diagram; and (e) is the actual application diagram. Detailed Implementation

[0037] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and equivalent alterations or modifications also fall within the scope defined by the claims of this application. Example

[0038] Step 1, Preparation of CMCs / CNF suspension: Weigh 0.204 g of cellulose nanofibers (CNF) and 0.408 g of carboxymethyl chitosan (CMCs) and disperse them in 50 mL of deionized water, stirring magnetically for 30 min. Then add 0.408 g of 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride (DMTMM) as an activator, and continue stirring magnetically until homogeneous to obtain the CMCs / CNF suspension.

[0039] 8 ml of CMCs / CNF suspension was added to a polytetrafluoroethylene mold (3 cm in diameter and height, with copper sheet as the bottom material and polytetrafluoroethylene as the other material) with copper sheet at the bottom. After gelation at 45 °C for 3 h, it was rapidly directionally frozen in liquid nitrogen and then freeze-dried in a freeze dryer under vacuum for 72 h to obtain V-CMCs / CNF aerogel with a vertical structure.

[0040] The vertically structured V-CMCs / CNF aerogel was directly impregnated into a CMCs / CNF suspension and placed in a vacuum environment for impregnation and filling for different times of 10 min, 20 min, 30 min and 40 min. Then it was allowed to stand at 45 ℃ for 3 h to obtain the V-CMCs / CNF aerogel / hydrogel composite material.

[0041] The V-CMCs / CNF aerogel / hydrogel composite material was carbonized on a 350℃ heating plate for 300 s to obtain samples. The samples were specifically designated as VC@CCAH-10 mins, VC@CCAH-20 mins, VC@CCAH-30 mins, and VC@CCAH-40 mins, respectively, based on the impregnation time set in this embodiment.

[0042] In summary, the Janus C@CMCs / CNF aerogel composite materials prepared by the above method have the following structures from top to bottom: a carbonized layer, an uncarbonized layer, and a composite hydrogel layer, denoted as V-CCA-C, V-CCA, and V-CCA-H.

[0043] Comparative Example 1: Preparation of R-Janus C@CMCs / CNF aerogel (RC@CCA) To prepare the CMCs / CNF suspension, 0.204 g of cellulose nanofibers (CNF) and 0.408 g of carboxymethyl chitosan (CMCs) were weighed and dispersed in 50 mL of deionized water, and the mixture was magnetically stirred for 30 min. Then, 0.408 g of 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride (DMTMM) was added as an activator, and the mixture was magnetically stirred until homogeneous to obtain the CMCs / CNF suspension.

[0044] 8 ml of CMCs / CNF suspension was added to a custom-made cryogenic mold (a cylindrical mold with a diameter and height of 3 cm and made entirely of polytetrafluoroethylene). After gelation at a constant temperature of 45 °C for 3 h, it was pre-frozen at -20 °C for 24 h. Then, it was transferred to a freeze dryer and freeze-dried under vacuum for 72 h to obtain CMCs / CNF aerogels with arbitrary structures.

[0045] CMCs / CNF aerogels of arbitrary structure were carbonized on a heating plate at 350℃ for 100 s, 200 s, 300 s, 400 s, and 500 s respectively to obtain R-Janus C@CMCs / CNF aerogels with different degrees of carbonization. The aerogels at different carbonization times were recorded as RC@CCA-100s, RC@CCA-200s, RC@CCA-300s, RC@CCA-400s, and RC@CCA-500s. The structures from top to bottom are the carbonized layer and the uncarbonized layer, denoted as R-CCA-C and R-CCA.

[0046] Comparative Example 2: Preparation of V-Janus C@CMCs / CNF aerogel (VC@CCA) To prepare the CMCs / CNF suspension, 0.204 g of cellulose nanofibers (CNF) and 0.408 g of carboxymethyl chitosan (CMCs) were weighed and dispersed in 50 mL of deionized water, and the mixture was magnetically stirred for 30 min. Then, 0.408 g of 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride (DMTMM) was added as an activator, and the mixture was magnetically stirred until homogeneous to obtain the CMCs / CNF suspension.

[0047] 8 ml of CMCs / CNF suspension was added to a polytetrafluoroethylene mold (3 cm in diameter and height, with copper sheet as the bottom material and polytetrafluoroethylene as the other material) with copper sheet at the bottom. After gelation at 45 °C for 3 h, it was rapidly directionally frozen in liquid nitrogen and then freeze-dried in a freeze dryer under vacuum for 72 h to obtain V-CMCs / CNF aerogel with a vertical structure.

[0048] Vertical V-CMCs / CNF aerogels were carbonized on a 350℃ heating plate for 100s, 200s, 300s, 400s, and 500s respectively to obtain V-Janus C@CMCs / CNF aerogels with different degrees of carbonization, denoted as VC@CCA-100s, VC@CCA-200s, VC@CCA-300s, VC@CCA-400s, and VC@CCA-500s. The structures from top to bottom are the carbonized layer and the uncarbonized layer, denoted as V-CCA-C and V-CCA respectively.

[0049] The materials prepared in Example 1 and Comparative Examples 1-2 were tested, and the results are as follows: like Figure 1As shown in (ac), R-CCA exhibits a honeycomb network structure in both the transverse and longitudinal directions. The carboxymethyl chitosan matrix itself can serve as a highly efficient hygroscopic and transporting medium. To further improve its moisture transport performance, this experiment utilized rapid directional freezing with liquid nitrogen to generate vertically growing ice crystals, combined with freeze-drying technology to improve its pore structure. Figure 1 As shown in (df), the V-CCA obtained after structural improvement forms a vertical channel structure in the longitudinal direction, while maintaining a good honeycomb network structure in the transverse direction. Based on this, we further composited CMCs / CNF hydrogel materials onto one side of the V-CCA, from... Figure 1 (gi) It can be observed that the cross-section of V-CCA-H still shows a porous structure with obvious vertical structures in the longitudinal direction. Within its pore structure, plate-like and granular dehydrated hydrogels are clearly observed, exhibiting a rougher internal structure compared to V-CCA, demonstrating successful hydrogel composite. The different hydrogel morphologies and sizes suggest that CMCs / CNF hydrogel materials can adaptively fill V-CCA with different pore sizes. Furthermore, since the Janus structure is constructed through one side of the carbonized aerogel, it is... Figure 1 As shown in (jl), the pore structure of V-CCA-C is relatively well preserved, maintaining a porous mesh structure in the transverse direction and still exhibiting a layered vertical channel structure in the longitudinal direction.

[0050] like Figure 2 The wettability differences of different structures in CMCs / CNF materials can be observed by observing the dynamic process of water droplets wetting the material surface. Figure 2 In (a) and (b), water droplets are fully wetted on the V-CCA surface within only 30 ms, while it takes twice as long to fully wet the R-CCA surface. This comparison demonstrates that vertical channels effectively improve moisture transport performance. Furthermore, through... Figure 2 (c) It can be observed that V-CCA-H completely adsorbs droplets in only 3 ms, demonstrating its superior hydrophilic properties. However, the carbonized aerogel, lacking hydrophilic functional groups on its surface, inhibits capillary permeation to some extent. Figure 2 (d) and (e) clearly show a significant decrease in the hydrophilicity of the carbonized layer, while the water droplet wetting speed of the vertically structured aerogel carbonized layer is still faster than that of the arbitrary structure aerogel carbonized layer.

[0051] like Figure 3 The EDS mapping elemental distribution spectra in (a) and (b) verify that the oxygen content of V-CCA-C is significantly reduced after high-temperature carbonization, thus proving that the high-temperature carbonization process can successfully construct Janus structures with oxygen gradients.

[0052] like Figure 4(a) XPS full spectrum analysis shows that the characteristic peaks of VC@CCAH are basically consistent before and after carbonization because the material remains unchanged. However, the C 1s signal intensity of the carbonized layer of the aerogel after carbonization is significantly enhanced, while the O 1s signal is relatively weakened, indicating that the carbon content in the aerogel is significantly increased after carbonization. Furthermore, from... Figure 4 (b) and (c), the C 1s phase of V-CCA exhibits characteristic peaks at 288.8 eV, 286.2 eV, and 284.8 eV, corresponding to the C=O, CO, and CC bonds in the CMCs / CNF molecules, respectively. However, the characteristic peaks of V-CCA-C show a significant increase in the peak intensity of the CC bond and a decrease in the proportion of C=O and CO bonds. This indicates that oxygen-containing functional groups decompose during carbonization, increasing the proportion of sp2 hybridized CC bonds and forming more graphitized carbon structures. Furthermore, from... Figure 4 (d) The C 1s high-resolution spectral analysis of V-CCA-H shows that it also has three characteristic peaks: C=O (289 eV), CO (286 eV) and CC (284.8 eV). The proportion of the CO bond peak is significantly higher than that of V-CCA and V-CCA-C. This is consistent with the result of the hydrogel introducing a large number of oxygen-containing functional groups, which confirms that the hydrogel loading effectively increases the hydrophilic oxygen-containing groups on the material surface, providing more carriers for ion dissociation and transport in the subsequent wet gas power generation process.

[0053] like Figure 5 As shown in the FTIR spectrum of (a), CMCs are in the range of 3380–3500 cm⁻¹. -1 The characteristic peaks shown are attributed to the stretching vibrations of the -NH2 and -OH groups, in the range of 3000-2800 cm⁻¹. -1 The characteristic peaks appearing at 1735 cm⁻¹ are attributed to the stretching vibrations of -CH and -CH₂. -1 At this location, both CMCs and CNF show obvious -COOH characteristic peaks, and V-CCA also shows this characteristic peak, indicating that both CMCs and CNF contain carboxyl functional groups. Furthermore, at 1648.9 cm⁻¹... -1 1583.0 cm -1 1458.4 cm -1 and 1263.4 cm -1 Three new amide characteristic peaks appeared at 1648.9 cm⁻¹. -1 The characteristic peak of amide I at 1583.0 cm⁻¹ is attributed to the stretching vibration of C=O. -1 and 1458.4 cm -1 The characteristic peak of amide II at 1263.4 cm⁻¹ is attributed to the bending vibration of NH₄⁺. -1The characteristic peak of amide III at [location] is attributed to the stretching vibration of CN. The appearance of this amide peak provides strong evidence for a covalent cross-linking reaction between -NH2 in CMCs molecules and -COOH in CNF molecules. This demonstrates that CMCs and CNF are well-cross-linked via covalent bonds, successfully preparing V-CCA. Simultaneously, [further details about the combination are needed]. Figure 5 (b) It can be seen that V-CCA and V-CCA-H are at 3500 cm -1 1500 cm -1 1000 cm -1 Significant characteristic peaks appeared at all locations, corresponding to -OH / -NH2, C=O, and COC, respectively, which are consistent, indicating that the composite hydrogel did not change the basic chemical structure of the material. Meanwhile, due to the removal of some -NH2 and -OH groups during carbonization, the stretching vibrations of the -NH2 and -OH groups were significantly weakened, with the peak at 1152 cm⁻¹ in V-CCA-C being significantly reduced. -1 1600 cm -1 and 2871cm -1 The corresponding COC, -COOH, and CH signals decreased, which confirmed that the oxygen-containing functional groups underwent thermal decomposition during carbonization and were released in the form of small molecules such as CO2 and H2O. This proved that the carbonization treatment successfully changed the chemical structure of V-CCA, reduced the proportion of oxygen-containing functional groups, increased the content of CC bonds, and endowed the material with a richer carbonized structure, which helps to improve its electron transport performance.

[0054] like Figure 6 (a) XRD spectroscopy reveals a sharp (002) diffraction peak at 26° in the carbonized layer, a typical characteristic of graphitized carbon. This indicates that the carbonization process effectively promoted the ordered arrangement and crystallization of the carbon framework, thus proving the effective construction of the Janus structure. Furthermore, from... Figure 6 (b) 1570 cm⁻¹ can be observed in the Raman spectrum. -1 The obvious G-band at 1360 cm -1 The D band at that location further confirms that graphitized carbon appeared in the carbonized sample.

[0055] like Figure 7The Zeta potential of V-CCA is strongly negative, at approximately -30.25 mV. This is due to the dissociation of carboxyl groups (-COOH) in CMCs molecules and hydroxyl groups (-OH) in CNF molecules. The negatively charged surface can effectively adsorb and promote the directional migration of ions. The Zeta potential of V-CCA-H is -33.08 mV, close to that of V-CCA, indicating that the filling of the hydrogel did not change the surface charge characteristics of the matrix, but only enhanced the ion adsorption capacity by increasing the density of hydrophilic groups. The absolute value of the Zeta potential of V-CCA-C is significantly reduced, indicating that the carbonization treatment reduced the number of oxygen-containing functional groups such as -COOH and -OH on the surface. In addition, the difference in surface charge further proves that a Janus structure with a charge gradient was successfully constructed.

[0056] Depend on Figure 8 (ac) shows the hygrokinetic curves of RC@CCA-300s, VC@CCA-300s, and VC@CCAH-30 mins under different humidity conditions. The figures show that the hygrokinetic properties of all three are positively correlated with humidity; the hygrokinetic properties increase with increasing humidity. Furthermore, the hygrokinetic performance of the three is compared... Figure 8 (d) It can be clearly shown that the moisture absorption performance of the three materials exhibits a progressive relationship. VC@CCAH-30 mins has the fastest moisture absorption rate and the highest equilibrium moisture absorption capacity; VC@CCA-300 s has the next fastest moisture absorption rate and the next highest equilibrium moisture absorption capacity. This is because, compared with RC@CCA-300s, the vertical channel structure inside VC@CCA-300 s enhances the directional transport of moisture. Furthermore, the hydrogel loaded on one side of VC@CCAH-30 mins is a semi-solid swollen gel system, rich in bound water and free water, with stronger hydration of hydrophilic groups and superior adsorption capacity for moisture in the environment. VC@CCAH can enhance the hydration of hydrophilic groups through hydrogel filling, and the vertical channels reduce the moisture transport resistance, thus enhancing the moisture transport performance. Through this dual synergistic effect, the moisture absorption efficiency is maximized. Furthermore, the hygroscopicity of the three-layer structure of VC@CCAH-30 mins (V-CCA-C, V-CCA, and V-CCA-H) from top to bottom was compared. Figure 8 (e) It can be seen that the hygroscopicity of the three substances increases significantly in a stepwise manner, providing an important basic structure for the moisture power generation performance generated by the "charge gradient" of the Janus structure.

[0057] Depend on Figure 9 (a) Figure 9 (b) shows the open-circuit voltage and short-circuit current of RC@CCA at different carbonization times. It is clear that different degrees of carbonization of the aerogel have a significant impact on both voltage and current. Figure 9As can be seen in (a), the open-circuit voltage initially increases with increasing carbonization time, rising from 0.345V to 0.384V at carbonization times of 100 s and 200 s, then reaching a peak of approximately 0.568V at a carbonization time of 300 s, after which it begins to decrease significantly to 0.41V. Figure 9 As shown in (b), the short-circuit current also exhibits the same pattern. The current initially increases with carbonization time, rising from 1.06 μA to 1.5 μA, reaching its highest value of approximately 2.7 μA at a carbonization time of 300 s. Subsequently, it decreases significantly, dropping to 2.0 μA at a carbonization time of 500 s. It can be seen that the current and voltage values ​​are relatively low in the early stages of carbonization. This is because when the carbonization time is short, the surface of CMCs / CNF aerogel still retains a large number of oxygen-containing hydrophilic groups (such as -OH, -COOH), resulting in a weak interfacial humidity gradient and insufficient driving force for ion directional migration. Therefore, the current and voltage are at a low level. However, as the carbonization time is further extended, the interfacial humidity gradient difference increases significantly. At the same time, the hydrophilic groups on the uncarbonized side are not affected and can still efficiently adsorb moisture and provide ion migration carriers. The two work synergistically to improve charge separation efficiency and ion migration flux, resulting in an upward trend in voltage and current. When the carbonization time exceeds 300 s, the aerogel is over-carbonized, which damages the hydrophilic groups on the uncarbonized side, reduces its hygroscopic capacity, decreases the supply of carriers for ion migration, and disrupts the stability of the humidity gradient. Consequently, the voltage and current decrease instead of increase. Therefore, the electrical signal performance is optimal when the carbonization time of RC@CCA is 300 s. Figure 9 (c) Figure 9 (d) shows the power density and current density at different carbonization levels. Both reach their peak values ​​at a carbonization time of 300 s, which is consistent with the above conclusion. It is further concluded that the RC@CCA with carbonization of 300 s achieves the best electrical signal performance. This ensures the hydrophobicity of the carbonized side to build a stable humidity gradient, while avoiding the destruction of the hydrophilic groups on the uncarbonized side, thus achieving the optimal wet gas power generation performance.

[0058] Depend on Figure 10 (a) Figure 10(b) It can be clearly observed that both open-circuit voltage and short-circuit current are positively correlated with humidity, increasing with increasing ambient humidity. When the humidity is 25% RH, 40% RH, 55% RH, 70% RH, and 85% RH, the voltage stabilizes at 0.021 V, 0.128 V, 0.34 V, 0.509 V, and 0.568 V, respectively, showing a gradual upward trend. Similarly, the short-circuit current also increases with increasing humidity, reaching 2.21 μA, 2.43 μA, 2.501 μA, 2.61 μA, and 2.705 μA, respectively. The electrical signal data shows that when the ambient humidity is low, the voltage and current are extremely low. This is because at low humidity, there are fewer water molecules that can be adsorbed in the environment, resulting in insufficient ion carriers for the migration of the uncarbonized aerogel layer after absorbing moisture. This leads to a smaller ion concentration gradient formed by the moisture absorption of the Janus structure between the carbonized and uncarbonized layers, and a weaker driving force for ion directional migration. Therefore, at relatively low ambient humidity, a smaller voltage and current are formed. As humidity increases, the moisture absorption capacity of the uncarbonized layer increases, allowing the uncarbonized aerogel layer to absorb more water molecules, and the ion carrier concentration increases significantly. At the same time, under high humidity, the difference in hydrophilicity between the carbonized and uncarbonized layers becomes more pronounced, and the interfacial humidity gradient difference continues to increase, further strengthening the driving force for ion directional migration. Ultimately, this results in a significant increase in open-circuit voltage and short-circuit current with increasing humidity. Figure 10 (c) Figure 10 (d) Both power density and current density are positively correlated with humidity. The current density increases from 0.28 μA·cm at 25% RH. -2 Increased to 0.36 μA·cm at 85% RH -2 The power density is 0.02 μW·cm⁻¹ -2 Significantly increased to 0.21 μW·cm -2 It increases with increasing humidity.

[0059] Depend on Figure 11 (ad) shows that when the temperature rises from 10℃ to 55℃, the open-circuit voltage increases from 0.36 V to 0.601 V, and the short-circuit current increases from 1.48 μA to 4.21 μA; simultaneously, the current density increases from 0.2 μA·cm⁻¹. -2 Increased to 0.56 μA·cm -2 The power density also increased from 0.072 μW·cm -2 Increased to 0.336 μW·cm -2However, when the temperature continued to rise to 55℃ and 70℃, the voltage began to decrease to around 0.5 V, and the short-circuit current dropped below 3.5 μA. The corresponding current density and power density also showed a significant decrease. This is because at excessively high temperatures, the aerogel's water adsorption capacity is limited, disrupting the adsorption balance of water molecules within the pores and causing them to shift towards desorption. This reduces the number of dissociable water molecules inside the aerogel, offsetting the positive effect of accelerated ion thermal motion, ultimately leading to a decrease in electrical signal performance with increasing temperature. Simultaneously, it was observed that when the ambient temperature was 10℃, the aerogel reached a stable value in approximately 3000 s. As the temperature increased, the required response time gradually decreased, reaching a stable value in only about 1500 s at an ambient temperature of 70℃, confirming that increased temperature can improve the transport efficiency of charge carriers.

[0060] Depend on Figure 12 In the eight-cycle test, the open-circuit voltage remained stable at around 0.56 V for the first six cycles, and began to decrease after the sixth cycle. This result indicates that the RC@CCA-300s can maintain stable power generation output for at least seven cycles, demonstrating certain cyclic performance.

[0061] Depend on Figure 13 (a) It can be clearly observed that the open-circuit voltage of VC@CCA exhibits a "rise then fall" pattern with increasing carbonization time: the voltage is 0.412 V after 100 s of carbonization, rises to 0.463 V after 200 s, continues to rise to a peak of 0.603 V after 300 s, and then begins to decrease with further carbonization time, reaching 0.526 V and 0.489 V at 400 s and 500 s, respectively. The short-circuit current follows the same pattern as the voltage. Figure 13 As shown in (b), the voltage and current initially increase and then decrease according to the carbonization time, specifically at 1.33 μA, 1.64 μA, 3.32 μA, 2.80 μA, and 2.32 μA, respectively, with a peak at 300 s. This indicates that in the early stage of carbonization, more hydrophilic groups are retained on the uncarbonized side, the difference in hydrophilicity between the two sides of the Janus structure is small, and the driving force of the ion concentration gradient is weak. Therefore, the voltage and current increase with the degree of carbonization. When the carbonization time is too long, the heat generated during carbonization may be conducted to the uncarbonized side, affecting its vertical pore structure, weakening the water adsorption capacity, and causing a decrease in the stability of the ion concentration gradient inside the aerogel. Consequently, the electrical signal decreases, and the voltage and current exhibit a peak change pattern of first increasing and then decreasing. Figure 13The variation patterns of power density and current density in (cd) further verify this conclusion. Both show a trend of first increasing and then decreasing, reaching a peak at a carbonization time of 300 s, with a maximum power density of 0.267 μW·cm. -2 The maximum current density is 0.442 μA·cm. -2 This further demonstrates that the degree of "carbonized side - uncarbonized side" obtained when the aerogel is carbonized for 300 s is optimal. At this time, the Janus structure is relatively superior, and the synergistic effect of the ion concentration gradient and the water transport performance inside the aerogel is optimal. Figure 13 The variation patterns of power density and current density in (cd) further verify this conclusion. Both show a trend of first increasing and then decreasing, reaching a peak at a carbonization time of 300 s, with a maximum power density of 0.267 μW·cm. -2 The maximum current density is 0.442 μA·cm. -2 This further demonstrates that the optimal degree of "carbonized side - uncarbonized side" is achieved when the aerogel is carbonized for 300 s. At this point, the Janus structure is relatively superior, and the synergistic effect of the ion concentration gradient and the internal moisture transport performance of the aerogel is optimal. Furthermore, by comparing the voltage and current of RC@CCA, VC@CCA with vertical channels exhibits superior electrical signal performance at different carbonization degrees. This indicates that the vertical channels have a positive promoting effect on improving electrical signal performance. VC@CCA can both promote moisture transport through vertical channels and construct a stable humidity gradient through the Janus structure; the synergistic effect of these two factors further optimizes its power generation performance.

[0062] Depend on Figure 14 (a) Figure 14 (b) It can be observed that both open-circuit voltage and short-circuit current show a significant upward trend with increasing humidity: at 25% RH, the voltage is only 0.026 V and the current is 2.302 μA; at 40% RH, the voltage rises to 0.242 V and the current rises to 2.48 μA; at 55% RH, the voltage continues to rise to 0.366 V and the current is 2.55 μA; at 70% RH, the voltage is 0.529 V and the current is 3.01 μA; at 85% RH, the voltage stabilizes at 0.603 V and the current reaches 3.32 μA. Figure 14 (c) Figure 14 (d) The corresponding power density and current density also showed a synchronous increase: as the humidity gradually increased from 25% RH to 85% RH, the power density and current density of VC@CCA-300 s increased from 0.007 μA·cm⁻¹. -2 0.306 μA·cm -2 Gradually increased to 0.267 μW·cm -20.442 μA·cm -2 Compared to RC@CCA-300s, VC@CCA-300s exhibits superior power generation performance under varying environmental humidity levels. This further demonstrates the positive effect of the vertical structure on moisture transport performance. Even at relatively low environmental humidity (25% RH), the directional moisture absorption capacity of the vertical channels is still superior to any arbitrary channel structure, allowing for the acquisition of more water molecules as ion carriers. As humidity increases, the promoting effect of the vertical channels on moisture transport performance and ion migration becomes more significant, ultimately resulting in a more pronounced increasing trend in all values ​​with rising humidity.

[0063] Depend on Figure 15 (a) Figure 15 (b) It can be seen that as the temperature gradually increases from 10 ℃ to 55 ℃, the open-circuit voltage gradually increases from 0.432 V to 0.625 V, and the short-circuit current increases from 2.312 μA to 5.71 μA. Subsequently, when the temperature continues to rise to 70 ℃, the voltage and current decrease to 0.568 V and 4.61 μA, respectively. The changes in current density and power density show a consistent pattern. Figure 15 (c) Figure 15 (d) It can be observed that the peak value is reached at 55 °C, which is 0.475 μW·cm. -2 0.761 μA·cm -2 The signal then decreased at 70 °C. This indicates that when the temperature is too high, the desorption rate of water molecules in the vertical channels exceeds the adsorption rate, and the stability of the humidity gradient in the oriented channels is also disrupted, ultimately leading to a decrease in the electrical signal. Furthermore, observations... Figure 15 (b) Regarding the voltage stabilization time, the higher the temperature, the shorter the response time of the aerogel. At 10℃, it took 3000 s for the voltage to stabilize, while at 70℃ it only took 1200 s, a faster response than RC@CCA-300s. In summary, compared to RC@CCA-300s, VC@CCA-300s exhibits a higher electrical signal value in a shorter time, indicating that C@CCA with vertical channels has superior and more stable wet gas power generation performance.

[0064] Depend on Figure 16 The results show that the open-circuit voltage remained stable at 0.60 V for the first seven cycles, and began to decrease slightly in the eighth cycle. Compared with the cycling performance of RC@CCA-300s, VC@CCA-300s exhibits better cycling stability, indicating that the constructed internal vertical channels have a more robust directional structure, which reduces channel damage during cycling and makes the ion concentration gradient under the Janus structure more stable, thus maintaining stable power generation performance.

[0065] Depend on Figure 17 (a) It can be seen that with the increase of hydrogel loading, the voltage initially shows a gradual upward trend, reaching 0.633 V, 0.641 V, and 0.689 V at VC@CCAH-10 mins, VC@CCAH-20 mins, and VC@CCAH-30 mins, respectively. However, when the impregnation and vacuum infusion time exceeds 30 mins, the voltage drops to 0.657 V. Figure 17 (b) The current of VC@CCAH also exhibited the same pattern. As the impregnation time increased from 10 mins to 40 mins, the currents were 3.54 μA, 3.62 μA, 3.72 μA, and 3.70 μA, respectively, reaching a peak at 30 min. This indicates that the voltage and current of VC@CCAH initially increased and then decreased with increasing impregnation time. The initial increase is because the CMCs / CNF hydrogel material provides more adsorption sites for the overall structure based on VC@CCA, enhancing its hygroscopic capacity and further facilitating the construction of the ion concentration gradient. Furthermore, the Janus-layered hygroscopic structure of VC@CCAH ensures the stability of the ion concentration gradient. However, excessive hydrogel can overfill the voids in the vertical channels and even block some directional channels, thus weakening the water transport capacity of the vertical channels and further reducing the uniformity and stability of the ion concentration gradient. On the other hand, an excessively thick hydrogel layer can cause excessive aggregation of hydrophilic groups in the uncarbonized layer, which reduces the interfacial humidity difference of the Janus structure, weakens the driving force for directional ion migration, and weakens the effect of the ion concentration gradient. At the same time, the swelling effect of excessive hydrogel can destroy the aerogel's framework structure to some extent, further affecting the construction of the humidity gradient, ultimately causing the open-circuit voltage to decrease instead of increase. The power density and current density in 17(c) and (d) show the same variation law as the voltage and current, further verifying the above law. Therefore, we selected VC@CCAH-30 mins, which currently has the best electrical signal, for subsequent tests.

[0066] Depend on Figure 18 As shown in the voltage and current curves under different humidity levels in (a) and (b), both the open-circuit voltage and short-circuit current exhibit a significant upward trend with increasing ambient humidity. At 25% RH, the voltage remains relatively constant at 0.022 V. As the humidity increases to 40% RH, 55% RH, and 75% RH, the voltage rises to approximately 0.304 V, 0.447 V, and 0.488 V respectively. When the humidity reaches 85% RH, the voltage stabilizes at approximately 0.689 V. The short-circuit current follows the same pattern as the voltage. Figure 18As shown in (b), the current is only 2.45 μA at 25% RH, and gradually increases to 3.72 μA as the humidity rises to 85% RH. Comparison shows that the electrical signal of VC@CCAH-30 mins under different ambient humidity levels is higher than that of RC@CCA-300s and VC@CCA-300s, further illustrating that the synergistic structure of the vertical channels and composite hydrogel further enhances the response performance to humidity. That is, the hydrogel provides more adsorption sites, while the vertical channels enhance the directional transport of water. As humidity increases, the hydrophilic groups of the hydrogel can efficiently adsorb water molecules from the environment, and the directional structure of the vertical channels ensures water penetration, causing the humidity gradient difference at the Janus interface to continuously increase, and the driving force of ion directional migration to be enhanced simultaneously, ultimately leading to a further increase in voltage and current with humidity. The corresponding changes in power density and current density further verify this conclusion. Figure 18 (c) and (d) demonstrate that the power density increased from nearly 0 at 25% RH to 0.342 μW·cm at 85% RH. -2 The current density also increased from 0.326 μA·cm⁻² at 25% RH to 0.496 μA·cm⁻² at 85% RH. -2 Both showed a clear positive correlation with humidity, and both showed higher values ​​than those mentioned above. This indicates that VC@CCAH-30 mins achieves better wet gas power generation performance in a high humidity environment (85% RH).

[0067] Depend on Figure 19 The power generation performance curves at different temperatures show that both open-circuit voltage and short-circuit current first increase and then decrease with temperature. At 10℃, the voltage is only 0.5 V, gradually increasing to a peak of approximately 0.689 V as the temperature rises to 55℃, before decreasing to around 0.58 V at 70℃. The current stabilizes at around 3.618 μA at 10℃, rises to a peak of 5.713 μA at 55℃, and then drops back to 4.601 μA at 70℃. Figure 19 The changes in power density and current density corresponding to (c) and (d) follow the same pattern as those of voltage and current. Meanwhile, according to... Figure 19(a) Voltage change rate: As mentioned earlier, increasing temperature accelerates the thermal motion rate of ions within the material. The electrical signal of VC@CCAH-30 mins at high temperature (70℃) only stabilizes around 1400 s. Simultaneously, due to the synergistic effect of vertical channels and hydrophilic groups, the electrical signal gradually increases with temperature. When the temperature rises to 55℃, the positive effect of ion thermal motion and the ion concentration gradient under the Janus structure reaches its optimum. However, at excessively high temperatures, not only does the desorption rate of water molecules within the vertical channels exceed the adsorption rate, disrupting the stability of the ion concentration gradient under the Janus structure, but water molecules within the hydrogel also desorb due to the high temperature, ultimately leading to a decrease in power generation performance.

[0068] Depend on Figure 20 (a) When the positive and negative electrode switching test was performed on VC@CCAH-30 mins at 85% RH, it was observed that the voltage rose rapidly in the initial state and stabilized at about 0.68 V; when the electrode was reversed, the voltage dropped rapidly and stabilized at about -0.68 V, showing that the voltage amplitude after reversal was basically the same as that in the forward state. This result indicates that the electrical signal of VC@CCAH-30 mins is the result of the concentration gradient formed by the directional migration of ions.

[0069] To investigate its durability, the VC@CCAH-30 mins was subjected to 8 cycles of testing under high humidity conditions (85% RH, 25 ℃). Figure 20 The results in (b) show that the open-circuit voltage is consistently between 0.68 V, indicating that the addition of hydrogel material, based on the stable internal directional structure of the vertical channels, makes water transport more stable and durable, thus achieving superior recyclability. Furthermore, due to... Figure 20 (c) It can be seen from the opening and closing of the moisture that the voltage gradually rises to a stable value under the action of moisture. When the action of moisture is turned off, the voltage drops rapidly. Then, when the moisture is restored, the voltage gradually rises back to the original value. This not only illustrates the key role of humidity conditions in power generation performance, but also shows stable cycle characteristics.

[0070] Depend on Figure 21 (ab) As shown in the load resistance correlation curves, voltage and current exhibit a typical "inverse correlation" pattern with changes in load resistance. When the resistance changes from 10... 1 Ω increased to 10 8 At a resistance of approximately Ω, the voltage gradually increases from 0.1 V to 0.68 V, while the current continuously decreases from 3.5 μA. The corresponding power exhibits a trend of "first increasing and then decreasing," especially at a resistance of approximately 10Ω. 5The power output reaches its peak at Ω, and then decreases as the resistance increases. This conforms to Ohm's law and power output characteristics: at low resistance, the current in the circuit is large, but the voltage is low; at high resistance, the voltage is close to the open-circuit voltage, but the current approaches zero; while the power reaches its maximum value in this equilibrium range. Therefore, the optimal load resistance for VC@CCAH-30 mins is approximately 10Ω. 5 Ω, at which point the maximum power output can be achieved.

[0071] Five VC@CCAH-30 mins capacitors were connected in series using carbon conductive adhesive, and charged and discharged using capacitors of 1 μF, 4.7 μF, and 10 μF respectively. The voltages measured with a digital multimeter eventually stabilized at approximately 3.4 V. The results are as follows: Figure 22 The capacitor charge-discharge curves show that VC@CCAH-30 mins can effectively charge capacitors of different capacities, and the voltages of 1 μF, 4.7 μF and 10 μF capacitors eventually stabilize at around 3.4 V. This result verifies that VC@CCAH has a certain energy storage capacity.

[0072] Depend on Figure 23 As shown in (a) and (b), the voltage increases in a stepwise manner with the increase of the number of series-connected devices. With a single sample, the voltage is stable at around 0.68 V. With each additional sample in series, the voltage increases in a stepwise manner: reaching 1.36 V with two samples, 2.082 V with three samples, and finally reaching approximately 3.392 V with five samples. Figure 23 As shown in (c) and (d), the current also exhibits a stepwise increasing trend with the increase of the number of parallel samples. The current is 3.73 μA with one sample, and stabilizes at around 17.4 μA with five parallel samples. Then... Figure 23 As shown in (e), when five samples are connected in series, a small calculator is connected and the calculator is activated, which shows that it can be powered and has certain practical application performance.

Claims

1. A method for preparing a Janus C@CMCs / CNF aerogel composite material, characterized in that, Includes the following steps: S1. Cellulose nanofibers and carboxymethyl chitosan were uniformly dispersed in deionized water and magnetically stirred for 30 min; then 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride was added as an activator, and magnetic stirring was continued until the mixture was uniform to obtain a CMCs / CNF suspension. S2. The CMCs / CNF suspension was transferred to a polytetrafluoroethylene cylindrical mold with a copper sheet at the bottom, gelled at a constant temperature of 45 ℃ for 3 h, and then placed in liquid nitrogen for rapid directional freezing, followed by freeze drying for 72 h to obtain V-CMCs / CNF aerogel with a vertical pore structure. S3. Immerse one side of the V-CMCs / CNF aerogel in the CMCs / CNF suspension, place it under vacuum for 10-40 min to impregnate and fill, and then let it stand at 45 ℃ for 3 h to obtain the V-CMCs / CNF aerogel / hydrogel composite material. S4. The unimpregnated side was carbonized using a one-sided carbonization process to finally prepare the V-Janus C@CMCs / CNF aerogel / hydrogel composite material.

2. The method of making Janus C@CMCs / CNF aerogel composites of claim 1, wherein, In step S1, the mass ratio of the cellulose nanofibers, carboxymethyl chitosan and 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride is 1:2:2, and the concentration of the cellulose nanofibers is 0.4 wt%.

3. The method of making Janus C@CMCs / CNF aerogel composites of claim 1, wherein, In step 3, the impregnation and filling time is 30 minutes.

4. The method for preparing the Janus C@CMCs / CNF aerogel composite material according to claim 1, characterized in that, In step 4, the carbonization conditions are 350 °C for 300 s.

5. Janus C@CMCs / CNF aerogel composite material prepared according to the preparation method of any one of claims 1-4.

6. The Janus C@CMCs / CNF aerogel composite of claim 5, wherein, The JanusC@CMCs / CNF aerogel composite material comprises, from top to bottom, a carbonized layer, an uncarbonized layer, and a composite hydrogel layer.

7. Application of Janus C@CMCs / CNF aerogel composite material according to claim 5 in wet gas power generation.

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