Use of a carbon nanomembrane in a permeation energy conversion device

Abstract

The application discloses application of a carbon nanochannel membrane in a light-enhanced permeation energy conversion device, and the carbon nanochannel membrane is prepared by sequentially compounding an ordered mesoporous carbon layer, [Fe(EDTA)] ‑ and poly-N-vinyl carbazole (PVK) on a porous ATO membrane. The prepared product has a pore diameter of 130 nm, a porosity of 55%, and a closely combined interface, and has high double conductivity and light-sensitive regulation, is suitable for a permeation energy conversion device, and can improve energy conversion efficiency and operation stability.

Description

Technical Field

[0001] This invention belongs to the field of nano-carbon materials and electrochemical devices, specifically relating to a porous carbon-based nanofilm, hereinafter referred to as carbon nanofilm, for use in energy conversion and electrochemical energy storage devices driven by salinity gradient / ion permeation, and the film has the function of photo-triggered modulation of ion flux and stable current. Background Technology

[0002] This invention relates to the field of materials technology for permeation energy conversion devices, specifically to background technology for carbon nanofilms suitable for permeation energy conversion devices, particularly for carbon nanofilms used as ion-conducting layers or composite membranes as core components of these devices. With the increasing prominence of the global energy crisis and environmental problems, the development and efficient utilization of clean and renewable energy have become key directions for scientific research and industry in various countries. Permeation energy conversion technologies (such as salinity gradient power generation), with their advantage of relying on widely available resources such as seawater and salt lakes to achieve synergistic development of energy recovery and water resource utilization, have gradually become a research hotspot and industrialization potential direction in the new energy field. As the core functional component of permeation energy conversion devices, the ion-conducting layer / composite membrane plays a crucial role in ion selective transport, charge conduction, and interface isolation. Its comprehensive performance directly determines the device's ion transport efficiency, energy conversion efficiency, long-term operational stability, and adaptability to operating conditions. Therefore, stringent requirements are placed on such components, requiring them to simultaneously possess excellent electronic conductivity, high-efficiency ion permeability, good structural stability, strong interface compatibility, and flexible external controllability.

[0003] To meet these performance requirements, researchers are constantly exploring novel composite thin film materials. Among them, carbon nanomaterials are widely used to prepare carbon nanofilms for ion-conducting layers due to their high specific surface area, excellent electronic conductivity, tunable porous structure, and good chemical stability. Common carbon nanomaterials include ordered mesoporous carbon, carbon nanotube (CNT) cross-linked porous carbon, reduced graphene oxide (rGO) porous carbon, and nitrogen-doped porous carbon. These materials can provide convenient pathways for ion transport by constructing continuous porous channels, while ensuring efficient electron conduction. Meanwhile, porous ATO (anodic oxide TiO2) films are often chosen as substrate materials for composite films due to their high mechanical strength, resistance to acid and alkali corrosion, excellent chemical stability, and good substrate support. When combined with carbon nanomaterials, they can effectively improve the structural stability of the film and avoid the structural collapse problem caused by the self-stacking of carbon nanolayers.

[0004] To further optimize the ion transport performance and functional adaptability of composite films, existing technologies often modify carbon nanotube-ATO composite films through two methods: Firstly, by loading EDTA-metal complexes (such as EDTA complexes of iron, nickel, and cobalt), the specific adsorption and conduction interactions between the complexes and ions are utilized to enhance the film's ion adsorption capacity and conduction stability, thereby increasing ion transport flux. Secondly, conjugated conductive polymers (such as polythiophene and its derivatives, polyaniline, polycarbazole and its derivatives, polyindole, etc.) are introduced, leveraging the conjugated structure of the polymer to regulate the film's conductivity, achieving preliminary adjustment of the ion transport rate. Currently, this type of composite modification approach has seen initial applications in fields such as permeation energy conversion and electrochemical energy storage, but it remains in the laboratory research and development stage and has not yet achieved large-scale industrialization.

[0005] However, existing carbon nanofilms and their preparation technologies still face numerous technical bottlenecks that urgently need to be addressed, making it difficult to meet the high-efficiency and stable operation requirements of permeation energy conversion devices under complex conditions (such as dynamic salinity changes, long-term electrolyte immersion, and electrochemical corrosion environments). The specific shortcomings can be summarized as follows: First, existing composite films are mostly constructed using simple coating and physical mixing methods, resulting in a loose interfacial bond between the carbon nanolayer and the ATO membrane. This leads to poor pore connectivity, easily causing pore misalignment, blockage, and tortuous ion transport paths. This not only increases ion transport resistance but also causes significant fluctuations in ion flux, severely affecting the stability of the device's energy conversion efficiency. Second, EDTA-metal complexes are mostly loaded onto the film surface and within the pores through physical adsorption. Poor load uniformity and weak adhesion to carbon nanotube substrates and ATO films make them prone to detachment and loss under long-term electrolyte immersion, ion impact, and electrochemical action. This prevents them from continuously optimizing ion adsorption and conduction, leading to increased concentration polarization at the electrode interface. The device current density can fluctuate by more than 20%, resulting in a significant decrease in operational reliability. Thirdly, the synergistic design between the conjugated conductive polymer and the carbon nanotube substrate is insufficient. Existing polymer modifications mostly focus on conductivity adjustment and lack the ability to achieve real-time and precise control of ion transport rate through external mild stimuli (such as light). Traditional electro- and thermal control methods suffer from high energy consumption, slow response, and damage to the device structure, making them unsuitable for the flexible adjustment of device performance under dynamic operating conditions.

[0006] Fourth, the synergistic design of the structural stability of the carbon nanomaterial substrate and the ATO membrane is lacking. The porous structure formed by the stacking of carbon nanomaterials is prone to collapse during long-term operation. Furthermore, the interfacial compatibility between the carbon nanomaterial substrate and the ATO membrane is poor, and after long-term immersion and electrochemical action, problems such as membrane peeling and cracking are likely to occur, significantly shortening the device's lifespan and increasing operation and maintenance costs. Fifth, the existing preparation process lacks a systematic synergistic design. The steps of carbon nanomaterial substrate composite, EDTA-metal complex deposition, and conjugated conductive polymer polymerization are independent of each other, without considering the interfacial compatibility of each functional layer. This results in significant interfacial impedance between layers, reducing the translayer conduction efficiency of electrons and ions, and further restricting the improvement of the overall performance of the composite film. In addition, the existing technology lacks sufficient precision in controlling key structural parameters such as pore size and porosity of the composite film, making it difficult to achieve a precise balance between ion transport efficiency and structural stability, further limiting its application in high-performance permeation energy conversion devices.

[0007] Currently, domestic and international research teams have conducted relevant improvement studies to address some of the aforementioned defects. For example, they have improved pore connectivity by optimizing the dispersion process of carbon nanomaterials or enhanced the loading stability of complexes through chemical bonding. However, these studies mostly optimize only a single defect and fail to achieve synergistic improvements in the structure, performance, and preparation process of each functional layer, thus failing to fundamentally solve the overall performance bottleneck of existing composite films. Therefore, developing a carbon nanofilm with a rational structural design, synergistic adaptation of each functional layer, controllable external illumination, excellent structural stability, and a feasible preparation process system is crucial to overcoming the many limitations of existing technologies. This is a key core technology for promoting the transition of permeation energy conversion devices from laboratory research to large-scale industrial application, and is of great significance for promoting technological progress and industrial upgrading in the field of clean and renewable energy.

[0008] Based on the shortcomings of existing technologies and the needs of industry development, this invention aims to provide a carbon nanofilm based on a porous ATO membrane, sequentially composited with a carbon nanolayer, an EDTA-metal complex, and a conjugated conductive polymer. By precisely designing the structural parameters and interfacial bonding methods of each functional layer, efficient connectivity between the pores of the carbon nanolayer and the ATO membrane is achieved, improving the loading uniformity and bonding stability of the EDTA-metal complex, and strengthening the π-π stacking synergy and photosensitivity of the conjugated conductive polymer and the carbon nanolayer. Simultaneously, the systematic and synergistic nature of the preparation process is optimized, improving the interfacial compatibility of each functional layer and reducing interfacial impedance. Ultimately, through the synergistic structure and performance of each functional layer, the core problems of existing thin films, such as unstable ion transport, severe interfacial polarization, lack of controllability, and poor structural stability, are solved. This significantly improves the energy conversion efficiency, operational stability, and service life of the permeation energy conversion device, providing core material support for the industrialization and promotion of permeation energy conversion technology.

[0009] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides an application of carbon nanofilms in permeation energy conversion devices.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: a carbon nanofilm, wherein the carbon nanofilm uses a porous ATO (anodic oxide TiO2) film as a substrate, and the surface and channels of the ATO film are sequentially composited with a carbon nanolayer, an EDTA-metal complex, and a conjugated conductive polymer; the carbon nanolayer is a continuous film layer composed of porous carbon nanomaterials, and its porous structure is connected with the channels of the ATO film to form a continuous ion transport channel;

[0012] The carbon nanolayer is one of the following: ordered mesoporous carbon, carbon nanotube (CNT) crosslinked porous carbon, reduced graphene oxide (rGO) porous carbon, and nitrogen-doped porous carbon.

[0013] Preferably, the EDTA-metal complex is [Fe(EDTA)]. - [Ni (EDTA)] 2- [Co (EDTA)] 2- One of them has a loading capacity of 0.5~2 mg / cm³. 2 .

[0014] Preferably, the conjugated conductive polymer includes one of polythiophene (PTh) and its derivatives (poly-3-methylthiophene PMT, poly-3-hexylthiophene P3HT), polyaniline (PANI), polycarbazole (PCz) and its derivatives, or polyindole (PIn), with a film thickness of 30~100nm, and forming π-π stacks with the carbon nanolayer.

[0015] Preferably, the pore size of the carbon nanofilm is 50~300nm.

[0016] Preferably, the porosity of the carbon nanofilm is 45-70%.

[0017] A method for preparing the aforementioned carbon nanofilm includes the following steps:

[0018] 1) Activation of ATO membrane: The ATO membrane was ultrasonically cleaned with anhydrous ethanol and deionized water for 10 min each, and dried with nitrogen gas. The ATO membrane was then placed in a 0.5 mol / L H2SO4 solution for constant potential polarization at 1.0 V vs. SCE for 3 min. After that, it was rinsed with deionized water and dried for later use.

[0019] 2) Carbon nano-base layer composite: Carbon nanomaterial dispersion is composited on the surface and pores of the activated ATO membrane in step 1), and then dried and cross-linked at high temperature to fix the carbon nano-base layer and the ATO membrane, so that the carbon nano-base layer is tightly bonded to the ATO membrane and the pores are connected, thus obtaining an ATO composite membrane loaded with carbon nano-base layer.

[0020] 3) EDTA-metal complex deposition: Prepare an EDTA-metal complex solution with a concentration of 0.01~0.1mol / L. Immerse the ATO composite membrane obtained in step 2) into the complex solution. Use a chemical bath deposition method to uniformly load the EDTA-metal complex onto the surface and pores of the ATO membrane. After deposition, clean and dry to obtain the ATO substrate membrane loaded with the complex.

[0021] 4) In-situ chemical oxidation polymerization of conjugated conductive polymer: Prepare a polymerization system containing conjugated conductive polymer monomers and oxidants, with a monomer concentration of 0.05~0.15 mol / L and a molar ratio of oxidant to monomer of 1:1~3:1; uniformly add the polymerization system to the surface of the ATO substrate film in step 3) by drop addition to form a porous carbon nanofilm.

[0022] 5) Post-treatment: After polymerization, the ATO membrane is immediately removed for cleaning, gentle drying and shaping. It is ultrasonically cleaned with anhydrous ethanol for 30 seconds at low speed and 100W to remove unpolymerized monomers and supporting electrolytes from the membrane surface. After drying with nitrogen, it is left to stand at room temperature for 12~24 hours to shape.

[0023] Preferably, in step 3), the pH value is adjusted to 8-10, the deposition temperature is 40-70℃, and the deposition time is 20-60 min; the cleaning is performed by rinsing with deionized water 2-3 times and drying with nitrogen.

[0024] Preferably, in step 4), the oxidant is one or more of ammonium persulfate, ferric chloride, and potassium persulfate; the dropping volume is 0.5~2 mL / cm³. 2 After prepolymerization at room temperature for 3-10 minutes, the base membrane is immersed in the polymerization system and the reaction continues for 5-15 minutes to complete the in-situ polymerization.

[0025] Preferably, the concentration of the carbon nanomaterial dispersion in step 2) is 0.1~0.5 mg / mL, the dispersion medium is a mixture of water and ethanol, and the volume ratio of the two is 1:1~3:1; the drying temperature is 60~80℃, the drying time is 20~40 min; the high-temperature crosslinking temperature is 200~300℃, and the heat preservation time is 1~2 h.

[0026] Application of a carbon nanofilm in a permeation energy conversion device, with a surface conductivity ≥10 -2 S / cm, ionic conductivity ≥10 -3S / cm, the carbon nanofilm is used as an ion-conducting layer or composite membrane, and the ion transport rate is controlled by photo-controlled conjugated conductive polymer to improve the energy conversion efficiency of the device.

[0027] This invention achieves a breakthrough in the comprehensive performance of carbon nanofilms through a four-layer synergistic structure design of "porous ATO membrane substrate - carbon nanolayer - EDTA - metal complex - conjugated conductive polymer" and corresponding process optimization, precisely solving the core bottlenecks of existing technologies. The specific technical effects are as follows:

[0028] Firstly, structural stability and interfacial compatibility are significantly improved: After high-temperature cross-linking and shaping, the carbon nanotube substrate is tightly bonded to the ATO membrane and the pores are efficiently connected. Combined with the uniform loading of EDTA-metal complex and the stable π-π stacking of polymer and carbon nanotube substrate, the problems of pore collapse, membrane peeling and complex loss are effectively avoided, which extends the service life of the film by more than 3 times under complex electrolyte conditions and greatly reduces the device operation and maintenance costs.

[0029] Secondly, ion transport performance and operational stability are optimized: Based on a precise pore size of 50–300 nm, a porosity of 45–70%, and a continuous ion transport channel design, combined with the ion adsorption and conduction effects of EDTA-metal complexes, ion transport resistance is significantly reduced, interfacial concentration polarization is alleviated, and device current density fluctuations are controlled within 5%, with surface conductivity ≥10. -2 S / cm, ionic conductivity ≥10 -3 S / cm, energy conversion efficiency improved by 15~25%.

[0030] Third, it enables gentle and precise control of ion transport: by utilizing the photosensitive properties of conjugated conductive polymers, the ion transport rate can be controlled in real time by adjusting the illumination parameters. This eliminates the need for high-energy-consuming and easily damaged control methods, resulting in rapid response, convenient operation, and adaptability to complex working conditions with dynamic changes in salinity and electrolyte concentration.

[0031] Fourth, the feasibility and scalability potential of the process are highlighted: by adopting mature technologies such as chemical bath deposition and in-situ polymerization, each step is coordinated and adapted, and the thin film structure parameters can be precisely controlled to ensure performance consistency. Moreover, no special high-end equipment is required and the cost is controllable, which solves the problems of fragmentation and insufficient parameter accuracy of existing processes and provides support for mass production.

[0032] Fifth, it has broad adaptability and expansion potential: the membrane can be used as an ion conduction layer / diaphragm for permeation energy conversion devices, and is also suitable for fields such as electrochemical energy storage and water purification; by adjusting the selection of functional layer materials and parameters, the membrane performance can be flexibly controlled, leaving ample room for subsequent optimization and expansion.

[0033] In summary, this invention, through synergistic innovation in structure and process, enables the thin film to achieve comprehensive advantages in stability, transport performance, controllability, and process feasibility, providing core material support for the industrialization of permeation energy conversion technology. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall device assembly;

[0035] Figure 2 A schematic diagram of the basic unit for ion transport → current generation;

[0036] Figure 3 The current-voltage (IV) characteristic curve is shown.

[0037] Figure 4 This is a schematic diagram of ion transport.

[0038] Figure 5 SEM image of membrane pores;

[0039] Figure 6 X-ray photoelectron spectroscopy (XPS) of the interaction between π-π stacks and interfaces. Detailed Implementation

[0040] The present invention will be further described below through specific embodiments. To make the inventive objectives, technical solutions, and beneficial technical effects of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the embodiments described in this specification are merely for explaining the present invention and are not intended to limit the present invention.

[0041] Unless otherwise stated, all instruments and reagents used in the examples are commercially available or synthesized using conventional methods and can be used directly without further processing, and all instruments used in the examples are commercially available.

[0042] Example 1:

[0043] Ordered mesoporous carbon was selected as the carbon nanolayer material, with the EDTA-metal complex being [Fe(EDTA)]⁻ and the conjugated conductive polymer being polythiophene (PTh). The specific steps are as follows: First, the porous ATO membrane was treated according to conventional activation procedures, sequentially ultrasonically cleaned with anhydrous ethanol and deionized water for 10 min each, dried under nitrogen, and then placed in a 0.5 mol / L H₂SO₄ solution for 3 min at a constant potential of 1.0 V (vs. SCE). After rinsing and drying, it was ready for use. A dispersion of ordered mesoporous carbon with a concentration of 0.3 mg / mL was prepared, using a water-ethanol mixture (volume ratio 2:1). This dispersion was then composited onto the surface and pores of the activated ATO membrane, dried at 70℃ for 30 min, and then crosslinked at 250℃ for 1.5 h to obtain an ATO composite membrane loaded with an ordered mesoporous carbon layer. A [Fe(EDTA)]⁻ solution with a concentration of 0.05 mol / L was also prepared. - The complexation solution was adjusted to pH 9, and the composite membrane was immersed in the solution. Chemical bath deposition was performed at 60°C for 40 min. After rinsing twice with deionized water, the membrane was dried at room temperature under nitrogen to obtain the substrate membrane loaded with the complex. A polymerization system with a polythiophene monomer concentration of 0.1 mol / L was prepared, using ammonium persulfate as the oxidant at a molar ratio of 2:1 to monomer. The ammonium persulfate was added dropwise to the substrate membrane surface at a rate of 1.0 mL / cm². After prepolymerization at room temperature for 6 min, the membrane was immersed in the polymerization system and the reaction continued for 10 min to complete in-situ polymerization. Finally, after standard post-treatment, the membrane was ultrasonically cleaned with anhydrous ethanol at 100 W for 30 s, dried under nitrogen, and allowed to stand at room temperature for 18 h for setting, yielding the finished carbon nanofilm with a pore size of 180 nm and a porosity of 58%, [Fe(EDTA)]. ⁻ Loading capacity is 1.2 mg / cm³ 2 The polythiophene film thickness is 65nm.

[0044] Example 2:

[0045] Cross-linked porous carbon nanotubes (CNTs) were selected as the carbon nanolayer material, and the EDTA-metal complex was [Ni(EDTA)]. 2- The conjugated conductive polymer is poly-3-methylthiophene (PMT). The porous ATO membrane was prepared using conventional activation treatment. A CNT dispersion with a concentration of 0.2 mg / mL was prepared, with a water-ethanol mixture (volume ratio 1:1) as the dispersion medium. This dispersion was then applied to the surface and pores of the activated ATO membrane, dried at 80℃ for 25 min, and then crosslinked at 220℃ for 2 h to form a composite membrane in which the CNT crosslinked porous carbon layer is tightly bonded to the ATO membrane. A [Ni(EDTA)] concentration of 0.03 mol / L was also prepared. 2-A complexing solution was prepared, pH adjusted to 8.5. The composite membrane was immersed in the solution and deposited in a chemical bath at 50°C for 50 min. After rinsing three times with deionized water, it was vacuum dried at 45°C for 20 min to obtain a substrate membrane loaded with the complex. A 0.08 mol / L poly-3-methylthiophene monomer polymerization system was prepared, with a potassium persulfate and ferric chloride mixture (mass ratio 1:1) as the oxidant and a monomer molar ratio of 1.5:1. This mixture was added dropwise to the substrate membrane surface at a rate of 0.8 mL / cm². After prepolymerization at room temperature for 8 min, the membrane was immersed in the system and the reaction continued for another 8 min. After standard post-treatment and shaping, the finished film had a pore size of 120 nm and a porosity of 52%, [Ni(EDTA)]. 2- The loading capacity was 0.9 mg / cm³. 2 The poly-3-methylthiophene film has a thickness of 45 nm.

[0046] Example 3:

[0047] Reduced graphene oxide (rGO) porous carbon was selected as the carbon nanolayer material, and the EDTA-metal complex was [Co(EDTA)]. 2- The conjugated conductive polymer is polyaniline (PANI). After activation treatment of the porous ATO membrane, a 0.4 mg / mL rGO dispersion (water to ethanol volume ratio 3:1) was composited onto its surface and within the pores. The membrane was dried at 65℃ for 35 min and then crosslinked at 280℃ for 1 h to obtain the rGO porous carbon composite ATO membrane. A 0.08 mol / L [Co(EDTA)] solution was also prepared. 2- The complexing solution was adjusted to pH 9.5, and chemically deposited at 70°C for 30 min. After rinsing twice with deionized water, the mixture was dried under nitrogen at room temperature. A 0.12 mol / L polyaniline monomer polymerization system was prepared, with ammonium persulfate as the oxidant at a molar ratio of 2.5:1, at a concentration of 1.5 mL / cm³. ² The [Co(EDTA)] film was added dropwise at a uniform rate, pre-polymerized at room temperature for 5 min, and then immersed in the system for 12 min of reaction. After post-treatment and shaping, the finished film had a pore size of 220 nm and a porosity of 63%. 2- The loading capacity was 1.6 mg / cm³. 2 The polyaniline film is 80nm thick.

[0048] Example 4:

[0049] Nitrogen-doped porous carbon was selected as the carbon nanomaterial substrate, and the EDTA-metal complex was [Fe(EDTA)]. - The conjugated conductive polymer is poly-3-hexylthiophene (P3HT). After routine activation, the porous ATO membrane is coated with a nitrogen-doped porous carbon dispersion (water to ethanol volume ratio 2:1) at a concentration of 0.15 mg / mL, dried at 75℃ for 20 min, and then crosslinked at 240℃ for 1.5 h. A 0.06 mol / L [Fe(EDTA)] solution is also prepared.- Complexing solution, pH=10, chemical bath deposition at 45℃ for 55 min, rinsed three times with deionized water, and vacuum dried at 60℃ for 15 min. Prepare a 0.09 mol / L poly-3-hexylthiophene monomer polymerization system, using potassium persulfate as the oxidant, with a molar ratio of 1:1 and a dropping volume of 2.0 mL / cm³. 2 After prepolymerization at room temperature for 10 minutes, the mixture was immersed in the system and the reaction continued for another 7 minutes. Following standard post-treatment, the finished film had a pore size of 260 nm and a porosity of 67%, [Fe(EDTA)]. - Loading capacity is 1.8 mg / cm³ 2 The thickness of the poly(3-hexylthiophene) film is 90 nm.

[0050] Example 5:

[0051] Nitrogen-doped porous carbon was selected as the carbon nanomaterial substrate, and the EDTA-metal complex was [Ni(EDTA)]. 2- The conjugated conductive polymer is polyindole (PIn). After activation of the porous ATO membrane, a nitrogen-doped porous carbon dispersion (water to ethanol volume ratio 3:1) with a concentration of 0.45 mg / mL was prepared, dried at 60℃ for 40 min, and then crosslinked at 290℃ for 1.2 h. A 0.09 mol / L [Ni(EDTA)] solution was also prepared. 2- Complexing solution, pH=8, chemical bath deposition at 65℃ for 25 min, rinsed twice with deionized water and dried at room temperature. Prepare a 0.14 mol / L polyindole monomer polymerization system, using ferric chloride as the oxidant, with a molar ratio of 3:1 and a dropping volume of 0.5 mL / cm³. 2 After prepolymerization at room temperature for 3 minutes, the film was immersed in the system for a reaction of 15 minutes. Following post-treatment and settling, the finished film had a pore size of 80 nm and a porosity of 48% [Ni(EDTA)]. 2- Loading capacity is 0.6 mg / cm³ 2 The polyindole film is 35 nm thick.

[0052] Example 6:

[0053] Reduced graphene oxide (rGO) porous carbon was selected as the carbon nanolayer material, and the EDTA-metal complex was [Co(EDTA)]. 2- The conjugated conductive polymer is polycarbazole (PCz). The porous ATO membrane was routinely activated and ready for use. A 0.35 mg / mL rGO dispersion was prepared using a water-ethanol mixture (2:1 volume ratio) and composited onto the surface and pores of the activated ATO membrane. The membrane was dried at 70℃ for 30 min and then crosslinked at 260℃ for 1.5 h to obtain the rGO porous carbon composite ATO membrane. A 0.07 mol / L [Co(EDTA)] concentration was also prepared. 2-The complexation solution was adjusted to pH 9, and chemically deposited at 60°C for 35 min. After rinsing twice with deionized water and drying under nitrogen at room temperature, a substrate membrane loaded with the complex was obtained. A 0.11 mol / L polycarbazole monomer polymerization system was prepared, using a mixture of ammonium persulfate and potassium persulfate (mass ratio 1:1) as the oxidant. The molar ratio of oxidant to monomer was 2:1, and the polymerization was carried out at 1.2 mL / cm³. 2 The amount of [Co(EDTA)] was uniformly added dropwise to the surface of the substrate membrane. After prepolymerization at room temperature for 7 minutes, the membrane was immersed in the polymerization system and the reaction continued for another 9 minutes to complete the in-situ polymerization. After standard post-treatment and shaping, the finished film had a pore size of 150 nm and a porosity of 60%. 2- Loading capacity is 1.3 mg / cm³ 2 The polycarbazole film is 70 nm thick and forms a stable π-π stack with the carbon nanotube substrate.

[0054] Example 7:

[0055] Ordered mesoporous carbon was selected as the carbon nanolayer material, and the EDTA-metal complex was [Fe(EDTA)]. - The conjugated conductive polymer is a polycarbazole derivative (poly-N-vinylcarbazole, PVK). After conventional activation, the porous ATO membrane is combined with an ordered mesoporous carbon dispersion (water to ethanol volume ratio 1:1) at a concentration of 0.25 mg / mL, dried at 75℃ for 25 min, and then crosslinked at 230℃ for 1.8 h. A 0.04 mol / L [Fe(EDTA)] solution is also prepared. - The complexing solution was adjusted to pH 8.5, and the mixture was deposited in a chemical bath at 55°C for 45 min. After rinsing three times with deionized water, it was dried. A 0.10 mol / L poly(N-vinylcarbazole) monomer polymerization system was prepared, with ferric chloride as the oxidant, a molar ratio of 2.5:1, and a dropping volume of 1.0 mL / cm³. 2 After prepolymerization at room temperature for 6 minutes, the film was immersed in the system for 11 minutes of reaction. Following post-treatment and shaping, the finished film had a pore size of 130 nm and a porosity of 55%, [Fe(EDTA)]. - The loading capacity was 1.0 mg / cm³. 2 The thickness of the poly-N-vinylcarbazole film is 60 nm.

[0056] Performance tests were conducted on Examples 1-7 (hereinafter also referred to as Ex1-7) for comparison, and comparative examples A was set as the original ATO film (without carbon layer), B as ATO + carbon nanolayer (without EDTA / polymer), and C as ATO + carbon nanolayer + EDTA-metal (without conductive polymer). The experiments are as follows:

[0057] 1. Structural stability and interface compatibility testing

[0058] Table 1 Comparison of structural stability of carbon nanofilms under long-term immersion in salt solution (0.5M NaCl, 25℃, immersion for 30 days, n=3, mean ± SD)

[0059] A −1.8±0.3 −3.7±0.5 — B −0.3±0.2 −1.6±0.4 — C −0.2±0.2 −1.6±0.3 76.7±3.1 Example 1 +0.2±0.2 −1.4±0.3 79.2±2.8 Example 2 −0.2±0.2 −1.3±0.3 76.7±3.0 Example 3 +0.4±0.3 −1.4±0.4 76.3±2.9 Example 4 +0.6±0.3 −1.5±0.4 77.8±3.2 Example 5 −0.4±0.3 −0.8±0.2 63.3±2.5 Example 6 +0.4±0.3 −1.7±0.4 76.2±3.1 Example 7 +1.0±0.4 −1.1±0.3 78.0±3.0

[0060] Table 2. Interface bonding strength (180° peel; rate 10 mm·min) -1 (n=5)

[0061] B 1.52±0.10 1.34±0.12 88.2% Slight peeling of the interface Ex1 1.72±0.09 1.58±0.10 91.9% substrate near-end fracture Ex2 1.65±0.08 1.49±0.09 90.3% Partial interface stripping Ex3 1.70±0.07 1.54±0.11 90.6% Substrate fracture tendency Ex4 1.85±0.08 1.69±0.09 91.4% Substrate fracture Ex5 1.60±0.10 1.40±0.12 87.5% Interface stripping Ex6 1.75±0.09 1.59±0.10 90.9% Substrate / interface composite fracture Ex7 1.80±0.08 1.66±0.09 92.2% Substrate fracture

[0062] 2. Ion transport performance and energy conversion efficiency testing

[0063] Table 3 Ionic conductivity and interfacial impedance (samples in 0.1M NaCl; 25°C; n=3)

[0064] sample σ_surface(S·cm⁻¹)mean±SD σ_ion(S·cm⁻¹)mean±SD <![CDATA[ASR(Ω·cm 2 )]]> Rs(Ω) Rct(Ω) B <![CDATA[(6.0±0.3)×10 -3 ]]> <![CDATA[(6.0±0.4)×10 -4 ]]> 12.5±0.8 7.8±0.4 62±5 C <![CDATA[(8.0±0.4)×10 -3 ]]> <![CDATA[(9.0±0.5)×10 -4 ]]> 10.2±0.7 6.4±0.3 50±4 Ex1 <![CDATA[(1.10±0.05)×10 -2 ]]> <![CDATA[(1.00±0.06)×10 -3 ]]> 9.0±0.6 5.6±0.3 44±3 Ex2 <![CDATA[(9.5±0.4)×10 -3 ]]> <![CDATA[(8.5±0.5)×10 -4 ]]> 10.5±0.7 6.6±0.3 52±4 Ex3 <![CDATA[(1.45±0.06)×10 -2 ]]> (1.30±0.07)×10-3 7.1±0.5 4.9±0.3 38±3 Ex4 <![CDATA[(1.05±0.05)×10 -2 ]]> <![CDATA[(9.8±0.5)×10 -4 ]]> 9.5±0.6 5.8±0.3 46±3 Ex5 <![CDATA[(8.5±0.4)×10 -3 ]]> <![CDATA[(7.8±0.5)×10 -4 ]]> 11.9±0.8 7.1±0.4 60±5 Ex6 <![CDATA[(1.30±0.05)×10 -2 ]]> <![CDATA[(1.10±0.06)×10 -3 ]]> 8.0±0.6 5.0±0.3 42±3 Ex7 <![CDATA[(1.10±0.05)×10 -2 ]]> <![CDATA[(1.02±0.06)×10 -3 ]]> 9.2±0.6 5.4±0.3 45±3

[0065] Note that Ex3 and Ex6 exhibit excellent performance in terms of conductivity and interface impedance;

[0066] Table 4. Simulation of salinity gradient power generation (0.5M / 0.01M NaCl, area 1.0cm²) 2 (Initial and 24h; n=3)

[0067] B 125±5 0.78±0.04 64±3 57±4 89.1% C 138±6 0.92±0.05 85±4 77±5 90.6% Ex1 150±6 1.05±0.05 95±4 88±5 92.6% Ex2 125±5 0.78±0.04 64±3 58±4 90.6% Ex3 160±7 1.12±0.06 120±6 110±7 91.7% Ex4 135±6 0.88±0.04 75±4 68±5 90.7% Ex5 110±5 0.62±0.03 41±2 39±3 95.1% Ex6 150±7 1.05±0.05 105±5 97±6 92.4% Ex7 130±6 0.90±0.05 78±4 71±5 91.0%

[0068] Note that Ex3 / Ex6 performs best in terms of power density and output stability;

[0069] Table 5 Ion flux and antipolarization (salinity gradient condition; Na⁺ flux × 10⁻⁶) -5 mol·m -2 ·s -1 (Short-time current fluctuation rate 1h, n=3)

[0070] B 5.2±0.3 4.6±0.3 88.5% 0.75±0.03 12.0% Ex1 6.0±0.3 5.4±0.3 90.0% 0.95±0.04 5.0% Ex2 5.2±0.3 4.6±0.3 88.5% 0.78±0.04 11.5% Ex3 7.2±0.4 6.5±0.4 90.3% 1.12±0.05 4.5% Ex4 6.1±0.3 5.3±0.3 86.9% 0.88±0.04 7.0% Ex5 4.8±0.3 4.2±0.3 87.5% 0.62±0.03 12.5% Ex6 6.8±0.4 6.0±0.3 88.2% 1.05±0.05 4.2% Ex7 5.9±0.3 5.3±0.3 89.8% 0.90±0.04 5.5%

[0071] 3. Photosensitive modulation performance test

[0072] Table 6. Illumination Response and Conductivity Regulation (White Light 1 sun, Dark / Light Switching; σ unit: S·cm) ⁻¹ (n=3)

[0073] C <![CDATA[(8.0 ± 0.4)×10 -3 ]]> <![CDATA[(9.6 ± 0.5)×10 -3 ]]> 20.0% 18±2 25±3 92% Ex1 <![CDATA[(1.10 ± 0.05)×10 -2 ]]> <![CDATA[(1.49 ± 0.06)×10 -2 ]]> 35.5% 12±1 18±2 94% Ex2 <![CDATA[(9.5 ± 0.4)×10 -3 ]]> <![CDATA[(1.14 ± 0.05)×10 -2 ]]> 20.0% 20±2 30±3 92% Ex3 <![CDATA[(1.45 ± 0.06)×10 -2 ]]> <![CDATA[(1.96 ± 0.08)×10 -2 ]]> 35.2% 10±1 15±2 90% Ex4 <![CDATA[(1.05 ± 0.05)×10 -2 ]]> <![CDATA[(1.26 ± 0.06)×10 -2 ]]> 20.0% 18±2 25±3 93% Ex5 <![CDATA[(8.5 ± 0.4)×10 -3 ]]> <![CDATA[(9.35 ± 0.4)×10 -3 ]]> 10.0% 25±3 40±4 89% Ex6 <![CDATA[(1.30 ± 0.05)×10 -2 ]]> <![CDATA[(1.69 ± 0.07)×10 -2 ]]> 30.0% 11±1 16±2 91% Ex7 <![CDATA[(1.10 ± 0.05)×10 -2 ]]> <![CDATA[(1.43 ± 0.06)×10 -2 ]]> 30.0% 13±1 19±2 92%

[0074] Note that Ex1, Ex3, Ex6, and Ex7 exhibit higher optical gain and faster response;

[0075] Table 7 Verification of ion transport regulation under illumination (transfer number t_Na) ⁺ With selectivity; n=3)

[0076] C 0.58 ± 0.02 0.68 ± 0.03 +17.2% 3.4 ± 0.2 4.1 ± 0.3 +18% Ex1 0.62 ± 0.02 0.72 ± 0.03 +16.1% 3.8 ± 0.2 4.6 ± 0.3 +20% Ex2 0.58 ± 0.02 0.66 ± 0.03 +13.8% 3.4 ± 0.2 3.9 ± 0.3 +15% Ex3 0.65 ± 0.02 0.78 ± 0.03 +20.0% 4.1 ± 0.2 5.2 ± 0.3 +25% Ex4 0.60 ± 0.02 0.69 ± 0.03 +15.0% 3.6 ± 0.2 4.4 ± 0.3 +18% Ex5 0.55 ± 0.02 0.61 ± 0.03 +10.9% 3.0 ± 0.2 3.3 ± 0.2 +12% Ex6 0.64 ± 0.02 0.78 ± 0.03 +21.9% 4.0 ± 0.2 5.1 ± 0.3 +26% Ex7 0.61 ± 0.02 0.72 ± 0.03 +18.0% 3.7 ± 0.2 4.5 ± 0.3 +22%

[0077] As can be seen from the table, Examples Ex1, Ex3, and Ex6 demonstrate superior performance in several key indicators, including surface / ionic conductivity, polarization resistance, and photoresponse (σ_surface ≥ 1 × 10⁻⁶). ⁻² S / cm;σ_ion≥1×10 -3 S / cm; current fluctuation rate ≤5%); Ex3 at Pmax (120µW·cm) ⁻² The effect is particularly evident in the gain of light modulation; in most embodiments, the EDTA-metal retains approximately 75–80% of its content within 30 days, and the porosity and quality are basically stable, indicating that the interlayer bonding and load are stable.

[0078] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A carbon nanofilm, characterized in that, The carbon nanofilm uses a porous ATO (anodic oxide TiO2) film as a substrate. The surface and pores of the ATO film are sequentially composited with a carbon nanolayer, an EDTA-metal complex, and a conjugated conductive polymer. The carbon nanolayer is a continuous film layer composed of porous carbon nanomaterials, and its porous structure is connected with the pores of the ATO film to form a continuous ion transport channel. The carbon nanolayer is one of the following: ordered mesoporous carbon, carbon nanotube (CNT) crosslinked porous carbon, reduced graphene oxide (rGO) porous carbon, and nitrogen-doped porous carbon.

2. The carbon nanofilm according to claim 1, characterized in that, The EDTA-metal complex is ([Fe(EDTA)]). - [Ni(EDTA)] 2- [Co(EDTA)] 2- One of them has a loading capacity of 0.5~2 mg / cm³. 2 .

3. The carbon nanofilm according to claim 1, characterized in that, The conjugated conductive polymers include one of polythiophene (PTh) and its derivatives (poly-3-methylthiophene PMT, poly-3-hexylthiophene P3HT), polyaniline (PANI), polycarbazole (PCz) and its derivatives, or polyindole (PIn), with a film thickness of 30~100nm, and forming π-π stacks with carbon nanolayers.

4. A carbon nanofilm according to claim 1, characterized in that, The carbon nanofilm has a pore size of 50~300nm.

5. A carbon nanofilm according to claim 1, characterized in that, The porosity of the carbon nanofilm is 45-70%.

6. A method for preparing a carbon nanofilm as described in any one of claims 1 to 5, characterized in that, The steps include the following: 1) Activation of ATO membrane: The ATO membrane was ultrasonically cleaned with anhydrous ethanol and deionized water for 10 min each, and dried with nitrogen gas. The ATO membrane was then placed in a 0. mol / L H2SO4 solution for constant potential polarization at 1.0 V vs. SCE for 3 min. After that, it was rinsed with deionized water and dried for later use. 2) Carbon nano-base layer composite: Carbon nanomaterial dispersion is composited on the surface and pores of the activated ATO membrane in step 1), and then dried and cross-linked at high temperature to fix the carbon nano-base layer and the ATO membrane, so that the carbon nano-base layer is tightly bonded to the ATO membrane and the pores are connected, thus obtaining an ATO composite membrane loaded with carbon nano-base layer. 3) EDTA-metal complex deposition: Prepare an EDTA-metal complex solution with a concentration of 0.01~0.1mol / L. Immerse the ATO composite membrane obtained in step 2) into the complex solution. Use a chemical bath deposition method to uniformly load the EDTA-metal complex onto the surface and pores of the ATO membrane. After deposition, clean and dry to obtain the ATO substrate membrane loaded with the complex. 4) In-situ chemical oxidation polymerization of conjugated conductive polymer: Prepare a polymerization system containing conjugated conductive polymer monomers and oxidants, with a monomer concentration of 0.05~0.15 mol / L and a molar ratio of oxidant to monomer of 1:1~3:1; uniformly add the polymerization system to the surface of the ATO substrate film in step 3) by drop addition to form a porous carbon nanofilm. 5) Post-treatment: After polymerization, the ATO membrane is immediately removed for cleaning, gentle drying and shaping. It is ultrasonically cleaned with anhydrous ethanol for 30 seconds at low speed and 100W to remove unpolymerized monomers and supporting electrolytes from the membrane surface. After drying with nitrogen, it is left to stand at room temperature for 12~24 hours to shape.

7. The method for preparing a carbon nanofilm according to claim 6, characterized in that, Step 3) Adjust the pH value to 8-10, the deposition temperature to 40-70℃, and the deposition time to 20-60min; rinse with deionized water 2-3 times and dry with nitrogen.

8. The method for preparing a carbon nanofilm according to claim 6, characterized in that, Step 4), the oxidant is one or more of ammonium persulfate, ferric chloride, and potassium persulfate; the dropping volume is 0.5~2 mL / cm. 2 After prepolymerization at room temperature for 3-10 minutes, the base membrane is immersed in the polymerization system and the reaction continues for 5-15 minutes to complete the in-situ polymerization.

9. The method for preparing a carbon nanofilm according to claim 6, characterized in that, Step 2) The concentration of the carbon nanomaterial dispersion is 0.1~0.5mg / mL, and the dispersion medium is a mixture of water and ethanol with a volume ratio of 1:1~3:1; the drying temperature is 60~80℃, the drying time is 20~40min; the high-temperature crosslinking temperature is 200~300℃, and the holding time is 1~2h.

10. An application of a carbon nanofilm in a permeation energy conversion device, characterized in that, Surface conductivity ≥10 ⁻² S / cm, ionic conductivity ≥10 -3 S / cm, the carbon nanofilm is used as an ion-conducting layer or composite membrane, and the ion transport rate is controlled by photo-controlled conjugated conductive polymer to improve the energy conversion efficiency of the device.

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