Carbon-nitrogen-rich carbonaceous conjugated polymer-based electro / optical devices, methods of assembling and applications thereof

Abstract

This invention relates to an electro / photochromic device based on a carbon-nitride conjugated polymer, its assembly method, and its application, belonging to the technical field of smart color-changing devices. The electro / photochromic device of this invention includes a carbon-nitride electrode and an FTO conductive glass placed opposite each other, a double-sided insulating adhesive sealing the carbon-nitride electrode and the FTO conductive glass, and an electrolyte solution injected into the gap between the carbon-nitride electrode and the FTO conductive glass. The assembly method is simple and easy to operate, and it has good application prospects in electro / photochromic smart windows.

Description

Technical Field

[0001] This invention belongs to the technical field of color-changing devices, and relates to an electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer, its assembly method, and its application. Background Technology

[0002] Smart dimming windows are functional devices whose light transmission characteristics (such as transmittance and transmitted light wavelength) can be adjusted through external excitation. They are mainly used in architectural glass curtain walls, car windows, aircraft windows, optical darkrooms, and other scenarios requiring dynamic adjustment of sunlight or artificial light transmittance. Materials with special effects such as electrochromic, photochromic, thermochromic, and pressure-sensitive color change can all be used to manufacture smart dimming windows. Among various materials, electrochromic materials have the highest controllability, allowing for precise adjustment of light transmittance through voltage, and have broad application prospects in the field of smart window technology. Photochromic materials can utilize solar radiation to achieve light modulation effects, making them suitable for outdoor environments and offering advantages in environmental protection and energy saving. Thermochromic and pressure-sensitive color change devices respond to different external stimuli, each possessing its own characteristics and advantages. Therefore, the multifunctionality of devices, especially multi-factor excitation, is an important direction for the development of smart windows.

[0003] Currently, the main types of electrochromic materials include: inorganic electrochromic materials (such as tungsten trioxide, titanium dioxide, etc.), conjugated conductive polymer electrochromic materials (such as polystyrene (PANI), polypyrrole (PPY), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS), etc.), organic small molecule electrochromic materials (such as viologen and its derivatives), and organometallic complexes (such as Prussian blue (PB), etc.). The structure of electrochromic devices generally includes: a transparent conductive substrate, an ion storage layer, an ion transport layer, a color-changing layer, and a conductive optical window. Organic small molecules and organometallic complexes are not suitable for manufacturing large-size devices and are generally used to manufacture small sensors or detectors, such as medical drug test strips or devices, and electronic displays. Inorganic electrochromic materials and conjugated conductive polymers are used to fabricate large-size devices and are therefore widely used in smart dimming windows. The significant advantages of inorganic electrochromic materials are: strong optical modulation, easy achievement of high contrast ratios above 90%, resulting in a completely opaque dark effect for the window; and a wide range of transmittance adjustment space, supporting gradient dimming. In recent years, visible and infrared dual-band light modulation effects have also been discovered, potentially enabling both dimming and temperature control in the future. Conjugated conductive polymers can achieve 40-60% optical modulation contrast ratios. Their significant advantage is their ease of processing, making them suitable for large-scale commercial production. The main disadvantages are: ① The color-changing stability of the device is not ideal, especially in cases of deep color changes, where local electrode reactions deteriorate, leading to a significant decrease in dimming effect. Although this can be recovered by replacing the electrolyte, it greatly increases maintenance costs in practical use; ② There is a significant performance degradation effect with large area coverage. Since smart windows generally require FTO or ITO conductive glass as the conductive substrate material, its resistance is a sheet resistance (typically 10-20 Ω / cm²). With increasing area, the resistance increases significantly. Since these two types of electrochromic materials generally operate based on lithium-ion insertion and extraction mechanisms, they exhibit significant overpotential effects, causing their operating voltage window to approach the limit that the electrolyte can withstand. Increased resistance of the conductive substrate exacerbates the overpotential effect, leading to a decrease in the device's color-changing performance, significant attenuation of optical modulation contrast, and severely impacting dimming effects; ③ Maintaining the colored state requires an external voltage, increasing device power consumption. Most applications of electrochromic devices require them to be in a colored state to reduce light transmittance.

[0004] Although many electrochromic devices possess optical memory capabilities, meaning they retain their color even after the applied voltage is removed, the retention time is relatively short, generally not exceeding half an hour. These drawbacks are caused by the electrochromic mechanism of these devices, necessitating the development of new electrochromic mechanisms and materials to fundamentally solve the problem. Summary of the Invention

[0005] In view of this, one objective of the present invention is to provide an electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer; a second objective of the present invention is to provide an assembly method for an electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer; and a third objective of the present invention is to provide an application of an electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer in the fabrication of an electro / photochromic smart dimming glass window.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] 1. An electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer, the electro / photochromic device comprising a carbon-rich carbon nitride electrode and an FTO conductive glass placed opposite each other, a double-sided insulating adhesive sealing the carbon-rich carbon nitride electrode and the FTO conductive glass together, and an electrolyte solution injected into the gap between the carbon-rich carbon nitride electrode and the FTO conductive glass.

[0008] The carbon-rich carbon nitride electrode is prepared as follows: an FTO conductive glass plate with a sintered titanium dioxide nanofilm is immersed in an aqueous solution of a carbon-rich carbon nitride conjugated polymer with a concentration of ≥0.001 g / mL, and allowed to stand at room temperature for more than 12 hours for chemical adsorption. After removal, it is dried at room temperature to obtain the carbon-rich carbon nitride electrode.

[0009] Preferably, the preparation method of the FTO conductive glass sheet with sintered titanium dioxide nanofilm is as follows: titanium dioxide nanocrystal sol with a particle size of no more than 50 nm is coated on FTO conductive glass to form a uniform colloidal film, and then dried at 80°C and calcined at 450°C for 3 min to obtain the FTO conductive glass sheet with sintered titanium dioxide nanofilm.

[0010] The thickness of the titanium dioxide nanofilm on the FTO conductive glass sheet with sintered titanium dioxide nanofilm is 1μm to 10μm.

[0011] Preferably, the structural formula of the carbon-rich carbon nitride conjugated polymer is as follows: Where n is an integer greater than or equal to 1.

[0012] Preferably, the electrolyte solution comprises ethylene carbonate (EC) or propylene carbonate (PC), acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate, wherein the mass ratio of ethylene carbonate (EC) or propylene carbonate (PC), acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate is 10:2-5:0.2-1.5:0.7-2.

[0013] Preferably, the double-sided insulating adhesive is 3M 300LSE tape.

[0014] 2. The assembly method described above, wherein the assembly method includes the following steps:

[0015] A carbon-rich carbon nitride electrode and an FTO conductive glass are placed opposite each other, with the carbon-rich carbon nitride conjugated polymer in the carbon-rich carbon nitride electrode facing the conductive surface of the FTO conductive glass. They are then sealed together using double-sided insulating adhesive. An electrolyte solution is then injected into the gap between the carbon-rich carbon nitride electrode and the FTO conductive glass to assemble an electro / photochromic device based on the carbon-rich carbon nitride conjugated polymer.

[0016] 3. Application of the above-mentioned electro / photochromic devices in the fabrication of electro / photochromic smart dimming glass windows.

[0017] The beneficial effects of this invention are as follows: This invention discloses an electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer, mainly using a carbon-rich carbon nitride electrode as the working electrode and FTO conductive glass as the counter electrode. It has the following features: ① Titanium dioxide is used as the electron transport material and structural support material in the working electrode, adsorbing the carbon-rich carbon nitride conjugated polymer onto the surface, resulting in a highly dispersed state of the polymer. This fully utilizes the microstructural advantages of its two-dimensional porous network to achieve high electrode reactivity; ② The electrolyte used employs a redox couple I3. - / I - Using titanium dioxide, carbon-nitride conjugated polymers, and I3 - / I - The invention utilizes the energy level relationships formed between carbon-nitride conjugated polymers (CNTs) to control electron injection and release, achieving a reverse color-changing mechanism based on the self-charging effect of CNTs, i.e., coloring (blue) in its natural state and bleaching when an external voltage is applied; ③ It utilizes the special effect of CNTs storing photogenerated charges to achieve photochromism; ④ It utilizes the excellent electron transport performance of CNTs to improve the performance degradation effect in large-area applications. The assembly method of the electro / photochromic device based on CNTs is simple and easy to operate, and has good application prospects in the fabrication of electro / photochromic smart dimming glass windows.

[0018] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0020] Figure 1 The preparation process of the carbon-rich carbon nitride conjugated polymer in Example 1;

[0021] Figure 2 The microstructure characterization of the carbon-rich carbon nitride conjugated polymer prepared in Example 1 includes: (a) a scanning electron microscope (SEM) image of the freeze-dried carbon-rich carbon nitride conjugated polymer sample; (b) an image and transmission electron microscope (TEM) image of the aqueous solution of the carbon-rich carbon nitride conjugated polymer; (c) spherical aggregates obtained by the carbon-rich carbon nitride conjugated polymer in a highly dispersed state; (d) the internal structure of the spherical aggregates; (e) bubble-like aggregates; (f) the resonance signal of the heptaazine ring under 13C liquid NMR spectroscopy; and (g) the resonance signal of a single carbon ring under 13C liquid NMR spectroscopy.

[0022] Figure 3 This is a schematic diagram of the fabrication process of the carbon-rich carbon nitride electrode in Example 1;

[0023] Figure 4 (a) is a photograph of the carbon nitride electrode with an active geometric area of ​​3 cm × 3 cm prepared in Example 1; (b) is a transmission electron microscope (SEM) image of the cross-section of the carbon nitride electrode prepared in Example 1; (c) is the C1s fine spectrum of the carbon nitride electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS); (d) is the N1s fine spectrum of the carbon nitride electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS); (e) is the Ti 2p fine spectrum of the carbon nitride electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS); and (f) is the O1s fine spectrum of the carbon nitride electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS).

[0024] Figure 5 A schematic diagram of the structure of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1;

[0025] Figure 6 The energy level relationship diagram is shown for the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1.

[0026] Figure 7(a) and (b) are photographs of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1, showing the color change under different voltages and the corresponding transmission spectrum changes, respectively; (c) shows the relationship between the maximum modulation optical contrast and the applied voltage of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1; (d) shows the comparison between the coloring / bleaching transmission spectrum of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 after 2080 color-changing cycles and the initial state; (e) shows the comparison between the coloring / bleaching transmission spectrum of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 after 72h and 120h of continuous color change and the initial state.

[0027] Figure 8 (a) is a photograph of the photochromic effect of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 under natural sunlight (cell area is 7cm×7cm); (b) is a photograph of the photochromic effect of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer under simulated sunlight (electrode area is 5cm×5cm).

[0028] Figure 9 Cyclic voltammetry (a) and electrochemical impedance spectroscopy (b) of the electro / photochromic device (6 cm × 6 cm) based on carbon-rich carbon nitride conjugated polymer prepared in Example 1.

[0029] Figure 10 (a) is a photograph of the carbon-rich carbon nitride electrode with an area of ​​8cm×8cm prepared in Example 1; (b) shows the transmission spectrum change of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer assembled with the electrode in (a) as the working electrode at a voltage of 1.5V; and (c) is a photograph of the electrochromic effect of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer assembled with the electrode in (a) as the working electrode. Detailed Implementation

[0030] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0031] Example 1

[0032] An electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer, the specific assembly method of which is shown below:

[0033] (1) Preparation of carbon-rich carbon nitride conjugated polymers:

[0034] Dicyandiamine, citric acid, and deionized water were mixed in a mass ratio of 1:1.9:60 to obtain a reactant, which was then introduced into a hydrothermal reactor and subjected to a hydrothermal reaction at 200°C for 30 min to obtain a precursor.

[0035] The above precursors were sealed and stored in an ammonia atmosphere at room temperature for 8 months to carry out the aging reaction, and an aqueous solution of carbon-nitrogen conjugated polymer was obtained.

[0036] The aqueous solution of the above-mentioned carbon-rich carbon nitride conjugated polymer was freeze-dried at -80°C and a vacuum of less than 30 Pa to obtain the carbon-rich carbon nitride conjugated polymer.

[0037] (2) Preparation of carbon-rich carbon nitride electrodes:

[0038] The carbon-rich carbon nitride conjugated polymer prepared in step (1) above is dissolved in deionized water to prepare a carbon-rich carbon nitride conjugated polymer aqueous solution with a concentration of 0.001 g / mL. The FTO conductive glass plate with sintered titanium dioxide nanofilm is immersed in the above carbon-rich carbon nitride conjugated polymer aqueous solution and left to stand at room temperature in the dark for 12 h to allow for sufficient chemical adsorption. The immersed glass plate is then removed from the solution and dried at room temperature to obtain the carbon-rich carbon nitride electrode.

[0039] (3) Assemble electro / photochromic devices based on carbon-nitride-rich carbon conjugated polymers:

[0040] The carbon-rich carbon nitride electrode prepared in step (2) is used as the working electrode, and the FTO conductive glass is used as the counter electrode. The two are placed opposite each other (the side of the carbon-rich carbon nitride conjugated polymer in the carbon-rich carbon nitride electrode is in contact with the FTO conductive glass). They are sealed together with double-sided insulating tape. Then, an electrolyte solution is injected into the gap between the two electrodes (ethylene carbonate (EC), acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate are mixed in a mass ratio of 10:2:0.2:0.7 and stirred thoroughly to form a uniform solution, which is the electrolyte solution). The carbon-rich carbon nitride electro / photoluminescent device can then be assembled.

[0041] Example 2

[0042] An electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer, the specific assembly method of which is shown below:

[0043] (1) Preparation of carbon-rich carbon nitride conjugated polymers:

[0044] Dicyandiamine, citric acid, and deionized water were mixed in a mass ratio of 1:1.9:60 to obtain a reactant, which was then introduced into a hydrothermal reactor and subjected to a hydrothermal reaction at 200°C for 30 min to obtain a precursor.

[0045] The above precursors were sealed and stored in an ammonia atmosphere at room temperature for 10 months to carry out the aging reaction, and an aqueous solution of carbon-nitride conjugated polymer was obtained.

[0046] The aqueous solution of the above-mentioned carbon-rich carbon nitride conjugated polymer was freeze-dried at -80°C and a vacuum of less than 30 Pa to obtain the carbon-rich carbon nitride conjugated polymer.

[0047] (2) Preparation of carbon-rich carbon nitride electrodes:

[0048] The carbon-rich carbon nitride conjugated polymer prepared in step (1) above is dissolved in deionized water to prepare a carbon-rich carbon nitride conjugated polymer aqueous solution with a concentration of 0.002 g / mL. The FTO conductive glass plate with sintered titanium dioxide nanofilm is immersed in the above carbon-rich carbon nitride conjugated polymer aqueous solution and left to stand at room temperature in the dark for 16 h to allow for sufficient chemical adsorption. The immersed glass plate is then removed from the solution and dried at room temperature to obtain the carbon-rich carbon nitride electrode.

[0049] (3) Assemble electro / photochromic devices based on carbon-nitride-rich carbon conjugated polymers:

[0050] The carbon-rich carbon nitride electrode prepared in step (2) is used as the working electrode, and the FTO conductive glass is used as the counter electrode. The two are placed opposite each other (the side of the carbon-rich carbon nitride conjugated polymer in the carbon-rich carbon nitride electrode is in contact with the FTO conductive glass). They are sealed together with double-sided insulating tape. Then, an electrolyte solution is injected into the gap between the two electrodes (propylene carbonate (EC), acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate are mixed in a mass ratio of 10:2:0.2:0.7 and stirred thoroughly to form a homogeneous solution, which is the electrolyte solution). The carbon-rich carbon nitride electro / photoluminescent device can then be assembled.

[0051] Example 3

[0052] An electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer, the specific assembly method of which is shown below:

[0053] (1) Preparation of carbon-rich carbon nitride conjugated polymers:

[0054] Dicyandiamine, citric acid, and deionized water were mixed in a mass ratio of 1:1.9:60 to obtain a reactant, which was then introduced into a hydrothermal reactor and subjected to a hydrothermal reaction at 190°C for 30 min to obtain a precursor.

[0055] The above precursors were sealed and stored in an ammonia atmosphere at room temperature for 12 months to carry out the aging reaction, and an aqueous solution of carbon-nitrogen conjugated polymer was obtained.

[0056] The aqueous solution of the above-mentioned carbon-rich carbon nitride conjugated polymer was freeze-dried at -80°C and a vacuum of less than 30 Pa to obtain the carbon-rich carbon nitride conjugated polymer.

[0057] (2) Preparation of carbon-rich carbon nitride electrodes:

[0058] The carbon-rich carbon nitride conjugated polymer prepared in step (1) above is dissolved in deionized water to prepare a carbon-rich carbon nitride conjugated polymer aqueous solution with a concentration of 0.003 g / mL. The FTO conductive glass plate with sintered titanium dioxide nanofilm is immersed in the above carbon-rich carbon nitride conjugated polymer aqueous solution and left to stand at room temperature in the dark for 18 hours to allow for sufficient chemical adsorption. The immersed glass plate is then removed from the solution and dried at room temperature to obtain the carbon-rich carbon nitride electrode.

[0059] (3) Assemble electro / photochromic devices based on carbon-nitride-rich carbon conjugated polymers:

[0060] The carbon-rich carbon nitride electrode prepared in step (2) is used as the working electrode, and the FTO conductive glass is used as the counter electrode. The two are placed opposite each other (the side of the carbon-rich carbon nitride conjugated polymer in the carbon-rich carbon nitride electrode is in contact with the FTO conductive glass). They are sealed together with double-sided insulating tape. Then, an electrolyte solution is injected into the gap between the two electrodes (ethylene carbonate (EC), acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate are mixed in a mass ratio of 10:3:0.2:0.7 and stirred thoroughly to form a homogeneous solution, which is the electrolyte solution). The carbon-rich carbon nitride electro / photoluminescent device can then be assembled.

[0061] Example 4

[0062] An electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer, the specific assembly method of which is shown below:

[0063] (1) Preparation of carbon-rich carbon nitride conjugated polymers:

[0064] Dicyandiamine, citric acid, and deionized water were mixed in a mass ratio of 1:1.9:60 to obtain a reactant, which was then introduced into a hydrothermal reactor and subjected to a hydrothermal reaction at 190°C for 30 min to obtain a precursor.

[0065] The above precursors were sealed and stored in an ammonia atmosphere at room temperature for 14 months to carry out the aging reaction, resulting in an aqueous solution of carbon-rich carbon nitride conjugated polymer.

[0066] The aqueous solution of the above-mentioned carbon-rich carbon nitride conjugated polymer was freeze-dried at -80°C and a vacuum of less than 30 Pa to obtain the carbon-rich carbon nitride conjugated polymer.

[0067] (2) Preparation of carbon-rich carbon nitride electrodes:

[0068] The carbon-rich carbon nitride conjugated polymer prepared in step (1) above is dissolved in deionized water to prepare a carbon-rich carbon nitride conjugated polymer aqueous solution with a concentration of 0.004 g / mL. The FTO conductive glass plate with sintered titanium dioxide nanofilm is immersed in the above carbon-rich carbon nitride conjugated polymer aqueous solution and left to stand at room temperature in the dark for 8 hours to allow for sufficient chemical adsorption. The immersed glass plate is then removed from the solution and dried at room temperature to obtain the carbon-rich carbon nitride electrode.

[0069] (3) Assemble electro / photochromic devices based on carbon-nitride-rich carbon conjugated polymers:

[0070] The carbon-rich carbon nitride electrode prepared in step (2) is used as the working electrode, and the FTO conductive glass is used as the counter electrode. The two are placed opposite each other (the side of the carbon-rich carbon nitride conjugated polymer in the carbon-rich carbon nitride electrode is in contact with the FTO conductive glass). They are sealed together with double-sided insulating tape. Then, an electrolyte solution is injected into the gap between the two electrodes (propylene carbonate (PC), acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate are mixed in a mass ratio of 10:3:0.2:0.7 and stirred thoroughly to form a homogeneous solution, which is the electrolyte solution). The carbon-rich carbon nitride electro / photoluminescent device can then be assembled.

[0071] Figure 1 This describes the preparation process of the carbon-rich carbon nitride conjugated polymer in Example 1. From... Figure 1 It can be seen that the carbon-rich carbon nitride conjugated polymer prepared in Example 1 has a heptaazine ring and a carbon ring hybrid conjugated skeleton, with a relative ratio of C=CC and C=NC of about 3, forming a structural unit with one heptaazine ring coordinating with six carbon rings.

[0072] Figure 2 The microstructure characterization of the carbon-rich carbon nitride conjugated polymer prepared in Example 1 includes: (a) a scanning electron microscope (SEM) image of the freeze-dried carbon-rich carbon nitride conjugated polymer sample; (b) an image and transmission electron microscope (TEM) image of the aqueous solution of the carbon-rich carbon nitride conjugated polymer; (c) spherical aggregates obtained by the carbon-rich carbon nitride conjugated polymer in a highly dispersed state; (d) the internal structure of the spherical aggregates; (e) bubble-like aggregates; (f) the resonance signal of the heptaazine ring pair under 13C liquid NMR spectroscopy; and (g) the resonance signal corresponding to a single carbon ring under 13C liquid NMR spectroscopy. Figure 2 It can be seen that the solid sample obtained by freeze-drying the carbon-rich carbon nitride conjugated polymer prepared in Example 1 has a foam-like morphology (e.g., Figure 2 (as shown in (a)); the carbon-rich carbon nitride conjugated polymer is readily soluble in water, and its aqueous solution is blue (as shown in (a)). Figure 2 As shown in (b)). The microstructure of the carbon-rich carbon nitride conjugated polymer obtained in a highly dispersed state exhibits significant two-dimensional structural features, and the polymers are interconnected to form a three-dimensional porous network (e.g., ...). Figure 2 (as shown in (c) to (e)). The carbon-rich carbon nitride conjugated polymer heptazine ring (as shown in Example 1) prepared in Example 1 was identified by liquid 13C nuclear magnetic resonance spectroscopy (NMR). Figure 2 (f) and carbon rings (such as) Figure 2 The molecular backbone structure shown in (g) is shown in the figure.

[0073] Figure 3 The schematic diagram shows the fabrication process of the carbon-rich carbon nitride electrode prepared in Example 1. Figure 4 (a) is a photograph of the carbon-nitride-rich electrode with an active geometric area of ​​3 cm × 3 cm prepared in Example 1; (b) is a transmission electron microscope (SEM) image of a cross-section of the carbon-nitride-rich electrode prepared in Example 1; (c) is the C1s fine spectrum of the carbon-nitride-rich electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS); (d) is the N1s fine spectrum of the carbon-nitride-rich electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS); (e) is the Ti 2p fine spectrum of the carbon-nitride-rich electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS); and (f) is the O1s fine spectrum of the carbon-nitride-rich electrode prepared in Example 1 by X-ray photoelectron spectroscopy (XPS). Figure 4 As can be seen, the carbon-rich carbon nitride electrode prepared in Example 1, from top to bottom, consists of a titanium dioxide layer adsorbed with carbon-rich carbon nitride, a SnO2:F conductive layer, and a glass substrate. The prepared carbon-rich carbon nitride electrode is a blue transparent thin film electrode (e.g., ...). Figure 4 As shown in (a)). Its cross-section was observed using a transmission electron microscope (SEM) (as shown in the image). Figure 4 As shown in (b), a uniform electrode material layer is visible on the FTO conductive glass, with a rough thickness of 2.78 μm measured according to the magnification scale. The surface bonding characteristics of the carbon-rich carbon nitride electrode were tested and analyzed using X-ray photoelectron spectroscopy (XPS). Peak fitting was performed on the fine XPS spectra of its constituent elements (C, N, O, Ti) (e.g., ...). Figure 4 As shown in (c) to (f), the main constituent groups of carbon-rich carbon nitride itself include: conjugated C=NC and C=CC, N–(C)3 or HN–(C)2, and the group that forms a chemical adsorption between carbon-rich carbon nitride and titanium dioxide is Ti-OC=O.

[0074] Figure 5This is a schematic diagram of the electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer prepared in Example 1. From... Figure 5 As can be seen from the example, the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 includes a carbon-rich carbon nitride electrode (a titanium dioxide film adsorbing carbon-rich carbon nitride) and an FTO conductive glass placed opposite each other, a double-sided insulating adhesive sealing the carbon-rich carbon nitride electrode and the FTO conductive glass, and an electrolyte solution injected into the gap between the carbon-rich carbon nitride electrode and the FTO conductive glass.

[0075] Figure 6 The energy level diagram for the electro / photochromic device based on carbon-nitride conjugated polymer prepared in Example 1 shows the energy values ​​of the conduction band bottom, valence band top, and band gap of TiO2, the energy values ​​of the LUMO orbital, HOMO orbital, and band gap of the carbon-nitride conjugated polymer, and I... 3- / I - The redox potential energy value.

[0076] Figure 7 Images (a) and (b) show photographs of the electro / photochromic device based on carbon-nitride conjugated polymers prepared in Example 1, showing color changes under different voltages and corresponding transmission spectrum changes. Image (c) shows the relationship between the maximum modulation optical contrast and the applied voltage of the electro / photochromic device based on carbon-nitride conjugated polymers. Image (d) shows the comparison between the coloring / bleaching transmission spectrum of the electro / photochromic device based on carbon-nitride conjugated polymers after 2080 color-changing cycles and the initial transmission spectrum. Image (e) shows the comparison between the coloring / bleaching transmission spectrum of the electro / photochromic device based on carbon-nitride conjugated polymers after 72 hours and 120 hours of continuous color change and the initial transmission spectrum. Figure 7 It can be seen that the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 was completely bleached at 1.6V, achieving a maximum optical modulation contrast of 50%. After 2080 color-changing cycles, the colored transmittance decreased by about 8%, while the bleached transmittance remained unchanged. After 72 hours of continuous bleaching, neither the colored nor the bleached transmittance changed. After 120 hours of continuous bleaching, the colored transmittance decreased by about 8%, while the bleached transmittance remained unchanged.

[0077] Figure 8 (a) is a photograph of the photochromic effect of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 under natural sunlight (cell area 7cm × 7cm); (b) is a photograph of the photochromic effect of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 under simulated sunlight (electrode area 5cm × 5cm). Figure 8It can be seen that, regardless of whether it is under natural sunlight or simulated sunlight, the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer can exhibit a significant color-changing effect, and the color-changing effect is the same as that of electrochromism.

[0078] Figure 9 Cyclic voltammetry (a) and electrochemical impedance spectroscopy (b) of the electro / photochromic device (6 cm × 6 cm) based on a carbon-rich carbon nitride conjugated polymer prepared in Example 1 are shown. Figure 9 As can be seen, the typical cyclic voltammetric characteristics of the electro / photochromic device based on carbon-nitride conjugated polymer prepared in Example 1 are that a positive current is generated with both increasing and decreasing applied positive potential, but no negative current is generated. The positive current peak generated by the electro / photochromic device based on carbon-nitride conjugated polymer during bleaching is located between 1.6V and 1.7V, and the positive current peak generated during blue restoration is located between 1.5V and 1.6V. The typical internal resistance of the electro / photochromic device based on carbon-nitride conjugated polymer is that as the applied voltage increases from 0.9V to 1.5V, the internal resistance of its working electrode decreases from 280Ω to approximately 10Ω.

[0079] Figure 10 (a) is a photograph of the carbon-rich carbon nitride electrode prepared in Example 1, with an area of ​​8cm × 8cm; (b) shows the transmission spectrum change of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer assembled with the electrode in (a) as the working electrode at 1.5V; (c) is a photograph of the electrochromic effect of the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer assembled with the electrode in (a) as the working electrode. Figure 10 It can be seen that the electro / photochromic device based on carbon-rich carbon nitride conjugated polymer prepared in Example 1 can still obtain about 50% optical modulation contrast at a voltage of 1.5V; and after the area of ​​carbon-rich carbon nitride electrode is increased to 8cm×8cm, it still obtains a good electrochromic effect.

[0080] Similarly, the above performance tests were performed on the electro / photochromic devices based on carbon-rich carbon nitride conjugated polymers prepared in other embodiments, and the results were basically consistent with the test results in Example 1 above, all showing good photochromic and electrochromic effects.

[0081] In summary, this invention discloses an electro / photochromic device based on a carbon-rich carbon nitride conjugated polymer. It primarily uses a carbon-rich carbon nitride electrode as the working electrode and FTO conductive glass as the counter electrode. Its features include: ① Titanium dioxide is used as both an electron transport material and a structural support material in the working electrode, adsorbing the carbon-rich carbon nitride conjugated polymer onto its surface. This results in a highly dispersed state of the polymer, fully utilizing its two-dimensional porous network microstructure to achieve high electrode reactivity; ② The electrolyte used employs a redox couple (I0.05). 3- / I - Using titanium dioxide, carbon-nitride conjugated polymers, and I 3- / I - The invention utilizes the energy level relationships formed between carbon-nitride conjugated polymers (CNTs) to control the injection and release of electrons, thereby achieving a reverse color-changing mechanism based on the self-charging effect of CNTs. This mechanism achieves colorization (blue) in its natural state and bleaching under applied voltage. Furthermore, it leverages the unique effect of CNTs storing photogenerated charges to achieve photochromism. Finally, it utilizes the excellent electron transport properties of CNTs to improve the performance degradation effect over large areas. The assembly method for the electro / photochromic device based on CNTs is simple and easy to operate, and it shows promising application prospects in electro / photochromic smart windows.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An electro / photochromic device based on a carbon-nitride-rich conjugated polymer, characterized in that, The electro / photochromic device includes a carbon nitride-rich electrode and an FTO conductive glass placed opposite each other, a double-sided insulating adhesive that seals the carbon nitride-rich electrode and the FTO conductive glass together, and an electrolyte solution injected into the gap between the carbon nitride-rich electrode and the FTO conductive glass. The carbon-rich carbon nitride electrode is prepared as follows: an FTO conductive glass plate with a sintered titanium dioxide nanofilm is immersed in an aqueous solution of a carbon-rich carbon nitride conjugated polymer with a concentration of greater than or equal to 0.001 g / mL, and allowed to stand at room temperature for more than 12 hours for chemical adsorption. After being taken out, it is dried at room temperature to obtain the carbon-rich carbon nitride electrode. The aqueous solution of the carbon-rich carbon nitride conjugated polymer was prepared by the following method: S1) Dicyandiamine, citric acid, and deionized water are mixed in a mass ratio of 1:1.9:60 to obtain reactants, which are then introduced into a hydrothermal reactor for hydrothermal reaction to obtain precursors. S2) The precursor obtained in S1 was sealed and stored at room temperature and in an ammonia atmosphere to carry out a aging reaction, resulting in an aqueous solution of carbon-rich carbon nitride conjugated polymer. S3) The aqueous solution of carbon-rich carbon nitride conjugated polymer obtained in S2 was freeze-dried at -80℃ and a vacuum degree below 30Pa to obtain carbon-rich carbon nitride conjugated polymer. S4) Dissolve the carbon-rich carbon nitride conjugated polymer prepared in S3 in deionized water to prepare an aqueous solution of the carbon-rich carbon nitride conjugated polymer with a concentration greater than or equal to 0.001 g / mL. When the hydrothermal reaction temperature in S1 is 200℃ and the heat preservation time is 30min, the sealed storage time in S2 is 8 months or 10 months. When the hydrothermal reaction temperature in S1 is 190℃ and the holding time is 30min, the sealed storage time in S2 is 12 months or 14 months.

2. The electro / photochromic device according to claim 1, characterized in that, The specific preparation method of the FTO conductive glass sheet with sintered titanium dioxide nanofilm is as follows: titanium dioxide nanocrystal sol with a particle size of no more than 50nm is coated on FTO conductive glass to form a uniform colloidal film, and then dried at 80°C and calcined at 450°C for 3min to obtain the FTO conductive glass sheet with sintered titanium dioxide nanofilm. The thickness of the titanium dioxide nanofilm on the FTO conductive glass sheet with sintered titanium dioxide nanofilm is 1μm~10μm.

3. The electro / photochromic device according to claim 1, characterized in that, The structural formula of the carbon-rich carbon nitride conjugated polymer is as follows: , where n is an integer greater than or equal to 1.

4. The electro / photochromic device according to claim 1, characterized in that, The electrolyte solution comprises ethylene carbonate or propylene carbonate, acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate, wherein the mass ratio of ethylene carbonate or propylene carbonate, acetonitrile, lithium iodide, and tetrabutylammonium hexafluorophosphate is 10: 2~5: 0.2~1.5: 0.7~2.

5. The electro / photochromic device according to claim 1, characterized in that, The double-sided insulating adhesive is 3M 300LSE tape.

6. The assembly method of the electro / photochromic device according to any one of claims 1 to 5, characterized in that, The assembly method includes the following steps: A carbon-rich carbon nitride electrode and an FTO conductive glass are placed opposite each other, with the carbon-rich carbon nitride conjugated polymer in the carbon-rich carbon nitride electrode facing the conductive surface of the FTO conductive glass. They are then sealed together using double-sided insulating adhesive. An electrolyte solution is then injected into the gap between the carbon-rich carbon nitride electrode and the FTO conductive glass to assemble an electro / photochromic device based on the carbon-rich carbon nitride conjugated polymer.

7. The application of the electro / photochromic device according to any one of claims 1 to 5 in the fabrication of electro / photochromic smart dimming glass windows.

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