A gas-liquid interface synthesized MOF film, a preparation method thereof and application thereof in photothermal aspects

Abstract

A MOF film synthesized by gas-liquid interface and a preparation method and application thereof in photothermal conversion are disclosed in the application, comprising the following steps: S1: preparing a GdOOH nanowire dispersion liquid; S2: mixing the GdOOH nanowire dispersion liquid, chlorobenzene, dichloromethane and methanol to obtain a mixed solution, and then adding 2,3,6,7,10,11-hexahydroxytriphenyl and polystyrene into the mixed solution to mix uniformly to obtain a ligand solution; S3: dropping the ligand solution obtained in step S2 on the water surface containing a metal ion aqueous solution, and then standing to obtain a MOF film. The photothermal conversion performance of the application is excellent, and is beneficial to the recyclability of the catalyst, has commercial application value, and is expected to lay a foundation for future invention of a general and convenient photothermal conversion material.

Description

Technical Field

[0001] This invention belongs to the field of photothermal conversion, and in particular relates to a MOF thin film synthesized at the gas-liquid interface, its preparation method, and its application in photothermal applications. Background Technology

[0002] With the continuous growth of energy demand and the increasing prominence of environmental problems, the development of efficient and sustainable energy conversion technologies has become a global focus. Photothermal conversion technology, as a highly efficient way to convert solar energy into thermal energy, has broad application prospects, such as solar-driven seawater desalination, thermoelectric power generation, and thermally driven adsorption refrigeration. However, existing photothermal conversion materials still face many challenges in terms of absorption efficiency, stability, and cost.

[0003] Metal-organic frameworks (MOFs) have shown great promise in materials science due to their unique porous structure, high specific surface area, and designability. In recent years, significant progress has been made in MOF thin films, which have demonstrated excellent performance in gas separation, sensing, and catalysis. However, research on applying MOF thin films to photothermal materials is still in its early stages. The porous structure and tunable chemical composition of MOF thin films give them unique advantages in light absorption and thermal conversion.

[0004] Nanomaterials are considered to have great potential in the field of photothermal conversion due to their unique optical and thermal properties. GdOOH nanowires, as a novel nanomaterial, have attracted attention due to their excellent optical absorption performance and thermal stability. However, single GdOOH nanowires still have some limitations in practical applications, such as limited light absorption range and insufficient thermal conductivity. Therefore, developing a MOF composite thin film material based on GdOOH nanowires to further improve photothermal conversion performance has significant scientific and application value.

[0005] MOF films prepared by traditional methods often suffer from problems such as fragility, low toughness, and limited coverage area. The long-term operational stability of MOF films is not ideal, and their film-forming properties and film quality are poor, which limits their performance in practical applications. This is because the traditional hydrothermal method for synthesizing MOF films is usually accompanied by homogeneous nucleation, which not only wastes a large amount of expensive precursors but also makes it difficult to control the crystallization process. Invention Content In view of this, the present invention aims to provide a gas-liquid interface synthesized MOF thin film, its preparation method and its application in photothermal fields, in order to solve at least one technical problem in the background art.

[0006] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A method for preparing MOF thin films synthesized at the gas-liquid interface includes the following steps: S1: Preparation of GdOOH nanowire dispersion; S2: GdOOH nanowire dispersion, chlorobenzene, dichloromethane and methanol are mixed to obtain a mixed solution. 2,3,6,7,10,11-hexahydroxytribenzene and organic polymer are added to the mixed solution and mixed evenly to obtain a ligand solution. S3: Drop the ligand solution obtained in step S2 onto the surface of water containing an aqueous solution of metal ions, and let it stand to obtain a MOF film.

[0007] Furthermore, in step S2, the volume ratio of the nanowire dispersion, chlorobenzene, dichloromethane, and methanol in the mixed solution is 2-3:1:2-3:1; In step S2, the GdOOH nanowire dispersion, chlorobenzene, dichloromethane and methanol are ultrasonically dispersed to obtain a mixed solution for 1.5-2.5 h. The organic polymer in step S2 includes one or more of polymethyl methacrylate, polyvinylpyrrolidone, or polystyrene; In step S2, the amount of 2,3,6,7,10,11-hexahydroxytriphenyl used is 1-5 mM, and the organic phase content of the organic polymer in step S2 is 1-6 wt%.

[0008] Furthermore, in step S3, the aqueous solution containing metal ions is a copper acetate aqueous solution with a concentration of 0.1 mM to 1.2 mM. The settling time for step S3 is 2.5-3.5 days.

[0009] Further, the preparation of GdOOH nanowire dispersion in step S1 includes dissolving GdOOH nanowires in cyclohexane at room temperature, stirring and sonicating to obtain GdOOH nanowire dispersion, stirring until the nanowires are uniformly dispersed, and letting stand for 10-20 hours.

[0010] Furthermore, the mass percentage of GdOOH nanowires in the GdOOH nanowire dispersion is 0.1%-5%.

[0011] Furthermore, the preparation of GdOOH nanowires includes the following steps: gadolinium metal salt, deionized water, and ethanol are ultrasonically dispersed to obtain a mixed solution; oleic acid and oleylamine are added to the mixed solution; the mixture is stirred vigorously; the mixed solution is reacted at high temperature; and after cooling to room temperature, the product is collected by centrifugation and washing. Gadolinium metal salts include GdCl3·6H2O.

[0012] A method for preparing MOF thin films synthesized at the gas-liquid interface, wherein the volume ratio of deionized water to ethanol is 1:5-20; The volume ratio of oleic acid to oleylamine is 1:1-8.

[0013] Furthermore, the reaction of the mixed solution at high temperature is 150-160℃ for 6-12 hours; The pressure of the mixed solution reacting at high temperature is 1-3 MPa.

[0014] The MOF thin film prepared by the above-mentioned method of gas-liquid interface synthesis.

[0015] The MOF thin film prepared by the above-mentioned method of gas-liquid interface synthesis is applied to photothermal conversion products.

[0016] Compared with existing technologies, the MOF thin film synthesized at the gas-liquid interface, its preparation method, and its application in photothermal fields described in this invention have the following advantages: The MOF composite film of this invention is mainly synthesized from 2,3,6,7,10,11-hexahydroxytriphenyl and copper acetate through a coordination reaction. The two are linked by coordinate bonds, exhibiting high photothermal performance, reaching temperatures up to over 100 degrees Celsius. Compared with existing technologies, the MOF film of this invention demonstrates superior photothermal conversion performance and facilitates catalyst recyclability, possessing commercial application value and potentially laying the foundation for the future development of a universal and convenient photothermal conversion material. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of powder X-ray diffraction of the GdOOH nanowires described in Example 1 of the present invention; Figure 2 This is a transmission electron microscope (TEM) image of the GdOOH nanowires described in Example 1 of this invention. Figure 3 This is an optical schematic diagram of the MOF composite thin film described in Embodiment 1 of the present invention; Figure 4 The image shows the photothermal properties of the MOF composite film described in Embodiment 1 of this invention. Figure 5 This is a thermal image of the MOF composite film described in Embodiment 1 of the present invention. Detailed Implementation

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0019] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] Example 1 The method for preparing the MOF composite film in this embodiment includes the following steps: Step A: Dissolve a certain amount of GdCl3·6H2O in a mixed solution of deionized water and ethanol (v:v=1:12) and disperse it evenly by ultrasonication. Then, add OA and OAm (v:v=1:3) to the mixed solution, stir vigorously, and seal the mixture in a high-pressure reactor lined with polytetrafluoroethylene. Heat the solution at 150°C for 7 hours. After cooling to room temperature, collect the product by centrifugation and wash with ethanol and cyclohexane to remove unreacted portions.

[0021] Step B: At room temperature, disperse a certain amount of GdOOH nanowires in cyclohexane (2% by mass), stir until the nanowires are uniformly dispersed, let stand for 15 hours, and remove air bubbles.

[0022] Steps C and D: Add the GdOOH nanowire dispersion to a mixed solution of chlorobenzene, dichloromethane, and ethanol, with a volume ratio of 2:1:2:1. Take a certain amount of the mixed solution and add the corresponding amount of 2,3,6,7,10,11-hexahydroxytriphenyl, the amount of 2,3,6,7,10,11-hexahydroxytriphenyl is 3mM; The dispersion was ultrasonically dispersed and then dropped onto a copper acetate aqueous solution (concentration 0.1 mg / mL-1.2 mg / mL). After standing for three days, a thin film was formed. The film was then transferred onto a glass substrate to obtain a GdOOH nanowire / MOF composite film.

[0023] Figure 1 This is a powder X-ray diffraction pattern of the GdOOH nanowires prepared in the above embodiments, by... Figure 1 It can be seen that the GdOOH nanowires have three sharp peaks, indicating good crystallinity.

[0024] Figure 2 These are transmission electron microscopy (TEM) images of the GdOOH nanowires prepared in the above embodiments. Figure 2 As can be seen from the electron microscope image, there is a clear nanowire structure, indicating that the nanowire structure was successfully synthesized.

[0025] Figure 3 This is an optical schematic diagram of the MOF composite thin film described in the above embodiments, by... Figure 3 The film is dense, uniform, intact, and without obvious cracks.

[0026] Figure 4 This is a graph showing the photothermal properties of MOF composite thin films, from... Figure 4It can be seen that when the thin film is irradiated by laser in the NIR-I region, the temperature can rapidly rise to over 100℃. As the power density decreases, the temperature gradually decreases, indicating that the composite thin film is also affected by the laser power density.

[0027] Figure 5 This is a thermal image of the MOF composite thin film described in the above embodiments, by... Figure 5 It can be seen that the temperature has risen to more than 100 degrees within ten seconds, indicating that the composite film heats up rapidly, which is equivalent to the temperature reaching its peak the moment the laser is turned on.

[0028] The process of this invention is simple and easy to operate, and it can produce materials with high photothermal conversion performance. It is expected to become a universal and convenient method for preparing photothermal materials.

[0029] This invention provides a novel method for preparing gas-liquid interfaces for the continuous production of large-area photothermal thin films. This method stabilizes the interface by introducing inorganic nanowires and organic polymers into the oil phase, thereby preparing composite thin films and improving their mechanical properties. This application achieves effective control over the mechanical properties of metal-organic framework (MOF) thin films. The prepared photothermal thin film can rapidly convert light energy into heat energy after absorbing light energy, and its temperature can be significantly increased, reaching up to 150°C or more.

[0030] Compared with existing technologies, the MOF thin film of this invention has the following significant advantages: First, its preparation process is continuous, breaking through the technical bottleneck of traditional preparation methods in scale-up production. It enables efficient and stable production of large-area photothermal thin films, significantly improving the success rate and production efficiency. Second, the film exhibits excellent photothermal performance and can be widely used in solar photothermal conversion, thermal management, and photothermal drive. Furthermore, the MOF thin film of this invention is reusable and has a long service life, which not only helps reduce resource waste but also aligns with the concept of sustainable development, giving it immense value and broad development prospects in commercial applications.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing MOF thin films synthesized at a gas-liquid interface, characterized in that: Includes the following steps: S1: Preparation of GdOOH nanowire dispersion; S2: GdOOH nanowire dispersion, chlorobenzene, dichloromethane and methanol are mixed to obtain a mixed solution. 2,3,6,7,10,11-hexahydroxytribenzene and organic polymer are added to the mixed solution and mixed evenly to obtain a ligand solution. S3: Drop the ligand solution obtained in step S2 onto the surface of water containing an aqueous solution of metal ions, and let it stand to obtain a MOF film.

2. The method for preparing a MOF thin film synthesized at a gas-liquid interface according to claim 1, characterized in that: In step S2, the volume ratio of the nanowire dispersion, chlorobenzene, dichloromethane, and methanol in the mixed solution is 2-3:1:2-3:1; In step S2, the GdOOH nanowire dispersion, chlorobenzene, dichloromethane and methanol are ultrasonically dispersed to obtain a mixed solution for 1.5-2.5 h. The organic polymer in step S2 includes one or more of polymethyl methacrylate, polyvinylpyrrolidone, or polystyrene; The organic phase content of the organic polymer in step S2 is 1-6 wt%.

3. The method for preparing a MOF thin film synthesized at a gas-liquid interface according to claim 1, characterized in that: The aqueous solution containing metal ions in step S3 is a copper acetate aqueous solution with a concentration of 0.1 mM to 1.2 mM. The settling time for step S3 is 2.5-3.5 days.

4. The method for preparing a MOF thin film synthesized at a gas-liquid interface according to claim 1, characterized in that: The preparation of GdOOH nanowire dispersion in step S1 includes dissolving GdOOH nanowires in cyclohexane at room temperature, stirring and sonicating to obtain GdOOH nanowire dispersion, stirring until the nanowires are uniformly dispersed, and letting stand for 10-20 hours.

5. The method for preparing a MOF thin film synthesized at a gas-liquid interface according to claim 4, characterized in that: The mass percentage of GdOOH nanowires in the GdOOH nanowire dispersion is 0.1%-5%.

6. The method for preparing a MOF thin film synthesized at a gas-liquid interface according to claim 4, characterized in that: The preparation of GdOOH nanowires includes the following steps: a metal salt of gadolinium, deionized water, and ethanol are ultrasonically dispersed to obtain a mixed solution. Oleic acid and oleylamine are added to the mixed solution, and the mixture is stirred vigorously. The mixed solution is reacted at high temperature, and the product is collected by centrifugation and washing after cooling to room temperature. Gadolinium metal salts include GdCl3·6H2O.

7. The method for preparing a MOF thin film synthesized at a gas-liquid interface according to claim 6, characterized in that: The volume ratio of deionized water to ethanol is 1:5-20; The volume ratio of oleic acid to oleylamine is 1:1-8.

8. The method for preparing a MOF thin film synthesized at a gas-liquid interface according to claim 6, characterized in that: The reaction of the mixed solution at high temperature is 150-160℃, and the reaction time is 6-12 hours; The pressure at which the mixed solution reacts at high temperature is 1-3 MPa.

9. The MOF thin film prepared by the method for preparing a gas-liquid interface synthesized MOF thin film according to any one of claims 1-8.

10. The MOF thin film prepared by the gas-liquid interface synthesis method according to any one of claims 1-8 is applied to photothermal conversion products.

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