A metal-organic framework-based air-water collection material, its preparation method, and an air-water collection device / system thereof.

Abstract

The present invention discloses an air-water collection material based on a metal-organic framework, its preparation method, and an air-water collection device and system. The invention proposes a method of using a metal-organic framework (MOF) as a substrate, grafting disodium ethylenediaminetetraacetic acid onto it with nucleophilic substitution, then combining the grafted MOF material with inorganic salt metal ions to form a highly hygroscopic chelate, and then using a mussel-like method to adhere the material to a cellulose viscose spunlace composite to form an adsorption material. The material can produce 0.50 to 3.51 g of water at a temperature of 30°C and a humidity range of 35% to 95%. H2O / g. The present invention also provides an air water collection device and system. At night, the ventilation condenser tube of the air water collection device is opened, allowing the air in the box to communicate with the outside air, and the air water collection material absorbs water from the air. During the day, the ventilation is closed, and the air water collection material uses the photothermal material to convert the absorbed solar energy into heat energy, which is used to release the water vapor adsorbed at night. The desorbed water vapor is then condensed and collected through the condenser tube, thereby converting the collected water molecules in the air into liquid water.

Description

Technical Field

[0001] This invention belongs to the field of adsorption-type air water collection technology, specifically relating to an air water collection material based on a metal-organic framework, its preparation method, and an air water collection device and system. Background Technology

[0002] Metal-organic frameworks (MOFs) are a new type of porous powdered material. Due to their large specific surface area, high porosity, low density, and chemical tunability, they can provide highly adsorbed, stable porous structures and catalytically active centers, making them promising for applications in water collection and catalysis. However, currently, MOFs are still used in bulk or powder form, and these bulk or powdered MOF materials are prone to agglomeration during use, thus reducing their water vapor adsorption capacity.

[0003] Lithium chloride is a high-performance hygroscopic salt. In a dry environment, one lithium chloride molecule can bind tightly with 1-5 water molecules. When the ambient humidity is 90%, one lithium chloride molecule can absorb approximately 26 water molecules. At this point, the amount of water absorbed by lithium chloride is more than 1000 times its own mass. However, during use, lithium chloride easily absorbs water molecules and is lost with the solution, resulting in a lack of reabsorption and recyclability.

[0004] Therefore, in view of the shortcomings of the above materials, there is an urgent need to study a new material that is convenient, safe and has high cycle stability. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide an air-water collection material based on a metal-organic framework.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including,

[0009] Nonwoven fabrics with photothermal functions, and air-water adsorption materials adhered to the surface of nonwoven fabrics;

[0010] Wherein, the air-water adsorption material is a chelate that satisfies the following (i) to (iv):

[0011] (i) Obtained by chelation of grafted metal-organic frameworks with inorganic salts;

[0012] (ii) The metal-organic framework material is selected from aluminum compounds, and the inorganic salt material is selected from lithium chloride;

[0013] (iii) The mass ratio of metal-organic framework to inorganic salt is 1:20 to 80;

[0014] (iv) Grafted metal-organic frameworks are obtained by nucleophilic substitution of the carboxyl group on the metal-organic framework ligand with disodium ethylenediaminetetraacetate.

[0015] As a preferred embodiment of the metal-organic framework-based air-water collection material of the present invention, the nonwoven fabric with photothermal function is a cellulose viscose spunlace fabric dyed with reactive dyes, wherein the owf of the cellulose viscose spunlace fabric and the reactive dye is 3-10%.

[0016] Another object of the present invention is to provide a method for preparing an air-collecting water material based on a metal-organic framework.

[0017] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including,

[0018] 3,5-pyrazole dicarboxylic acid, NaOH and AlCl3·6H2O were synthesized by solution reflux condensation. The product was washed and activated to obtain MOF-303.

[0019] MOF-303 was added to an aqueous solution of disodium ethylenediaminetetraacetate and stirred until uniformly dispersed. A nucleophilic substitution reaction was carried out at room temperature for 0.5–1 h to obtain MOF-303-EDTA.

[0020] MOF-303-EDTA was added to an aqueous solution of lithium chloride and subjected to a metal ion chelation reaction at 20–40 °C for 12–24 h. After the reaction was completed, the mixture was centrifuged, the precipitate was washed, and dried to obtain MOF-303-LiCl@EDTA.

[0021] MOF-303-LiCl@EDTA was dispersed in Tris-HCl buffer solution, dopamine hydrochloride was added, and the mixture was stirred to carry out an oxidative self-polymerization reaction. The unreacted solution was sprayed onto the surface of a nonwoven fabric with photothermal function. An air water adsorption material adhering to the surface of the nonwoven fabric with photothermal function was obtained through a mussel-like reaction, which is an air water collection material.

[0022] The mass ratio of MOF-303 to lithium chloride is 1:20 to 80, and the mass ratio of MOF-303-LiCl@EDTA, dopamine hydrochloride and cellulose viscose hydroentangled fabric is 10:1 to 50:25.

[0023] As a preferred embodiment of the preparation method of the air-collecting water material based on the metal-organic framework described in this invention, wherein: in the solution condensation reflux method, Al 3+ The dropping rate of inorganic salts was 10–30 mL / h, the oil bath reaction temperature was 65–120℃, and the oil bath reaction time was 1–24 h.

[0024] In a preferred embodiment of the preparation method of the air-water collecting material based on the metal-organic framework described in this invention, the molar ratio of 3,5-pyrazole dicarboxylic acid, NaOH and AlCl3·6H2O is 1:2 to 3:1.

[0025] In a preferred embodiment of the preparation method of the air-water collecting material based on the metal-organic framework described in this invention, the molar ratio of MOF-303 to disodium ethylenediaminetetraacetate is 1:1 to 2.

[0026] In a preferred embodiment of the preparation method of the air-collecting water material based on the metal-organic framework described in this invention, the preparation method of the nonwoven fabric with photothermal function includes,

[0027] The reactive dye KN-B was added to an aqueous solution and stirred until it was evenly dispersed. Then, cellulose viscose hydroentangled fabric was added. After the reaction, the fabric was washed and dried to obtain cellulose viscose hydroentangled fabric with photothermal function.

[0028] The owf of cellulose viscose hydroentangled fabric and reactive dye is 3-10%, the reaction temperature is 60-80℃, and the reaction time is 0.5-1h.

[0029] Another object of the present invention is to provide an application of an air-collecting water material based on a metal-organic framework in collecting water molecules in the air and converting them into liquid water.

[0030] Another object of the present invention is to provide an air water collection device.

[0031] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including,

[0032] The enclosure 100, and the venting condenser pipe 200 connected to the interior of the enclosure 100;

[0033] The top of the housing 100 is provided with an openable vent 101;

[0034] Several air-water collecting materials 201 folded into cone shapes are fixed to the outside of the ventilated condenser pipe 200, and they surround the outside of the ventilated condenser pipe 200 in a tree-like manner; several small holes are also provided on the surface of the ventilated condenser pipe 200.

[0035] Another object of the present invention is to provide an air-water collection system.

[0036] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including,

[0037] At night, when the vent 101 is opened, the air in the box 100 is connected to the outside air. Several air water collection materials 201, which are folded into cones and surround the outside of the vent condenser pipe 200 in a tree-like shape, absorb water vapor from the air.

[0038] During the day, with the vent 101 closed, the air receiving sunlight is activated. Several conical air-water collecting materials 201, arranged in a tree-like pattern around the outside of the vent condenser pipe 200, convert the absorbed solar energy into heat energy, releasing the water vapor absorbed at night.

[0039] Beneficial effects of this invention:

[0040] (1) In this invention, aluminum compounds are used as metal-organic framework materials. The MOF is selected to have an xhh topology. In the pore structure of MOF-303, there are a large number of adjacent hydrophilic functional groups, which have a strong affinity for water molecules. After the carboxyl group on the MOF ligand undergoes a nucleophilic substitution reaction with disodium ethylenediaminetetraacetate (EDTA-2Na), it chelates with LiCl, which makes MOF-303-LiCl@EDTA have a higher water absorption capacity.

[0041] (2) The present invention uses nonwoven fabric with photothermal function as carrier material. Since cellulose viscose spunlace fabric has good moisture absorption and obvious groove structure on its surface, it is more conducive to the adhesion of MOF-303-LiCl@EDTA material on its surface, which increases the overall moisture absorption of MOF-303-LiCl@EDTA imitation mussel adhering to viscose spunlace fabric composite material; after addition reaction with reactive black dye, it becomes an excellent photothermal material.

[0042] (3) The present invention selects polydopamine to mimic mussel adhesion, which enhances the adhesion strength of MOF-303-LiCl@EDTA on the surface of cellulose viscose hydroentangled fabric, and prevents or reduces the problem of decreased adsorption caused by MOF-303-LiCl@EDTA.

[0043] (4) The air-water collection device with a metal-organic framework composite material prepared in this invention has several air-water collection materials folded into cone shapes fixed to the outside of the ventilating condenser tube, arranged in a tree-like pattern around the outside of the ventilating condenser tube, and several small holes are also provided on the surface of the ventilating condenser tube. This device promotes green planning, green design, and green production in all aspects and throughout the entire process, achieving efficient, low-energy, and low-cost air-water collection based on the efficient utilization of solar energy resources, strict protection of the ecological environment, and effective control of greenhouse gas emissions. Experimental results show that, within the temperature range of 30℃ and humidity range of 35-95% in the constant temperature and humidity chamber, the water production can reach 0.50-3.51g. H2O / g. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0045] Figure 1 This is a physical image of the air-water collecting material prepared in Example 1 of the present invention.

[0046] Figure 2 These are SEM images of the products from each step of Embodiment 1 of the present invention.

[0047] Figure 3 The images shown are XRD patterns of the products from each step of Embodiment 1 of the present invention.

[0048] Figure 4 This is a comparison chart of the water collection performance of the products from each step of Example 1 of the present invention.

[0049] Figure 5 This is a diagram of the air-water collection device according to Embodiment 2 of the present invention.

[0050] Figure 6 This is a schematic diagram of the application of the air water collection device in Embodiment 2 of the present invention. Detailed Implementation

[0051] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0052] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0053] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0054] The moisture absorption performance test of the water-collecting material in this invention was conducted in a constant temperature and humidity chamber.

[0055] Operating conditions: Temperature 30℃, relative humidity 35-95%;

[0056] Unless otherwise specified, all raw materials used in this invention are commercially available in the field.

[0057] Example 1

[0058] This embodiment provides a method for preparing an air-collecting water material based on a metal-organic framework:

[0059] 1) Synthesis of MOF-303:

[0060] 1.2g NaOH was dissolved in 50ml deionized water and stirred until the solution was clear. Then 1.74g 3,5-pyrazoledicarboxylic acid was added to the NaOH aqueous solution and stirred at 65℃ until the solution was clear to obtain solution A.

[0061] Add 3.6g of AlCl3·6H2O to 50ml of deionized water and stir at room temperature for 15min to obtain solution B;

[0062] Solution B was transferred to a 60 ml syringe and added dropwise to solution A at a rate of 23 ml / h. The reaction mixture was heated and stirred at 120 °C for 2.5 h under normal pressure reflux conditions. After the reaction was completed, the solution was cooled to room temperature within 1 h. Then, it was centrifuged at 5000 rpm for 10 min with deionized water and anhydrous ethanol and washed six times. The washed precipitate was placed in a forced-air drying oven to air dry and then placed in a vacuum drying oven at 100 °C for 2 h to activate it. Finally, a fully activated and desoluble MOF-303 product was obtained.

[0063] 2) Synthesis of MOF-303-EDTA:

[0064] 0.4 g of disodium ethylenediaminetetraacetate (EDTA-2Na) was dissolved in 10 ml of deionized water and stirred until the solution was clear. Then, 0.1 g of MOF-303 was added to the EDTA-2Na aqueous solution and stirred at 800 r / min for 60 min to obtain a MOF-303-EDTA mixed solution. The mixture was then centrifuged at 7000 rpm for 10 min, the supernatant was removed, and the solution was washed twice with deionized water to remove unreacted EDTA-2Na. The solution was then dried in a vacuum drying oven at 100 °C for 6 h to finally obtain the product MOF-303-EDTA.

[0065] 3) Synthesis of MOF-303-LiCl@EDTA:

[0066] 6g LiCl was dissolved in 10ml of deionized water and stirred at 1000r / min for 30min to obtain solution A; then the MOF-303-EDTA powder obtained in step 2) was added to solution A and stirred at 500r / min for 24h to obtain a homogeneous suspension B of MOF-303-LiCl@EDTA.

[0067] Suspension B was centrifuged at 10,000 rpm for 10 min to remove the supernatant. MOF-303-LiCl@EDTA was then washed rapidly with ethanol to remove excess lithium chloride adhering to the outer surface of MOF-303. The washed precipitate was then air-dried in a forced-air drying oven and then dried and activated in a vacuum drying oven at 100°C for 8 h to finally obtain the MOF-303-LiCl@EDTA product.

[0068] 4) Synthesizing nonwoven fabrics with photothermal properties:

[0069] 0.64g of reactive dye KN-B was dissolved in 240ml of deionized water and stirred at 500r / min for 30min to obtain solution A. Then the magnetic stirring was turned off, the heating switch was turned on and the temperature was set to 75℃. Cellulose viscose hydroentangled fabric was placed in the solution and immersed at 75℃ for 45min. After that, it was taken out, cleaned and dried.

[0070] 5) Synthesis of air-water collection materials based on metal-organic frameworks:

[0071] MOF-303-LiCl@EDTA was dissolved in 5 ml of Tris-HCl buffer solution and stirred at 500 r / min for 1 h to obtain solution A;

[0072] Add 0.01g of dopamine and stir at 1000r / min for 30min at 50℃. Apply the unreacted solution to the surface of photothermal cellulose viscose hydroentangled fabric through a spray gun and complete the self-oxidative polymerization of polydopamine in an oven at 50℃ to synthesize an air-water collection material based on a metal-organic framework.

[0073] Figure 1 The image shows a physical picture of the product obtained in this embodiment, which is an air-water collecting material based on a metal-organic framework. It can be seen that the front of the air-water collecting material is black, and the absorbed light and heat are used to desorb water vapor adsorbed by the air-water collecting material based on the metal-organic framework. The back is white and black in an alternating pattern, which can utilize the light and heat material for desorption, and at the same time, it is also conducive to the adsorption of water vapor in the air.

[0074] Figure 2 These are SEM images of the products obtained in each step of this embodiment. Figure 2 A represents the ungrafted metal-organic framework obtained in step 1). Figure 2 B is the grafted metal-organic framework obtained in step 2).

[0075] Figure 2 C Figure 2 D shows the SEM images of the nonwoven fabric without grafted photothermal function at different magnifications, and it can be seen that its surface is smooth.

[0076] Figure 2 E, Figure 2 F represents the SEM images of the nonwoven fabric with grafted photothermal function, i.e., the final product of this embodiment, at different magnifications. It can be seen that there are a large number of metal-organic frameworks on its surface, and they are evenly distributed.

[0077] Figure 3 The XRD patterns of the products from each step in this embodiment show that the diffraction peak positions of MOF-303-LiCl@EDTA are basically consistent with those of MOF-303 at 2θ = 8.7°, 14.9°, and 17.5°, and are also basically consistent with those of LiCl at 2θ = 23.3°, 26.4°, 30.6°, 33.2°, 35.6°, and 40.6°. This indicates that the air-water collecting material based on the metal-organic framework was successfully synthesized on MOF-303-LiCl@EDTA, and the fiber matrix accounts for the majority of the mass, with its peak intensity slightly lower than that of MOF-303-LiCl@EDTA powder.

[0078] Comparative Example 1

[0079] This comparative example uses MOF-303 synthesized in step 1) of Example 1 as the water collection material.

[0080] Comparative Example 2

[0081] This comparative example uses MOF-303-EDTA synthesized in step 2) of Example 1 as the water collection material.

[0082] Comparative Example 3

[0083] This comparative example uses MOF-303-LiCl@EDTA synthesized in step 3) of Example 1 as the water collection material.

[0084] Comparative Example 4

[0085] This comparative example uses the nonwoven fabric with photothermal function synthesized in step 4 of Example 1 as the water collection material.

[0086] The final product of step 5) of Example 1 and the products of Comparative Examples 1-4 were used as water collection materials, and their water collection performance was tested. The results are shown in Table 1 and... Figure 4 As shown.

[0087] Table 1

[0088]

[0089] It can be seen that the water vapor adsorption capacity of the MOF-303 raw material is 0.39g. H2O The water vapor adsorption capacity of the LiCl raw material is 0.46 g / g. H2O / g, the water vapor adsorption capacity of the photothermal raw material is 0.49g. H2O / g, the amount of air-water harvesting material based on metal-organic frameworks is 3.51g. H2O / g, which is four times the combined adsorption capacity of MOF-303-LiCl@EDTA and the photothermal nonwoven fabric. Therefore, the air-water collecting material based on the metal-organic framework is not merely the sum of the adsorption properties of MOF-303-LiCl@EDTA and the photothermal nonwoven fabric, but rather a new chemical bond is generated during the preparation of the metal-organic framework-based air-water collecting material. In addition to the known chelating chemical forces, it may also be the sulfone group (-SO2-) of the photothermal material and Li + New bonds are formed due to electrostatic interactions.

[0090] Example 2

[0091] This embodiment was used to investigate the effect of the molar ratio of grafted metal-organic framework to inorganic salt on the water collection performance of the product. The difference from Example 1 is that the amount of lithium chloride in step 3) was adjusted to 2g, 4g, 6g and 8g respectively, so that the mass ratio of metal-organic framework to inorganic salt was 1:20 to 80. The remaining steps were the same as in Example 1. The water collection effect of each material was measured and the results are shown in Table 2.

[0092] Table 2

[0093]

[0094] Example 3

[0095] This embodiment is used to investigate the effect of different grafting conditions on the water collection performance of the grafted metal framework material. The conditions of the grafting reaction in step 2) of Example 1 were adjusted as follows:

[0096] A: 0.2g disodium ethylenediaminetetraacetate (EDTA-2Na), grafting reaction time 60min.

[0097] B: 0.2g disodium ethylenediaminetetraacetate (EDTA-2Na), grafting reaction time 30min.

[0098] C: 0.4g disodium ethylenediaminetetraacetate (EDTA-2Na), grafting reaction time 30min.

[0099] Grafted metal frame materials with different grafting conditions were obtained. The remaining steps were the same as in Example 1. Corresponding air water collection materials were prepared, and the water collection performance was measured and compared with that in Example 1. The results are shown in Table 3.

[0100] Table 3

[0101]

[0102] As shown in Tables 2 and 3, the ratio of metal framework material to inorganic salt and the degree of metal framework grafting have a significant impact on the water collection effect of the material. This may be because when the metal framework material reacts with a high concentration of disodium ethylenediaminetetraacetate in solution for a longer time, the grafting reaction is more complete, resulting in a higher content of grafted metal framework material. Furthermore, when chelated with lithium chloride, more Li will be released. + Chelated with ethylenediaminetetraacetic acid, while unchelated Li + Further combining with sulfone groups enhances the water collection performance of air-water collection materials based on metal-organic frameworks.

[0103] Example 4

[0104] Reference Figures 5-6 This embodiment provides an air water collection device and its application system using the air water collection material prepared in Embodiment 1. Specifically:

[0105] like Figure 5 The image shows a front view (left) and a cross-sectional view (right) of an air-to-water collection device, which includes:

[0106] The enclosure 100, and the venting condenser pipe 200 connected to the interior of the enclosure 100;

[0107] The top of the housing 100 is provided with an openable vent 101;

[0108] Several air-water collecting materials 201 folded into cone shapes are fixed to the outside of the ventilated condenser pipe 200, and they surround the outside of the ventilated condenser pipe 200 in a tree-like manner; several small holes are also provided on the surface of the ventilated condenser pipe 200.

[0109] Air-to-water collection systems, such as Figure 6 As shown:

[0110] At night, when the vent 101 is opened, the air in the box 100 is connected to the outside air. Several air moisture collection materials 201, which are folded into cones and surround the outside of the vent condenser pipe 200 in a tree-like shape, absorb water vapor from the air. The weight difference before and after is weighed, and the amount of moisture absorbed is calculated.

[0111] During the day, with the vent 101 closed, the air-water collection material 201, which is folded into a cone shape and surrounds the vent condenser tube 200 in a tree-like manner, converts the adsorbed solar energy into heat energy, releases the water vapor adsorbed at night, weighs the weight difference before and after, calculates the amount of moisture absorbed, and collects the desorbed water vapor by condensing the condenser tube and weighing the liquid.

[0112] The air-water collection device based on a metal-organic framework composite material in this embodiment has several folded conical air-water collection materials fixed to the outside of the ventilation condenser pipe, arranged in a tree-like pattern around the outside of the ventilation condenser pipe, and several small holes are also provided on the ventilation condenser surface. This device promotes green planning, green design, and green production in all aspects and throughout the entire process, achieving efficient, low-energy, and low-cost air-water collection based on the efficient use of solar energy resources, strict protection of the ecological environment, and effective control of greenhouse gas emissions.

[0113] In summary, this invention uses aluminum compounds as the metal-organic framework material. The MOF selected possesses an xhh topology, and its porous structure contains numerous adjacent hydrophilic functional groups, exhibiting a strong affinity for water molecules. Furthermore, the carboxyl groups on the MOF ligand undergo a nucleophilic substitution reaction with disodium ethylenediaminetetraacetate (EDTA-2Na), followed by chelation with LiCl, resulting in MOF-303-LiCl@EDTA exhibiting even higher water absorption. Experimental results show that, within a constant temperature and humidity chamber at 30℃ and a humidity range of 35-95%, the water production can reach 0.50–3.51 g. H2O / g.

[0114] This invention uses a nonwoven fabric with photothermal properties as the carrier material. Due to the good moisture absorption of cellulose viscose spunlace fabric and its distinct grooved surface, it facilitates the adhesion of MOF-303-LiCl@EDTA material to its surface and enhances the moisture absorption of the metal-organic framework-based air-collecting material. After addition reaction with reactive black dye, it becomes an excellent photothermal material. This invention utilizes the mussel-like adhesive properties of polydopamine to enhance the adhesion strength of MOF-303-LiCl@EDTA to the surface of the cellulose viscose spunlace fabric, preventing or reducing the problem of decreased adsorption due to MOF-303-LiCl@EDTA detachment.

[0115] 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 technical solutions 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 air-water collection material based on a metal-organic framework, characterized in that: include, Nonwoven fabrics with photothermal functions, and air-water adsorption materials adhered to the surface of nonwoven fabrics; Wherein, the air-water adsorption material is a chelate that satisfies the following (i) to (iv): (i) Obtained by chelation of grafted metal-organic frameworks with inorganic salts; (ii) The metal-organic framework material is selected from aluminum compounds, and the inorganic salt material is selected from lithium chloride; (iii) The mass ratio of metal-organic framework to inorganic salt is 1:20~80; (iv) The grafted metal-organic framework is obtained by nucleophilic substitution reaction between the carboxyl group on the metal-organic framework ligand and disodium ethylenediaminetetraacetate.

2. The air-water harvesting material based on a metal-organic framework as described in claim 1, characterized in that: The nonwoven fabric with photothermal function is a cellulose viscose hydroentangled fabric dyed with reactive dyes, wherein the amount of reactive dyes used is 3-10 owf.

3. The method for preparing air-water collecting materials based on metal-organic frameworks as described in any one of claims 1 or 2, characterized in that: include, 3,5-pyrazole dicarboxylic acid, NaOH, and AlCl3·6H2O were synthesized by solution reflux condensation. The product was washed and activated to obtain MOF-303. MOF-303 was added to an aqueous solution of disodium ethylenediaminetetraacetate and stirred until uniformly dispersed. A nucleophilic substitution reaction was carried out at room temperature for 0.5-1 h to obtain MOF-303-EDTA. MOF-303-EDTA was added to an aqueous solution of lithium chloride and subjected to a metal ion chelation reaction at 20-40°C for 12-24 hours. After the reaction was completed, the mixture was centrifuged, the precipitate was washed, and dried to obtain MOF-303-LiCl@EDTA. MOF-303-LiCl@EDTA was dispersed in Tris-HCl buffer solution, dopamine hydrochloride was added, and the mixture was stirred to carry out an oxidative self-polymerization reaction. The unreacted solution was sprayed onto the surface of a nonwoven fabric with photothermal function. An air water adsorption material adhering to the surface of the nonwoven fabric with photothermal function was obtained through a mussel-like reaction, which is an air water collection material. The mass ratio of MOF-303 to lithium chloride is 1:20~80, and the mass ratio of MOF-303-LiCl@EDTA, dopamine hydrochloride and cellulose viscose hydroentangled fabric is 10:1~50:

25.

4. The method for preparing air-water collecting materials based on metal-organic frameworks as described in claim 3, characterized in that: The solution condensation reflux method, wherein Al 3+ The dropping rate of inorganic salts is 10-30 mL / h, the oil bath reaction temperature is 65-120℃, and the oil bath reaction time is 1-24 h.

5. The method for preparing air-water collecting materials based on metal-organic frameworks as described in claim 3, characterized in that: The molar ratio of 3,5-pyrazole dicarboxylic acid, NaOH and AlCl3·6H2O is 1:2 to 3:

1.

6. The method for preparing air-water collecting materials based on metal-organic frameworks as described in claim 3, characterized in that: The molar ratio of MOF-303 to disodium ethylenediaminetetraacetate is 1:1~2.

7. The method for preparing air-water collecting materials based on metal-organic frameworks as described in claim 3, characterized in that: The method for preparing the nonwoven fabric with photothermal function includes, The reactive dye KN-B was added to an aqueous solution and stirred until it was evenly dispersed. Then, cellulose viscose hydroentangled fabric was added. After the reaction, the fabric was washed and dried to obtain cellulose viscose hydroentangled fabric with photothermal function. The amount of reactive dye used is 3-10 owf%, the reaction temperature is 60-80℃, and the reaction time is 0.5-1h.

8. The application of the air-collecting water material obtained by any one of the preparation methods described in claims 3 to 7 in collecting water molecules in the air and converting them into liquid water.

9. An air-to-water collection device, characterized in that: Including the air-collecting water material of claim 1, further comprising: The housing (100) and the venting condenser pipe (200) communicating with the interior of the housing (100); The top of the housing (100) is provided with an openable vent (101). The ventilated condenser pipe (200) has several air-water collecting materials (201) folded into cone shapes fixed to its exterior, which surround the exterior of the ventilated condenser pipe (200) in a tree-like manner; the surface of the ventilated condenser pipe (200) is also provided with several small holes.

10. An air-to-water collection system, characterized in that: Including the air-water collection device of claim 9, it further includes, At night, when the vent (101) is opened, the air in the box (100) is connected to the outside air. Several air water collection materials (201) folded into cones and surrounding the outside of the vent condenser pipe (200) in a tree-like shape absorb water vapor from the air. During the day, the vent (101) is closed to receive sunlight. Several air-water collecting materials (201) folded into cones and arranged in a tree-like shape around the outside of the vent condenser pipe (200) convert the adsorbed solar energy into heat energy and release the water vapor adsorbed at night.

Images