Tough photo-thermal evaporation material, preparation method thereof and photo-thermal evaporation device with three-dimensional arch bridge structure

Abstract

The invention belongs to the technical field of photothermal conversion, and particularly relates to a tough photothermal evaporation material, a preparation method thereof and a three-dimensional arch bridge structure photothermal evaporation device. The device comprises a base; the at least one three-dimensional arch bridge structure is fixed on the base, and each three-dimensional arch bridge structure is made of a tough photo-thermal evaporation material. The material comprises a base material layer; the ZIF-67 layer grows on the base material layer, and each ZIF-67 particle is coated with a molybdenum disulfide layer with a high specific surface area. According to the technical scheme, the photo-thermal conversion efficiency can be improved, heat distribution is optimized, salt deposition is effectively inhibited, and the water evaporation rate and the long-term stability are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of photothermal conversion, and particularly relates to a tough photothermal evaporation material, a preparation method thereof, and a three-dimensional arch structure photothermal evaporation device. Background Art

[0002] Traditional seawater desalination technologies, such as electrodialysis and reverse osmosis, although they can effectively remove salts, have defects such as high equipment costs, high energy consumption, complex operations, and possible generation of secondary pollutants, which limit their large-scale application. In recent years, the interfacial water evaporation technology driven by solar energy has gradually attracted attention. This technology uses a photothermal material to absorb solar energy and generate heat, thereby promoting the evaporation of water at the water-air interface. Compared with traditional technologies, this method not only has low energy consumption and simple operation, but also avoids pollutant emissions, and has significant advantages of environmental friendliness and sustainable development.

[0003] Currently, the research on photothermal materials mainly focuses on semiconductor materials, metal nanomaterials, metal-organic frameworks (MOFs), polymer materials, and MXene materials, etc. These materials have good solar energy absorption and thermal conversion properties. However, in addition to excellent photothermal conversion ability, an ideal photothermal material also needs to have strong hydrophilicity and long-term operation stability to meet the actual application requirements. Although two-dimensional (2D) photothermal materials have high light absorption ability, they have obvious deficiencies in interfacial heat concentration and transmission efficiency, resulting in limited water evaporation rate. In addition, such two-dimensional materials also face problems such as low photothermal conversion efficiency, insufficient salt tolerance, and poor scalability in practical applications such as seawater desalination. Therefore, the development of three-dimensional (3D) photothermal conversion materials with novel structures and better performance has become the current research trend. Summary of the Invention

[0004] To solve the deficiencies of the prior art, the present invention provides a tough photothermal evaporation material, a preparation method thereof, and a three-dimensional arch structure photothermal evaporation device. The technical solution of the present invention can improve the photothermal conversion efficiency, optimize the heat distribution, and effectively inhibit salt deposition, thereby enhancing the water evaporation rate and long-term stability.

[0005] The technical solution provided by the present invention is as follows:

[0006] A tough photothermal evaporation material, comprising:

[0007] A substrate layer;

[0008] And a ZIF-67 layer grown on the substrate layer, and each ZIF-67 particle is coated with a molybdenum disulfide layer with a high specific surface area.

[0009] Based on the above technical solution:

[0010] The ZIF-67 layer can increase the toughness of the substrate layer and ensure the mechanical properties during device fabrication, as compared with other MOF materials such as ZIF-8, etc.;

[0011] ZIF-67 can induce molybdenum disulfide to form a micro-structure with a high specific surface area;

[0012] The synergy of ZIF-67 and molybdenum disulfide can ensure that only a thin layer is formed on the material surface after water absorption, improving the photothermal evaporation performance, as compared with using only the ZIF-67 layer.

[0013] Specifically: The substrate layer is a carbon cloth layer (CC).

[0014] Specifically: The morphology of the ZIF-67 particles is a polyhedral structure.

[0015] Specifically: A spherical structure formed by dense sheet-like molybdenum disulfide.

[0016] Molybdenum disulfide in this morphology has a very high specific surface area, which can be as high as 100 - 150 m 2 / g, thus enhancing the photothermal evaporation performance.

[0017] The present invention also provides a method for preparing a tough photothermal evaporation material, comprising the following steps:

[0018] 1) Immerse the substrate layer in an alcoholic solution of a cobalt source and 2-methylimidazole, and age to obtain a substrate layer grown with ZIF-67;

[0019] 2) Place the substrate layer grown with ZIF-67 into a mixed solution of a molybdenum source and a sulfur source, and perform a hydrothermal reaction to coat a molybdenum disulfide layer on the surface of the ZIF-67 particles to obtain the tough photothermal evaporation material.

[0020] Based on the above technical solutions:

[0021] ZIF-67 can be prepared by a room temperature solvent method;

[0022] A molybdenum disulfide layer with a high specific surface area can be prepared by a hydrothermal reaction.

[0023] Preferably, in step 1):

[0024] The cobalt source is cobalt(II) nitrate hexahydrate;

[0025] The alcohol is methanol;

[0026] The molar ratio of cobalt to 2-methylimidazole is (1.6 - 2.0):1, preferably 1.8:1.

[0027] Compared with other reaction systems, the ZIF-67 prepared by the above system has higher toughness, higher structural uniformity and nucleation controllability, which is beneficial to the stable growth of the subsequent MoS2 layer and the improvement of the overall material properties.

[0028] Preferably, in step 2):

[0029] The molybdenum source is ammonium molybdate tetrahydrate;

[0030] The sulfur source is thiourea;

[0031] The molar ratio of molybdenum to sulfur is (4.0 - 4.5):1, preferably 4.3:1;

[0032] The hydrothermal reaction is as follows: first, heat up to 180 - 200 °C at a heating rate of 3 - 5 °C / min, and then keep warm for 12 - 24 h.

[0033] The above system can ensure the preparation of a spherical structure formed by dense flaky molybdenum disulfide.

[0034] A three-dimensional arch structure photothermal evaporation device, comprising:

[0035] A base;

[0036] And a three-dimensional arch structure fixed on the base, and the material of the three-dimensional arch structure is the ductile photothermal evaporation material described above.

[0037] Preferably: the material of the base is polystyrene foam.

[0038] As the base material of the photothermal evaporation device, polystyrene foam has better heat insulation performance and buoyancy stability than other materials.

[0039] Specifically: both ends of the three-dimensional arch structure are inserted and fixed on the base.

[0040] Based on the above technical solution, the ductile photothermal evaporation material is in direct physical contact with the base material, which can improve the heat distribution and moisture transport, help to inhibit the accumulation of salts in the evaporation area, and improve the evaporation efficiency and service life.

[0041] Preferably, the arch span of the arch structure is between 0.5 - 4 cm to optimize heat management and evaporation rate.

[0042] Specifically, each of the three-dimensional arch structures is arranged in a row-column layout.

[0043] Specifically, each of the three-dimensional arch structures is arranged in a fan-shaped layout.

[0044] Specifically, each of the three-dimensional arch structures is arranged in a polygonal layout. Preferably, it is arranged as an equilateral polygon. More preferably, it is arranged as a triangle.

[0045] Specifically, the arch spacing is 0.5 - 4 cm. Preferably, it is 0.5 cm.

[0046] Under 1 sun irradiation condition, the pure water evaporation rate of the three-dimensional arch structure photothermal evaporation device can reach 3.64 kg m -2 h -1 , and in 3.5 wt% NaCl solution, the evaporation rate reaches 3.27 kg m -2 h -1 , and shows excellent anti-salt deposition ability.

[0047] The beneficial effects of the present invention include:

[0048] 1) Adopting a three-dimensional arch structure to improve the photothermal conversion efficiency, optimize the light absorption path, and enhance the evaporation efficiency.

[0049] 2) Effectively suppressing salt deposition, ensuring long-term stable operation, and avoiding the problem that traditional evaporators are vulnerable to salt pollution.

[0050] 3) By combining flexible carbon cloth and metal-organic framework materials, the mechanical properties, stability, and durability of the structure are improved, enabling the evaporator to maintain high efficiency in extreme environments.

[0051] 4) The device has broad application potential and can be used in multiple fields such as seawater desalination, sewage purification, and agricultural irrigation, providing an efficient and sustainable solution for water-scarce regions.

[0052] In summary, the present invention can efficiently utilize solar energy to drive water evaporation, while optimizing interfacial heat management, reducing salt deposition, and improving long-term operation stability. It can be used for fresh water preparation and water resource purification. The three-dimensional arch structure photothermal evaporation device provided by the present invention has excellent acid and alkali resistance and long-term stability, and still maintains high evaporation performance under extreme environmental conditions. It is applicable to the fields of seawater desalination, wastewater treatment, and agricultural irrigation, and is applicable to the technical field of efficient fresh water preparation driven by solar energy. Brief Description of the Drawings

[0053] Figure 1 SEM images of materials at different stages.

[0054] Figure 2 Physical diagrams of evaporators with different arch structure spacings.

[0055] Figure 3 Unit area mass change of evaporators with different arch spacings under 1 sun condition.

[0056] Figure 4 Physical diagrams of arch evaporation structures in three different arrangements.

[0057] Figure 5 It is a comparison chart of the evaporation rates of three arrangement modes under different light incident angles.

[0058] Figure 6 It is a process chart of the gradual dissolution of salts on the evaporator surface over time under no-light conditions.

[0059] Figure 7 It is a comparison chart of the wettability and surface morphology of different materials.

[0060] Figure 8 It is a schematic structural diagram of a three-dimensional arch structure photothermal evaporation device.

[0061] Figure 9 It is a working principle diagram of a three-dimensional arch structure photothermal evaporation device.

[0062] Appendix Figure 8 In the following, the list of structures represented by each label is as follows:

[0063] 1. Base; 2. Three-dimensional arch structure. Specific implementation mode

[0064] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0065] Unless otherwise specified, the test methods used in the examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, are reagents and materials that can be obtained commercially.

[0066] 1. Preparation of a three-dimensional arch structure photothermal evaporation device

[0067] 1) Cut the carbon cloth into a rectangular piece of 2×6 cm 2 , and ultrasonically clean it successively with deionized water and ethanol, with each cleaning time being 15 min, to remove surface impurities and oil.

[0068] 2) Dry the cleaned carbon cloth at 60 °C for 2 hours, then soak it in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3, and soak it at room temperature for 12 hours to enhance the surface activity of the carbon cloth. Dissolve 0.2 g of cobalt nitrate hexahydrate in 20 mL of methanol, place the carbon cloth in it and stir for 30 min; dissolve 0.1 g of dimethylimidazole in 25 mL of methanol, quickly add it to the above solution, continue to stir for 1 h and then let it stand for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. Wash the product 3 times with ethanol and water, and dry it at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0069] 3) Dissolve 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea in 25 mL of deionized water, and stir at room temperature for 1 hour. Immerse ZIF-67 / CC into this solution, transfer it to a high-pressure reactor, heat it up to 180 °C, and carry out a hydrothermal reaction for 12 h. After the reaction is completed, cool it naturally to room temperature, take out the sample, wash it with deionized water, dry it at a temperature of 60 °C for 12 h to obtain a tough photothermal evaporation material, denoted as MoS2@ZIF-67 / CC composite material.

[0070] 2. Evaporator structure construction

[0071] Use a polystyrene foam board with a thickness of 0.5 cm as a support, cut it into a circular foam block with a diameter of about 5 cm, and open two slots with a width of 2 cm at its center position. The slot spacings are set to 0.5 cm, 1 cm, 2 cm, 3 cm, and 4 cm respectively for inserting both ends of the arched carbon cloth, so as to construct arched structures with different spans. Place the carbon cloth material at the bottom of the foam about 0.5 cm in water to achieve stable capillary water supply.

[0072] 3. Arched arrangement setting

[0073] Arrange multiple arched evaporation units in three different arrangements: (1) Parallel arrangement, all arched structures are arranged in parallel in the same direction; (2) Fan-shaped arrangement, radially expanded around the center; (3) Triangular arrangement, equilateral triangles are staggered for enhancing the photothermal response. Place the carbon cloth material at the bottom of the foam about 0.5 cm in water to achieve stable capillary water supply.

[0074] 4. Photothermal performance test

[0075] Place the evaporator under a solar simulator (AM 1.5G, 1 kW·m -2 ) to conduct evaporation performance tests, use an electronic balance to monitor the evaporation mass, and set six different incident angles of 15°, 30°, 45°, 60°, 75°, and 90° to simulate all-weather solar irradiation conditions to evaluate the influence of different arched sizes and arrangement structures on the evaporation efficiency.

[0076] Example 1

[0077] 1. Preparation of a three-dimensional arched structure photothermal evaporation device

[0078] 1) Cut the carbon cloth into a rectangular sheet of 2×6 cm 2 , and ultrasonically clean it with deionized water and ethanol in turn, with each cleaning time being 15 min to remove surface impurities and oil stains.

[0079] 2) The cleaned carbon cloth was dried at 60 °C for 2 hours, and then immersed in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. 0.2 g of cobalt nitrate hexahydrate was dissolved in 20 mL of methanol, and the carbon cloth was placed therein and stirred for 30 min; another 0.1 g of dimethylimidazole was dissolved in 25 mL of methanol and quickly added to the above solution, and stirring was continued for 1 h followed by standing for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. The product was washed 3 times with ethanol and water and dried at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0080] 3) 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea were dissolved in 25 mL of deionized water and stirred at room temperature for 1 hour. The ZIF-67 / CC was immersed in this solution, transferred to a high-pressure reaction kettle, and the heating rate was 5 °C / min, which was the same for each example. The temperature was raised to 180 °C for hydrothermal reaction for 12 h. After the reaction was completed, it was naturally cooled to room temperature, the sample was taken out, washed with deionized water, the drying temperature was 60 °C, and the drying time was 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0081] 2. Evaporator structure construction

[0082] A polystyrene foam board with a thickness of 0.5 cm was used as a support, cut into a circular foam block with a diameter of about 5 cm, and two slots with a width of 2 cm were opened at its center position, and the slot spacing was set to 4 cm for inserting both ends of the arched carbon cloth, so as to construct arched structures with different spans. The carbon cloth material at the bottom of the foam was placed in water about 0.5 cm to achieve stable capillary water supply.

[0083] 3. Photothermal performance test

[0084] The evaporator was placed under a solar simulator (AM 1.5G, 1 kW·m -2 ) for evaporation performance test, an electronic balance was used to monitor the evaporation mass, and the incident angle was set to 90°, and then the evaporation performance test was carried out. The measured evaporation rate was 2.68 kg m - 2 h -1 .

[0085] Example 2

[0086] 1) The carbon cloth was cut into a rectangular piece of 2×6 cm 2 , and successively ultrasonically cleaned with deionized water and ethanol, and the cleaning time for each step was 15 min to remove surface impurities and oil stains.

[0087] 2) The cleaned carbon cloth was dried at 60 °C for 2 hours, and then immersed in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. 0.2 g of cobalt(II) nitrate hexahydrate was dissolved in 20 mL of methanol, and the carbon cloth was placed therein and stirred for 30 min; another 0.1 g of 2-methylimidazole was dissolved in 25 mL of methanol and quickly added to the above solution, and stirring was continued for 1 h followed by standing for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. The product was washed 3 times with ethanol and water and dried at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0088] 3) 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea were dissolved in 25 mL of deionized water and stirred at room temperature for 1 hour. The ZIF-67 / CC was immersed in this solution, transferred to a high-pressure reactor, heated to 180 °C and subjected to hydrothermal reaction for 12 h. After the reaction, it was naturally cooled to room temperature, the sample was taken out, washed with deionized water, dried at 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0089] 2. Evaporator structure construction

[0090] A polystyrene foam board with a thickness of 0.5 cm was used as a support, cut into a circular foam block with a diameter of about 5 cm, and two slots with a width of 2 cm were opened at its center position, and the slot spacing was set to 3 cm for inserting both ends of the arched carbon cloth, so as to construct arched structures with different spans. The carbon cloth material at the bottom of the foam was placed about 0.5 cm in water to achieve stable capillary water supply.

[0091] 3. Photothermal performance test

[0092] The evaporator was placed under a solar simulator (AM 1.5G, 1 kW·m -2 ) for evaporation performance test, an electronic balance was used to monitor the evaporation mass, and an incident angle of 90° was set, and then the evaporation performance test was carried out. The measured evaporation rate was 2.80 kg m - 2 h -1 .

[0093] Example 3

[0094] 1) The carbon cloth was cut into a rectangular sheet of 2×6 cm 2 , and ultrasonically cleaned successively with deionized water and ethanol, and the cleaning time for each step was 15 min to remove surface impurities and oil stains.

[0095] 2) The cleaned carbon cloth was dried at 60 °C for 2 hours, and then immersed in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. 0.2 g of cobalt nitrate hexahydrate was dissolved in 20 mL of methanol, and the carbon cloth was placed therein and stirred for 30 min; another 0.1 g of dimethylimidazole was dissolved in 25 mL of methanol and quickly added to the above solution, and stirring was continued for 1 h and then left standing for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. The product was washed 3 times with ethanol and water and dried at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0096] 3) 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea were dissolved in 25 mL of deionized water and stirred at room temperature for 1 hour. The ZIF-67 / CC was immersed in this solution, transferred to a high-pressure reactor, heated to 180 °C and subjected to a hydrothermal reaction for 12 h. After the reaction was completed, it was naturally cooled to room temperature, the sample was taken out, washed with deionized water, dried at a temperature of 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0097] 2. Evaporator structure construction

[0098] A polystyrene foam board with a thickness of 0.5 cm was used as a support, cut into a circular foam block with a diameter of about 5 cm, and two slots with a width of 2 cm were opened at its center position, and the slot spacing was set to 2 cm for inserting both ends of the arched carbon cloth, thereby constructing arched structures with different spans. The carbon cloth material at the bottom of the foam was placed about 0.5 cm in water to achieve stable capillary water supply.

[0099] 3. Photothermal performance test

[0100] The evaporator was placed under a solar simulator (AM 1.5G, 1 kW·m- 2 ) for evaporation performance testing. An electronic balance was used to monitor the evaporation mass, and an incident angle of 90° was set, and then the evaporation performance was tested. The measured evaporation rate was 3.08 kg m - 2 h -1 .

[0101] Example 4

[0102] 1) The carbon cloth was cut into a 2×6 cm 2 rectangular sheet and ultrasonically cleaned successively with deionized water and ethanol, and the cleaning time for each step was 15 min to remove surface impurities and oil stains.

[0103] 2) The cleaned carbon cloth was dried at 60 °C for 2 hours, and then immersed in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. 0.2 g of cobalt(II) nitrate hexahydrate was dissolved in 20 mL of methanol, and the carbon cloth was placed therein and stirred for 30 min; another 0.1 g of dimethylimidazole was dissolved in 25 mL of methanol and quickly added to the above solution, and stirring was continued for 1 h and then left standing for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. The product was washed 3 times with ethanol and water and dried at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0104] 3) 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea were dissolved in 25 mL of deionized water and stirred at room temperature for 1 hour. The ZIF-67 / CC was immersed in this solution, transferred to a high-pressure reaction kettle, heated to 180 °C and subjected to a hydrothermal reaction for 12 h. After the reaction, it was naturally cooled to room temperature, the sample was taken out, washed with deionized water, dried at a temperature of 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0105] 2. Evaporator structure construction

[0106] Using a polystyrene foam board with a thickness of 0.5 cm as a support, it was cut into a circular foam block with a diameter of about 5 cm, and two slots with a width of 2 cm were opened at its center position, and the slot spacing was set to 1 cm for inserting both ends of the arched carbon cloth, thereby constructing arched structures with different spans. The carbon cloth material at the bottom of the foam was placed about 0.5 cm in water to achieve stable capillary water supply.

[0107] 3. Photothermal performance test

[0108] The evaporator was placed under a solar simulator (AM 1.5G, 1 kW·m- 2 ) for evaporation performance testing. An electronic balance was used to monitor the evaporation mass, and an incident angle of 90° was set, and then the evaporation performance was tested. The measured evaporation rate was 3.36 kg m - 2 h -1 .

[0109] Example 5

[0110] 1) The carbon cloth was cut into a rectangular sheet of 2×6 cm 2 , and ultrasonically cleaned with deionized water and ethanol in turn, and the cleaning time for each step was 15 min to remove surface impurities and oil stains.

[0111] 2) The cleaned carbon cloth was dried at 60 °C for 2 hours, and then immersed in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. 0.2 g of cobalt(II) nitrate hexahydrate was dissolved in 20 mL of methanol, and the carbon cloth was placed therein and stirred for 30 min; another 0.1 g of 2-methylimidazole was dissolved in 25 mL of methanol and quickly added to the above solution, and stirring was continued for 1 h followed by standing for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. The product was washed 3 times with ethanol and water and dried at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0112] 3) 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea were dissolved in 25 mL of deionized water and stirred at room temperature for 1 hour. The ZIF-67 / CC was immersed in this solution, transferred to a high-pressure reaction kettle, heated to 180 °C, and subjected to a hydrothermal reaction for 12 h. After the reaction, it was naturally cooled to room temperature, the sample was taken out, washed with deionized water, dried at a temperature of 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0113] 2. Evaporator structure construction

[0114] A polystyrene foam board with a thickness of 0.5 cm was used as a support, cut into a circular foam block with a diameter of about 5 cm, and two slots with a width of 2 cm were opened at its center position, and the slot spacing was set to 0.5 cm for inserting both ends of the arched carbon cloth, thereby constructing arched structures with different spans. The carbon cloth material at the bottom of the foam was placed about 0.5 cm in water to achieve stable capillary water supply, and then the evaporation performance test was carried out.

[0115] 3. Photothermal performance test

[0116] The evaporator was placed under a solar simulator (AM 1.5G, 1 kW·m- 2 ) for evaporation performance testing, an electronic balance was used to monitor the evaporation mass, and an incident angle of 90° was set, and then the evaporation performance test was carried out. The measured evaporation rate was 3.64 kg m - 2 h -1 .

[0117] Example 6

[0118] 1. Preparation of a three-dimensional arch structure photothermal evaporation device

[0119] 1) The carbon cloth was cut into a rectangular piece of 2×6 cm 2 , ultrasonically cleaned successively with deionized water and ethanol, and the cleaning time for each step was 15 min to remove surface impurities and oil stains.

[0120] 2) The cleaned carbon cloth was dried at 60 °C for 2 hours, and then immersed in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. 0.2 g of cobalt(II) nitrate hexahydrate was dissolved in 20 mL of methanol, and the carbon cloth was placed therein and stirred for 30 min; another 0.1 g of 2-methylimidazole was dissolved in 25 mL of methanol and quickly added to the above solution, and stirring was continued for 1 h followed by standing for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. The product was washed 3 times with ethanol and water and dried at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0121] 3) 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea were dissolved in 25 mL of deionized water and stirred at room temperature for 1 hour. The ZIF-67 / CC was immersed in this solution, transferred to a high-pressure reaction kettle, heated to 180 °C, and subjected to a hydrothermal reaction for 12 h. After the reaction, it was naturally cooled to room temperature, the sample was taken out, washed with deionized water, dried at 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0122] 2. Evaporator structure construction

[0123] A polystyrene foam board with a thickness of 0.5 cm was used as a support, cut into a circular foam block with a diameter of about 5 cm, and a notch with a width of 2 cm was opened, and the notch spacing was set to 0.5 cm for inserting both ends of the arched carbon cloth.

[0124] 3. Arched arrangement setting

[0125] Three different arrangement methods were used to arrange multiple arched evaporation units: (1) Parallel arrangement, all arched structures were arranged in parallel in the same direction; (2) Fan-shaped arrangement, radially expanded around the center; (3) Triangular arrangement, equilateral triangles were staggered to enhance the photothermal response. The carbon cloth material at the bottom of the foam was placed about 0.5 cm in water to achieve stable capillary water supply.

[0126] 4. Photothermal performance test

[0127] The evaporator was placed under a solar simulator (AM 1.5G, 1 kW·m- 2 ) for evaporation performance testing. An electronic balance was used to monitor the evaporation mass, and an incident angle of 15° was set, and then the evaporation performance test was carried out. The measured evaporation rates were 1.54, 1.59 and 1.63 kg m -2 h -1 .

[0128] Example 7

[0129] 1. Preparation of a Three-Dimensional Arch Structure Photothermal Evaporation Device

[0130] 1) Cut the carbon cloth into rectangular pieces of 2×6 cm, and ultrasonically clean them successively with deionized water and ethanol, with each cleaning step lasting for 15 min to remove surface impurities and oil. 2 5) Dry the cleaned carbon cloth at 60 °C for 2 hours, then soak it in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. Dissolve 0.2 g of cobalt(II) nitrate hexahydrate in 20 mL of methanol, immerse the carbon cloth in it and stir for 30 min; dissolve 0.1 g of 2-methylimidazole in 25 mL of methanol, quickly add it to the above solution, continue to stir for 1 h and then let it stand for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. Wash the product 3 times with ethanol and water, and dry it at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0131] 2) Dissolve 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea in 25 mL of deionized water and stir at room temperature for 1 hour. Immerse the ZIF-67 / CC into this solution, transfer it to a high-pressure reaction kettle, heat it to 180 °C and carry out a hydrothermal reaction for 12 h. After the reaction is completed, naturally cool it to room temperature, take out the sample, wash it with deionized water, and dry it at 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0132] 3) Use a polystyrene foam board with a thickness of 0.5 cm as a support, cut it into a circular foam block with a diameter of about 5 cm, and open a notch with a width of 2 cm, with the notch spacing set at 0.5 cm for inserting both ends of the arched carbon cloth.

[0133] 2. Construction of the Evaporator Structure

[0134] Arrange multiple arched evaporation units in three different arrangements: (1) Parallel arrangement, where all arched structures are arranged parallel in the same direction; (2) Fan-shaped arrangement, which radiates around the center; (3) Triangular arrangement, with equilateral triangles staggered, to enhance the photothermal response. Place the carbon cloth material at the bottom of the foam about 0.5 cm in water to achieve stable capillary water supply.

[0135] 3. Setting of the Arch Arrangement Method

[0136] 4. Photothermal Performance Test

[0137] Place the evaporator in a solar simulator (AM 1.5G, 1 kW·m-

[0138] 2) and irradiate it with simulated sunlight for 30 min. 2)The evaporation performance test was carried out under [specific conditions]. An electronic balance was used to monitor the evaporation mass, and an incident angle of 30° was set. Then, the evaporation performance test was carried out, and the evaporation rates were 1.78, 1.83, and 1.89 kg m -2 h -1 .

[0139] Example 8

[0140] 1. Preparation of the three-dimensional arch structure photothermal evaporation device

[0141] 1) Cut the carbon cloth into a rectangular piece of 2×6 cm 2 . Ultrasonically clean it with deionized water and ethanol in turn, and the cleaning time for each step is 15 min to remove surface impurities and oil stains.

[0142] 2) Dry the cleaned carbon cloth at 60 °C for 2 hours, and then soak it in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. Dissolve 0.2 g of cobalt(II) nitrate hexahydrate in 20 mL of methanol, immerse the carbon cloth in it and stir for 30 min; dissolve 0.1 g of 2-methylimidazole in 25 mL of methanol, quickly add it to the above solution, continue to stir for 1 h, and then let it stand for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. Wash the product 3 times with ethanol and water, and dry it at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0143] 3) Dissolve 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea in 25 mL of deionized water, and stir at room temperature for 1 hour. Immerse the ZIF-67 / CC in this solution, transfer it to a high-pressure reaction kettle, heat it to 180 °C, and carry out a hydrothermal reaction for 12 h. After the reaction, cool it to room temperature naturally, take out the sample, wash it with deionized water, and dry it at 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0144] 2. Construction of the evaporator structure

[0145] Use a polystyrene foam board with a thickness of 0.5 cm as the support, cut it into a circular foam block with a diameter of about 5 cm, and open a notch with a width of 2 cm. The notch spacing is set to 0.5 cm for inserting both ends of the arched carbon cloth.

[0146] 3. Setting of the arched arrangement method

[0147] Arrange multiple arched evaporation units in three different arrangement methods: (1) Parallel arrangement, all arched structures are arranged in parallel in the same direction; (2) Sector arrangement, radiating around the center; (3) Triangular arrangement, equilateral triangles are staggered for enhancing the photothermal response. Place the carbon cloth material at the bottom of the foam in water about 0.5 cm to achieve stable capillary water supply.

[0148] 4. Photothermal performance test

[0149] Place the evaporator under a solar simulator (AM 1.5G, 1 kW·m- 2 ) to conduct evaporation performance tests. Use an electronic balance to monitor the evaporation mass, set the incident angle at 45°, and then conduct evaporation performance tests. The measured evaporation rates are respectively 2.23, 2.34, and 2.42 kg m -2 h -1 .

[0150] Example 9

[0151] 1. Preparation of a three-dimensional arch-structured photothermal evaporation device

[0152] 1) Cut the carbon cloth into rectangular pieces of 2×6 cm 2 , and ultrasonically clean it successively with deionized water and ethanol, with each cleaning step lasting for 15 min to remove surface impurities and oil stains.

[0153] 2) Dry the cleaned carbon cloth at 60 °C for 2 hours, and then immerse it in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. Dissolve 0.2 g of cobalt(II) nitrate hexahydrate in 20 mL of methanol, place the carbon cloth in it and stir for 30 min; dissolve 0.1 g of 2-methylimidazole in 25 mL of methanol, quickly add it to the above solution, continue to stir for 1 h, and then let it stand for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. Wash the product 3 times with ethanol and water, and dry it at 60 °C for 12 h to obtain the ZIF-67 / CC material.

[0154] 3) Dissolve 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea in 25 mL of deionized water, and stir at room temperature for 1 hour. Immerse the ZIF-67 / CC into this solution, transfer it to a high-pressure reaction kettle, heat it to 180 °C for 12 h for hydrothermal reaction. After the reaction, naturally cool it to room temperature, take out the sample, wash it with deionized water, and dry it at 60 °C for 12 h to obtain the MoS2@ZIF-67 / CC composite material.

[0155] 2. Construction of the evaporator structure

[0156] Use a polystyrene foam board with a thickness of 0.5 cm as the support, cut it into a circular foam block with a diameter of about 5 cm, and open a notch with a width of 2 cm, and set the notch spacing at 0.5 cm for inserting both ends of the arched carbon cloth.

[0157] 3. Setting of the arched arrangement method

[0158] Multiple arched evaporation units are arranged in three different ways: (1) parallel arrangement, where all arched structures are arranged in parallel in the same direction; (2) fan-shaped arrangement, which radiates around the center; (3) triangular arrangement, where equilateral triangles are staggered, for enhancing the photothermal response. The carbon cloth material at the bottom of the foam is placed about 0.5 cm in water to achieve stable capillary water supply.

[0159] 4. Photothermal performance test

[0160] The evaporator is placed under a solar simulator (AM 1.5G, 1 kW·m- 2 ) for evaporation performance testing. An electronic balance is used to monitor the evaporation mass, and an incident angle of 60° is set. Then, the evaporation performance test is carried out, and the measured evaporation rates are 2.81, 2.94, and 2.98 kg m -2 h -1 .

[0161] Example 10

[0162] 1. Preparation of a three-dimensional arch structure photothermal evaporation device

[0163] 1) Cut the carbon cloth into a 2×6 cm 2 rectangular sheet, and ultrasonically clean it successively with deionized water and ethanol for 15 min each to remove surface impurities and oil.

[0164] 2) Dry the cleaned carbon cloth at 60 °C for 2 hours, then soak it in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 at room temperature for 12 hours to enhance the surface activity of the carbon cloth. Dissolve 0.2 g of cobalt(II) nitrate hexahydrate in 20 mL of methanol, immerse the carbon cloth in it and stir for 30 min; dissolve 0.1 g of 2-methylimidazole in 25 mL of methanol, quickly add it to the above solution, continue to stir for 1 h and then let it stand for 24 h to complete the in-situ growth of ZIF-67 on the carbon cloth. Wash the product 3 times with ethanol and water, and dry it at 60 °C for 12 h to obtain ZIF-67 / CC material.

[0165] 3) Dissolve 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea in 25 mL of deionized water, and stir at room temperature for 1 hour. Immerse ZIF-67 / CC in this solution, transfer it to a high-pressure reaction kettle, heat it to 180 °C for 12 h of hydrothermal reaction. After the reaction, cool it naturally to room temperature, take out the sample, wash it with deionized water, and dry it at 60 °C for 12 h to obtain MoS2@ZIF-67 / CC composite material.

[0166] 2. Evaporator structure construction

[0167] Using a polystyrene foam board with a thickness of 0.5 cm as a support, it is cut into a circular foam block with a diameter of about 5 cm, and a notch with a width of 2 cm is opened. The notch spacing is set to 0.5 cm for inserting both ends of the arched carbon cloth.

[0168] 3. Arrangement of arched structures

[0169] Three different arrangements are used to arrange multiple arched evaporation units: (1) parallel arrangement, where all arched structures are arranged parallel in the same direction; (2) fan-shaped arrangement, which spreads radially around the center; (3) triangular arrangement, with equilateral triangles staggered, to enhance the photothermal response. The carbon cloth material at the bottom of the foam is placed about 0.5 cm in water to achieve stable capillary water supply.

[0170] 4. Photothermal performance test

[0171] The evaporator is placed under a solar simulator (AM 1.5G, 1 kW·m- 2 ) for evaporation performance testing. An electronic balance is used to monitor the evaporation mass, and an incident angle of 75° is set. Then, the evaporation performance is tested, and the evaporation rates are 3.18, 3.25, and 3.34 kg m -2 h -1 .

[0172] Example 11

[0173] 1. Preparation of a three-dimensional arched structure photothermal evaporation device

[0174] 1) Cut the carbon cloth into a 2×6 cm 2 rectangular sheet and ultrasonically clean it successively with deionized water and ethanol for 15 minutes each to remove surface impurities and oil.

[0175] 2) Dry the cleaned carbon cloth at 60 °C for 2 hours, then soak it in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3 for 12 hours at room temperature to enhance the surface activity of the carbon cloth. Dissolve 0.2 g of cobalt(II) nitrate hexahydrate in 20 mL of methanol, place the carbon cloth in it and stir for 30 minutes; dissolve 0.1 g of 2-methylimidazole in 25 mL of methanol, quickly add it to the above solution, continue to stir for 1 hour and then let it stand for 24 hours to complete the in-situ growth of ZIF-67 on the carbon cloth. The product is washed 3 times with ethanol and water and dried at 60 °C for 12 hours to obtain the ZIF-67 / CC material.

[0176] 3) Dissolve 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea in 25 mL of deionized water and stir at room temperature for 1 hour. Immerse the ZIF-67 / CC in this solution and transfer it to an autoclave, heating it to 180°C for a hydrothermal reaction for 12 hours. After the reaction, cool it naturally to room temperature, remove the sample, wash it with deionized water, and dry it at 60°C for 12 hours to obtain the MoS2@ZIF-67 / CC composite material.

[0177] 2. Evaporator structure construction

[0178] A 0.5 cm thick polystyrene foam board was used as a support, which was cut into circular foam blocks with a diameter of about 5 cm. A 2 cm wide slot was opened, and the slot spacing was set to 0.5 cm for inserting the two ends of the arched carbon cloth.

[0179] 3. Arch arrangement setting

[0180] The arched evaporation units were arranged in three different configurations: (1) parallel, with all arches arranged parallel to the same direction; (2) fan-shaped, with the arches radially extending from the center; and (3) triangular, with equilateral triangles arranged in a staggered pattern to enhance the photothermal response. The carbon cloth material at the bottom of the foam was placed approximately 0.5 cm below the water to achieve a stable capillary water supply.

[0181] 4. Photothermal performance test

[0182] The evaporator was placed in a solar simulator (AM 1.5G, 1kW·m- 2 ) were used to test the evaporation performance. The evaporation mass was monitored using an electronic balance and the incident angle was set at 90°. The evaporation performance test was then carried out. The test evaporation rates were 3.63, 3.63, and 3.65 kg m -2 h -1 .

[0183] like Figure 1 As shown, scanning electron microscopy (SEM) shows the microstructural evolution of materials at different stages: Figure 1 Part a is the original carbon cloth (CC), which shows a smooth surface and neatly arranged carbon fibers. Figure 1 Parts b and c are ZIF-67 / CC formed by in-situ growth of ZIF-67 on the carbon cloth surface, where Figure 1 Part b shows that a large number of polyhedral structures are evenly covered on the carbon fiber surface. Figure 1 Part c is a local magnified image showing the clear outline of a single ZIF-67 crystal; Figure 1 Parts d, e, and f are the final MoS2@ZIF-67 / CC composite structures. It can be observed that the surface is covered with dense flaky MoS2 nanostructures.Figure 1 Parts e and f show the structural characteristics of the intertwined stacking of nanosheets at different scales. Overall, this multi-level rough structure helps to enhance light absorption and water enrichment ability while increasing the specific surface area, thus improving the photothermal conversion efficiency.

[0184] As Figure 2 shown, the physical pictures of the evaporators with different arched structure spacings (d = 0.5 cm, 1 cm, 2 cm, 3 cm, and 4 cm) in Examples 1 to 5 are presented. The arched evaporator is composed of ductile MoS2@ZIF-67 / CC carbon cloth, and both ends of the arch are inserted into the polystyrene foam brackets and kept in contact with the water surface. As the span of the arched structure decreases, the bending degree of the carbon cloth increases, and the evaporation surface gradually transitions from a gentle bend to a high-curvature structure. This change helps to optimize the photothermal response and the water supply path.

[0185] As Figure 3 shown, it is the change of mass per unit area of the evaporators with different arch spacings under 1 sun condition during the test. The results show that the evaporation rate gradually increases with the decrease of the arched spacing, which are 2.68, 2.80, 3.08, 3.36, and 3.64 kg m -2 h -1 ⁻² h⁻¹, respectively, and the evaporator with d = 0.5 cm shows the highest evaporation rate, indicating that the closely arranged three-dimensional structure has significant advantages in improving the evaporation efficiency.

[0186] As Figure 4 shown, the physical pictures of the arched evaporation structures with three different arrangements are presented, including parallel arrangement, fan-shaped arrangement, and triangular arrangement. Each structure is composed of three pieces of arched MoS2@ZIF-67 / CC carbon cloth and is fixed by inserting into the polystyrene foam. The appearance of the structure remains the same, only the arrangement is different, which is used to test the influence of the arrangement on the photothermal performance.

[0187] As Figure 5 shown, it is the comparison chart of evaporation rates of the three arrangements at different light incident angles (15° - 90°). It can be seen from the figure that the triangular arrangement shows higher evaporation efficiency under all angle conditions, especially more obvious at low-angle incidence, indicating that it is more conducive to capturing the obliquely incident light and improving the photothermal utilization efficiency. The evaporator structure is based on a polystyrene foam board with a thickness of 0.5 cm as the bracket, cut into a circular foam block with a diameter of about 5 cm, with a notch width of 2 cm, and the notch spacing is set to 0.5 cm for inserting both ends of the arched carbon cloth.

[0188] As Figure 6As shown, the evaporator that has experienced salt crystal deposition is re-immersed in deionized water, and the dissolution process of the surface salt is observed under dark conditions. The results show that within a 100-minute period, the surface salt gradually dissolves, and the appearance of the material basically returns to its original state, with no obvious residual crystals. This indicates that the evaporation structure in the present invention has good self-cleaning and regeneration capabilities, which helps to maintain stable evaporation performance during long-term use.

[0189] As Figure 7 shown, it is a comparative diagram of the wetting properties and structural morphologies of different material surfaces according to the present invention. Figure 7 Part a-I shows the completely hydrophobic property of the CC surface observed under an optical microscope. Water droplets cannot spread on its surface and only stay or slide in a spherical shape, showing extremely low water retention ability. Figure 7 Part a-II shows the superhydrophilic property of ZIF-67 / CC, which is mainly attributed to the high specific surface area and porous structure of ZIF-67. These properties significantly enhance the water adsorption ability. In addition, the metal ions (such as Co 2+ ) exposed on the surface of ZIF-67 and the polar groups in the organic ligands further improve the hydrophilicity through hydrogen bonding and electrostatic interactions. However, this superhydrophilic property results in excessive water retention on the surface. The excessive water not only hinders the effective transfer of heat but also significantly reduces the evaporation efficiency because a large amount of heat is carried away during the evaporation process. Figure 7 Part a-III shows the surface property of MoS2@ZIF-67 / CC, in which MoS2 is formed by in-situ growth on the surface of ZIF-67 / CC and partially coats the porous surface of ZIF-67 with its two-dimensional sheet structure. This coating effectively reduces the adsorption of excessive water, while adjusting the surface roughness and reducing the influence of capillary action on water retention. In addition, the moderate hydrophilicity of MoS2 further optimizes the water distribution behavior, forming a uniform thin water film on the surface. This thin water film can not only make full use of heat for efficient evaporation but also avoid heat loss caused by water retention, thus significantly improving the evaporation efficiency and the utilization rate of photothermal energy. Figure 7Part b shows the wetting behavior and capillary water transport ability of the MoS2@ZIF-67 / CC material. At different arch spacings (0.5, 1, 2, and 3 cm), water droplets can spread rapidly and form a uniform water film, showing excellent wetting performance. This is mainly attributed to the regulation of the hydrophilicity of the ZIF-67 / CC surface by MoS2 coating. The porous structure of ZIF-67 provides a large specific surface area, and the two-dimensional sheet structure of MoS2 reduces the contact angle, enabling water to be evenly distributed on the surface. Even as the spacing decreases and the height increases, the wetting performance remains highly consistent, indicating that the geometric structure change does not significantly affect the surface hydrophilicity. When the spacing is 0.5 cm, despite the increase in the arch height, water can still rapidly transport along the material surface to the top and evenly diffuse to the filter paper. This benefits from the porous network of ZIF-67 and the two-dimensional sheet of MoS2 optimizing the water transport path and hydrophilicity, and the stable capillary force of the arch structure overcomes the capillary force attenuation caused by the increase in height. These results verify the excellent wettability and capillary water transport performance of MoS2@ZIF-67 / CC under complex geometric structures. The test results of the water contact angle show that the CC surface exhibits significant hydrophobicity, with a water contact angle of 114°, indicating that water droplets cannot spread on its surface ( Figure 7 Part c), while MoS2@ZIF-67 / CC shows complete wettability ( Figure 7 Part d). This indicates that the composite structure of MoS2-coated ZIF-67 / CC effectively regulates the surface properties of the material, making it change significantly from hydrophobic to highly hydrophilic compared with CC, which is beneficial to the rapid adsorption and uniform distribution of water, further verifying the effectiveness of the MoS2 coating structure in regulating the surface hydrophilicity of the material.

[0190] Acid and alkali resistance tests:

[0191] The acid resistance test was carried out on the product obtained in Example 5, and the method and results are as follows:

[0192] 100 mL of acidic (hydrochloric acid solution with pH = 1), alkaline (sodium hydroxide solution with pH = 13), and neutral (deionized water with pH = 7) solutions were respectively prepared. MoS2@ZIF-67 / CC samples (2 cm × 6 cm) with the same size were completely immersed in the above solutions and left to soak at room temperature (about 25°C) for 8 hours. After the soaking, the samples were taken out, rinsed thoroughly with deionized water, and then air-dried naturally. During the soaking process, no obvious color change occurred in the three solutions, the liquid remained clear and transparent throughout, and no solid particles settled or suspended, indicating that no component dissolution or photothermal material shedding occurred in the material in the solution. The appearance of the dried samples was the same as before soaking, and no cracking, warping, or obvious deformation was observed, and the structural integrity was good.

[0193] Comparative Example 1

[0194] Referring to the preparation method of the three-dimensional arch bridge structure photothermal evaporation device in Example 5, the difference is that ZIF-67 is replaced by ZIF-8, and the specific steps are as follows:

[0195] 1) Cut the carbon cloth into a rectangular sheet of 2×6 cm 2 , and ultrasonically clean it successively with deionized water and ethanol, with the cleaning time of 15 min for each step, to remove surface impurities and oil.

[0196] 2) Dry the cleaned carbon cloth at 60 °C for 2 hours, then soak it in a mixed acid of concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3, and soak it at room temperature for 12 hours to enhance the surface activity of the carbon cloth. Dissolve 0.18 g of zinc nitrate hexahydrate in 20 mL of methanol, put the carbon cloth into it and stir for 30 min; another dissolve 0.1 g of dimethylimidazole in 25 mL of methanol, quickly add it to the above solution, continue to stir for 1 h and then stand for 24 h to complete the in-situ growth of ZIF-8 on the carbon cloth. Wash the product 3 times with ethanol and water, and dry it at 60 °C for 12 h to obtain the ZIF-8 / CC material.

[0197] 3) Dissolve 0.6 g of ammonium molybdate tetrahydrate and 1.1 g of thiourea in 25 mL of deionized water, and stir at room temperature for 1 hour. Immerse the ZIF-8 / CC into this solution, transfer it to a high-pressure reaction kettle, heat it up to 180 °C and carry out a hydrothermal reaction for 12 h. After the reaction is completed, naturally cool it to room temperature, take out the sample, wash it with deionized water, and the drying temperature is 60 °C and the drying time is 12 h to obtain the MoS2@ZIF-8 / CC composite material.

[0198] Compare the performance of the obtained MoS2@ZIF-8 / CC composite material and MoS2@ZIF-67 / CC composite material, and the results are as follows: In the MoS2@ZIF-8 / CC material, the crystal structure of ZIF-8 is unevenly distributed on the surface of the carbon cloth, the growth is slow, the nucleation density is low, the formed skeleton is relatively sparse, and there is a lack of a complete three-dimensional support network. Limited by the relatively weak coordination ability of Zn 2 +, the adhesion between ZIF-8 and the carbon cloth is poor. The morphology of the subsequently grown MoS2 is disordered and agglomerated, lacking a uniform lamellar structure, resulting in a decrease in the overall specific surface area. In addition, due to the instability of the composite interface, the photothermal response ability of the material decreases, the heat conduction is uneven during the evaporation process, and the water transport efficiency decreases, ultimately resulting in the evaporation performance being significantly lower than that of the control sample using ZIF-67. The results show that ZIF-67 is more suitable as a precursor for constructing metal-organic frameworks on the surface of carbon cloth, which can provide richer coordination sites and more uniform nucleation conditions, promote the uniform growth of MoS2 nanosheets and the stable construction of the composite structure, thereby improving the comprehensive performance of the photothermal evaporation device.

[0199] Comparative Example 2

[0200] Referring to the preparation method of the three-dimensional arch-shaped structure photothermal evaporation device in Reference Example 5, the difference is that cobalt(II) hexahydrate nitrate in the used metal-organic framework precursor is replaced with cobalt(II) acetate, and the remaining preparation steps and conditions remain the same. Finally, the MoS2@ZIF-67 (cobalt(II) acetate source) / CC composite material is obtained. The performance of this material is compared with that of MoS2@ZIF-67 / CC prepared using cobalt(II) nitrate precursor, and the results are as follows: Under the same light intensity (1 sun), the evaporation rate of the composite material synthesized using cobalt(II) acetate is 3.21 kg m -2 h -1 , compared with 3.64 kg m -2 h -1 in Reference Example 5, it shows a decrease. During the testing process, it was also found that the crystallinity of the ZIF-67 structure formed by the cobalt(II) acetate precursor is relatively low, resulting in a decrease in the subsequent loading efficiency of MoS2, poor adhesion of the composite layer, and weakened overall photothermal response ability.

[0201] Comparative Example 3 Referring to the preparation method of the three-dimensional arch-shaped structure photothermal evaporation device in Reference Example 5, the difference is that the solvent methanol used for preparing ZIF-67 is replaced with deionized water, and the remaining reaction conditions remain the same. The MoS2@ZIF-67 (aqueous system) / CC composite material is prepared. The photothermal evaporation performance is tested under the same light intensity (1 sun). The results show that the evaporation rate of the sample prepared using water as the solvent is 3.15 kg m -2 h -1 , compared with 3.64 m - 2 h -1 of the sample obtained using methanol, it shows a decrease. This performance difference is mainly attributed to the fact that in the aqueous phase system, the crystallization rate of ZIF-67 crystals is relatively slow, and it is difficult to form a regular and dense octahedral structure, resulting in a decrease in its surface porosity. Subsequently, MoS2 grows unevenly on its surface, ultimately affecting the photothermal conversion efficiency and water transport capacity of the composite material. Therefore, the results show that methanol as the solvent for ZIF-67 synthesis is more conducive to forming a complete and uniform MOF structure, thereby obtaining more excellent photothermal performance and evaporation efficiency.

[0202] Comparative Example 4

[0203] Referring to the preparation method of the three-dimensional arch bridge structure photothermal evaporation device in Example 5, the difference is that: ammonium molybdate tetrahydrate, the molybdenum source for hydrothermal synthesis of MoS2, is replaced by sodium molybdate (Na2MoO4), and the rest of the reaction conditions remain the same. Finally, the MoS2@ZIF-67 (sodium molybdate source) / CC composite material is prepared. The test results show that the morphology of MoS2 in the prepared material changes from the uniform and dense flaky structure in the original example to an irregular morphology with loose structure and broken lamellae, and the specific surface area decreases, which is not conducive to the efficient transport of water and the construction of the evaporation interface. Under the same light intensity (1 sun), the photothermal evaporation performance of this material is tested, and the obtained evaporation rate is 3.23 kg m -2 h -1 , lower than 3.64 kg kg m -2 h -1 of the material prepared using ammonium molybdate tetrahydrate. In addition, the photothermal responsiveness of the material surface decreases, and the heat distribution is uneven, affecting its overall evaporation efficiency. It can be seen that ammonium molybdate tetrahydrate as the molybdenum source is more conducive to forming a regular and continuous MoS2 nanosheet structure, improving the specific surface area and photothermal performance of the composite material, while sodium molybdate has a weak nucleation ability in this system, resulting in a decline in the overall performance of the material.

[0204] Comparative Example 5

[0205] Referring to the preparation method of the three-dimensional arch bridge structure photothermal evaporation device in Example 5, the difference is that: thiourea, the sulfur source for hydrothermal synthesis of MoS2, is replaced by thioacetamide (TAA), and the rest of the reaction conditions remain the same. Finally, the MoS2@ZIF-67 (TAA source) / CC composite material is prepared. The results show that the morphology of MoS2 in the prepared material changes significantly, from the uniform and continuous nanosheet structure in the original example to a granular and aggregated structure, with a rough surface and disordered arrangement, and the overall specific surface area decreases significantly. Under the same light intensity (1 sun), the evaporation performance is tested, and the results show that the evaporation rate of this material is 3.36 kg m -2 h -1 , lower than 3.64 kg m -2 h -1 of the material prepared using thiourea; at the same time, the photothermal conversion efficiency also decreases, and both the water transport efficiency and the photothermal response ability are affected. The above results show that thiourea as the sulfur source is more conducive to promoting the uniform growth of MoS2 and forming a lamellar structure under hydrothermal conditions, thereby improving the specific surface area and evaporation performance of the composite material; while replacing it with thioacetamide will cause a decrease in crystal quality and performance degradation.

[0206] Comparative Example 6

[0207] Referring to the preparation method of the three-dimensional arch structure photothermal evaporation device in Reference Example 5, the difference is that: in the hydrothermal reaction stage, the heating rate is changed from the original set 5 °C / min to 2 °C / min, and the remaining reaction conditions remain the same. Finally, the MoS2@ZIF-67 (low heating rate) / CC composite material is prepared. The results show that the lower heating rate slows down the nucleation rate in the initial stage of the reaction. The morphology of MoS2 changes from the original regular lamellar structure to an irregular agglomerated structure with broken lamellae and blurred edges. The specific surface area decreases and the surface active sites decrease. Testing its evaporation performance under the same light intensity (1 sun), the results show that the evaporation rate is reduced to 2.78 kgm -2 h -1 , lower than 3.64 kgm in Reference Example 5 -2 h -1 ; In addition, the photothermal conversion efficiency also decreases, the thermal response is sluggish, and the water evaporation rate fluctuates greatly. This indicates that the lower heating rate is not conducive to the orderly growth of MoS2 nanosheets, affects its structural integrity and specific surface area, and thus leads to the reduction of photothermal performance and evaporation efficiency. The originally set heating rate of 5 °C / min is more conducive to forming a photothermal material with excellent performance.

[0208] Comparative Example 7

[0209] Referring to the preparation method of the three-dimensional arch structure photothermal evaporation device in Reference Example 5, the difference is that: in the hydrothermal reaction stage, the heating rate is adjusted from 5 °C / min to 6 °C / min, and the remaining reaction conditions remain the same. Finally, the MoS2@ZIF-67 (high heating rate) / CC composite material is prepared. The test results show that the faster heating rate increases the temperature gradient in the reaction system, resulting in rapid nucleation of MoS2 but incomplete grain development, and finally forming a granular or flocculent structure, lacking continuity and regularity, and the specific surface area is significantly reduced. Conducting evaporation performance tests under the same light intensity (1 sun), the evaporation rate drops to 2.74 kgm -2 h -1 , compared with 3.64 kgm in Example 5 -2 h -1 significantly reduced; at the same time, the photothermal conversion efficiency decreases, the thermal response rate is unstable, and the water transport path is blocked. The above results show that too fast a heating rate is not conducive to the orderly growth of MoS2 crystals, easily causes morphological disorder and reduced adhesion, and finally leads to a decrease in specific surface area and evaporation performance. Therefore, controlling a reasonable heating rate (such as 5 °C / min) is more conducive to obtaining a photothermal material with uniform morphology and excellent performance.

[0210] In a specific embodiment, such as Figure 8As shown in the figure, the three-dimensional arch structure photothermal evaporation device includes: a base 1; and at least one three-dimensional arch structure 2 fixed on the base, and the material of each three-dimensional arch structure is a ductile photothermal evaporation material. Its working principle is as Figure 9 shown.

[0211] In summary, the present invention proposes a three-dimensional arch structure photothermal evaporation device based on MoS2@ZIF-67 / CC. By adjusting the span and arrangement of the arch structure, the evaporation efficiency can be effectively improved. The prepared material has good photothermal conversion performance. The arch structure helps to enhance the contact area between the evaporation interface and the air and ensure continuous and stable water supply. Under different light incident angle conditions, this structure still maintains good evaporation performance and has a certain anti-salt crystallization ability and renewability. The structure of the present invention is simple, and the preparation process is controllable, and it is applicable to related application scenarios such as solar-driven water evaporation and desalination.

[0212] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tough photothermal evaporation material, characterized in that, Comprising: A substrate layer; And a ZIF-67 layer grown on the substrate layer, with each ZIF-67 particle coated with a molybdenum disulfide layer having a high specific surface area.

2. The tough photothermal evaporation material according to claim 1, wherein: The substrate layer is a carbon cloth layer.

3. The tough photothermal evaporation material according to claim 1, characterized in that: The morphology of the ZIF-67 particles is a polyhedral structure.

4. The ductile photothermal evaporation material according to claim 1, characterized in that, The morphology of molybdenum disulfide is: a spherical structure formed by dense sheet-like molybdenum disulfide.

5. A method for preparing a ductile photothermal evaporation material according to any one of claims 1 to 4, characterized in that, Including the following steps: 1) Immerse the substrate layer in an alcohol solution of a cobalt source and 2-methylimidazole, and age to obtain a substrate layer grown with ZIF-67; 2) Place the substrate layer grown with ZIF-67 into a mixed solution of a molybdenum source and a sulfur source, perform a hydrothermal reaction, and coat a molybdenum disulfide layer on the surface of the ZIF-67 particles to obtain the tough photothermal evaporation material.

6. The preparation method of the ductile photothermal evaporation material according to claim 5, wherein, In step 1): The cobalt source is cobalt nitrate hexahydrate; The alcohol is methanol; The molar ratio of cobalt to 2-methylimidazole is (1.6 - 2.0):

1.

7. The preparation method of the tough photothermal evaporation material according to claim 5, characterized in that, In step 2): The molybdenum source is ammonium molybdate tetrahydrate; The sulfur source is thiourea; The molar ratio of molybdenum to sulfur is (4.0 - 4.5):1; The hydrothermal reaction is: first heat up to 180 - 200 °C at a heating rate of 3 - 5 °C / min, and then keep warm for 12 - 24 h.

8. A three-dimensional arch bridge structure photothermal evaporation device, characterized in that, Including: A base; And at least one three-dimensional arch structure fixed on the base, and the material of each three-dimensional arch structure is the tough photothermal evaporation material according to any one of claims 1 to 4.

9. The three-dimensional arch structure photothermal evaporation device according to claim 8, wherein: The material of the base is polystyrene foam; And / or, both ends of the three-dimensional arch structure are respectively plugged and fixed on the base.

10. The three-dimensional arch structure photothermal evaporation device according to claim 8, wherein: Each of the three-dimensional arch structures is arranged in a row-column layout; Or, each of the three-dimensional arch structures is arranged in a fan-shaped layout; Or, each of the three-dimensional arch structures is arranged in a polygonal layout; The arch spacing is 0.5 - 4 cm.

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