Lotus-shaped solar energy evaporator, preparation method and application thereof

Abstract

The application discloses a lotus-shaped solar evaporator, a preparation method and application thereof, and belongs to the technical field of evaporators. The lotus-shaped evaporator comprises a transmission part for one-way transmission of water, a first transmission channel penetrating through two ends in the transmission part, and an evaporation part for evaporation, a second transmission channel in the transmission part being in communication with the first transmission channel; wherein one end of the transmission part is in contact with the evaporation part, the other end of the transmission part is a hydrophobic surface, and the contact angle of the hydrophobic surface is greater than 90 degrees. The application can effectively promote water evaporation, has good salt resistance, can effectively reduce heat loss caused by water backflow, minimizes heat loss of the system, and can effectively improve the evaporation rate and the light-heat conversion efficiency.

Description

Technical Field

[0001] This invention relates to the field of evaporator technology, and in particular to a lotus-shaped solar evaporator, its preparation method, and its application. Background Technology

[0002] Solar-driven interfacial evaporation is an important method for seawater desalination and can effectively address water scarcity. Among these methods, evaporators based on solar thermal conversion have attracted widespread attention due to their high energy efficiency. To date, thin-film based evaporators, carbonized plant-based evaporators, foam-based evaporators, nanofiber-based evaporators, and hydrogel-based evaporators have been developed. Hydrogel-based evaporators, with their excellent water conduction and retention capabilities, can effectively increase the evaporation rate of water from photothermal materials, thus representing a novel type of solar thermal conversion evaporator.

[0003] Traditional hydrogel-based evaporators feature a disordered three-dimensional network structure, providing effective channels for water transport within the evaporator. The hydrophilic groups within the hydrogel network weaken the binding forces between water molecules. By adjusting the type and number of hydrophilic groups, the enthalpy of vaporization can be reduced, allowing more water to evaporate with less energy, thus increasing the photothermal evaporation rate. For example, Yang's team fabricated a photothermal hydrogel evaporator using poly(ethylene glycol) diacrylate (PEGDA) as the monomer and polyaniline (PANI) as the photothermal material, achieving an evaporation rate of 1.4 kgm⁻²h⁻¹ under simulated solar illumination. However, this disordered channel structure hinders rapid water transport during evaporation and also impedes the rapid escape of water vapor from the evaporation surface. Furthermore, it weakens the convection between the water inside the evaporator and the bulk water at the bottom, preventing salts migrating into the evaporator from diffusing into the bulk water in a timely manner. Over time, salt precipitation can clog the evaporator, damaging the evaporation system. To mitigate the adverse effects of traditional disordered channel hydrogels on evaporators, researchers introduced a novel hydrogel-based evaporator structure with ordered micron-sized channels, where photothermal materials are distributed within the hydrogel bulk phase or on localized surfaces. On one hand, the vertical channels facilitate water transport and water vapor escape, accelerating the evaporation process. On the other hand, the vertical channels also accelerate convection between the water inside the evaporator and the bulk water, thereby accelerating the diffusion of salt from the evaporator into the bulk water under the induction of concentration gradient differences, preventing salt crystallization and blockage of the evaporator. For example, Deng's team prepared a carbon nanotube (CNTs)@SiO2 nanofiber aerogel with vertically arranged channels. The vertical structure promoted convection and diffusion, giving the aerogel good salt resistance, achieving an evaporation rate of 1.5 kgm⁻²h⁻¹ under one solar radiation intensity. However, while accelerating water convection, the vertical channels also cause rapid heat transfer from the evaporator to the bulk water, resulting in heat loss and reduced heat utilization of the evaporation system. To reduce convective heat loss in hydrogel-based evaporators with vertical channels, researchers further introduced a T-shaped evaporator structure. This structure consists of a disk with a photothermal conversion agent attached to the top and a cylinder with vertical channels attached to the bottom, with the diameter of the disk being much larger than that of the cylinder. This evaporator structure ensures that water can be rapidly transferred to the evaporator surface because of the vertical water supply channels inside the cylindrical region. Simultaneously, it reduces convective heat loss in the photothermal region (disk region) because the cross-sectional area of ​​the photothermal region (disk region) is much larger than that of the convective region (cylindrical region). For example, Feng's team fabricated a T-shaped evaporator with a vertical channel cellulose-PVA aerogel (CPA) as the bottom column and a CPA aerogel (CPA@CNT) coated with multi-walled carbon nanotubes (MCNT) as the top disk, increasing the evaporation rate to 1.9 kg m⁻² h⁻¹ under one solar intensity.Furthermore, in a T-type evaporator, as water diffuses from the cylindrical region to the larger disc region, insufficient water supply at the edges of the disc region can lead to salt crystallization. Although the accumulated salt crystals at the edges will eventually fall off under gravity, the salt precipitation during evaporation still clogs the evaporator surface, affecting the efficiency and long-term stability of water evaporation. Simultaneously, while the T-shaped structure effectively reduces convective heat loss in the evaporator as a whole, the reflux effect in the cylindrical region is not fundamentally weakened. Therefore, addressing these two issues with T-type evaporators is urgently needed. Summary of the Invention

[0004] 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.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] This invention discloses a T-shaped hydrogel with a lotus seedpod-like structure prepared by liquid nitrogen directional freezing. The transport section has vertically arranged ordered channels, and divergent inclined channels are distributed at the junction of the transport and evaporation sections. Furthermore, by treating the bottom with hydrophobic material, unidirectional water transport is achieved, reducing heat loss from water recirculation and improving energy utilization.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a lotus-shaped solar evaporator, comprising,

[0008] A transmission unit for unidirectional water transmission, the transmission unit having a first transmission channel extending through both ends; and,

[0009] An evaporation section for evaporation, wherein the transmission section has a second transmission channel communicating with the first transmission channel;

[0010] One end of the transmission section is in contact with the evaporation section, and the other end of the transmission section is a hydrophobic surface with a contact angle greater than 90°.

[0011] In a preferred embodiment of the lotus-shaped solar evaporator of the present invention, the light-illuminated area of ​​the evaporation section is greater than the contact area between the transmission section and the evaporation section.

[0012] The term "illuminated area" as used in this article refers to the area of ​​the surface of the evaporator that is illuminated. If the evaporator is a cylinder, then the "illuminated area" refers to the surface area of ​​the top of the evaporator.

[0013] The term "contact area" as used in this article refers to the area of ​​the contact part between the transmission section and the evaporation section. If both the evaporation section and the transmission section are cylinders, then the "contact area" refers to the surface area of ​​the top of the transmission section, that is, the cylinder diameter of the transmission section is smaller than the cylinder diameter of the evaporation section.

[0014] In a preferred embodiment of the lotus-shaped solar evaporator of the present invention, the first transmission channel is a vertical channel within the transmission section facing the evaporation section; the second transmission channel is an inclined channel within the evaporation section at an angle to the vertical channel.

[0015] As a preferred embodiment of the lotus-shaped solar evaporator of the present invention, the material of the transmission section is selected from a polymer rich in hydrophilic groups that has undergone hydrophobic treatment at the bottom. The hydrophilic groups include ether bonds composed of carboxylic acid groups, sulfonic acid groups, phosphate groups, amino groups, quaternary ammonium groups, oxygen-containing groups, and hydroxyl groups, as well as one or more of carboxylic acid esters and block polyethers.

[0016] As a preferred embodiment of the lotus seedpod-inspired solar evaporator of the present invention, the hydrophobic treatment includes chemically modifying the material surface to make it hydrophobic, including introducing a compound containing hydrophilic and hydrophobic groups onto the material surface or coating the material surface with a film containing hydrophobic components.

[0017] Alternatively, nanostructures can be prepared on the surface of a material to increase the surface area of ​​the material and form air envelopes to achieve surface hydrophobicity. The nanostructures include nanopillars or nanorods.

[0018] Alternatively, a layer of a substance containing hydrophobic components may be deposited on the surface of the material to make the surface hydrophobic, wherein the substance containing hydrophobic components includes PTFE or graphite.

[0019] As a preferred embodiment of the lotus-shaped solar evaporator of the present invention, the material of the evaporation section is selected from a hydrophilic substrate loaded with photothermal material;

[0020] The photothermal material includes one or more of the following: thermally vibrating carbon-based materials, conjugated polymers, MXenes, carbon nanomaterials, semiconductor-based plasma nanoparticles (i.e., non-radiative relaxation semiconductors), noble metal-based plasma nanocrystals (i.e., plasma locally heated metals), transition metal sulfides, transition metal dichalcogenides, oxide nanoparticles, and biophotothermal reagents.

[0021] As a preferred embodiment of the lotus-shaped solar evaporator of the present invention, the thermally vibrating carbon-based material includes one or more of carbon nanotubes, multi-walled carbon nanotubes, and graphene.

[0022] The conjugated polymer includes one or more of the following: polypyrrole, dihydroindole green and other photothermal agents, dopamine and other melanin-based photothermal agents, polyaniline, thiophene, and PEDOT:PSS.

[0023] The carbon nanomaterials include graphene oxide and its derivatives.

[0024] The semiconductor-based plasma nanoparticles, i.e., nonradiative relaxation semiconductors, include copper sulfide and Cu. 2-x One or more of S(Se)NPs and other composite materials;

[0025] The plasma nanocrystals based on noble metals, namely plasma locally heated metals, include one or more composite materials such as AuNPs, AuNRs, AgNPs, dendritic gold nanoparticles, gold nanocages, and gold nanorods CYS-AuNRs.

[0026] The oxide nanoparticles include iron(II,III) oxide nanoparticles; the biophotothermal reagent includes one or more of melanin and hemoglobin molecules.

[0027] Another object of the present invention is to provide a method for preparing a lotus-shaped solar evaporator, comprising,

[0028] The precursor material of the transport section and the precursor material of the evaporation section are poured into a mold to form a shape in which one end of the transport section contacts the evaporation section;

[0029] An ice crystal template is formed inside the precursor materials of the transport section and the evaporation section by liquid nitrogen freezing; wherein, free water is present in the precursor materials of the transport section and the evaporation section.

[0030] The ice crystal template was removed by freeze-drying;

[0031] The precursor material of the heating transport section and the precursor material of the evaporation section are heated to form a hydrogel, thus obtaining the transport section and the evaporation section;

[0032] The end of the transmission section away from the evaporation section is hydrophobically modified.

[0033] As a preferred embodiment of the preparation method of the lotus-shaped solar evaporator of the present invention, the precursor materials of the transport section and the precursor materials of the evaporation section include ceramics, metals, polymers, biomacromolecules and carbon nanomaterials, wherein free water, i.e. mechanically bound water and physicochemically bound water, is required.

[0034] As a preferred embodiment of the preparation method of the lotus seedpod-like solar evaporator of the present invention, wherein: the precursor material of the transport section is a polymer rich in hydrophilic groups selected from those with hydrophobic bottom treatment, wherein the hydrophilic groups include ether bonds and hydroxyl groups composed of carboxylic acid groups, sulfonic acid groups, phosphate groups, amino groups, quaternary ammonium groups, and oxygen-containing groups, and one or more of carboxylic acid esters and block polyethers, and water form a homogeneous mixture.

[0035] In this process, the precursor material is placed in a gradient temperature field and cooled. As the temperature decreases, the solvent (usually water) gradually solidifies along the temperature gradient. The resulting ice crystal pillars compress, push out, and embed the colloidal particles between the ice crystal pillars; that is, the ice crystals act as an orientation template for the colloidal particles, providing a physical confinement. The frozen sample is then placed in a freeze dryer to remove the ice crystal template; the colloidal particles arranged by the ice crystals are retained, resulting in a material with an oriented structure.

[0036] As a preferred embodiment of the preparation method of the lotus seedpod-like solar evaporator of the present invention, the precursor material of the evaporation section is a homogeneous mixture formed by water and a hydrophilic substrate loaded with photothermal material.

[0037] The photothermal material includes one or more of the following: thermally vibrating carbon-based materials, conjugated polymers, MXenes, carbon nanomaterials, semiconductor-based plasma nanoparticles (i.e., non-radiative relaxation semiconductors), noble metal-based plasma nanocrystals (i.e., plasma locally heated metals), transition metal sulfides, transition metal dichalcogenides, oxide nanoparticles, and biophotothermal reagents.

[0038] Another object of the present invention is to provide the application of the lotus-shaped solar evaporator described above in water evaporation.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The PPy@PAM-co-CMC / PAM-co-CMC hydrogel after liquid nitrogen directional freezing has an ordered arrangement of channels, which not only enhances the binding of incident light and improves light absorption, but also accelerates the water transport rate in the channels, reduces the escape resistance of vapor, and makes water vapor easier to escape, effectively promoting water evaporation.

[0041] (2) The T-shaped structure PPy@PAM-co-CMC / PAM-co-CMC hydrogel evaporator has a novel inclined channel in the disc area, which can promote the uniform wetting of water molecules throughout the disc area, avoid the edge salt crystallization phenomenon caused by insufficient water content at the edge, and make the evaporator have good salt resistance.

[0042] (3) The fluorine modification of the bottom of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel gives it a certain degree of hydrophobicity on one side, which reduces the backflow of water from the evaporator to the bulk water, thereby reducing the heat loss carried away by the backflow and minimizing the heat loss of the system. This improves the evaporation rate and photothermal conversion efficiency, which are 2.63 kgm³ and 2.63 kgm³, respectively. -2 h -1 and 93.4%. Attached Figure Description

[0043] 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:

[0044] Figure 1 This is a flowchart illustrating the preparation process of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel evaporator of the present invention.

[0045] Figure 2 Macroscopic photographs of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel evaporator of Embodiment 1 of the present invention, and ultra-depth-of-field microscope images of the vertical channel of the PAM-co-CMC hydrogel and the tilted channel of the PPy@PAM-co-CMC hydrogel.

[0046] Figure 3 Infrared spectra of PAM-co-CMC hydrogel and PPy@PAM-co-CMC hydrogel in Example 1 of this invention;

[0047] Figure 4 EDS spectra of fluorine in different regions of the PAM-co-CMC hydrogel in Example 1 of the present invention (the inset shows the contact angle at the bottom);

[0048] Figure 5 The following are the curves showing (a) water content change over time for hydrogels with different precursor solutions in Example 2 of the present invention; (b) the corresponding saturated water content; (c) water transport rate; and (d) water evaporation rate.

[0049] Figure 6 (a) Evaporation mass loss; (b) Evaporation rate of hydrogels with different PPy doping amounts in Example 3 of the present invention;

[0050] Figure 7 (a) Absorption spectra of hydrogels with different PPy doping amounts in Example 3 of the present invention; (b) Evaporation surface equilibrium temperature;

[0051] Figure 8 (a) Contact angle; (b) Water evaporation rate of hydrogels modified with different fluorine concentrations in Example 4 of this invention;

[0052] Figure 9 (a) Evaporation mass loss of the hydrogel in NaCl solutions of different concentrations in Example 5 of the present invention; (b) Salinity comparison before and after purification;

[0053] Figure 10 Comparison of UV-Vis absorption spectra of (a) methyl orange solution and (b) rhodamine B solution before and after purification in Example 5 of this invention (the inset shows photographs of the solutions before and after purification).

[0054] Figure 11 The evaporation stability test results of the hydrogel in NaCl solutions of different concentrations in Example 6 of the present invention are as follows: (a) 3.5 wt%; (b) 10 wt%.

[0055] Figure 12 The results of the salt resistance test for (a) the inclined channel and (b) the vertical channel hydrogel of Example 6 of the present invention are shown.

[0056] Figure 13 The results of the simulation experiment of dye water in Example 7 of the present invention are as follows: (a) bidirectional transmission; (b) unidirectional transmission and (c) no transmission;

[0057] Figure 14 The results of the outdoor experiment in Example 9 of the present invention are as follows: (a) a photograph of the evaporation system; (b) an infrared temperature image of the evaporator surface; (c) changes in sunlight intensity and ambient temperature during the 7-hour outdoor experiment; and (d) changes in the content of purified water.

[0058] Figure 15 For the performance comparison of ordered and disordered channel hydrogels in Comparative Example 1 of the present invention, (a) absorption spectrum; (b) water transport rate; (c) evaporation mass loss; (d) evaporation surface equilibrium temperature;

[0059] Figure 16 For the performance comparison of the inclined channel and vertical channel hydrogels of Comparative Example 2 of the present invention, (a) absorption spectrum; (b) water transport rate; (c) evaporation mass loss; (d) evaporation surface equilibrium temperature;

[0060] Figure 17 The following is a comparison of the performance of fluorinated and unfluorinated hydrogels in Comparative Example 3 of this invention: (a) evaporation rate; (b) temperature change curve.

[0061] Figure 18 The images show infrared thermographs of the fluorinated and unfluorinated hydrogels of Comparative Example 3 of this invention. Detailed Implementation

[0062] 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.

[0063] 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.

[0064] Secondly, the term "one 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.

[0065] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0066] Example 1

[0067] (1) Preparation of PPy

[0068] 1.622 g of anhydrous FeCl3 was dissolved in 100 mL of deionized water and stirred until completely dissolved. Then, 175 μL of pyrrole was added to the FeCl3 solution and stirred for 3 h. After standing and aging for 12 h, the reaction solution was filtered to obtain solid PPy. Finally, the solid PPy was washed three times each with anhydrous ethanol and deionized water, dried in a vacuum drying oven at 70 °C for 8 h, and ground to obtain PPy powder.

[0069] (2) Preparation of PPy@PAM-co-CMC / PAM-co-CMC precursor solution

[0070] Dissolve 1.0 g of CMC in 20 mL of deionized water while stirring continuously to prevent clumping. Stop stirring when no obvious particles remain in the solution, and let it stand for one day to obtain the CMC solution. Then, mix 2.0 g of AM, 0.03 g of MBA, 0.02 g of APS, and 5 mL of deionized water, and pour this mixture into the CMC solution. Stir for 3 hours to obtain the CMC / AM(MBA+APS) complex, i.e., solution A.

[0071] Mix 10 mL of solution A with 0.2 g of PPy powder obtained in step (1) and stir thoroughly to obtain PPy / CMC / AM(MBA+APS) complex, i.e. solution B.

[0072] (3) Construction of PPy@PAM-co-CMC / PAM-co-CMC evaporator

[0073] A homemade T-shaped mold was prepared. The dimensions of the T-shaped mold are: bottom diameter of 1cm and height of 2cm for the transfer section, and diameter of 3cm and height of 1cm for the evaporation section.

[0074] Pour solution A from step (2) into the cylinder of the self-made T-shaped mold, and pour solution B from step (2) into the disc of the self-made T-shaped mold.

[0075] Subsequently, the bottom of the T-shaped mold was brought into contact with the bottom of the inner copper bowl, while the liquid nitrogen cooling source was brought into contact with the bottom of the outer copper bowl. Solution A and solution B were then directionally frozen for 15 minutes to obtain sample A.

[0076] Sample A was then placed in a freeze dryer and dried for 24 hours. After freeze-drying, the sample was heated in an oven at 80°C for 2 hours to obtain sample B.

[0077] Then, sample B was immersed in a 2 wt% FeCl3 solution for 2 hours to obtain the lotus-shaped evaporator PPy@PAM-co-CMC / PAM-co-CMC. Finally, the lotus-shaped evaporator PPy@PAM-co-CMC / PAM-co-CMC was washed three times with deionized water for subsequent use.

[0078] (4) Hydrophobic modification of PPy@PAM-co-CMC / PAM-co-CMC evaporators

[0079] First, a 0.010% (v / v) trichloro(1H,1H,2H,2H-tridecylfluoron-octyl)silane solution was prepared using dichloromethane as a solvent. Then, the trichloro(1H,1H,2H,2H-tridecylfluoron-octyl)silane solution was applied to the bottom of the lotus-shaped evaporator obtained in step (3) using spin coating technology at a spin coating rate of 500 rpm and a spin coating time of 2 min, to obtain PPy@PAM-co-CMC / PAM-co-CMC(-F).

[0080] The PPy@PAM-co-CMC / PAM-co-CMC hydrogel was characterized, such as... Figure 2 As shown, macroscopic photographs (a) of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel evaporator of Embodiment 1 of the present invention, and ultra-depth-of-field microscopic images of the vertical channel (b) and the tilted channel (c) of the PAM-co-CMC hydrogel.

[0081] Figure 2In (a), the overall macroscopic morphology of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel evaporator exhibits a T-shaped structure. For example... Figure 2 As shown in (b), vertical channels are distributed inside the cylindrical region of the T-type evaporator. Figure 2 As shown in (c), the micron channels inside the disk region exhibit a certain tilt angle. The tilted channels in the disk region are larger than those in the cylindrical region.

[0082] Infrared characterization was performed on the cylindrical and disk regions of the PPy@PAM-co-CMC / PAM-co-CMC evaporator, namely PAM-co-CMC hydrogel and PPy@PAM-co-CMC hydrogel. The results are as follows: Figure 3 As shown in the figure. The characteristic peak in the figure is at 3314 cm⁻¹. -1 The point is the stretching vibration of -NH2 in polyacrylamide; 2933 cm⁻¹ -1 The point is the CH stretching vibration of the polymer chain; 1599 cm⁻¹ -1 The point is the stretching vibration of the carboxyl group C=O; 1416 cm -1 The presence of CN-stretching vibrations at this point confirms the successful preparation of the PAM-co-CMC hydrogel. Furthermore, in addition to these characteristic peaks, the figure also shows a peak at 1638 cm⁻¹. -1 The position is a CN bond in the pyrrole ring; 1062 cm -1 The out-of-plane deformation of the CH ring at the point of contact demonstrates the successful preparation of PPy@PAM-co-CMC hydrogel.

[0083] Elemental analysis was performed on the bottom of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel modified with fluorinated silanizing agents, such as... Figure 4 As shown. The study found that the bottom surface of the cylindrical region of the evaporator contained a large amount of F element. Figure 4 (a) shows a contact angle of 95°, proving the hydrophobic modification was successful. However, as the distance from the bottom surface increases... Figure 4 The decreasing fluorine content at the bottom of the hydrogel in (b) and (c) demonstrates that the fluorinated silanizing agent only modifies the bottom of the hydrogel.

[0084] Example 2

[0085] The difference between this embodiment and Example 1 lies in the preparation of the precursor solution in step (2). The mass ratio of deionized water to CMC in the CMC solution is controlled to be 10:1, 15:1, 20:1, 25:1, and 30:1, respectively, and labeled as CAH1, CAH2, CAH3, CAH4, and CAH5. The remaining preparation process conditions are the same as in Example 1.

[0086] The properties of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel prepared in Example 2 were tested, and the results are as follows: Figure 5 As shown.

[0087] Figure 5 (a) The change in water content of the hydrogel over time was tested. Water content (Q) represents the weight of water contained in each gram of the corresponding dry gel.

[0088] Figure 5 (b) shows the saturated water content values ​​for different samples. As can be seen from the graph of water content changes, the channel size formed during directional freezing with liquid nitrogen increases with the increase of water content in the hydrogel precursor solution, and the saturated water content of CAH1 to CAH5 also gradually increases.

[0089] Figure 5 (c) represents the water transport rate corresponding to CAH1 to CAH5. The water transport rate (V) is defined as the water absorption rate (g / min) of the gel as it transitions from a semi-saturated to a saturated state. As the channel size of CAH1 to CAH5 increases, the water transport rate also gradually increases, indicating that the vertically arranged porous channels of the hydrogel are conducive to rapid water transport.

[0090] Figure 5 (d) shows the water evaporation rate for different PPy@PAM-co-CMC / PAM-co-CMC samples. The study found that the water evaporation rate first increased and then decreased with increasing MH2O / MCMC ratio. The evaporation rate reached its peak at MH2O / MCMC ratio of 20:1, approximately 2.27 kg / m³. -2 h -1 .

[0091] Example 3

[0092] The difference between this embodiment and Example 1 is in the preparation of solution B in step (2). The doping amount of PPy powder is controlled to be 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL and 25 mg / mL respectively. The other preparation process conditions are the same as in Example 1.

[0093] The properties of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel prepared in Example 3 were tested, and the results are as follows: Figure 6 , Figure 7 As shown.

[0094] Figure 6(a) and (b) investigated the evaporation mass and evaporation rate of the hydrogel with different doping concentrations. With increasing PPy doping concentration, the water evaporation rate of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel showed a trend of first increasing and then decreasing. When the PPy doping concentration was 20 mg / mL, the water evaporation rate of the evaporator reached its highest value of 2.63 kg / mL under one solar irradiation. -2 h -1 .

[0095] Figure 7 (a) is the curve showing the change in light absorption capacity. Figure 7 Figure (b) shows the infrared image of the equilibrium temperature of the evaporation surface. It can be observed that increasing PPy content leads to higher light absorption intensity, resulting in an increase in the evaporator surface temperature. Initially, greater light capture provides more energy for water evaporation, thus increasing the evaporation rate. However, when the evaporator surface temperature is too high, the water supply rate becomes mismatched with the excessively rapid evaporation rate, leading to insufficient water storage on the evaporator surface. The heat generated by the photothermal material is used for ineffective heating, resulting in a decrease in the water evaporation rate. Therefore, the evaporator exhibits optimal evaporation performance when the PPy doping concentration is 20 mg / mL.

[0096] Example 4

[0097] The difference between this embodiment and Example 1 lies in the preparation of the trichloro(1H,1H,2H,2H-tetrafluorooctyl)silane solution in step (4), where the volume fractions are controlled to be 0.003%, 0.005%, 0.007%, 0.01%, and 0.02%, respectively. All other preparation process conditions are the same as in Example 1.

[0098] The properties of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel prepared in Example 4 were tested, and the results are as follows: Figure 8 As shown.

[0099] The test results for the contact angle are as follows: Figure 8 As shown in (a), it can be observed that the contact angle at the bottom of the hydrogel gradually increases with the increase of fluorine concentration, confirming that the hydrophobicity is increasing.

[0100] In addition, such as Figure 8 As shown in (b), the evaporation rate of the PPy@PAM-co-CMC / PAM-co-CMC evaporator first increases and then decreases with increasing fluorosilane reagent concentration. The highest evaporation rate reaches 2.47 kgm³ when the fluorosilane reagent concentration is 0.01%. -2 h -1 .

[0101] The contact angle of the hydrogel surface treated with 0.003% fluorosilane reagent is 23°. At this point, the hydrophobicity of the bottom of the hydrogel is too weak, so the hydrophobic layer cannot act as a barrier. Water will be transported bidirectionally, resulting in a large reflux heat loss, and therefore the evaporation rate of water is also slow. On the other hand, the contact angle of the hydrogel surface treated with 0.01% fluorosilane reagent is 95°, which shows a certain degree of hydrophobicity. At this point, the water in the evaporator is transported almost unidirectionally, which reduces convective heat loss, and therefore the evaporation rate of water is faster.

[0102] It is worth noting that when the concentration of the fluorosilylating agent is 0.02%, the contact angle at the bottom of the hydrogel is as high as 121°. At this point, the gel surface is too hydrophobic, which will prevent water from being transported upward across the bottom hydrophobic layer, resulting in a severe water shortage on the upper surface of the hydrogel, thereby reducing the water evaporation rate.

[0103] Example 5

[0104] The detergency performance of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel prepared in Example 1 was tested, and the results are as follows: Figure 9 , Figure 10 As shown.

[0105] The evaporator was used in photothermal evaporation experiments in a 3.5 wt% NaCl solution (simulated seawater) and a 10 wt% NaCl solution, respectively.

[0106] Figure 9 (a) shows the curve of water evaporation mass changing over time, with corresponding evaporation rates of 2.52 kg / m³. -2 h -1 and 2.21 kgm -2 h -1 The same evaporator produces a slightly lower evaporation rate for high-concentration salt solutions than for low-concentration salt solutions.

[0107] Use a salinity pen to test the salinity of the condensed water after evaporation.

[0108] Experimental results are as follows Figure 9 As shown in (b), the salt concentration in the condensate of the two salt solutions dropped to 0 wt%, proving that the evaporator has good seawater desalination capabilities.

[0109] Using methyl orange (MO) and rhodamine B (RhB) as pollutant models, the wastewater purification capacity of the evaporator was tested.

[0110] UV-Vis absorption spectra before and after purification are as follows: Figure 10As shown, the MO solution and RhB solution before purification had strong absorption peaks at 465 nm and 554 nm, respectively. After purification, the absorption peaks of the above solutions disappeared. The inset shows the photos of the solutions before and after purification, which fully proves that the condensate obtained by the evaporator does not contain organic molecules and achieves wastewater purification.

[0111] Example 6

[0112] The salt resistance stability of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel prepared in Example 1 was tested, and the results are as follows: Figure 11 , Figure 12 As shown.

[0113] The hydrogel evaporator was subjected to photothermal evaporation cycle experiments in NaCl solutions with simulated seawater concentrations of 3.5 wt% and 10 wt%, respectively. The evaporation stability of the hydrogel in NaCl solutions of different concentrations was tested as follows: Figure 11 As shown, (a) is 3.5 wt%; (b) is 10 wt%.

[0114] from Figure 11 As can be seen, the PPy@PAM-co-CMC / PAM-co-CMC evaporator exhibits a stable evaporation rate in both salt solutions of different concentrations during 10 evaporation cycles. The inset is a SEM image of the evaporator after long-term stability testing, where the ordered channel structure of the hydrogel can still be observed.

[0115] Hydrogels with vertical and inclined channels were placed in a 10 wt% NaCl solution for photothermal evaporation tests.

[0116] Salt resistance test of hydrogels, such as Figure 12 As shown, (a) is an inclined channel; (b) is a vertical channel.

[0117] like Figure 12 As shown, the hydrogel with inclined channels did not exhibit salt crystallization on its surface even after evaporation for up to 10 hours. In contrast, the hydrogel with vertical channels showed salt crystals appearing at the edges of its evaporated surface after 5 hours of illumination, with crystallization becoming more pronounced after 10 hours.

[0118] Example 7

[0119] The water transport properties of the PPy@PAM-co-CMC / PAM-co-CMC hydrogel prepared in Example 1 were tested. The water transport properties of the evaporator were simulated using dyed water, and the results are as follows: Figure 13 As shown, (a) represents bidirectional transmission; (b) represents unidirectional transmission; and (c) represents no transmission.

[0120] Figure 13 In (a), the hydrophobic modification is insufficient, and the hydrophilicity at the bottom of the hydrogel remains strong. The dye water transport experiment also demonstrates that water possesses bidirectional transport capabilities. Therefore, the degree of water reflux inside the evaporator is still relatively high, reducing heat utilization efficiency.

[0121] Figure 13 In (c), the bottom of the hydrogel is too hydrophobic, and the strong hydrophobic force prevents water from flowing back into the bulk water during reverse osmosis. However, the evaporator also fundamentally blocks water transport, preventing water from reaching the evaporation surface of the evaporator and thus preventing the evaporation process from taking place.

[0122] Figure 13 In (b), the degree of hydrophobic modification at the bottom of the hydrogel is just enough to enable unidirectional water transport in the evaporator, that is, water can overcome the hydrophobic force under the action of strong capillary force and be transported upward to the evaporation surface.

[0123] Example 8

[0124] An outdoor experiment was conducted on the PPy@PAM-co-CMC / PAM-co-CMC hydrogel prepared in Example 1. The evaporator was placed under natural sunlight for one day of outdoor testing. The results are as follows: Figure 14 As shown, (a) is a photograph of the evaporation system; (b) is an infrared temperature image of the evaporator surface; (c) shows the changes in sunlight intensity and ambient temperature during the 7-hour outdoor experiment; and (d) shows the changes in the content of purified water.

[0125] Figure 14 The photographs in (a) correspond to the left and front views of the outdoor evaporation apparatus, respectively. A T-shaped evaporator, supported by foam, was placed in a beaker containing raw water and evaporated under sunlight. The evaporated water slid down the sloping condenser wall to the bottom of the apparatus for collection. The outdoor test was conducted on December 11, 2021, on the rooftop of the School of Chemistry and Materials Engineering at Jiangnan University. Changes in natural light intensity and ambient temperature during the test were observed. Figure 14 The information is recorded in (c). Figure 14 (b) The initial and maximum temperatures of the evaporator surface were measured using an infrared thermal imager. During the seven-hour testing period from 9:00 AM to 4:00 PM, Figure 14 (d) shows the trend of purified water content. Outdoor temperatures are low, natural light intensity is weak and unstable, and the evaporation effect is far less than in the laboratory. However, the purified water can still solve people's drinking water problems, fully demonstrating that the hydrogel evaporator has excellent water purification capabilities.

[0126] Comparative Example 1

[0127] Comparative Example 1: To verify the effect of ordered channels on the properties of PPy@PAM-co-CMC / PAM-co-CMC hydrogel, Comparative Example 1 differs from the liquid nitrogen directional freezing method in step (3) of Example 1. In this comparative example, the prepared hydrogel precursor solution was poured into a mold, then placed in an oven at 80°C for 2 hours to cure, and then ion crosslinked in a 2wt% FeCl3 solution. The remaining preparation process conditions were the same as in Example 1, resulting in a conventional disordered PPy@PAM-co-CMC / PAM-co-CMC hydrogel.

[0128] The properties of these two hydrogels with different channel structures were compared, such as Figure 15 As shown in (c), ordered hydrogels experience greater water evaporation mass loss, i.e., a higher evaporation rate.

[0129] like Figure 15 As shown in (a), the ordered channel can confine the incident light, resulting in higher absorption of the incident light.

[0130] like Figure 15 As shown in (d), the incident light is converted into heat, resulting in a high surface temperature of 51.0°C, which in turn increases the evaporation rate of water.

[0131] Comparative Example 2

[0132] Comparative Example 2: To verify the effect of the inclined channels in the disk region on the properties of PPy@PAM-co-CMC / PAM-co-CMC hydrogel, Comparative Example 2 differs from step (3) in Example 1. In this comparative example, the disk region is equipped with vertical channels. Specifically, the cylindrical region and the disk region are cooled with liquid nitrogen, and then placed in a mold. Some hydrogel is added at the junction and frozen to combine the two. Then, the internal ice crystals are removed by freeze-drying, thereby achieving the presence of vertical channels in both the cylindrical region and the disk region. The remaining preparation process conditions are the same as in Example 1.

[0133] The properties of these two different channel hydrogels were compared, and the results are as follows: Figure 16 As shown.

[0134] Figure 16 (a) It can be seen that the light-trapping ability of the tilted channel in PPy@PAM-co-CMC / PAM-co-CMC is stronger than that of the vertical channel.

[0135] Figure 16 (c) It can be observed that the hydrogel with inclined channels in the disk region has a greater water evaporation mass loss and a corresponding high evaporation rate.

[0136] like Figure 16As shown in (d), the hydrogel with inclined channels in the disk region converts more incident light into heat, resulting in a surface temperature as high as 50.9°C and a corresponding high evaporation rate.

[0137] Comparative Example 3

[0138] To demonstrate the effect of fluorine modification on the properties of PPy@PAM-co-CMC / PAM-co-CMC hydrogel, Comparative Example 2 does not include step (4) of Example 1. This comparative example does not perform hydrophobic treatment on one side of the hydrogel, and the remaining preparation process conditions are the same as those in Example 1.

[0139] The properties of two hydrogels, one with fluorine modification and the other without, were compared, and the results are as follows: Figure 17 , 3 As shown in -12.

[0140] Figure 17 (a) It was confirmed that the water evaporation rate of the evaporator modified with fluorine was significantly higher.

[0141] Figure 18 These correspond to the equilibrium temperature graphs of the two systems. It can be seen that the equilibrium temperature of the evaporation surface of the untreated hydrogel is around 49℃, slightly lower than the equilibrium temperature of the hydrogel after hydrophobic treatment, reaching 51.1℃. Conversely, the temperature of the bulk water in the untreated evaporation system is relatively higher, rising to 37.4℃, higher than the 33.9℃ temperature of the bulk water in the hydrophobic treated evaporation system.

[0142] The photothermal conversion efficiency of the hydrogels prepared in Example 1, Comparative Example 1, and Comparative Example 3 was tested. The equivalent evaporation efficiency of the PPy@PAM-co-CMC / PAM-co-CMC hydrogels was tested, and the photothermal conversion efficiency was calculated. In the photothermal evaporation process, the photothermal conversion efficiency is also a key parameter for evaluating the performance of the evaporation system. The following formula was used for calculation:

[0143] η = mL v / P in (1)

[0144] Where m is the water evaporation rate (kg / m³) -2 h -1 ), L v It is the enthalpy of vaporization of water, P in Optical input power (kW m) -2Because of the influence of hydrophilic groups on hydrogen bonding in hydrogels, the energy required for evaporation in hydrogel evaporators is lower, meaning the evaporation enthalpy is effectively reduced. An experiment was designed to estimate the evaporation enthalpy of water in hydrogels. The test procedure is as follows: A supersaturated potassium carbonate solution (stable humidity around 45%) was prepared. Pure water and hydrogel samples with the same surface area, along with the supersaturated potassium carbonate solution, were placed in a sealed container for the same amount of time. The equivalent evaporation enthalpy can be obtained by using the same energy input (U). in The mass loss of pure water during this period is estimated by the evaporation of water under certain conditions. The equivalent evaporation of water in different hydrogel samples is calculated using the following formula:

[0145] U in =E0m0=E equ m g (2)

[0146] In the formula, E0 and m0 represent the vapor evaporation rate of bulk water (2450 kJ / kg). -1 and quality change, m g This refers to the change in the mass of the hydrogel.

[0147] Using Equations 1 and 2, the evaporation enthalpy of the disordered channel PPy@PAM-co-CMC / PAM-co-CMC hydrogel was calculated to be reduced to 1497 kJ / kg. -1 The evaporation rate is 2.11 kg / m³. -2 h -1 Substituting the values ​​into the formula, the photothermal conversion efficiency reached 87.8%; for hydrogels with ordered channels but without fluorine modification, the evaporation rate increased to 2.45 kg / m³. -2 h -1 The evaporative enthalpy decreased even more, reaching 1277 kJ / kg. -1 The calculated photothermal conversion efficiency reached as high as 88.4%; and the evaporation rate of the fluorine-modified hydrogel PPy@PAM-co-CMC / PAM-co-CMC with ordered channels was further increased to 2.63 kg / m³. - 2 h -1 The calculated photothermal conversion efficiency is as high as 93.4%, which effectively improves the energy utilization rate in the evaporation process.

[0148] The evaporation performance of other T-type evaporators was compared, and the results are shown in Table 3-3.

[0149] Table 3-3

[0150]

[0151] Among them, Document 1 is Liu H, Jin R, Duan S, et al. Anisotropic evaporator with a T-Shape design for high-performance solar-driven zero-liquid discharge[J]. Small, 2021, 17(24): 2100969.

[0152] Document 2 is Chen K, Li L, Zhang J. Design of a separated solar interfacial evaporation system for simultaneous water and salt collection[J]. ACS Applied Materials & Interfaces, 2021, 13(49): 59518 - 59526.

[0153] Document 3 is Liu K, Zhang W, Cheng H, et al. A nature-inspired monolithic integrated cellulose aerogel-based evaporator for efficient solar desalination[J]. ACS Applied Materials & Interfaces, 2021, 13(8): 10612 - 10622.

[0154] Document 4 is Huang Q, Liang X, Zhang X, et al. Efficient-heat-utilization 3D T-shaped porous sponge assists 2D photothermal films to achieve self-acting salt rejection and extra evaporation under high-concentration brine[J]. Desalination, 2021, 499: 114806.

[0155] Example 9

[0156] (1) The Al sheet was ultrasonically washed in deionized water, anhydrous ethanol and acetone for 20 min in sequence. In the typical synthesis of Co3O4@Al sheet, 582 mg Co(NO3)2·6H2O and 600 mg urea were dissolved in 50 mL of deionized water.

[0157] (2) The solution was transferred to a Teflon-lined stainless steel autoclave, and the Al sheet was immersed in the solution. One side of the aluminum sheet was protected with a superhydrophobic coating. The autoclave was then transferred to an oven and kept at 120°C for 10 hours to grow 2CoCO3·3Co(OH)2·H2O nanoplatelets on the Al sheet.

[0158] (3) After cooling to room temperature, the prepared 2CoCO3·3Co(OH)2·H2O@Al sheet was rinsed several times with deionized water and ethanol. The superhydrophobic coating on the other side was removed with cotton wool containing anhydrous ethanol. Next, the sample was annealed in air at 400℃ for 2 hours in a tube furnace at a heating rate of 5℃ / min. -1 This forms Co3O4@Al sheets.

[0159] (4) Add 50 μL of pyrrole to 45 mL of deionized water and stir for 10 min to form solution A. Simultaneously, add 0.16 g of ammonium persulfate to 5 mL of deionized water and stir to form solution B. Immerse the Co3O4@Al sheet in solution A, and slowly add solution B dropwise into solution A. Place the Co3O4@Al sheet in an incubator and maintain at 30 °C for 1 h to allow pyrrole to oxidatively polymerize and generate Ppy. Finally, thoroughly wash the Ppy@Co3O4@Al sheet with deionized water and dry it under a nitrogen stream.

[0160] (5) The separated SIE system consists of PPy@Co3O4@Al sheets and T-shaped superhydrophilic PE / PP nonwoven fabric, quartz square cylinders and polystyrene foam directly below the PPy@Co3O4@Al sheets.

[0161] Test results show that the T-type water evaporation system obtained in Example 9 separates the photothermal surface from the evaporation surface, exposing it outside the closed SIE system. This completely avoids salt scale formation on the photothermal surface and greatly improves the freshwater collection rate. It features simultaneous water and salt collection, long-term stable concentrated brine evaporation rate, high salt collection efficiency and constant concentrated brine concentration during the SIE process, and maintains a high water collection rate even in cold winters with weak sunlight under natural light conditions.

[0162] Example 10

[0163] (1) Vinyltrimethoxysilane VTMS (1.32 g) was added dropwise to 55 g CNF suspension (1.2 wt%) and mixed. The mixture was mechanically stirred at room temperature for 4 hours. The silanized cellulose aerogel obtained after freeze-drying was abbreviated as SCA.

[0164] (2) Dissolve PVA (5.0 g) in deionized water (50 mL) and stir at 95 °C for 10 h. Store the PVA solution (10 wt%) at room temperature. Add KH560 (0.38 g) dropwise to a mixed suspension (35 g) of CNF (1.2 wt%) and PVA solution. Stir the mixture mechanically for 4 hours and freeze-dry to obtain cellulose aerogel, abbreviated as CPA.

[0165] (3) The hydrophobic SCA precursor suspension was placed in a glass mold (with a movable column mold in the middle with a diameter of about 1.6 cm). The precursor suspension was first frozen into an ice gel in liquid nitrogen. After removing the middle column mold, the hydrophilic CPA precursor suspension was poured into the hollow ice gel. The mixture was placed at 20°C for 30 minutes to allow it to melt and interpenetrate at the interface. Then, the mixture was frozen in liquid nitrogen, freeze-dried, and stored at 110°C for 30 minutes to promote cross-linking.

[0166] (4) The cured aerogel was placed in deionized water and acetone to remove the physically adsorbed silane coupling agent. Then, it was vacuum dried at 30°C for 24 hours. Finally, MCNT and carbon nanotube dispersant (TNWDIS) were added to deionized water to prepare an MCNT suspension (10 wt%). The mixture was sonicated for 30 minutes. Then, the inverted aerogel was immersed in the MCNT suspension (9 g), freeze-dried for more than 24 hours after freezing.

[0167] Test results show that the T-type water evaporation system obtained in Example 10, inspired by wood and mushrooms, achieves thermal localization by combining hydrophobic SCA (with inherently low thermal conductivity) with mushroom-shaped CPA (with vertically arranged channels and porous structure similar to wood), effectively suppressing heat dissipation and improving solar-to-thermal conversion efficiency. It exhibits almost no salt deposition in actual seawater in East China and continuous evaporation for 8 hours under a single solar irradiation, demonstrating significant salt tolerance in high-concentration brine (17.5 wt%).

[0168] Example 11

[0169] (1) The Ti3C2Tx precipitate was mixed with ultrapure water to prepare a solution. 1 mL of Ti3C2Tx solution of different concentrations was dropped into a piece of air-cloth paper with a diameter of 33 mm and placed in a vacuum drying oven at 60℃ for 1 h to obtain TAP.

[0170] (2) Immerse the completely dried TAP cloth in 10 mL of dopamine-Tris-HCl (2 g·L⁻¹). -1 The solution was shaken in a solution of dopamine (pH = 8.8) for 4 hours, then placed in a vacuum drying oven at 60°C for 1 hour to obtain TPAP. The completely dried AP was then immersed in 10 mL of dopamine Tris-HCl (2 g·L⁻¹). -1 The mixture was shaken in a solution of pH 8.8 for 4 hours, and then placed in a vacuum drying oven at 60°C for 1 hour to obtain PAP.

[0171] (3) Cut the melamine foam into platforms and pillars, and after successful assembly, form 3DTPS. Then, TPAP and PAP are assembled onto the surface of the melamine foam platform.

[0172] Test results show that the T-type water evaporation system obtained in this embodiment 11 has the characteristics of being simple, easy to expand, highly versatile, and low in cost.

[0173] Example 12

[0174] (1) Balsa wood was cut into 1.5cm × 1.5cm × 0.1cm pieces along both the longitudinal direction (wood growth direction, L-wood) and the longitudinal direction (growth direction, V-wood) to prepare L-wood and V-wood respectively. Then, only one surface of the prepared L-wood sample was immersed in a FeCl3 aqueous solution (15wt%) for 2 seconds. It was then air-dried at room temperature for 24 hours to obtain Fe... 3+ / wood. Finally, take a piece of Fe 3+ Wood is carbonized at 250°C for 20 seconds to form Cl wood.

[0175] (2) Prepare another piece of natural l-shaped wood with dimensions of 2.0×2.0×0.1cm. We carve a rectangular groove on the edge of the natural l-wood to form the shell (top) of the l-wood membrane, which is perpendicularly connected to the natural l-wood membrane (support) to form a T-shaped evaporator.

[0176] Test results show that the T-type water evaporation system obtained in Example 12 has a yield of 2.43 kg·m· evaporation efficiency under one solar irradiation. -2 ·h -1 With a high evaporation rate, it operated stably outdoors for 7 days, simultaneously achieving water purification evaporation and salt collection (including Cu). 2+ CrO4 2- Co 2+ This achieves zero liquid discharge.

[0177] Example 13

[0178] (1) Cut commercially available microporous alumina ceramics into different sizes. Then cut them into T-shaped blocks of different sizes using an abrasive wheel cutter. Boil them in boiling water for 20 minutes and wash them 5 times with deionized water to remove surface and internal impurities.

[0179] (2) 150 mL of HAuCl4·3H2O (0.01 M) solution was added to 50 mL of SnCl2 (0.045 M) solution to carry out the reaction. The solution was immediately deposited on the upper surface of the pre-wetted CM sample. Residual impurities were then washed with deionized water. The above process was repeated 10 times, resulting in 10 layers of uniform and pure gold nanoparticles deposited on the surface.

[0180] (3) The prepared samples were baked in an oven at 150°C for 2 hours to enhance the bonding force between Au nanoparticles and CM.

[0181] Test results show that the T-type water evaporation system obtained in Example 13 can effectively purify wastewater of various dye concentrations. Furthermore, the generator exhibits good pH stability, thermal stability, and robust mechanical properties, which is beneficial for meeting the complex conditions encountered in practical applications. Simultaneously, the generator, which becomes clogged after long-term purification of high-concentration wastewater, can be regenerated through calcination, solving the problem of reduced evaporation rate caused by organic accumulation.

[0182] 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. A lotus-pod-inspired solar evaporator, characterized in that: include, A transmission unit for unidirectional water transmission, the transmission unit having a first transmission channel extending through both ends; and, An evaporation section for evaporation, wherein the transmission section has a second transmission channel communicating with the first transmission channel; Wherein, one end of the transmission section is in contact with the evaporation section, and the other end of the transmission section is a hydrophobic surface, wherein the contact angle of the hydrophobic surface is greater than 90°. The first transmission channel is a vertical channel within the transmission section that faces the evaporation section; the second transmission channel is an inclined channel within the evaporation section that is at an angle to the vertical channel.

2. The lotus-shaped solar evaporator according to claim 1, characterized in that: The light-illuminated area of ​​the evaporation section is greater than the contact area between the transmission section and the evaporation section.

3. The lotus-shaped solar evaporator according to claim 1, characterized in that: The material of the transport section is selected from a polymer rich in hydrophilic groups that has undergone hydrophobic treatment at the bottom. The hydrophilic groups include ether bonds composed of carboxylic acid groups, sulfonic acid groups, phosphate groups, amino groups, quaternary ammonium groups, oxygen-containing groups, and hydroxyl groups, as well as one or more of carboxylic acid esters and block polyethers.

4. The lotus-shaped solar evaporator according to claim 3, characterized in that: The hydrophobic treatment includes chemically modifying the material surface to make it hydrophobic, including introducing a compound containing hydrophilic and hydrophobic groups onto the material surface or coating the material surface with a film containing hydrophobic components. Alternatively, nanostructures can be prepared on the surface of a material to increase the surface area of ​​the material and form air envelopes to achieve surface hydrophobicity. The nanostructures include nanopillars or nanorods. Alternatively, a layer of a substance containing hydrophobic components may be deposited on the surface of the material to make the surface hydrophobic, wherein the substance containing hydrophobic components includes PTFE or graphite.

5. The lotus-shaped solar evaporator according to claim 1, characterized in that: The material of the evaporation section is selected from a hydrophilic substrate loaded with photothermal material; The photothermal material includes one or more of the following: thermally vibrating carbon-based materials, conjugated polymers, MXenes, carbon nanomaterials, semiconductor-based plasma nanoparticles (i.e., non-radiative relaxation semiconductors), noble metal-based plasma nanocrystals (i.e., plasma locally heated metals), transition metal sulfides, transition metal dichalcogenides, oxide nanoparticles, and biophotothermal reagents.

6. The method for preparing the lotus-shaped solar evaporator as described in any one of claims 1 to 5, characterized in that: The preparation method of the lotus-shaped solar evaporator includes... The precursor material of the transport section and the precursor material of the evaporation section are poured into a mold to form a shape in which one end of the transport section contacts the evaporation section; An ice crystal template is formed inside the precursor materials of the transport section and the evaporation section by liquid nitrogen freezing; wherein, free water is present in the precursor materials of the transport section and the evaporation section. The ice crystal template was removed by freeze-drying; The precursor material of the heating transport section and the precursor material of the evaporation section are heated to form a hydrogel, thus obtaining the transport section and the evaporation section; The end of the transmission section away from the evaporation section is hydrophobically modified.

7. The method for preparing a lotus-shaped solar evaporator according to claim 6, characterized in that: The precursor material for the transport section is a homogeneous mixture of a polymer selected from those with hydrophobic bottom treatment and rich in hydrophilic groups, wherein the hydrophilic groups include ether bonds composed of carboxylic acid groups, sulfonic acid groups, phosphate groups, amino groups, quaternary ammonium groups, oxygen-containing groups, and hydroxyl groups, and one or more of carboxylic acid esters and block polyethers, and water.

8. The method for preparing a lotus-shaped solar evaporator according to claim 6, characterized in that: The precursor material for the evaporation section is a homogeneous mixture of a hydrophilic substrate material loaded with photothermal material and water. The photothermal material includes one or more of the following: thermally vibrating carbon-based materials, conjugated polymers, MXenes, carbon nanomaterials, semiconductor-based plasma nanoparticles (i.e., non-radiative relaxation semiconductors), noble metal-based plasma nanocrystals (i.e., plasma locally heated metals), transition metal sulfides, transition metal dichalcogenides, oxide nanoparticles, and biophotothermal reagents.

9. The application of the lotus-shaped solar evaporator as described in any one of claims 1 to 5 in water evaporation.

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