Shape-adjustable thermal plasmon interface evaporator and preparation method and application thereof

Abstract

The invention relates to a shape-adjustable thermal plasmon interface evaporator and a preparation method and application thereof. The thermal plasmon interface evaporator sequentially comprises a porous hydrophilic substrate layer and a thermal plasmon photo-thermal layer, the thermal plasmon photo-thermal layer comprises a thermal plasmon material and hydrogel wrapping the thermal plasmon material; the super-efficient full-spectrum solar energy absorption and efficient heat energy conversion are achieved, the absorption rate reaches up to 96% or above, the performance is highly stable, the structure is flexible and adjustable, the large-scale expansion potential is excellent, the excellent evaporation performance is kept under the complex working condition, the evaporation rate reaches up to 7.75 kg.m <-2 >. H <-1 > or above preferably, and the application range is wide. And the preparation method breaks through the technical bottleneck of a traditional interface evaporator, stable 2D and 3D evaporator arrays can be conveniently constructed, and an important technical support and an industrialization path are provided for large-scale application of a solar interface evaporation technology in the fields of seawater desalination, sewage purification and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of photothermal materials and solar interface evaporation, and in particular to a shape-adjustable thermal plasmon interface evaporator, a preparation method thereof, and applications thereof. Background Art

[0002] Solar-Driven Interfacial Evaporation (SDIE) is an emerging water treatment technology that focuses solar energy at the air-water interface to achieve localized heating, thereby driving efficient water evaporation and purification. Compared to traditional energy-intensive processes such as reverse osmosis and multi-stage flash evaporation, SDIE offers advantages such as a simple structure, no need for external power supply, low energy consumption, low operation and maintenance costs, and ease of deployment. It is particularly suitable for distributed desalination and water purification in areas with limited water or electricity supplies, and exhibits promising prospects for sustainable development.

[0003] In the SDIE system, the photothermal layer is the core component for achieving light energy capture and photothermal conversion. Its spectral absorption capacity, photothermal conversion efficiency and long-term stability jointly determine the overall evaporation performance and water production sustainability of the system. In recent years, nanophotothermal materials based on localized surface plasmon resonance (LSPR) and multi-body coupling effects have become key materials for achieving efficient photothermal conversion due to their strong light absorption, wide spectrum response and efficient non-radiative relaxation capabilities. Among them, "thermal plasmon" materials represented by transition metal nitrides (TMNs, such as TiN, ZrN or HfN, etc.) are gradually replacing traditional precious metals (such as Au or Ag, etc.) to become a new generation of high-performance photothermal materials by virtue of their synergistic properties such as metal-like free electron behavior and ceramic-grade chemical inertness.

[0004] Compared with traditional precious metals, TMNs thermoplasmonic materials have the following significant advantages: (1) a broadband, strong absorption, and tunable plasmon response band, covering the visible to near-infrared band, expanding the efficiency of solar energy utilization; (2) a higher imaginary part of the dielectric constant, which promotes non-radiative attenuation paths and effectively improves the light-to-heat conversion efficiency; (3) excellent thermal stability and chemical inertness (melting point up to 3000K), enabling long-term stable operation in high temperature, high light intensity, and salt spray corrosion environments. These advantages make TMNs thermoplasmonic materials the most promising candidate system for stable operation of photothermal layer materials in seawater desalination, high-salinity wastewater treatment, and extreme environments.

[0005] However, although TMNs exhibit excellent photothermal performance, the practical application of their nanoparticles faces significant challenges. Typical TMNs nanoparticles are usually 10-100nm in size and have high surface energy and strong chemical inertness, which makes it difficult to achieve firm, uniform and long-lasting adhesion on typical porous substrates (such as wood pulp cotton, carbon foam, etc.). Traditional physical adsorption methods can only form a weak "point-surface" contact interface, which makes the material susceptible to physical vibration, fluid shear force, salt crystallization and precipitation during long-term operation and fall off, significantly reducing the structural integrity and evaporation performance of the photothermal layer. This adhesion stability problem has become a key technical bottleneck limiting the actual promotion and application of TMNs thermoplasmonic materials in SDIE.

[0006] In existing technologies, physical composite methods such as coating and dipping-drying are often used to construct the photothermal layer. However, these methods struggle to fundamentally address issues such as uneven particle deposition, poor bonding strength, and susceptibility to aging and shedding. For example, the TiN / carbon foam double-layer structure disclosed in CN110398077A utilizes a coating method to composite TiN nanostructured materials with carbon foam. However, the coating exhibits severe delamination in saltwater conditions, and the evaporation rate decreases significantly over time. The three-dimensional array evaporator disclosed in CN114956237A, while expanding the illuminated area, similarly struggles to maintain efficient and stable operation due to issues such as uneven deposition of the photothermal layer, limited vapor diffusion, and particle shedding.

[0007] Furthermore, SDIE technology faces a wide range of practical application demands, including large-area coverage two-dimensional thin film structures and three-dimensional columnar structural units suitable for household and portable scenarios. Therefore, there is an urgent need to develop a TMNs thermoplasmonic photothermal layer integration method that combines shape adjustability and structural stability with easy scalability. This method should also effectively address the challenges of strong nanoparticle adhesion and long-term stability on porous substrates, thereby advancing SDIE technology towards practical engineering applications. Summary of the Invention

[0008] To solve the above technical problems, the present invention provides a shape-adjustable thermal plasmonic interface evaporator, its preparation method and application, and proposes a method for constructing an interface evaporation structure based on a "physical encapsulation + chemical cross-linking" synergistic fixation strategy to achieve a firm, uniform and controllable loading of thermal plasmonic nanoparticles on a porous hydrophilic substrate, solving the key bottleneck problems of current thermal plasmonic materials in solar-driven interface evaporation (SDIE) systems, such as weak adhesion, uneven deposition and poor structural stability.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a shape-adjustable thermal plasmon interface evaporator, the thermal plasmon interface evaporator comprising, in sequence, a porous hydrophilic base layer and a thermal plasmon photothermal layer;

[0011] The thermal plasmon photothermal layer includes a thermal plasmon material and a hydrogel encapsulating the thermal plasmon material.

[0012] The present invention utilizes the synergistic effect of the porous hydrophilic substrate layer and the photothermal layer including the thermal plasmonic material, and the two are combined to construct an interface evaporator with stable and controllable structure, strong scalability and excellent evaporation performance, wherein the porous hydrophilic substrate layer has a 3D porous structure and high hydrophilicity, which not only enhances the water vapor channel and increases the evaporation area, but also forms a good hydrothermal gradient control capability, thereby improving the evaporation efficiency; at the same time, the thermal plasmonic material is wrapped by hydrogel, making it easier to stably attach the thermal plasmonic material to the porous hydrophilic substrate layer in the future to avoid falling off, thereby improving the structure and performance of the interface evaporator. Its performance is stable; it overcomes the problems of high substrate material cost, poor hydrophilicity, low porosity and insufficient capillary driving force in existing interface evaporators, fundamentally improves evaporation efficiency and system reliability, and provides a practical solution for solar interface evaporation technology in complex practical environments. The shape-adjustable thermal plasmon interface evaporator can flexibly adjust its size and shape according to actual needs, meeting the needs of different application scenarios from 2D to 3D, taking into account high light-to-heat conversion efficiency, excellent material durability and flexible controllability of interface structure shape, significantly improving evaporation performance and environmental adaptability.

[0013] Preferably, the porous hydrophilic base layer comprises any one of wood pulp cotton, carbon foam material, and hierarchical pore hydrogel, preferably wood pulp cotton.

[0014] It is worth noting that the shape of the porous hydrophilic base layer is adjustable.

[0015] Preferably, the wood pulp cotton comprises a multi-level pore structure.

[0016] Preferably, the wood pulp cotton comprises macropores of 50 to 2000 μm and micropores of 1 to 10 μm.

[0017] Among them, the 50-2000μm macropores can be, for example, 50μm, 100μm, 300μm, 500μm, 800μm, 1000μm, 1200μm, 1500μm, 1800μm or 2000μm, etc.; the 1-10μm micropores can be, for example, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, etc.

[0018] The present invention further prefers that the porous hydrophilic base layer is wood pulp cotton because it has a multi-level pore structure, high hydrophilicity and good plasticity, which not only enhances the water vapor channel and increases the evaporation area, but also forms a good hydrothermal gradient control capability, significantly improves the photothermal evaporation efficiency and structural stability, and has a low cost.

[0019] Preferably, the porosity of the porous hydrophilic base layer is 90-98%, for example, it may be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97% or 98%.

[0020] Preferably, the mass ratio of the thermoplasmonic material to the hydrogel in the thermoplasmonic photothermal layer is (0.2-0.4):1, for example, it can be 0.2:1, 0.22:1, 0.25:1, 0.28:1, 0.3:1, 0.32:1, 0.35:1, 0.38:1 or 0.4:1, etc.

[0021] The present invention further preferably has a mass ratio of the thermal plasmonic material to the hydrogel in the thermal plasmonic photothermal layer of (0.2-0.4):1, which reduces reagent waste while ensuring that the thermal plasmonic material is wrapped by the hydrogel. If the mass ratio of the thermal plasmonic material to the hydrogel is too low, that is, the mass of the hydrogel is too high, resulting in waste. If the mass ratio of the thermal plasmonic material to the hydrogel is too high, that is, the mass of the hydrogel is too low, the thermal plasmonic material cannot be fully wrapped, causing it to fall off easily, thereby reducing the photothermal conversion efficiency and the evaporation efficiency.

[0022] Preferably, the particle size distribution of the thermal plasmon material is 10 to 100 nm, for example, 10 nm, 15 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm.

[0023] Preferably, the thermal plasmonic material includes any one or a combination of at least two of transition metal nitrides, non-noble metals, heavily doped semiconductor materials or MXene materials, wherein typical but non-limiting combinations include a combination of transition metal nitrides and non-noble metals, a combination of transition metal nitrides and MXene materials, or a combination of non-noble metals and heavily doped semiconductor materials, etc.

[0024] Preferably, the transition metal nitride includes TiN and / or ZrN.

[0025] Preferably, the non-noble metal includes Cu and / or Al.

[0026] Preferably, the heavily doped semiconductor material comprises Cu2S.

[0027] Preferably, the MXene material comprises Ti3C2. Preferably, the thermal plasmon photothermal layer and the porous hydrophilic base layer are connected via a crosslinking agent.

[0028] The present invention further preferably connects the thermal plasmon photothermal layer and the porous hydrophilic base layer via a cross-linking agent, thereby further improving the bonding force between the porous hydrophilic base layer and the photothermal layer, thereby making the structure of the shape-adjustable thermal plasmon interface evaporator more stable and the performance more stable during long-term use.

[0029] In a second aspect, the present invention provides a method for preparing the shape-adjustable thermal plasmon interface evaporator according to the first aspect, the method comprising the following steps:

[0030] (1) mixing the thermal plasmonic material and the hydrogel solution and performing ultrasonic dispersion to obtain a photothermal precursor solution,

[0031] (2) Immersing one side of the porous hydrophilic base layer in the photothermal precursor solution of step (1), and then thermally curing to obtain the thermal plasmon interface evaporator.

[0032] The method for preparing the shape-adjustable thermal plasmonic interface evaporator described in the present invention first mixes the thermal plasmonic material with a hydrogel solution and ultrasonically disperses it, so that the thermal plasmonic material is evenly wrapped by the hydrogel to obtain the photothermal precursor solution, thereby improving its dispersibility and enhancing its initial adhesion ability on the substrate surface; then, an immersion method is used to utilize capillary action to cause the photothermal precursor solution to rise to one side of the porous hydrophilic substrate layer, thereby obtaining a shape-adjustable thermal plasmonic interface evaporator with a composite structure of a thermal plasmonic material-porous hydrophilic substrate layer. The preparation method solves the problem of difficulty in attaching the thermal plasmonic material to the porous hydrophilic substrate layer. The resulting thermal plasmonic interface evaporator has a stable structure, high evaporation efficiency, simple operation, and low cost.

[0033] Preferably, the mass ratio of the thermal plasmon material in step (1) to the hydrogel in the hydrogel solution is (0.2-0.4):1, for example, it can be 0.2:1, 0.22:1, 0.25:1, 0.28:1, 0.3:1, 0.32:1, 0.35:1, 0.38:1 or 0.4:1, etc.

[0034] Preferably, the mixing temperature in step (1) is 60-90°C, for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C.

[0035] Preferably, the mixing in step (1) comprises adding a thermoplasmonic material to the hydrogel solution.

[0036] Preferably, the mixing is performed under stirring conditions.

[0037] Preferably, the stirring speed is 300-600 r / min, for example, 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min, 550 r / min or 600 r / min.

[0038] Preferably, the ultrasonic dispersion time in step (1) is 15 to 30 minutes, for example, 15 minutes, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes or 30 minutes.

[0039] Preferably, the ultrasonic power of the ultrasonic dispersion in step (1) is 100-250W, for example, it can be 100W, 120W, 150W, 180W, 200W, 220W or 250W.

[0040] Preferably, the ultrasonic frequency of the ultrasonic dispersion in step (1) is 35 to 45 kHz, for example, 35 kHz, 38 kHz, 40 kHz, 42 kHz or 45 kHz.

[0041] Preferably, before the impregnation in step (2), the porous hydrophilic substrate is first subjected to a first washing and a first drying in sequence.

[0042] The present invention further preferably performs a first washing and a first drying in sequence before the immersion in step (2), wherein the first washing is to wash away impurities in the porous hydrophilic substrate to prevent the impurities from entering the subsequent process.

[0043] Preferably, the number of times of the first washing is ≥ 3 times, for example, it can be 3 times, 4 times, 5 times or 6 times.

[0044] Preferably, the first drying temperature is 40-80°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[0045] Preferably, the first drying time is 2 to 5 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours.

[0046] Preferably, the immersion time in step (2) is 8 to 15 minutes, for example, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes or 15 minutes.

[0047] Preferably, after the impregnation in step (2), the process further includes injecting a crosslinking agent into the porous hydrophilic base layer.

[0048] The present invention further preferably includes injecting a crosslinking agent into the porous hydrophilic base layer after the impregnation, utilizing the crosslinking agent to undergo a crosslinking reaction with the hydrogel in the thermal plasmonic photothermal layer, in situ constructing a -C=N-Schiff base covalent bond network, and realizing molecular-level chemical coupling between the photothermal layer and the base layer, thereby improving the bonding strength between the thermal plasmonic photothermal layer and the porous hydrophilic base layer, effectively preventing the photothermal layer from falling off during long-term use, and improving the overall structural stability and durability of the thermal plasmonic interface evaporator.

[0049] Preferably, the cross-linking agent comprises any one of glutaraldehyde, adipaldehyde or succinaldehyde, or a combination of at least two thereof, wherein typical but non-limiting combinations include a combination of glutaraldehyde and adipaldehyde, a combination of adipaldehyde and succinaldehyde, or a combination of glutaraldehyde and succinaldehyde.

[0050] The injection amount of the cross-linking agent of the present invention is appropriately excessive to ensure that the cross-linking reaction is fully carried out, so that the bonding force between the photothermal layer and the porous hydrophilic base layer is stronger, and the crystallization stability of the shape-adjustable thermal plasmon interface evaporator is improved.

[0051] Preferably, the temperature of the thermal curing in step (2) is 70-130°C, for example, it can be 70°C, 80°C, 90°C, 100°C, 110°C, 120°C or 130°C.

[0052] Preferably, the thermal curing time in step (2) is 2 to 5 hours, for example, it can be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours.

[0053] Preferably, after the thermal curing in step (2), the thermal plasmon interface evaporator is further subjected to a second washing and a second drying in sequence.

[0054] The present invention further preferably includes sequentially performing a second washing and a second drying on the thermal plasmon interface evaporator after the thermal curing, wherein the second washing is for washing away unreacted substances.

[0055] Preferably, the number of times of the second washing is ≥ 2 times, for example, it can be 2 times, 3 times, 4 times, 5 times or 6 times.

[0056] Preferably, the second drying temperature is 50-90°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C.

[0057] Preferably, the second drying time is 0.5 to 2 hours, for example, 0.5 hours, 0.8 hours, 1 hour, 1.2 hours, 1.5 hours, 1.8 hours or 2 hours.

[0058] As a further preferred technical solution of the present invention, the preparation method comprises the following steps:

[0059] (1) adding the thermal plasmon material to the hydrogel solution at a mass ratio of the thermal plasmon material to the hydrogel in the hydrogel solution of (0.2-0.4):1 at 60-90° C., and ultrasonically dispersing the hydrogel solution at 100-250 W and 35-45 kHz for 15-30 min to obtain a photothermal precursor solution.

[0060] (2) The porous hydrophilic base layer is first washed at least three times, and then dried at 40 to 80° C. for 2 to 5 hours. One side of the porous hydrophilic base layer after the first drying is then immersed in the photothermal precursor solution of step (1) for 8 to 15 minutes. The crosslinker is then injected into the porous hydrophilic base layer at a ratio of the injection amount of the crosslinker to the volume of the porous hydrophilic base layer of (0.02 to 0.1):1, and thermally cured at 70 to 130° C. for 2 to 5 hours. The porous hydrophilic base layer is then washed at least twice, and finally dried at 50 to 90° C. for 0.5 to 2 hours to obtain the shape-adjustable thermal plasmon interface evaporator.

[0061] In a third aspect, the present invention provides an application of the shape-adjustable thermal plasmon interface evaporator described in the first aspect, wherein the shape-adjustable thermal plasmon interface evaporator is used in the field of seawater desalination or sewage purification.

[0062] The shape-adjustable thermal plasmonic interface evaporator described in this invention leverages the structural scalability of its porous hydrophilic substrate to adapt to diverse application scenarios. It achieves efficient photothermal evaporation without any auxiliary energy input other than solar energy. It can be widely used in solar-driven evaporation scenarios such as seawater desalination and wastewater purification, providing a new material system and process path for large-scale engineering applications of SDIE. Compared with existing technologies, this invention has at least the following advantages:

[0063] (1) The shape-adjustable thermal plasmon interface evaporator provided by the present invention utilizes the porous hydrophilic substrate layer and the hydrogel-wrapped thermal plasmon photothermal layer to combine the two to construct a thermal plasmon interface evaporator with stable and controllable structure, strong scalability and excellent evaporation performance. It has strong solar energy absorption and rapid water extraction, and draws a large amount of additional energy from the environment for the evaporation process itself. The light absorption efficiency is as high as 96% or more in the entire solar spectrum range, and the evaporation rate is preferably as high as 7.75 kg·m -2 ·h -1 As described above, the structure of the thermal plasmon interface evaporator is expandable, that is, the size and shape can be flexibly adjusted according to actual needs, thereby meeting the needs of different application scenarios.

[0064] (2) The preparation method of the shape-adjustable thermal plasmonic interface evaporator provided by the present invention adopts a method of first physical packaging and then chemical cross-linking to stably attach the thermal plasmonic material to the porous hydrophilic substrate layer, thereby obtaining an interface evaporator with stable structure and excellent photothermal performance. This solves the problem that it is difficult to attach the thermal plasmonic material to the porous hydrophilic substrate layer, which leads to easy falling off and low evaporation rate, and realizes continuous and stable interface evaporation. It is simple to operate and low in cost, making it possible to construct a stable 3D interface evaporator array.

[0065] (3) Application of the shape-adjustable thermal plasmon interface evaporator provided by the present invention. The shape-adjustable thermal plasmon interface evaporator is applied to fields such as seawater desalination or sewage purification, and can achieve high-efficiency photothermal evaporation without auxiliary energy input except solar energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 1 is a schematic structural diagram of the thermal plasmon interface evaporator according to Example 1 of the present invention;

[0067] Figure 2 is a graph showing changes in the wetting height and wetting rate of the wood pulp cotton used in Example 1 of the present invention over time;

[0068] Figure 3 1. The physical image, SEM and EDS images of the thermal plasmon interface evaporator described in Example 1 of the present invention;

[0069] Figure 4 is a comparison diagram of FTIR spectra of the wood pulp cotton described in Example 1 of the present invention and the thermal plasmon interface evaporator;

[0070] Figure 5 This is a broadband solar absorption spectrum of the thermal plasmon interface evaporator described in Example 1 of the present invention;

[0071] Figure 6 1. Graph showing the evaporation rate and upper surface steady-state temperature variation of the thermal plasmon interface evaporator at different exposure heights according to Example 1 of the present invention;

[0072] Figure 7 1 is a comparison diagram of the absorption spectra of the dye before and after treatment by the thermal plasmon interface evaporator described in Example 1 of the present invention;

[0073] Figure 8 3 is a comparison chart of ion concentration changes before and after desalination of seawater by the thermal plasmonic interface evaporator described in Example 1 of the present invention. In the figure, the WHO dotted line represents the maximum allowable ion concentration in drinking water as specified by the World Health Organization; the EPA dotted line represents the water quality standard specified by the U.S. Environmental Protection Agency;

[0074] Figure 9 This is a test chart of reducing pH using the thermal plasmon interface evaporator described in Example 1 of the present invention;

[0075] In the figure: 1. Porous hydrophilic base layer; 2. Photothermal layer. DETAILED DESCRIPTION

[0076] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0077] The wood pulp cotton used in the following examples is a steamer absorbent sponge from Shenzhen Hongchengxing Industrial (Group) Co., Ltd.;

[0078] The hydrogel solution used in the following examples was prepared by adding 7.5 g of polyvinyl alcohol (PVA, molecular weight 15,000-25,000) and 2.5 g of carboxymethyl chitosan to 100 mL of deionized water, and stirring the mixture under magnetic stirring at 70° C. for 2 hours to obtain the hydrogel solution.

[0079] It is worth noting that the hydrogel solution of the present invention can wrap the thermal plasmonic material and react with the crosslinking agent to be crosslinked, without any other restrictions, that is, other preparation methods are also applicable to prepare hydrogel solutions with the above functions.

[0080] It is worth noting that the shape and structure of the thermal plasmon interface evaporator of the present invention can be expanded, that is, the external dimensions can be adjusted by cutting the porous hydrophilic base layer.

[0081] 1. Implementation

[0082] Example 1

[0083] This embodiment provides a shape-adjustable thermal plasmon interface evaporator, such as Figure 1 As shown, the thermal plasmon interface evaporator comprises a porous hydrophilic base layer 1 and a thermal plasmon photothermal layer 2 in sequence; the porous hydrophilic base layer 1 is wood pulp cotton with a porosity of 95%,

[0084] The thermal plasmon photothermal layer 2 includes TiN nanoparticles and a hydrogel that wraps the TiN nanoparticles. The mass ratio of the TiN nanoparticles to the hydrogel is 0.3:1. The average particle size of the TiN nanoparticles is 20 nm. The thickness of the thermal plasmon photothermal layer 2 is 5 μm. The thermal plasmon photothermal layer 2 is connected to the porous hydrophilic base layer 1 via glutaraldehyde.

[0085] The geometric structure of the wood pulp cotton used in this embodiment is a cuboid with a length, width and height of 1.75 cm, 1.75 cm and 14.5 cm respectively.

[0086] In this embodiment, the wood pulp cotton was placed in a rhodamine b solution (concentration of 0.5 wt%) to conduct a hydrophilicity test. The results are as follows: Figure 2 As shown, it can be seen that: with the increase of time, the wetting height of the wood pulp cotton gradually increases. After 15 minutes, the wetting height of the wood pulp cotton can reach more than 9 cm, and the wetting rate of the wood pulp cotton can be as high as 0.45 cm / s.

[0087] like Figure 3 As shown, it is a physical picture, SEM and EDS picture of the thermal plasmon interface evaporator described in this embodiment; it can be seen that: the wood pulp cotton has a multi-level pore structure, and the TiN nanoparticles are evenly distributed on the surface of the wood pulp cotton.

[0088] like Figure 4 As shown, it is a comparison diagram of the FTIR spectra of the wood pulp cotton and the thermal plasmon interface evaporator in this embodiment. It can be seen that: C=N double bonds are formed in the thermal plasmon photothermal layer, proving that the cross-linking reaction occurs fully.

[0089] This embodiment further provides a method for preparing the above-mentioned shape-adjustable thermal plasmon interface evaporator, the method comprising the following steps:

[0090] (1) adding TiN nanoparticles to the hydrogel solution at a mass ratio of 0.3:1 at 80° C., and ultrasonically dispersing the solution at 125 W and 40 kHz for 20 min to obtain a photothermal precursor solution.

[0091] (2) The porous hydrophilic substrate layer 1 is first washed three times, and then dried at 60°C for 4 hours. One side of the porous hydrophilic substrate layer 1 after the first drying is then immersed in the photothermal precursor solution of step (1) for 12 minutes. 2.5 mL of glutaraldehyde solution is then injected into the porous hydrophilic substrate layer 1 and thermally cured at 90°C for 3 hours. The porous hydrophilic substrate layer 1 is then washed three times and finally dried at 80°C for 1 hour to obtain the thermal plasmon interface evaporator.

[0092] Example 2

[0093] This embodiment provides a shape-adjustable thermal plasmon interface evaporator, which comprises a porous hydrophilic base layer and a thermal plasmon photothermal layer in sequence; the porous hydrophilic base layer is wood pulp cotton with a porosity of 95%,

[0094] The thermal plasmon photothermal layer includes TiN nanoparticles and a hydrogel that wraps the TiN nanoparticles. The mass ratio of the TiN nanoparticles to the hydrogel is 0.2:1. The average particle size of the TiN nanoparticles is 25 nm. The thickness of the thermal plasmon photothermal layer is 8 μm. The thermal plasmon photothermal layer is connected to the wood pulp cotton via adipaldehyde.

[0095] This embodiment further provides a method for preparing the above-mentioned shape-adjustable thermal plasmon interface evaporator, the method comprising the following steps:

[0096] (1) adding TiN nanoparticles to the hydrogel solution at a mass ratio of 0.2:1 at 60° C., and ultrasonically dispersing the solution at 100 W and 35 kHz for 30 min to obtain a photothermal precursor solution.

[0097] (2) The 3D porous hydrophilic base layer was first washed four times, and then dried for 5 hours at 40°C. One side of the first dried 3D porous hydrophilic base layer was immersed in the photothermal precursor solution of step (1) for 8 minutes. 2.5 mL of adipaldehyde solution was injected into the 3D porous hydrophilic base layer, and thermally cured at 70°C for 5 hours. The 3D porous hydrophilic base layer was then washed for three times and finally dried for 2 hours at 50°C to obtain the thermal plasmon interface evaporator.

[0098] The wood pulp cotton used in this embodiment is the same as the wood pulp cotton described in Example 1.

[0099] Example 3

[0100] This embodiment provides a shape-adjustable thermal plasmon interface evaporator, which comprises a porous hydrophilic base layer and a thermal plasmon photothermal layer in sequence; the porous hydrophilic base layer is wood pulp cotton with a porosity of 95%,

[0101] The thermal plasmon photothermal layer includes TiN nanoparticles and a hydrogel that wraps the TiN nanoparticles. The mass ratio of the TiN nanoparticles to the hydrogel is 0.4:1. The average particle size of the TiN nanoparticles is 18 nm. The thickness of the thermal plasmon photothermal layer is 7 μm. The thermal plasmon photothermal layer is connected to the wood pulp cotton via glutaraldehyde.

[0102] This embodiment further provides a method for preparing the above-mentioned shape-adjustable thermal plasmon interface evaporator, the method comprising the following steps:

[0103] (1) adding TiN nanoparticles to the hydrogel solution at a mass ratio of 0.4:1 at 90° C., and ultrasonically dispersing the solution at 150 W and 45 kHz for 15 min to obtain a photothermal precursor solution.

[0104] (2) The 3D porous hydrophilic base layer was first washed three times, and then dried at 80°C for 1 hour. One side of the first dried 3D porous hydrophilic base layer was then immersed in the photothermal precursor solution of step (1) for 15 minutes. 2.5 mL of glutaraldehyde solution was then injected into the 3D porous hydrophilic base layer, and thermally cured at 120°C for 1 hour. The 3D porous hydrophilic base layer was then washed four times, and finally dried at 90°C for 0.5 hours to obtain the thermal plasmon interface evaporator.

[0105] The wood pulp cotton used in this embodiment is the same as the wood pulp cotton described in Example 1.

[0106] Example 4

[0107] This embodiment provides a shape-adjustable thermal plasmonic interface evaporator. The thermal plasmonic interface evaporator is the same as in Example 1, except that the amount of the TiN nanoparticles is maintained unchanged, the amount of the hydrogel is adjusted so that the mass ratio of the TiN nanoparticles to the hydrogel is 0.5:1, and the mass ratio of the TiN nanoparticles to the hydrogel is adjusted accordingly in the preparation method.

[0108] Example 5

[0109] This embodiment provides a shape-adjustable thermal plasmonic interface evaporator. The thermal plasmonic interface evaporator is the same as that of Example 1, except that the amount of the TiN nanoparticles is maintained unchanged, the amount of the hydrogel is adjusted so that the mass ratio of the TiN nanoparticles to the hydrogel is 0.1:1, and the mass ratio of the TiN nanoparticles to the hydrogel is adjusted accordingly in the preparation method.

[0110] Example 6

[0111] This embodiment provides a method for preparing a shape-adjustable thermal plasmon interface evaporator. The preparation method is the same as that of Example 1, except that the immersion time is 5 minutes.

[0112] Example 7

[0113] This embodiment provides a method for preparing a shape-adjustable thermal plasmon interface evaporator. The preparation method is the same as that of Example 1, except that the immersion time in step (2) is 20 minutes.

[0114] Example 8

[0115] This embodiment provides a method for preparing a shape-adjustable thermal plasmon interface evaporator. The preparation method is the same as that of Example 1, except that the glutaraldehyde solution is injected into the photothermal precursor solution during the immersion process.

[0116] Example 9

[0117] This embodiment provides a method for preparing a shape-adjustable thermal plasmon interface evaporator. The preparation method is the same as that of Example 1, except that the glutaraldehyde solution is not injected in step (2).

[0118] 2. Comparative Example

[0119] Comparative Example 1

[0120] This comparative example provides a method for preparing a shape-adjustable thermal plasmon interface evaporator. The preparation method is the same as Example 1, except that in step (2), no impregnation is performed, but the photothermal precursor solution in step (1) is coated on one side of the porous hydrophilic base layer by a coating method, and the coating thickness is the same as the thickness of the photothermal layer in step (1).

[0121] Comparative Example 2

[0122] This comparative example provides a shape-adjustable thermal plasmon interface evaporator. The thermal plasmon interface evaporator is the same as Example 1 except that the TiN nanoparticles are replaced with carbon black nanoparticles (with an average diameter of 20 nm) and the preparation method is adjusted accordingly.

[0123] 3. Test and its results

[0124] ① The shape-adjustable thermal plasmon interface evaporator provided in Example 1 was subjected to an interface evaporation test. The evaporator was fixed on the water surface of a beaker by polyethylene foam, and the exposed height of the interface evaporator was maintained at 0 cm, 4 cm, 8 cm, and 12 cm respectively. The evaporator was heated under standard sunlight intensity (1000 W / m 2 ) were used to conduct interface evaporation experiments. The results are shown in Table 1 and Figure 5 and Figure 6 As shown;

[0125] Table 1

[0126]

[0127] From Table 1 we can see that:

[0128] The thermal plasmon interface evaporator provided by the present invention is 1000W / m 2Under sunlight intensity, the evaporation rate per unit area increases with increasing exposure height. This means that the geometric parameters of the thermal plasmon interface evaporator are easily adjustable, and its shape is adjustable. The evaporation rate per unit area shows an overall increasing trend within the water capillary transport height, and can operate stably for more than 144 hours.

[0129] like Figure 5 As shown, it is a broadband solar absorption spectrum of the thermal plasmon interface evaporator described in Example 1. It can be seen that its light absorption rate reaches more than 96% in the entire solar spectrum range;

[0130] like Figure 6 As shown in the figure, it can be observed that under the condition of 1000W / m2 light intensity (standard solar light intensity), the evaporation rate and top steady-state temperature (i.e., top average temperature) of the shape-adjustable thermal plasmon interface evaporator show an increasing trend with the increase of the exposure height (i.e., the height above the water surface). When the exposure height increases from 0cm (i.e., 2D interface evaporator) to 12cm, the evaporation rate per unit area increases from about 2.08kg·m -2 h-1 gradually increased to 7.94 kg·m -2 ·h-1, far exceeding the thermal limit (about 1.47kg·m -2 ·h-1), indicating that the evaporation performance of the shape-adjustable thermal plasmonic interface evaporator is significantly better than that of the traditional 2D interface evaporator at a higher exposure height. The top steady-state temperature first increases to a plateau and then rises with the increase of exposure height. It is about 35°C at 0 cm, rises to about 36.5°C at 8 cm, and rises to about 37.5°C at 12 cm, indicating that the water transport-evaporation process is highly regulated, thereby achieving thermal management.

[0131] Further analysis revealed that the evaporation rate of the shape-tunable thermal plasmonic interface evaporator exhibited a steady growth trend at different exposure heights, with a particularly significant increase above 4 cm. This is attributed to its excellent water transport properties and ability to fully utilize ambient energy input. In contrast, the evaporation rate and temperature performance at a height of 0 cm (2D interface evaporator) were weak, highlighting the significant advantages of the shape-tunable structure in terms of photothermal efficiency and evaporation rate.

[0132] Therefore, the shape-adjustable thermal plasmonic interface evaporator provided by the present invention exhibits significantly superior performance in terms of light-to-heat conversion efficiency and evaporation rate, achieving an interface evaporation effect far exceeding the thermal limit. Furthermore, the shape-adjustable thermal plasmonic interface evaporator boasts strong dimensional flexibility, allowing the exposed height to be flexibly adjusted according to actual needs, thereby optimizing performance.

[0133] ② The shape-adjustable thermal plasmon interface evaporators provided in the above embodiments and comparative examples were subjected to interface evaporation tests, and their evaporation rates per unit area and stable working times were calculated. The results are shown in Table 2.

[0134] Test method: The obtained thermal plasmon interface evaporator was fixed on the water surface of a beaker through polyethylene foam, and the exposed height of the interface evaporator was maintained at 12 cm. 2 ) irradiation to carry out interface evaporation experiments.

[0135] Table 2

[0136]

[0137] From the data in Table 2 we can see that:

[0138] (1) From Examples 1 to 3, it can be seen that the shape-adjustable thermal plasmon interface evaporator provided by the present invention has a high thermal conductivity of 1000 W / m 2 Under the conditions of sunlight intensity and exposure height of 12 cm, the evaporation rate per unit area is as high as 7.75 kg·m -2 ·h-1 or more, the preparation method has a simple process flow, the raw materials are cheap and easy to obtain, and the production cost is low. (2) Combining Example 1 with Example 4 and Example 5, it can be seen that the mass ratio of the TiN nanoparticles to the hydrogel in Example 4 is too high, and some TiN nanoparticles are not fully coated and are easy to fall off, resulting in a decrease in the evaporation rate per unit area; the mass ratio of the TiN nanoparticles to the hydrogel in Example 5 is too low, there is too much hydrogel, the evaporation rate decreases, and waste is caused. This shows that the present invention further prefers that the mass ratio of the thermal plasmonic material to the hydrogel in the hydrogel solution is in the range of (0.2 to 0.4):1, which further improves the evaporation efficiency.

[0139] (3) Combining Example 1 with Example 6 and Example 7, it can be seen that the immersion time in Example 6 is too short, resulting in incomplete formation of the photothermal layer and a decrease in the evaporation rate; the immersion time in Example 7 is too long, which in turn reduces the evaporation rate. This shows that the present invention further prefers that the immersion time is 8 to 15 minutes, which can further improve the performance of the thermal plasmon interface evaporator.

[0140] (4) Combining Example 1 with Example 8 and Example 9, it can be seen that the improper injection of the crosslinker in Example 8 caused the crosslinking reaction to occur mainly on the surface of the substrate, resulting in weak bonding strength, a large evaporation rate per unit area, and a significant decrease in the stable working time. In Example 9, no crosslinker was added, and the photothermal layer was not solidified, resulting in an extremely unstable structure, a significant decrease in the evaporation rate and stable working time. This shows that the present invention further improves the bonding strength between the photothermal layer and the substrate through the crosslinker, and further regulates the injection time of the crosslinker, thereby further improving the performance of the resulting interface evaporator.

[0141] (5) Combining Example 1 with Comparative Examples 1 and 2, it can be seen that the insufficient bonding force of the coating method in Comparative Example 1 leads to structural instability and decreased evaporation performance; Comparative Example 2 uses carbon black nanoparticles instead of TiN nanoparticles, resulting in decreased photothermal conversion efficiency and a lower evaporation rate per unit area.

[0142] ③ The Rhodamine B aqueous solution, seawater, hydrochloric acid aqueous solution and sodium hydroxide aqueous solution were treated respectively using the thermal plasmon interface evaporator described in Example 1. The treatment results are as follows: Figures 7 to 9 As shown;

[0143] like Figure 7 As shown, it can be seen that after the Rhodamine B aqueous solution is subjected to interfacial evaporation using the thermal plasmon interface evaporator described in Example 1, the absorption intensity in the 400-700 nm band decreases significantly, indicating that the dye is effectively removed in the 400-700 nm band;

[0144] like Figure 8 As shown in the figure, it can be seen that after the thermal plasmon interface evaporator described in Example 1 is used to evaporate the real seawater (Qingdao Huangdao), the Na + , K + Mg 2+ and Ca 2+ The concentration of chlorinated parasites decreased significantly and met both WHO and EPA standards;

[0145] like Figure 9 As shown in the figure, a and b are the color changes of the pH test paper before and after the treatment of a 1 mol / L hydrochloric acid aqueous solution by the shape-adjustable thermal plasmon interface evaporator described in Example 1. Compared with the pH standard card (e in the figure), it can be seen that the pH of the hydrochloric acid solution is significantly increased and the acidity is reduced; c and d in the figure are the color changes of the pH test paper before and after the treatment of a 1 mol / L sodium hydroxide solution by the thermal plasmon interface evaporator described in Example 1. Compared with the pH standard card (e in the figure), it can be seen that the pH of the sodium hydroxide solution is significantly reduced and the alkalinity is reduced;

[0146] This shows that the shape-adjustable thermal plasmon interface evaporator of the present invention is suitable for applications such as dye removal, seawater desalination, and reducing solution pH, and has excellent treatment effects.

[0147] In summary, the shape-adjustable thermal plasmon interface evaporator provided by the present invention has a stable and controllable structure, strong scalability, and excellent evaporation performance, which meets the needs of different application scenarios and provides reliable guarantees for the large-scale application of solar interface evaporation technology in fields such as seawater desalination or sewage purification.

[0148] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A shape-adjustable thermal plasmon interface evaporator, characterized in that: The thermal plasmon interface evaporator comprises a porous hydrophilic base layer and a thermal plasmon photothermal layer in sequence; The thermal plasmon photothermal layer includes a thermal plasmon material and a hydrogel encapsulating the thermal plasmon material.

2. The thermal plasmon interface evaporator according to claim 1, characterized in that: The porous hydrophilic base layer comprises any one of wood pulp cotton, carbon foam material or hierarchical pore hydrogel, preferably wood pulp cotton; Preferably, the porosity of the porous hydrophilic base layer is 90-98%.

3. The thermal plasmon interface evaporator according to claim 1 or 2, characterized in that: The mass ratio of the thermoplasmonic material to the hydrogel in the thermoplasmonic photothermal layer is (0.2-0.4):1; Preferably, the particle size distribution of the thermal plasmon material is 10 to 100 nm; Preferably, the thermal plasmonic material comprises any one or a combination of at least two of transition metal nitrides, non-noble metals, heavily doped semiconductor materials or MXene materials; Preferably, the transition metal nitride comprises TiN and / or ZrN; Preferably, the non-noble metal comprises Cu and / or Al; Preferably, the heavily doped semiconductor material comprises Cu2S; Preferably, the MXene material comprises Ti3C2.

4. The thermal plasmon interface evaporator according to any one of claims 1 to 3, characterized in that: The thermal plasmon photothermal layer and the porous hydrophilic base layer are connected via a cross-linking agent.

5. A method for preparing a shape-adjustable thermal plasmon interface evaporator according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: (1) mixing the thermal plasmonic material and the hydrogel solution and performing ultrasonic dispersion to obtain a photothermal precursor solution, (2) Immersing one side of the porous hydrophilic base layer in the photothermal precursor solution of step (1), and then thermally curing to obtain the thermal plasmon interface evaporator.

6. The preparation method according to claim 5, characterized in that The mass ratio of the thermal plasmon material in step (1) to the hydrogel in the hydrogel solution is (0.2-0.4):1; Preferably, the mixing temperature in step (1) is 60-90°C; Preferably, the ultrasonic dispersion time in step (1) is 15 to 30 minutes; Preferably, the ultrasonic power of the ultrasonic dispersion in step (1) is 100 to 250 W; Preferably, the ultrasonic frequency of the ultrasonic dispersion in step (1) is 35 to 45 kHz.

7. The preparation method according to claim 5 or 6, characterized in that: Prior to the impregnation in step (2), the porous hydrophilic substrate is first subjected to a first washing and a first drying in sequence; Preferably, the number of the first washing is ≥3 times; Preferably, the first drying temperature is 40-80°C; Preferably, the first drying time is 2 to 5 hours.

8. The preparation method according to any one of claims 5 to 7, characterized in that The soaking time in step (2) is 8 to 15 minutes; Preferably, after the impregnation in step (2), the step further includes injecting a crosslinking agent into the porous hydrophilic base layer; Preferably, the cross-linking agent comprises any one of glutaraldehyde, adipaldehyde or succinaldehyde, or a combination of at least two thereof; Preferably, the temperature of the thermal curing in step (2) is 70-130°C; Preferably, the thermal curing time in step (2) is 2 to 5 hours.

9. The preparation method according to any one of claims 5 to 8, characterized in that: After the thermal curing in step (2), the thermal plasmon interface evaporator is subjected to a second washing and a second drying in sequence; Preferably, the number of the second washing is ≥2 times; Preferably, the second drying temperature is 50-90°C; Preferably, the second drying time is 0.5 to 2 hours.

10. An application of the shape-adjustable thermal plasmon interface evaporator according to any one of claims 1 to 4, characterized in that: The shape-adjustable thermal plasmon interface evaporator is used in the fields of seawater desalination or sewage purification.

Images