A super-wettable CuS@SiO2 photothermal composite material and its preparation method and application

Abstract

The present invention discloses a super-wettable CuS@SiO2 photothermal composite material, the preparation method of which comprises the following steps: sequentially adding an alkaline solution and a hydrolyzable silicon source to a CuS nanosheet dispersion for a stirring reaction to obtain a super-hydrophilic CuS@SiO2 photothermal composite material; then adding a silane-based low-surface-energy substance for a surface modification reaction to obtain a super-hydrophobic CuS@SiO2 photothermal composite material. The CuS@SiO2 photothermal composite material obtained by the present invention has good super-wettability, near-infrared plasma resonance performance, and photothermal conversion effect; a super-hydrophobic CuS@SiO2 photothermal coating prepared using the super-hydrophobic CuS@SiO2 photothermal composite material can be applied to fields such as photothermal anti-icing; a super-wettable Janus structure water evaporator prepared using the super-hydrophilic and super-hydrophobic CuS@SiO2 photothermal composite material has good solar-driven synchronous photocatalytic purification and photothermal water evaporation performance, and is suitable for promotion and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional materials, and in particular relates to a super-wettable CuS@SiO2 photothermal composite material and a preparation method and application thereof. Background Art

[0002] Traditional desalination technologies, such as reverse osmosis, multi-stage flash evaporation, multi-effect distillation, and electrodialysis, consume large amounts of fossil energy, increase operating costs, and cause environmental pollution. Solar-driven interfacial photothermal evaporation (SDIE), a novel desalination process, converts sunlight into heat through photothermal conversion materials. This allows for rapid localized heat localization at the air-water interface, significantly improving energy efficiency during the gas-liquid conversion process. It holds great promise for application in solar-driven water treatment.

[0003] On the other hand, as an inevitable natural phenomenon, ice accumulation has caused widespread damage to agriculture, animal husbandry, aviation, electrified railway systems and other fields. Traditional deicing technologies include thermal ice melting, mechanical deicing, liquid deicing and other methods, which have disadvantages such as high power consumption, low deicing efficiency, low safety, and environmental pollution. The construction of superhydrophobic surfaces can overcome the shortcomings of the above-mentioned traditional methods and is considered to be one of the most promising anti-icing technologies. In recent years, the combination of photothermal materials and superhydrophobic materials to manufacture photothermal superhydrophobic surfaces for application in the field of anti-icing has received widespread attention; however, most of the existing methods have disadvantages such as expensive raw materials, complex equipment, and poor wear resistance, weather resistance and aging resistance of the products. Therefore, the further development of superhydrophobic photothermal composite anti-icing materials with simple preparation process, low cost and excellent comprehensive performance is a current research hotspot.

[0004] CuS, a novel plasmon resonance nanomaterial, possesses a strong near-infrared plasmon resonance effect and a wide absorption band. It offers high photothermal conversion efficiency and long-term durability. It also boasts advantages such as low cost, low toxicity, high purity, good biocompatibility, and superior photostability, making it a promising photothermal conversion material. However, CuS is poorly soluble in most solvents. In the field of photothermal water evaporation, if CuS particles are directly used for desalination or wastewater treatment, they cannot effectively remain at the air-seawater interface for the normal gas-liquid conversion process, making efficient photothermal conversion difficult. Furthermore, the material cannot be recycled during or after use, causing environmental pollution. Furthermore, in the field of photothermal deicing, CuS particles, as metal sulfides, are difficult to directly modify with low-energy materials to achieve superhydrophobic properties. Summary of the Invention

[0005] The main purpose of the present invention is to address the deficiencies in the existing technology and provide a simple, easy-to-use and scalable super-wettable CuS@SiO2 photothermal composite material. First, CuS nanoparticles with good localized surface plasmon resonance performance are prepared, and then SiO2 is coated on the surface of the CuS nanoparticles, and silane-based low-surface-energy substances are further introduced to modify the surface. The obtained CuS@SiO2 photothermal composite material has good super-wettability, near-infrared plasma resonance performance and photothermal conversion effect. The prepared super-hydrophobic CuS@SiO2 photothermal coating can be applied to the field of photothermal anti-icing and de-icing. The prepared super-wettable Janus structure water evaporator has good solar-driven synchronous photocatalytic purification and photothermal water evaporation performance, and has great potential application value in the fields of sewage treatment and seawater desalination.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for preparing a super-wettable CuS@SiO2 photothermal composite material comprises the following steps:

[0008] (1) Sulfur powder, octadecene (ODE), and oleylamine (OM) are sequentially added to a reaction vessel, and a first heating reaction is performed under vacuum conditions to obtain an orange-red transparent S precursor solution;

[0009] (2) A protective atmosphere (such as Ar gas) is introduced to cool the S precursor solution to room temperature, and then copper salt is added. A second heating reaction is carried out under vacuum conditions, and then a protective atmosphere (such as Ar gas) is introduced to cool the solution to room temperature to obtain a black-green CuS dispersion.

[0010] (3) The CuS dispersion obtained in step (2) is centrifuged using alcohol solvent I as a detergent to obtain a CuS nanocrystal precipitate; toluene is then added to uniformly disperse the precipitate to obtain a CuS-toluene dispersion;

[0011] (4) adding the CuS-toluene dispersion obtained in step (3) to the alcohol solvent II under magnetic stirring conditions, stirring to uniformly disperse the dispersion and volatilize the toluene;

[0012] (5) adding an alkali solution and a hydrolyzable silicon source to the dispersion obtained in step (4) in sequence, and continuing the stirring reaction to obtain a super-hydrophilic CuS@SiO2 photothermal composite material;

[0013] (6) Adding a silane-based low surface energy material to the reaction system obtained in step (5), continuing the stirring reaction, and obtaining a super-hydrophobic CuS@SiO2 photothermal composite material.

[0014] In the above scheme, the superwetting is superhydrophilic and / or superhydrophobic, and the superhydrophilic CuS@SiO2 photothermal composite material and the superhydrophobic CuS@SiO2 photothermal composite material obtained in steps (5) and (6) respectively are both superwetting CuS@SiO2 photothermal composite materials, mainly composed of nano CuS@SiO2 particles and nano SiO2 particles.

[0015] In the above scheme, the copper salt can be selected from one or more of copper acetate monohydrate, copper nitrate dihydrate, etc.

[0016] In the above solution, the CuS nanocrystal precipitate has a nano-sheet structure, and the sheet diameter is 10 to 30 nm.

[0017] In the above scheme, the hydrolyzable silicon source can be selected from one or more of tetraethyl orthosilicate, tetrabutyl orthosilicate, etc.

[0018] In the above solution, the silane-based low surface energy material can be selected from one or more of hexamethyldisilazane (HMDS), methyltriethoxysilane (MTES), hexadecyltrimethoxysilane (HDTMS), etc.

[0019] In the above scheme, the solution system obtained in step (5) is directly sprayed on the surface of the substrate and dried to obtain a super-hydrophilic CuS@SiO2 composite coating.

[0020] In the above scheme, the solution system obtained in step (6) is directly sprayed on the surface of the substrate and dried to obtain a super-hydrophobic CuS@SiO2 composite coating.

[0021] In the above scheme, the heating rates of steps (1) to (2) are both 8 to 10°C / min.

[0022] In the above scheme, the temperature of the first heating reaction in step (1) is 90-100° C. and the time is 20-40 minutes.

[0023] In the above scheme, the temperature used for the second heating reaction in step (2) is 150-220° C. and the time is 20-40 minutes.

[0024] In the above scheme, the temperature used in steps (3) to (6) is room temperature.

[0025] In the above scheme, in step (3), the rotation speed used for centrifugal separation is 3500-4500 rpm and the centrifugation time is 4-6 minutes.

[0026] In the above scheme, the alcohol solvent I in step (3) is one of methanol, ethanol, and ethanol / acetone mixed solvent.

[0027] In the above scheme, the alcohol solvent II in step (4) is one of methanol, ethanol, isopropanol, etc.

[0028] In the above scheme, the alkali solution in step (5) is a NaOH aqueous solution or ammonia water, wherein the NaOH concentration is 1-1.8 mol / L and the ammonia water concentration is 25-29 wt%.

[0029] In the above scheme, the molar ratio of sulfur powder and copper salt in steps (1) to (2) is 2:1.

[0030] In the above scheme, the volume ratio of octadecene and oleylamine in steps (1) to (2) is 4:(1 to 4).

[0031] In the above scheme, the concentration of CuS in the CuS-toluene dispersion is (0.10-0.15) g / mL.

[0032] In the above scheme, the volume ratio of the CuS-toluene dispersion, alcohol solvent II, alkali solution, hydrolyzable silicon source, and silane low surface energy substance in steps (4) to (6) is (1 to 5): (5 to 7): (0.2 to 0.4): (1 to 1.4): (0.6 to 1).

[0033] In the above scheme, the stirring treatment time of step (4) is 0.5 to 1 hour.

[0034] In the above scheme, the stirring reaction time of step (5) is 20 to 24 hours.

[0035] In the above scheme, the stirring reaction time of step (6) is 6 to 12 hours.

[0036] The present invention also provides a CuS@SiO2 photothermal water evaporator with a super-hydrophobic / super-hydrophilic Janus structure prepared using the above-mentioned super-wettable CuS@SiO2 photothermal composite material, and the specific preparation steps include:

[0037] The super-hydrophobic aqueous solution system obtained in step (5) is sprayed on the upper surface of the foam substrate, and the super-hydrophilic aqueous solution system obtained in step (6) is immersed in the lower surface of the foam substrate. After drying, a CuS@SiO2 photothermal water evaporator with a super-hydrophobic / super-hydrophilic Janus structure is obtained.

[0038] The present invention also provides a photothermal composite anti-icing coating prepared using the above-mentioned super-wettable CuS@SiO2 photothermal composite material, and the specific preparation steps include:

[0039] 1) Under stirring conditions, hydroxy acrylic resin, fluorocarbon resin, alkyd resin, polypropylene resin, silane coupling agent, and filler are added to an organic solvent (such as butyl acetate) in sequence, and stirred for 12 to 24 hours to obtain a resin primer;

[0040] 2) On the surface of the glass substrate, the resin primer obtained in step 1) is first sprayed as a binder to improve the wear resistance and weather resistance of the coating. Then, when the primer reaches surface dryness, the super-hydrophobic CuS@SiO2 photothermal composite coating is sprayed and dried to obtain a super-hydrophobic CuS@SiO2 photothermal anti-icing coating.

[0041] In the above scheme, the mass ratio of the hydroxy acrylic resin, fluorocarbon resin, alkyd resin and polypropylene resin is (80-90): (15-20): (40-45): (10-15).

[0042] In the above solution, the mass ratio of the hydroxy acrylic resin to the organic solvent is 90:(250-300).

[0043] In the above solution, the volume ratio of the silane coupling agent to the organic solvent is (0.5-2):100.

[0044] In the above scheme, the mass ratio of the filler to the resin introduced into the resin primer (the sum of acrylic resin, fluorocarbon resin, alkyd resin and polypropylene resin) is (10-15): (155-170).

[0045] The super-wettable CuS@SiO2 photothermal composite material prepared according to the above scheme exhibits excellent super-wetting properties, near-infrared plasma resonance, high photothermal conversion efficiency, and long-term durability. The super-hydrophobic CuS@SiO2 photothermal composite coating is used in combination with a resin primer to construct a photothermal composite anti-icing coating on a substrate. This anti-icing coating not only exhibits wear resistance, weather resistance, and long-term stable photothermal performance, but also possesses certain anti-fouling, self-cleaning, and anti-corrosion functions, making it suitable for photothermal anti-icing applications.

[0046] On the other hand, since the super-wettable CuS@SiO2 photothermal composite coating (super-hydrophobic and super-hydrophilic coatings) has excellent super-wetting properties, high photothermal conversion efficiency and photocatalytic degradation properties, it can be combined with a porous substrate to prepare a CuS@SiO2 photothermal water evaporator with a super-hydrophobic / super-hydrophilic Janus structure, which has excellent simultaneous photocatalytic purification and photothermal water evaporation performance, and takes into account outstanding self-floating, self-cleaning and vapor diffusion functions, and is suitable for seawater desalination and dye wastewater treatment.

[0047] The principle of the present invention is:

[0048] First, CuS nanoparticles with good localized surface plasmon resonance properties were prepared. Then, they were added to an alkaline solution of a hydrolyzable silicon source and stirred to react. SiO2 was coated on the surface of the CuS nanoparticles. The resulting composite material was further surface-modified with a silane-based low-surface-energy substance to regulate its wetting properties, thereby obtaining superhydrophilic and superhydrophobic CuS@SiO2 photothermal composite materials, respectively.

[0049] The present invention combines a super-hydrophobic CuS@SiO2 photothermal composite coating with a resin primer to construct a photothermal composite anti-icing coating on a substrate. The coating has a micro-nano hierarchical structure: the super-hydrophobic CuS@SiO2 coating is deposited on the surface of the resin primer described in the present invention, so that micron-scale papillary composite deposits further grow on the surface of the resulting anti-icing coating. The particle size of the micron-scale papillary composite deposits is concentrated between 70 and 100 μm and is mainly composed of nano-scale CuS@SiO2 composite nanoparticles and SiO2 nanoparticles. The present invention combines the surface modification of low-surface-energy materials with the construction of micro-nano structures. The low-surface-energy micro-nano rough structure constructed gives the CuS@SiO2 anti-icing coating excellent super-hydrophobicity and wear and weather resistance. It also promotes the stable embedding of copper sulfide photothermal nanoparticles on the substrate, further ensuring the long-term stability of the photothermal performance of the resulting composite coating. In addition, the excellent super-hydrophobicity enables the anti-icing coating to also have certain anti-fouling, self-cleaning, and anti-corrosion functions.

[0050] The present invention combines the obtained super-hydrophilic and super-hydrophobic CuS@SiO2 photothermal composite material with a porous substrate to prepare a CuS@SiO2 photothermal water evaporator with a super-hydrophobic / super-hydrophilic Janus structure. On the one hand, the excellent super-hydrophobicity of the upper layer of the evaporator gives the evaporator excellent self-floating properties, avoiding the problems of the traditional evaporator that the hydrophobic agent easily falls off or oxidatively decomposes under strong light and loses its floatability by introducing a hydrophobic agent and an external support to make the evaporator floatable, and the addition of a supporting substrate is not conducive to the conduction of salt and the transport of water. On the other hand, the excellent super-hydrophilicity of the lower layer of the evaporator ensures an adequate water supply, and seawater can be continuously sucked from the lower layer to the liquid surface for a vapor-liquid exchange process. In addition, the evaporator of the present invention has a self-cleaning property. It can use the non-irradiation time to eliminate the crystallized salt on the surface and inside of the evaporator without affecting the normal use during the irradiation period, greatly improving the energy utilization efficiency of the evaporator for solar energy.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1) To address the limitations of CuS in applications such as photocatalysis and photothermal deicing, the present invention proposes, for the first time, to first coat its surface with SiO2 and then modify it with a low-surface-energy material to ultimately obtain superhydrophilic and superhydrophobic CuS@SiO2 photothermal composite materials, respectively. This approach can effectively address the application limitations of CuS in various fields such as photocatalysis and photothermal deicing.

[0053] 2) The CuS@SiO2 photothermal composite material of the present invention has high near-infrared photothermal conversion efficiency, high chemical stability, low cost, simple preparation method, and can be prepared in large quantities, and has great application prospects;

[0054] 3) The super-hydrophobic CuS@SiO2 photothermal composite coating prepared by the present invention can achieve the synergistic effect of active deicing and passive anti-icing in the field of photothermal anti-icing / deicing, and has good wear resistance and weather resistance; the prepared super-hydrophobic / super-hydrophilic Janus structure CuS@SiO2 photothermal water evaporator has low cost and can simultaneously and efficiently achieve the two functions of photothermal evaporation of water and photocatalytic degradation of dye solution, and can be applied to fields such as seawater desalination and wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a morphology photograph of the super-hydrophobic CuS@SiO2 photothermal composite coating obtained in Example 1.

[0056] Figure 2 This is a contact angle photograph of the super-hydrophobic CuS@SiO2 photothermal composite coating obtained in Example 1.

[0057] Figure 3 This is the TEM characterization image of the super-hydrophobic CuS@SiO2 photothermal composite material obtained in Example 1.

[0058] Figure 4 This is the absorption curve of the super-hydrophobic CuS@SiO2 photothermal composite material obtained in Example 1.

[0059] Figure 5 This is the XRD curve of the super-hydrophobic CuS@SiO2 photothermal composite material obtained in Example 1.

[0060] Figure 6 This is the FTIR curve of the super-wettable CuS@SiO2 photothermal composite material obtained in Example 1.

[0061] Figure 7 The super-hydrophobic CuS@SiO2 photothermal composite coating obtained in Example 1 was 2 Below is a graph showing the surface temperature changing with time.

[0062] Figure 8 This is a morphology photograph of the Janus-structured CuS@SiO2 photothermal water evaporator prepared in Example 3.

[0063] Figure 9 This is a contact angle photograph of the Janus-structured CuS@SiO2 photothermal water evaporator prepared in Example 3.

[0064] Figure 10 These are the morphology images of the CuS@SiO2 photothermal composite anti-icing coating sample and the superhydrophobic SiO2 coating sample described in Application Example 1.

[0065] Figure 11 This is the SEM photo of the CuS@SiO2 photothermal composite anti-icing coating sample described in Application Example 1.

[0066] Figure 12 The CuS@SiO2 photothermal composite anti-icing coating sample and the ordinary super-hydrophobic SiO2 coating sample described in Application Example 1 were tested under a light intensity of 0.5kW / m 2 , comparison chart of delayed freezing time at different temperatures.

[0067] Figure 13 This is a comparison chart of the delayed freezing time of the CuS@SiO2 photothermal composite anti-icing coating sample described in Application Example 1 and the ordinary superhydrophobic SiO2 coating sample at -20°C and different light intensities.

[0068] Figure 14 The CuS@SiO2 photothermal composite anti-icing coating sample and the ordinary super-hydrophobic SiO2 coating sample described in Application Example 1 were tested at -15℃ and 1kW / m 2 Comparison of morphologies of ice melting process under different light intensities.

[0069] Figure 15 This is the surface morphology and contact angle comparison diagram of the CuS@SiO2 photothermal composite anti-icing coating sample before and after the wear resistance experiment described in Application Example 1.

[0070] Figure 16 This is a before-and-after comparison of the degradation of sodium chloride-methylene blue dye solution by the Janus structure CuS@SiO2 water evaporator described in Application Example 2.

[0071] Figure 17 This is a comparison chart of the mass loss of seawater simulated by the Janus structure CuS@SiO2 water evaporator described in Application Example 2 and melamine foam (MF).

[0072] Figure 18 This is a comparison chart of the absorbance changes of the dye solution caused by the Janus structure CuS@SiO2 water evaporator and MF described in Application Example 2 within two hours. DETAILED DESCRIPTION

[0073] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. These descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0074] Example 1

[0075] A super-hydrophobic CuS@SiO2 photothermal composite material and coating, the preparation method of which comprises the following steps:

[0076] 1) Weigh 0.256 g of sulfur powder (8 mmol) into a 50 mL three-necked flask, then add 40 mL of octadecene (ODE) and 10 mL of oleylamine (OM). Under vacuum conditions, heat the flask to 90°C at a rate of 10°C / min and maintain at this temperature for 30 min to obtain an orange-red transparent sulfur precursor solution.

[0077] 2) Ar gas was introduced and the obtained S precursor solution was cooled to room temperature. Then, 0.799 g of copper acetate monohydrate Cu(Ac)2·H2O (4 mmol) was added and the mixture was evacuated at room temperature for 30 min. The mixture was then heated to 200°C at a rate of 10°C / min and kept at this temperature for 30 min to obtain a black-green dispersion. The mixture was further cooled to room temperature under an Ar atmosphere to obtain a CuS black-green dispersion (concentration of 0.008 M).

[0078] 3) washing the CuS dispersion obtained in step 2) twice by centrifugation (4000 rpm, 5 min) using methanol as a detergent to separate the nanocrystal precipitate, and then adding toluene to uniformly disperse the precipitate to obtain a CuS-toluene dispersion, wherein the solid-to-liquid ratio of the CuS nanocrystal precipitate to toluene is 0.13 g / mL;

[0079] 4) Under magnetic stirring, slowly pour 6 mL of the CuS-toluene dispersion obtained in step 3) into 25 mL of ethanol and stir for 30 minutes to evenly disperse and evaporate the toluene.

[0080] 5) To the mixed solution obtained in step 4), 1.5 mL of NaOH solution (1.8 mol / L) and 5 mL of ethyl orthosilicate were added in sequence and stirred for 24 h;

[0081] 6) Add 5.0 mL of hexamethyldisilazane (HMDS) to the solution system in step 5) and continue stirring for 12 h to obtain a super-hydrophobic CuS@SiO2 photothermal composite coating;

[0082] 7) Spraying the coating obtained in step 6) on the surface of the substrate and drying it to obtain a super-hydrophobic CuS@SiO2 photothermal composite coating.

[0083] Figure 1 、 2The morphology photos and contact angle photos of the coating sample obtained in this example are respectively. The results show that the methylene blue droplets can "stand" well on the coating surface, and the measured water contact angle is 156°. The obtained coating sample exhibits good superhydrophobic properties.

[0084] Figure 3 The following are transmission electron microscopy (TEM) images of the coating solution (product obtained in step 6) obtained in this example. A hydrolyzable silicon source was in situ hydrolyzed in the presence of flaky CuS nanocrystals and an alkaline solution, and then modified with a low-surface-energy substance to produce a super-hydrophobic CuS@SiO2 nanocomposite (as shown in Figures a and b). The prepared CuS@SiO2 nanocomposite is composed of amorphous SiO2 and CuS phases, including CuS@SiO2 nanoparticles and SiO2 nanoparticles. The typical micromorphology of the CuS@SiO2 nanoparticles is characterized by in-situ growth of amorphous, low-surface-energy SiO2 encapsulating the flaky CuS phase to form a core-shell structure (as shown in Figures c and d).

[0085] Figure 4 This is the UV-visible absorption spectrum of the coating solution obtained in this example. The sample has a strong absorption peak in the near-infrared (its peak position is between 1200 and 1400 nm), which indicates that the synthesized photothermal composite coating has strong near-infrared localized surface plasmon resonance performance.

[0086] Figure 5 The XRD pattern of the coating obtained in this example shows that the diffraction peak of CuS contained in the coating is consistent with the result of the copper blue (CuS) spectrum (JCPDS 00-06-0464). Therefore, it can be seen that the nanocrystalline component coated with SiO2 in the composite coating prepared by the present invention is CuS.

[0087] Figure 6 The FTIR spectrum of the super hydrophobic CuS@SiO2 coating is at 845, 1254, 2852 and 2961 cm -1 Absorption peaks appeared at 845 and 1254 cm -1 The absorption bands at 2961cm correspond to the stretching vibration of Si-CH3, -1 Corresponding to the stretching vibration of -CH3 group, located at 2852cm -1 The peak at 960 cm is the symmetrical stretching vibration of the CH chain, indicating that the hydrophilic group Si-OH on the surface of SiO2 in the coating obtained in this example is replaced by the hydrophobic group Si-CH3. -1 The peak at is the bending vibration peak of Si-OH bond. The Si-OH peak indicates that the super-hydrophilic CuS@SiO2 sample has a hydroxyl-terminated surface and good super-hydrophilicity.

[0088] Figure 7 The model is CEL-S500-T5, and the light intensity is 1kW / m 2 A xenon lamp (1 sun) was used to irradiate the composite coating prepared in this example and the uncoated glass substrate at the same time, and a thermocouple was used to record the temperature change in real time to test the light-to-heat conversion performance. Figure 6 As can be seen, under 1 sun illumination, the temperature of the CuS@SiO2 composite coating increased from 21°C to 75°C in 250 seconds, an increase of 54°C; while the temperature of the glass substrate only increased to 36°C, an increase of only 15°C. This shows that the CuS@SiO2 coating prepared by the present invention has a good light-to-heat conversion effect.

[0089] Example 2

[0090] A super-hydrophobic CuS@SiO2 photothermal composite material and coating, the preparation method of which comprises the following steps:

[0091] 1) Weigh 0.256 g of sulfur powder (8 mmol) into a 50 mL three-necked flask, then add 40 mL of octadecene (ODE) and 10 mL of oleylamine (OM). Under vacuum conditions, heat the flask to 90°C at a rate of 10°C / min and maintain at this temperature for 30 min to obtain an orange-red transparent sulfur precursor solution.

[0092] 2) Ar gas was introduced and the obtained S precursor solution was cooled to room temperature. Then, 0.799 g of copper acetate monohydrate Cu(Ac)2·H2O (4 mmol) was added and the mixture was evacuated at room temperature for 30 min. The mixture was then heated to 200°C at a rate of 10°C / min and kept at this temperature for 30 min to obtain a black-green dispersion. The mixture was further cooled to room temperature under an Ar atmosphere to obtain a CuS black-green dispersion (concentration of 0.008 M).

[0093] 3) washing the CuS dispersion obtained in step 2) twice by centrifugation (4000 rpm, 5 min) using methanol as a detergent to separate the nanocrystal precipitate, and then adding toluene to uniformly disperse the precipitate to obtain a CuS-toluene dispersion, wherein the solid-to-liquid ratio of the CuS nanocrystal precipitate to toluene is 0.13 g / mL;

[0094] 4) Under magnetic stirring, slowly pour 6 mL of the CuS-toluene dispersion obtained in step 3) into 25 mL of ethanol and stir for 30 minutes to evenly disperse and evaporate the toluene.

[0095] 5) To the mixed solution obtained in step 4), 2 mL of aqueous ammonia solution (26 wt%) and 4 mL of butyl orthosilicate were added in sequence and stirred for 24 h;

[0096] 6) Add 1 mL of hexadecyltrimethoxysilane (HDTMS) to the solution system in step 5) and continue stirring for 12 h to obtain a super-hydrophobic CuS@SiO2 photothermal composite coating;

[0097] 7) Spraying the coating obtained in step 6) on the surface of the substrate and drying it to obtain a super-hydrophobic CuS@SiO2 photothermal composite coating.

[0098] Example 3

[0099] A CuS@SiO2 photothermal water evaporator with a super-hydrophobic / super-hydrophilic Janus structure, the preparation method of which comprises:

[0100] 1) Prepare a super-hydrophobic CuS@SiO2 photothermal composite material by referring to steps 1) to 6) of Example 1;

[0101] 2) Prepare a super-hydrophilic CuS@SiO2 photothermal composite material by referring to steps 1) to 5) of Example 1;

[0102] 3) Prepare melamine foam (hereinafter referred to as MF) and cut it into squares (area 2.5×2.5cm 2 , with a thickness of 0.5 cm), and 1 mL of the superhydrophobic CuS@SiO2 photothermal composite material was sprayed on the upper surface of the MF, and 2.5 mL of the superhydrophilic CuS@SiO2 material was taken and the lower surface of the MF was immersed in it to allow it to be fully absorbed, and then dried to obtain the superhydrophobic / superhydrophilic Janus structure CuS@SiO2 photothermal water evaporator.

[0103] The morphology photos and upper surface contact angle photos of the obtained CuS@SiO2 photothermal water evaporator are shown in the figure. Figure 8 、 9 As shown in the figure, the methylene blue droplets can stand well on the upper surface of the water evaporator, and the water contact angle of the upper surface is measured to be 155°. The obtained coating sample exhibits good superhydrophobic properties.

[0104] Application Example 1

[0105] According to the preparation method described in Example 1, a super-hydrophobic CuS@SiO2 composite photothermal coating was prepared and applied to the anti-icing field. The solution system obtained in step 6) of Example 1 was combined with a resin primer. The primer was first sprayed and then the super-hydrophobic CuS@SiO2 composite material was sprayed. A photothermal composite anti-icing coating was constructed on the surface of a glass substrate. The coating was compared with a glass sheet coating sample coated only with a super-hydrophobic SiO2 coating to explore the deicing effect of the obtained CuS@SiO2 photothermal composite anti-icing coating. The specific steps include:

[0106] (1) Under magnetic stirring conditions, 9 g of hydroxy acrylic resin FX-9024, 1.5 g of fluorocarbon resin, 4 g of alkyd resin, 1.2 g of PP polypropylene resin, 0.3 mL of KH550 solution (KH550: H2O = 0.12 mL: 0.18 mL), and 2 g of nylon powder were added to 30 mL of butyl acetate in sequence and stirred for 24 h to obtain a resin primer;

[0107] (2) On the surface of the glass substrate, first spray the resin primer obtained in step 1), then spray the super-hydrophobic CuS@SiO2 photothermal composite coating described in Example 1, and dry it to obtain a super-hydrophobic CuS@SiO2 photothermal anti-icing coating.

[0108] The specific test steps are as follows:

[0109] a) Comparison of the delayed freezing time of the CuS@SiO2 photothermal composite anti-icing coating and the superhydrophobic SiO2 coating under the same light intensity and different temperatures: The two glass slides were placed on a condensation table at the same ambient temperature. When the surface temperature of the glass slide stabilized to the same temperature as the ambient temperature, equal amounts of methylene blue dye droplets were added. The xenon lamp was then turned on to irradiate the coating surface and the time was measured to record the time it took for the droplets to completely freeze.

[0110] b) Comparison of the delayed freezing time of CuS@SiO2 photothermal composite anti-icing coating and superhydrophobic SiO2 coating at the same temperature and different light intensities, using the same method as above.

[0111] c) Comparison of the ice melting effects of the two coatings under the same lighting conditions: Using a cylindrical mold, add equal amounts of water to the surfaces of the two glass sheets, place them on a condensation table, and freeze for 6 hours. Ensure that icicles of the same shape and volume adhere to the two glass sheets. Ensure that the glass sheets are tilted at a 30° angle to the condensation table. When the surface temperatures of the two glass sheets stabilize to the same temperature as the ambient temperature, turn on the xenon lamp and increase the intensity to 1kW / m 2 Then start irradiation and timing, and record the time it takes for the icicle to slide.

[0112] d) Test of the wear resistance of CuS@SiO2 photothermal composite anti-icing coating: A 10 cm × 10 cm × 0.5 mm anti-icing coating glass slide was placed under a load of 1000 g at a constant slow speed (about 1 cm s -1 ) was moved across sandpaper (800 grit) in 10-cm cycles, with 20 cm being considered one abrasion cycle. After 500 abrasion cycles, the contact angle of the sample was measured.

[0113] Figure 10 These are the morphology pictures of the obtained CuS@SiO2 photothermal composite anti-icing coating samples and superhydrophobic SiO2 coatings; the area of ​​the glass sheets is 10×5 cm.

[0114] Figure 11This is a scanning electron microscope (SEM) image of the anti-icing coating sample obtained in this application example, representing that the coating has a micro-nano hierarchical structure: the super-hydrophobic CuS@SiO2 coating obtained by the present invention is deposited on the surface of the resin primer, and the surface of the super-hydrophobic coating obtained shows micron-scale papillary composite deposits, and the particle size of the micron-scale papillary composite deposits is approximately between 70 and 100 μm (as shown in Figures a and b), mainly composed of CuS@SiO2 composite nanoparticles and nano-scale SiO2 particles. The present invention combines the surface modification of low surface energy materials with micro-nanostructures and other means to construct a micro-nano rough structure that gives the CuS@SiO2 anti-icing coating excellent super-hydrophobicity and wear and weather resistance.

[0115] Figure 12 The CuS@SiO2 photothermal composite anti-icing coating sample and the ordinary super-hydrophobic SiO2 coating sample were compared at 0.5kW / m 2 Comparison of delayed freezing times at different temperatures. As the ambient temperature decreases, the difference in delayed freezing time between the superhydrophobic CuS@SiO2 coating sample and the conventional superhydrophobic SiO2 coating sample widens. For example, at -20°C, the CuS@SiO2 coating sample's delayed freezing time is 1.96 times that of the conventional superhydrophobic SiO2 coating sample. When the temperature drops to -15°C, the CuS@SiO2 coating sample doesn't even freeze within 30 minutes, while the conventional superhydrophobic SiO2 coating sample completely freezes after 17 minutes.

[0116] Figure 13 The figure shows the comparison of the delayed freezing time of the CuS@SiO2 photothermal composite anti-icing coating sample and the ordinary super-hydrophobic SiO2 coating sample at -20°C and different light intensities. As can be seen from the figure, the freezing time of the ordinary super-hydrophobic SiO2 coating sample does not change much under different light intensities, while the freezing time of the CuS@SiO2 anti-icing coating sample is significantly prolonged as the light intensity increases, even at 1kW / m 2 Under these conditions, the droplet on the CuS@SiO2 anti-icing coating sample did not freeze within 30 minutes, while the superhydrophobic SiO2 coating sample completely froze in about 5 minutes, confirming the excellent anti-icing performance of the sample.

[0117] Figure 14 The CuS@SiO2 photothermal composite anti-icing coating sample and the ordinary super-hydrophobic SiO2 coating sample were tested at -20℃ and 1kW / m 2The morphology comparison diagram of the ice melting process under light intensities of different wavelengths. Within 30 minutes, the icicles on the surface of the ordinary superhydrophobic SiO2 coating sample hardly changed. However, as the illumination time increased, the icicles on the surface of the CuS@SiO2 anti-icing coating sample gradually melted into water droplets at the point where the bottom of the icicles contacted the coating surface and rolled down. Then, after 30 minutes, the icicles slipped and then detached from the CuS@SiO2 coating surface and slid onto the condensation table. However, the icicles on the surface of the ordinary superhydrophobic SiO2 coating sample still did not detach from the coating surface after 1 hour. The comparison of the time it took for the icicles to detach from the two coating surfaces confirmed the deicing performance of the CuS@SiO2 anti-icing coating sample.

[0118] Figure 15 The following is a comparison of the wear resistance test results of the anti-icing coating samples obtained in this application example. The left picture shows the surface morphology and contact angle of the coating before the test, and the right picture shows the surface morphology and contact angle of the coating after the test. The CuS@SiO2 photothermal anti-icing coating with a size of 2.5cm×2.5cm×0.8mm (under a load of 100g, 1600Pa) was heated at a constant slow speed (about 1cm·s -1 ) on 800-grit sandpaper for a 20-cm horizontal movement to complete one abrasion cycle. After 500 abrasion cycles, the coating surface showed obvious scratches, but the contact angle still reached 150°, indicating that the resulting anti-icing coating has good wear resistance.

[0119] Application Example 2

[0120] The super-hydrophobic CuS@SiO2 composite photothermal coating of the present invention is applied to prepare water evaporation materials, and a CuS@SiO2 photothermal water evaporation material with a super-hydrophobic / super-hydrophilic Janus structure is constructed and applied to the field of water evaporation + photocatalysis; specifically as follows:

[0121] A NaCl-MB dye solution with a sodium chloride concentration of 3.5 wt% and a methylene blue concentration of 5 mg / L was prepared to simulate seawater. The CuS@SiO2 photothermal water evaporator with the Janus structure obtained in Example 3 was placed in a beaker filled with 50 mL of the NaCl-MB dye solution. The beaker was then placed in a dark environment for 30 minutes to achieve adsorption-desorption equilibrium. The beaker was then placed on a balance and a CEL-S500-T5 xenon lamp was used at 1 kW / m 2 The beaker was illuminated at a constant light intensity. The mass loss of the dye solution was recorded every 10 minutes. Additionally, 3 mL of dye solution was pipetted from the beaker every 20 minutes, stored, and the absorbance change was measured. Because CuS micro-nanoparticles readily generate electrons and holes, which react with H₂O₂ and accelerate degradation, 0.5 mL of H₂O₂ (30 wt%) was added to 50 mL of methyl blue dye solution to promote degradation.

[0122] Figure 16Comparative photographs of the Janus-structured CuS@SiO2 water evaporator described in Application Example 3 before and after 90 minutes in a NaCl-MB dye solution. As can be seen, the evaporator's lower surface exhibits excellent superhydrophilicity and is immersed in the dye solution, allowing it to adsorb dye molecules and facilitate dye degradation. The upper surface exhibits excellent superhydrophobicity and thus floats above the liquid surface, ensuring that the evaporator can receive light at close range to maximize its photocatalytic degradation effect. Furthermore, after 90 minutes, the dye solution's color changes from blue to colorless, indicating that most of the methyl blue molecules in the dye solution have been degraded into small organic molecules such as H2O and CO2, and the dye solution has gradually become pure salt water.

[0123] Figure 17 The figure shows the evaporation efficiency of the above-mentioned Janus structure CuS@SiO2 water evaporator evaporating NaCl-MB dye solution. As can be seen from the figure, within 2 hours, the evaporation efficiency of the dye solution by "MF" (i.e., pure foam without CuS@SiO2 composite material) is much lower than the evaporation efficiency of the Janus structure CuS@SiO2 water evaporator. Figure 15 The slope of the curve shows that the evaporation efficiency of "MF" is 0.534 kg / m 2 / h, while the evaporation efficiency of the Janus structure CuS@SiO2 water evaporator is 2.148kg / m 2 / h, which is 4.02 times more efficient than the former. It can be seen that the Janus structure CuS@SiO2 water evaporator has excellent photothermal evaporation effect, and the CuS@SiO2 nanocomposite material provides an effective way for solar-driven seawater desalination.

[0124] Figure 18 The absorbance curve for the NaCl-MB dye solution over a 120-minute evaporation period is shown below. As can be seen, after 120 minutes, the absorbance of the pure dye solution containing only MF decreased only slightly; however, the absorbance of the dye solution containing the Janus-structured CuS@SiO2 water evaporator decreased significantly within 90 minutes. Calculations show that within one hour, the degradation rate of the dye solution containing only MF was 21%, while the degradation rate of the dye solution containing the Janus-structured CuS@SiO2 water evaporator was 91%, 4.3 times greater. This demonstrates that the Janus-structured CuS@SiO2 water evaporator also exhibits excellent photocatalytic performance in dye degradation.

[0125] Comparative Example 1

[0126] A CuS@SiO2 photothermal composite dispersion, the preparation method of which comprises the following steps:

[0127] 1) Under stirring conditions, 1.5 mL of NaOH solution (1.8 mol / L) and 5 mL of tetraethyl orthosilicate (TEOS) were added to 25 mL of ethanol in sequence, and the mixture was hydrolyzed for 24 h under stirring conditions to obtain a super-hydrophilic SiO2 dispersion system;

[0128] 2) adding 5 mL of hexamethyldisilazane (HMDS) to the dispersion obtained in step (1) and continuing stirring for 8 h to obtain a superhydrophobic SiO2 dispersion;

[0129] 3) Weigh 0.256 g of sulfur powder (8 mmol) into a 50 mL three-necked flask, then add 40 mL of octadecene (ODE) and 10 mL of oleylamine (OM). Under vacuum, heat the flask to 90°C at a rate of 10°C / min and maintain at this temperature for 30 min to obtain an orange-red, transparent sulfur precursor solution.

[0130] 4) Ar gas was introduced and the obtained S precursor solution was cooled to room temperature. Then, 0.799 g of copper acetate monohydrate Cu(Ac)2·H2O (4 mmol) was added and the mixture was evacuated at room temperature for 30 min. The mixture was then heated to 200°C at a rate of 10°C / min and kept at this temperature for 30 min to obtain a black-green dispersion. The mixture was further cooled to room temperature under an Ar atmosphere to obtain a CuS black-green dispersion (concentration of 0.008 M).

[0131] 5) washing the CuS dispersion obtained in step 2) twice by centrifugation (4000 rpm, 5 min) using methanol as a detergent to separate the nanocrystal precipitate, and then adding toluene to uniformly disperse the precipitate to obtain a CuS-toluene dispersion, wherein the solid-to-liquid ratio of the CuS nanocrystal precipitate to toluene is 0.13 g / mL;

[0132] 6) Add 6 mL of the CuS-toluene dispersion obtained in step 5) to the super-hydrophobic SiO2 dispersion obtained in step 1), and stir and mix for 4 h to obtain a super-hydrophilic CuS@SiO2 photothermal composite dispersion.

[0133] 7) Add 6 mL of the CuS-toluene dispersion obtained in step 5) to the super-hydrophobic SiO2 dispersion obtained in step 2), and stir and mix for 4 h to obtain a super-hydrophobic CuS@SiO2 photothermal composite dispersion.

[0134] Comparative Example 2

[0135] A CuS@SiO2 photothermal composite dispersion, the preparation method of which comprises the following steps:

[0136] 1) Under magnetic stirring, weigh 0.78 g of commercially available high-purity CuS particles (particle size 50-100 nm, purity 99.9%) and slowly pour them into 25 mL of ethanol and stir for 30 minutes to evenly disperse them.

[0137] 2) adding 1.5 mL of NaOH solution (1.8 mol / L) and 5 mL of ethyl orthosilicate to the solution obtained in step 1) in sequence, and performing a hydrolysis reaction under stirring for 24 hours to obtain a super-hydrophilic CuS@SiO2 photothermal composite dispersion;

[0138] 3) Add 5.0 mL of hexamethyldisilazane (HMDS) to the solution system in step 2) and continue stirring for 12 hours to obtain a superhydrophobic CuS@SiO2 photothermal composite dispersion.

[0139] The super-wettable CuS@SiO2 photothermal composite dispersion obtained in Comparative Examples 1 and 2 was used to prepare a CuS@SiO2 photothermal water evaporator with a super-hydrophobic / super-hydrophilic Janus structure. The specific preparation method includes: preparing melamine foam (abbreviated as MF) and cutting it into squares (area 2.5×2.5 cm 2 , with a thickness of 0.5 cm), and 1 mL of the superhydrophobic CuS@SiO2 photothermal composite material was sprayed on the upper surface of the MF, and 2.5 mL of the superhydrophilic CuS@SiO2 material was taken and the lower surface of the MF was immersed in it to allow it to be fully absorbed, and then dried to obtain the superhydrophobic / superhydrophilic Janus structure CuS@SiO2 photothermal water evaporator.

[0140] The super-hydrophobic CuS@SiO2 photothermal composite dispersion obtained in the above-mentioned comparative examples 1 and 2 is used to prepare a photothermal composite anti-icing coating. The specific preparation method includes: 1) Under stirring conditions, hydroxy acrylic resin, fluorocarbon resin, alkyd resin, polypropylene resin, silane coupling agent, and filler are added to an organic solvent (butyl acetate, etc.) in sequence, and stirred (12 to 24 hours to obtain a resin primer; 2) On the surface of a glass substrate (7.5×2.5 cm), the resin primer obtained in step 1) is first sprayed as a binder to improve the wear and weather resistance of the coating, and then when the primer reaches surface dry, the super-hydrophobic CuS@SiO2 photothermal composite coating is sprayed and dried to obtain a super-hydrophobic CuS@SiO2 photothermal anti-icing coating.

[0141] Comparative Example 3

[0142] A CuS@SiO2 photothermal composite dispersion, the preparation method of which comprises the following steps:

[0143] 1) Weigh 0.256 g of sulfur powder (8 mmol) into a 50 mL three-necked flask, then add 40 mL of octadecene (ODE) and 10 mL of oleylamine (OM). Under vacuum conditions, heat the flask to 90°C at a rate of 10°C / min and maintain at this temperature for 30 min to obtain an orange-red transparent sulfur precursor solution.

[0144] 2) Ar gas was introduced and the obtained S precursor solution was cooled to room temperature. Then, 0.799 g of copper acetate monohydrate Cu(Ac)2·H2O (4 mmol) was added and the mixture was evacuated at room temperature for 30 min. The mixture was then heated to 200°C at a rate of 10°C / min and kept at this temperature for 30 min to obtain a black-green dispersion. The mixture was further cooled to room temperature under an Ar atmosphere to obtain a CuS black-green dispersion (concentration of 0.008 M).

[0145] 3) washing the CuS dispersion obtained in step 2) twice by centrifugation (4000 rpm, 5 min) using methanol as a detergent to separate the nanocrystal precipitate, and then adding toluene to uniformly disperse the precipitate to obtain a CuS-toluene dispersion, wherein the solid-to-liquid ratio of the CuS nanocrystal precipitate to toluene is 0.13 g / mL;

[0146] 4) Under magnetic stirring, slowly pour 6 mL of the CuS-toluene dispersion obtained in step 3) into 25 mL of ethanol and stir for 30 minutes to evenly disperse and evaporate the toluene.

[0147] 5) To the mixed solution obtained in step 4), 1.5 mL of NaOH solution (1.8 mol / L) and 5 mL of tetramethyl orthosilicate were sequentially added, and the mixture was hydrolyzed for 24 h under stirring to obtain a super-hydrophilic CuS@SiO2 photothermal composite coating;

[0148] 6) Add 5.0 mL of hexamethyldisilazane (HMDS) to the solution system in step 5) and continue stirring for 12 hours to obtain a hydrophobic CuS@SiO2 photothermal composite coating;

[0149] The CuS@SiO2 dispersion of Comparative Example 3 was used to prepare a Janus structure CuS@SiO2 water evaporator. The specific steps included: preparing melamine foam (abbreviated as MF) and cutting it into squares (area 2.5×2.5 cm 2 , with a thickness of 0.5 cm), and 1 mL of the hydrophobic CuS@SiO2 photothermal composite material obtained in step 6) was sprayed on the upper surface of MF, and 2.5 mL of the superhydrophilic CuS@SiO2 material obtained in step 5) was taken and the lower surface of MF was immersed in it to allow it to be fully absorbed, and then dried to obtain a CuS@SiO2 photothermal water evaporator with a Janus structure.

[0150] The hydrophobic CuS@SiO2 photothermal composite material obtained in the above comparative example 3 is used to prepare a hydrophobic CuS@SiO2 photothermal coating. The specific steps include: 1) Under stirring conditions, hydroxy acrylic resin, fluorocarbon resin, alkyd resin, polypropylene resin, silane coupling agent, and filler are added to an organic solvent (butyl acetate, etc.) in sequence, and stirred (12 to 24 hours to obtain a resin primer); 2) On the surface of a glass substrate (7.5×2.5 cm), the resin primer obtained in step 1) is first sprayed as a binder to improve the wear and weather resistance of the coating, and then when the primer reaches surface dry, the hydrophobic CuS@SiO2 photothermal composite coating is sprayed and dried to obtain a hydrophobic CuS@SiO2 photothermal anti-icing coating.

[0151] The performance test results of the photothermal water evaporator and the photothermal anti-icing coating prepared in Example 1 and Comparative Examples 1 to 3 are shown in Table 1.

[0152] Table 1 Performance test results of the water evaporator and anti-icing coating prepared in Example 1 and Comparative Examples 1 to 3

[0153]

[0154]

[0155] By comparison with the above table, it can be seen that the super-wettable CuS@SiO2 photothermal composite material obtained in the present invention has excellent superhydrophobicity and photothermal conversion performance. Since the typical microscopic morphology of the CuS@SiO2 photothermal composite material prepared by the present invention is that SiO2 in situ coats the flaky CuS nanocrystal phase to grow to obtain a core-shell structure, after being modified by a low surface energy material, it is combined with a resin-based primer to construct a special micro-nano rough structure, which makes the CuS@SiO2 anti-icing coating have excellent superhydrophobicity and wear resistance and weather resistance. The CuS@SiO2 photothermal composite anti-icing coating described in the present invention can effectively capture air and reduce the actual contact area between water droplets and the substrate due to its special micro-nano structure and effective low surface energy modification, thereby enhancing its superhydrophobic properties and significantly delaying the freezing time; the Janus structure CuS@SiO2 photothermal water evaporator not only has good self-floating properties, but also can efficiently capture sunlight and continuously reflect it in the micro-nano porous structure to improve the absorption of sunlight, thereby giving full play to the photothermal conversion effect to increase the surface temperature, enhance the water evaporation rate of the evaporator and the efficiency of photocatalytic degradation of dye solution.

[0156] Comparative Example 4

[0157] A super-hydrophobic CuS@SiO2 photothermal composite anti-icing coating, the specific preparation steps include:

[0158] (1) Under magnetic stirring conditions, 6 g of alkyd resin, 1.8 g of PP polypropylene resin, 1 g of fluorocarbon resin, 0.6 mL of KH550 solution (KH550:H2O=0.24 mL:0.36 mL), and 2 g of nylon powder were added to 30 mL of butyl acetate in sequence and stirred for 24 h to obtain a resin primer;

[0159] (2) Preparation of super-hydrophobic CuS@SiO2 photothermal composite coating, see Example 1;

[0160] (3) On the surface of the glass substrate, the resin primer obtained in step (1) is first sprayed, and then the super-hydrophobic CuS@SiO2 photothermal composite coating described in Example 1 is sprayed, and dried to obtain a super-hydrophobic CuS@SiO2 photothermal anti-icing coating.

[0161] The super-hydrophobic CuS@SiO2 photothermal composite anti-icing coating obtained in Comparative Example 4 was compared with the super-hydrophobic CuS@SiO2 photothermal composite anti-icing coating described in Application Example 1 to test the wear resistance of the two coatings. The specific steps are as follows:

[0162] Two CuS@SiO2 photothermal anti-icing coatings of the same size (2.5 cm × 2.5 cm × 0.8 mm) were heated at a constant slow speed (about 1 cm·s -1 ) is moved horizontally 20 cm on sandpaper (800 mesh) to complete one abrasion cycle. The contact angle of the sample is measured every 100 abrasion cycles.

[0163] Finally, it was measured that the contact angle of the super-hydrophobic CuS@SiO2 photothermal composite anti-icing coating obtained in Comparative Example 4 was 144° after 300 wear cycles, while the contact angle of the super-hydrophobic CuS@SiO2 photothermal composite anti-icing coating described in Application Example 1 was 150° after 500 wear cycles, and the coating still maintained super-phobicity.

[0164] The present invention is not limited to the above-described embodiments. Persons skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are deemed to be within the scope of protection of the present invention. Any matters not described in detail in this specification constitute prior art known to those skilled in the art.

Claims

1. A method for preparing a super-wettable CuS@SiO2 photothermal composite material, characterized in that: The steps include: (1) Sulfur powder, octadecene, and oleylamine are sequentially added to a reaction vessel, and a first heating reaction is performed under vacuum conditions to obtain an orange-red transparent S precursor solution; (2) Cool the S precursor solution to room temperature by introducing a protective atmosphere, then add copper salt and conduct a second heating reaction under vacuum conditions, then cool it to room temperature by introducing a protective atmosphere to obtain a black-green CuS dispersion. (3) The CuS dispersion obtained in step (2) is centrifuged using alcohol solvent I as a detergent to obtain a nanocrystal precipitate; toluene is then added to uniformly disperse the precipitate to obtain a CuS-toluene dispersion; (4) Under magnetic stirring conditions, the CuS-toluene dispersion obtained in step (3) is added to the alcohol solvent II and stirred to uniformly disperse the CuS and volatilize the toluene; (5) adding alkali solution and hydrolyzable silicon source to the dispersion obtained in step (4) in sequence, and continuing to stir and react to obtain a super-hydrophilic CuS@SiO2 photothermal composite material; (6) Adding a silane-based low surface energy material to the reaction system obtained in step (5), and continuing the stirring reaction to obtain a super-hydrophobic CuS@SiO2 photothermal composite material; The hydrolyzable silicon source is one or more of tetraethyl orthosilicate and tetrabutyl orthosilicate; The silane-based low surface energy substance is one or more of hexamethyldisilazane, methyltriethoxysilane, and hexadecyltrimethoxysilane; The volume ratio of the CuS-toluene dispersion, alcohol solvent II, alkali solution, hydrolyzable silicon source, and silane low surface energy substance in steps (4) to (6) is (1-5): (5-7): (0.2-0.4): (1-1.4): (0.6-1).

2. The preparation method according to claim 1, characterized in that The temperature used in step (1) of the first heating reaction is 90-100°C and the time is 20-40 min; the temperature used in step (2) of the second heating reaction is 150-220°C and the time is 20-40 min.

3. The preparation method according to claim 1, characterized in that The concentration of CuS in the CuS-toluene dispersion is (0.10-0.15) g / mL.

4. The preparation method according to claim 1, characterized in that The stirring treatment time of step (4) is 0.5~1h; the stirring reaction time of step (5) is 20~24h; and the stirring reaction time of step (6) is 6~12h.

5. The super-wettable CuS@SiO2 photothermal composite material prepared by the preparation method according to any one of claims 1 to 4.

6. A CuS@SiO2 photothermal water evaporator with a super-hydrophobic / super-hydrophilic Janus structure prepared using the super-wettable CuS@SiO2 photothermal composite material according to claim 1.

7. A photothermal composite anti-icing coating prepared using the super-wettable CuS@SiO2 photothermal composite material according to claim 1.

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