An ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, its preparation method and application

Abstract

This invention discloses an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, its preparation method, and its application, belonging to the field of photothermal evaporator technology. The ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material includes a hydrophobic substrate, on the upper surface of which an ultrathin ZnO-CuS hydrophilic layer is grown. This ultrathin ZnO-CuS hydrophilic layer comprises CuS nanosheets and ZnO nanoparticles attached to the CuS nanosheets. The surface of the ultrathin ZnO-CuS hydrophilic layer forms numerous micropores and chambers. The presence of these micropores and chambers constructs light traps, while the ZnO nanoparticles reduce light reflection and increase light absorption. The photothermal evaporator prepared using this material can solve the technical problems of preventing salt deposition, effectively treating organic pollutants, and achieving high-efficiency evaporation in existing technologies.

Description

Technical Field

[0001] This invention belongs to the field of photothermal evaporator technology, specifically relating to an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, its preparation method, and its application. Background Technology

[0002] Due to global climate change, social development, and population growth, freshwater and energy resources, essential to human production and daily life, are facing severe shortages. Utilizing clean energy for seawater desalination can increase freshwater supply. Seawater accounts for approximately 97% of global water resources, but only 2.5% is freshwater available for human consumption. Therefore, there is an urgent need for technologies to extract clean water from seawater and wastewater. Compared to typical traditional fossil fuel thermal distillation processes, which suffer from high investment costs and increased carbon emissions, solar interfacial evaporation (SIE) technology converts solar energy into heat energy through photothermal materials, confining the heat to the air-water interface, effectively suppressing heat loss and improving the water evaporation rate and photothermal conversion efficiency. Therefore, solar-driven interfacial evaporation is considered a low-cost, environmentally friendly, and sustainable technology for solving water scarcity problems, with promising applications in the water treatment field. In recent years, SIE has made substantial progress in developing advanced photothermal materials, such as metal plasma, carbon-based materials, and polymers. Among them, SIE based on carbon cloth has great potential in practical applications. By treating the surface fibers of carbon cloth, the surface contains a large number of pores, which helps to increase the specific surface area and further improve the solar absorption efficiency and water transport performance.

[0003] Water pollution has become one of the most concerning environmental issues globally. Photocatalytic degradation, which can degrade various organic pollutants into harmless products (e.g., CO2, H2O), has proven to be a highly efficient, green, and promising wastewater treatment technology. Photocatalytic degradation refers to the process in which, in the presence of a catalyst, the catalyst absorbs photons and generates highly oxidizing / reducing free radicals through a chain reaction, leading to the degradation of substances. Traditional powdered photocatalysts are difficult to collect and recycle after use, easily causing secondary pollution. Therefore, the growth of nanostructured photocatalysts on suitable substrates has attracted widespread attention.

[0004] Besides using seawater as a source of evaporation water to obtain fresh water, if we can utilize solar interface evaporation to treat and recycle the large amounts of wastewater generated in daily life, high-concentration brine from industrial production, and wastewater containing toxic, harmful, and difficult-to-degrade organic pollutants, it will have significant practical implications for water conservation and environmental friendliness.

[0005] However, existing solar interface evaporators, during long-term use or in the evaporation process of treating high-concentration brine or wastewater, suffer from salt ion accumulation on the evaporator surface due to insufficient water supply or difficulties in salt ion reflux, leading to salt deposits that affect the evaporation rate and the evaporator's lifespan. Furthermore, for organic pollutants, simply treating organic wastewater through solar evaporation causes the organic pollutants to concentrate after evaporation, resulting in more severe pollution. Therefore, developing a system that can simultaneously achieve efficient evaporation, brine collection, and organic pollutant degradation has significant application value. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention aims to provide an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, its preparation method and application, so as to solve the technical problems of how to prevent salt deposition, effectively treat organic pollutants and achieve efficient evaporation in the prior art.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] This invention provides an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, comprising a hydrophobic substrate, on the upper surface of which an ultrathin ZnO-CuS hydrophilic layer is grown. The ultrathin ZnO-CuS hydrophilic layer includes CuS nanosheets and ZnO nanoparticles attached to the CuS nanosheets. A large number of micropores and cavities are formed on the surface of the ultrathin ZnO-CuS hydrophilic layer. The presence of micropores and cavities constructs light traps, and the ZnO nanoparticles reduce light reflection and improve light absorption.

[0009] In one embodiment, the thickness of the ultrathin ZnO-CuS hydrophilic layer is 300 nm ± 5.

[0010] This invention also provides a method for preparing an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, comprising the following steps:

[0011] Prepare a hydrophobic substrate with a single-sided ultrathin copper plating layer;

[0012] Sodium hydroxide granules and sulfur powder were mixed in DMF, and deionized water was added to prepare a yellow mixed solution.

[0013] A hydrophobic substrate with a single-sided ultrathin copper plating layer was immersed in a yellow mixed solution. The single-sided ultrathin copper plating layer reacted to generate copper sulfide nanosheets. After rinsing and drying, a hydrophobic substrate with a copper sulfide nanosheet layer was obtained.

[0014] Zinc oxide was sputtered onto one side of a hydrophobic substrate on which copper sulfide nanosheets are grown to prepare ZnO-CuS@CC photothermal material.

[0015] In one embodiment, the hydrophobic substrate is a hydrophobic carbon cloth.

[0016] In one embodiment, the process for preparing the hydrophobic substrate with a single-sided ultrathin copper plating layer is as follows:

[0017] The cleaned hydrophobic substrate is fixed onto a magnetron sputtering device, a copper target is placed in, argon gas is introduced after vacuuming, and the oxides on the surface of the copper target are pre-sputtered to clean it. Then, sputtering is performed for 5-20 minutes to deposit copper on the hydrophobic carbon cloth, thus obtaining a hydrophobic substrate with a single-sided ultrathin copper plating layer.

[0018] In one embodiment, the thickness of the single-sided ultrathin copper plating layer is 80–100 nm.

[0019] In one embodiment, the thickness of the copper sulfide nanosheet layer is 210–220 nm.

[0020] In one embodiment, the ratio of sodium hydroxide, sulfur powder and DMF is 2:1:2, and the volume ratio of DMF to deionized water is 1:15.

[0021] In one embodiment, the process of sputtering zinc oxide onto one side of the hydrophobic substrate on which the copper sulfide nanosheets are grown is as follows:

[0022] The hydrophobic substrate on which copper sulfide nanosheets are grown rotates at a speed of 13 r / min. A DC power supply is used to sputter the Zn target, with 30 sccm-50 sccm of argon and 15 sccm-30 sccm of oxygen introduced. The power supply is started under a vacuum of 0.6 Pa, with a current of 0.2 A-0.3 A and a sputtering power of 40 W-80 W. The Zn target surface glows and discharges, and sputtering lasts for 5 min-10 min.

[0023] The present invention also provides an application of the above-mentioned ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material in a photothermal evaporator. The photothermal evaporator includes the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, a water storage tank and an outlet tank respectively covered with a dust-free cloth, and the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material serves as a bridge between the water storage tank and the outlet tank and overlaps with the dust-free cloths covered on the water storage tank and the outlet tank respectively.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention provides an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material. A photothermal evaporator using this material can simultaneously achieve efficient photothermal water evaporation and photocatalytic degradation of organic pollutants. The ZnO-CuS heterojunction acts as a photocatalyst, absorbing light with sufficient energy to excite electrons from the valence band to the conduction band, generating electron-hole pairs. These photogenerated electrons and holes react with water, surface hydroxyl groups, and O2 to produce active free radicals, such as hydroxyl radicals (·OH) and superoxide radicals (·O2). - These free radicals react with pollutant molecules adsorbed on the catalyst surface, oxidizing and decomposing the pollutants into CO2, H2O, and other light byproducts. This can be applied in seawater desalination and wastewater treatment. Both CuS and ZnO possess excellent catalytic performance; combining them to form a heterojunction photocatalyst is significant for improving photocatalytic efficiency.

[0026] This invention prepares an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, which is applied in a solar evaporator to achieve high photothermal conversion efficiency and evaporation rate. By growing an ultrathin ZnO-CuS hydrophilic layer (only about 300 nm thick) on a hydrophobic substrate, a small amount of water can be confined to the evaporation interface to form a thin water film. The ZnO-CuS@CC photothermal material also has good light absorption properties, which can convert solar energy into heat energy. The heat is localized to the thin water film on the evaporator surface, thereby reducing heat conduction loss to the large volume of water and enabling rapid evaporation on the surface. Driven by rapid evaporation, the numerous cavities and pores on the surface of the hydrophilic layer are rapidly replenished through capillary action, ensuring a continuous water supply and achieving efficient water evaporation.

[0027] The ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal evaporator prepared in this invention exhibits stability in the evaporation of high-concentration brine. Through unidirectional conduction, salt ions are rapidly conducted from the storage tank to the surface of the photothermal material for evaporation. The microporous structure of the ZnO-CuS@CC photothermal material surface facilitates the rapid discharge of salt ions into the outlet liquid tank. The large influx of salt ions into the outlet liquid tank prevents salt deposition on the surface, ensuring rapid evaporation and stable operation of the evaporator. This achieves brine concentration, and multiple cycles ultimately result in zero liquid discharge. Attached Figure Description

[0028] Figure 1 This is a SEM image of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material prepared in Example 1 of this invention.

[0029] Figure 2 Photographs showing the contact angles of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material of this invention;

[0030] Figure 3 This is a schematic diagram of the photothermal evaporator of the present invention;

[0031] Figure 4 The diagram shows the evaporation performance of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal evaporator of this invention.

[0032] Figure 5 The image shows the photothermal catalytic performance of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC of this invention. Detailed Implementation

[0033] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0034] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0035] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0036] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0037] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0038] This invention provides an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, comprising an ultrathin ZnO-CuS hydrophilic layer grown on the upper surface of a hydrophobic substrate. The ultrathin ZnO-CuS hydrophilic layer includes CuS nanosheets and ZnO nanoparticles attached to the CuS nanosheets. A large number of micropores and cavities are formed on the surface of the ultrathin ZnO-CuS hydrophilic layer. The presence of micropores and cavities constructs light traps, and the ZnO nanoparticles reduce light reflection and improve light absorption.

[0039] One of the inventive aspects of this invention is that the thickness of the ultrathin ZnO-CuS hydrophilic layer is approximately 300 nm.

[0040] Firstly, both zinc oxide and copper sulfide in the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material are semiconductor materials and can act as photocatalysts on their own. Combining them to form a heterojunction allows for charge transfer and rearrangement between the different materials at the interface, creating high-electron-affinity "holes" and low-electron-affinity "electrons." This uneven charge distribution endows the heterojunction with catalytic properties, accelerating chemical reactions. The grain boundaries of the heterojunction often contain more active sites, which readily adsorb reactants and expel products, thus improving catalytic efficiency. Secondly, the addition of ZnO reduces the reflectivity of the photothermal material, increasing light absorption. Simultaneously, zinc oxide surfaces often exhibit numerous oxide groups, such as hydroxyl groups, which can form hydrogen bonds with water molecules, thus exhibiting hydrophilicity. Therefore, the addition of zinc oxide increases the hydrophilicity of CuS@CC, facilitating water transport during the evaporation process.

[0041] Another aspect of the present invention provides a method for preparing an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, comprising the following steps:

[0042] A hydrophobic substrate with a single-sided ultrathin copper plating layer of 80–100 nm thickness was prepared.

[0043] The specific process for obtaining a hydrophobic substrate with a single-sided ultrathin copper plating layer is as follows: the cleaned hydrophobic substrate is fixed onto a magnetron sputtering device, a copper target is placed in, argon gas is introduced after vacuuming, the oxide on the surface of the copper target is pre-sputtered to clean it, and then sputtering is performed for 5-20 minutes to deposit copper on the hydrophobic carbon cloth, thus obtaining a hydrophobic substrate with a single-sided ultrathin copper plating layer.

[0044] Sodium hydroxide and sulfur powder were mixed in DMF, and deionized water was added to prepare a yellow mixed solution. Specifically, the ratio of sodium hydroxide, sulfur powder, and DMF was 2:1:2, and the volume ratio of DMF to deionized water was 1:15.

[0045] A hydrophobic substrate with a single-sided ultrathin copper plating layer was immersed in a yellow mixed solution. The single-sided ultrathin copper plating layer reacted to generate copper sulfide nanosheets. After rinsing and drying, a hydrophobic substrate with a copper sulfide nanosheet layer was obtained, wherein the thickness of the copper sulfide nanosheet layer was 210-220 nm.

[0046] Zinc oxide was sputtered onto the same side of a hydrophobic substrate on which copper sulfide nanosheets were grown to obtain ZnO-CuS@CC photothermal material. Specifically, the hydrophobic substrate on which the copper sulfide nanosheets were grown rotated at 13 r / min. A DC power supply was used to sputter the Zn target, with 30-50 sccm of argon gas and 15-30 sccm of oxygen gas introduced. The power supply was started under a vacuum of 0.6 Pa, with a current of 0.2-0.3 A and a sputtering power of 40-80 W. Glow discharge occurred on the Zn target surface, and sputtering lasted for 5-10 min.

[0047] In another aspect, the present invention provides a photothermal evaporator, which includes an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, a water storage tank and an outlet tank respectively covered with a dust-free cloth, wherein the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material serves as a bridge between the water storage tank and the outlet tank and overlaps with the dust-free cloths covered on the water storage tank and the outlet tank respectively.

[0048] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0049] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0050] Example 1

[0051] This embodiment provides an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material and its preparation method. The following is the preparation method of ZnO-CuS@CC photothermal material:

[0052] Step 1: First, ultrasonically clean the hydrophobic carbon cloth (10cm×10cm) to remove impurities and contaminants from the surface.

[0053] Step 2: Fix the cleaned hydrophobic carbon cloth onto the worktable of the magnetron sputtering equipment, close the baffle, place a copper target with a purity of 99.99%, and evacuate to 1.8 × 10⁻⁶. -3At 50 sccm, argon gas was introduced, and the DC power supply was turned on. The current was set to 0.2 A and the power to 80 W. The Cu target surface was initiating a glow discharge, and the surface was bombarded for 5 minutes to remove oxides from the copper target surface. The stage rotation speed was set to 9 r / min, and the baffle was opened. Sputtering was performed for 5 minutes to obtain a hydrophobic carbon cloth with a single-sided ultrathin copper plating layer.

[0054] Step 3: Measure 0.5 mL of DMF into a beaker, then weigh 0.5 g of sodium hydroxide and 0.2 g of sulfur powder into the beaker containing DMF, add 20 mL of deionized water, heat and stir at 50 °C for 20 min to obtain a yellow mixed solution.

[0055] Step 4: After the solution cools to room temperature, immerse the hydrophobic carbon cloth with the deposited single-sided ultrathin copper plating into the solution. After reacting for 1-2 seconds, the side containing the plating turns black rapidly, generating copper sulfide nanosheets. Then rinse the surface with propanol and deionized water, and dry it in a drying oven at 60°C for 6 hours.

[0056] Step 5: Continue sputtering zinc oxide onto the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown using a magnetron sputtering device. Use a Zn target with a purity of 99.99%, rotate the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown at a speed of 13 r / min, and use a DC power supply to sputter the Zn target. Introduce 50 sccm of argon and 30 sccm of oxygen. Start the power supply under a vacuum of 0.6 Pa, with a current of 0.2 A and a sputtering power of 40 W. The Zn target surface will glow and discharge, and the sputtering time will be 10 min.

[0057] After the above 5 steps, ZnO-CuS@CC photothermal material is obtained.

[0058] The upper surface of this photothermal material has CuS nanosheets and ZnO nanoparticles grown on it, exhibiting good wettability, while the lower surface remains hydrophobic.

[0059] This embodiment provides a solar evaporator using the above-mentioned material. The solar evaporator includes ZnO-CuS@CC photothermal material and a cleanroom cloth. The ZnO-CuS@CC photothermal material (3×2cm in size) is used as a bridge to connect a water storage tank filled with solution and an outlet tank. Cleanroom cloths of the same width are mounted on both sides for water supply and water outlet, forming a unidirectional flow evaporator.

[0060] Example 2

[0061] This embodiment provides an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material and its preparation method. The following is the preparation method of ZnO-CuS@CC photothermal material:

[0062] Step 1: First, ultrasonically clean the hydrophobic carbon cloth (10cm×10cm) to remove impurities and contaminants from the surface.

[0063] Step 2: Fix the cleaned hydrophobic carbon cloth onto the worktable of the magnetron sputtering equipment, close the baffle, place a copper target with a purity of 99.99%, and evacuate to 1.8 × 10⁻⁶. -3 At 50 sccm, argon gas was introduced, and the DC power supply was turned on. The current was set to 0.2 A and the power to 80 W. The Cu target surface was initiating a glow discharge, and the surface was bombarded for 5 minutes to remove oxides from the copper target surface. The stage rotation speed was set to 9 r / min, and the baffle was opened. Sputtering was performed for 10 minutes to obtain a hydrophobic carbon cloth with a single-sided ultrathin copper plating layer.

[0064] Step 3: Measure 0.5 mL of DMF into a beaker, then weigh 0.5 g of sodium hydroxide and 0.2 g of sulfur powder into the beaker containing DMF, add 20 mL of deionized water, heat and stir at 50 °C for 20 min to obtain a yellow mixed solution.

[0065] Step 4: After the solution cools to room temperature, immerse the hydrophobic carbon cloth with the deposited single-sided ultrathin copper plating into the solution. After reacting for 1-2 seconds, the side containing the plating turns black rapidly, generating copper sulfide nanosheets. Then rinse the surface with propanol and deionized water, and dry it in a drying oven at 60°C for 6 hours.

[0066] Step 5: Continue sputtering zinc oxide onto the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown using a magnetron sputtering device. Use a Zn target with a purity of 99.99%, rotate the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown at a speed of 13 r / min, and sputter the Zn target using a DC power supply. Introduce 30 sccm of argon and 15 sccm of oxygen. Start the power supply under a vacuum of 0.6 Pa, with a current of 0.3 A and a sputtering power of 80 W. The Zn target surface will glow and discharge, and the sputtering time will be 5 min.

[0067] After the above 5 steps, ZnO-CuS@CC photothermal material is obtained.

[0068] The upper surface of this photothermal material has CuS nanosheets and ZnO nanoparticles grown on it, exhibiting good wettability, while the lower surface remains hydrophobic.

[0069] This embodiment provides a solar evaporator using the above-mentioned material. The solar evaporator includes ZnO-CuS@CC photothermal material and a cleanroom cloth. The ZnO-CuS@CC photothermal material (3×2cm in size) is used as a bridge to connect a water storage tank filled with solution and an outlet tank. Cleanroom cloths of the same width are mounted on both sides for water supply and water outlet, forming a unidirectional flow evaporator.

[0070] Example 3

[0071] This embodiment provides an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material and its preparation method. The following is the preparation method of ZnO-CuS@CC photothermal material:

[0072] Step 1: First, ultrasonically clean the hydrophobic carbon cloth (10cm×10cm) to remove impurities and contaminants from the surface.

[0073] Step 2: Fix the cleaned hydrophobic carbon cloth onto the worktable of the magnetron sputtering equipment, close the baffle, place a copper target with a purity of 99.99%, and evacuate to 1.8 × 10⁻⁶. -3 At 50 sccm, argon gas was introduced, and the DC power supply was turned on. The current was set to 0.2 A and the power to 80 W. The Cu target surface was initiating a glow discharge, and the surface was bombarded for 5 minutes to remove oxides from the copper target surface. The stage rotation speed was set to 9 r / min, and the baffle was opened. Sputtering was performed for 15 minutes to obtain a hydrophobic carbon cloth with a single-sided ultrathin copper plating layer.

[0074] Step 3: Measure 0.5 mL of DMF into a beaker, then weigh 0.5 g of sodium hydroxide and 0.2 g of sulfur powder into the beaker containing DMF, add 20 mL of deionized water, heat and stir at 50 °C for 20 min to obtain a yellow mixed solution.

[0075] Step 4: After the solution cools to room temperature, immerse the hydrophobic carbon cloth with the deposited single-sided ultrathin copper plating into the solution. After reacting for 1-2 seconds, the side containing the plating turns black rapidly, generating copper sulfide nanosheets. Then rinse the surface with propanol and deionized water, and dry it in a drying oven at 60°C for 6 hours.

[0076] Step 5: Continue sputtering zinc oxide onto the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown using a magnetron sputtering device. Use a Zn target with a purity of 99.99%, rotate the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown at a speed of 13 r / min, and sputter the Zn target using a DC power supply. Introduce 50 sccm of argon and 30 sccm of oxygen. Start the power supply under a vacuum of 0.6 Pa, with a current of 0.2 A and a sputtering power of 40 W. The Zn target surface will glow and discharge, and the sputtering time will be 5 min.

[0077] After the above 5 steps, ZnO-CuS@CC photothermal material is obtained.

[0078] The upper surface of this photothermal material has CuS nanosheets and ZnO nanoparticles grown on it, exhibiting good wettability, while the lower surface remains hydrophobic.

[0079] This embodiment provides a solar evaporator using the above-mentioned material. The solar evaporator includes ZnO-CuS@CC photothermal material and a cleanroom cloth. The ZnO-CuS@CC photothermal material (3×2cm in size) is used as a bridge to connect a water storage tank filled with solution and an outlet tank. Cleanroom cloths of the same width are mounted on both sides for water supply and water outlet, forming a unidirectional flow evaporator.

[0080] Example 4

[0081] This embodiment provides an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material and its preparation method. The following is the preparation method of ZnO-CuS@CC photothermal material:

[0082] Step 1: First, ultrasonically clean the hydrophobic carbon cloth (10cm×10cm) to remove impurities and contaminants from the surface.

[0083] Step 2: Fix the cleaned hydrophobic carbon cloth onto the worktable of the magnetron sputtering equipment, close the baffle, place a copper target with a purity of 99.99%, and evacuate to 1.8 × 10⁻⁶. -3 At 50 sccm, argon gas was introduced, and the DC power supply was turned on. The current was set to 0.2 A and the power to 80 W. The Cu target surface was initiating a glow discharge, and the surface was bombarded for 5 minutes to remove oxides from the copper target surface. The stage rotation speed was set to 9 r / min, and the baffle was opened. Sputtering was performed for 20 minutes to obtain a hydrophobic carbon cloth with a single-sided ultrathin copper plating layer.

[0084] Step 3: Measure 0.5 mL of DMF into a beaker, then weigh 0.5 g of sodium hydroxide and 0.2 g of sulfur powder into the beaker containing DMF, add 20 mL of deionized water, heat and stir at 50 °C for 20 min to obtain a yellow mixed solution.

[0085] Step 4: After the solution cools to room temperature, immerse the hydrophobic carbon cloth with the deposited single-sided ultrathin copper plating into the solution. After reacting for 1-2 seconds, the side containing the plating turns black rapidly, generating copper sulfide nanosheets. Then rinse the surface with propanol and deionized water, and dry it in a drying oven at 60°C for 6 hours.

[0086] Step 5: Continue sputtering zinc oxide onto the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown using a magnetron sputtering device. Use a Zn target with a purity of 99.99%, rotate the hydrophobic carbon cloth on which the copper sulfide nanosheets are grown at a speed of 13 r / min, and use a DC power supply to sputter the Zn target. Introduce 50 sccm of argon and 30 sccm of oxygen. Start the power supply under a vacuum of 0.6 Pa, with a current of 0.2 A and a sputtering power of 40 W. The Zn target surface will glow and discharge, and the sputtering time will be 10 min.

[0087] After the above 5 steps, ZnO-CuS@CC photothermal material is obtained.

[0088] The upper surface of this photothermal material has CuS nanosheets and ZnO nanoparticles grown on it, exhibiting good wettability, while the lower surface remains hydrophobic.

[0089] This embodiment provides a solar evaporator using the above-mentioned material. The solar evaporator includes ZnO-CuS@CC photothermal material and a cleanroom cloth. The ZnO-CuS@CC photothermal material (3×2cm in size) is used as a bridge to connect a water storage tank filled with solution and an outlet tank. Cleanroom cloths of the same width are mounted on both sides for water supply and water outlet, forming a unidirectional flow evaporator.

[0090] Figure 1 The SEM surface morphology and EDS energy spectrum of the ZnO-CuS@CC photothermal material prepared in Example 1 of this invention are shown in Figure a. As shown in Figure a, the original hydrophobic carbon cloth fiber has a smooth surface and a diameter of approximately 8 μm. Through magnetron sputtering of Cu (with a copper layer thickness of 80-100 nm on the fiber surface, as shown in Figure e) and a redox method, a large number of copper sulfide nanosheets are grown on the surface of the carbon cloth fiber (Figure b). Numerous micropores and cavities are formed on the surface, with a thickness of approximately 210 nm (Figure f). The presence of these pores and cavities constructs light traps, significantly improving light absorption characteristics. Subsequently, a large number of ZnO nanoparticles are attached to the surface of the copper sulfide nanosheets by magnetron sputtering of zinc. The ZnO-CuS@CC photothermal material was generated (Fig. c, inset is a partial magnified view). The ZnO-CuS on the surface forms an ultrathin hydrophilic layer with a thickness of only about 300 nm (Fig. g), which is conducive to the formation of a thin water film on the surface, accelerating the diffusion of capillary water and the transport of solutes. ZnO nanoparticles can reduce light reflection and further improve the light absorption performance of the material. The EDS spectrum shown in Fig. d shows that there are elements such as Zn, Cu, O and S in the photothermal material, which further proves the successful preparation of ZnO-CuS@CC photothermal material.

[0091] Figure 2 This image shows the water contact angle of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material. As can be seen, when 50 μL of water droplets are placed on the upper and lower surfaces of the ZnO-CuS@CC photothermal material, the hydrophilic layer of the grown ZnO-CuS nanomaterial is completely absorbed after 0.2 s, while the untreated bottom carbon cloth remains hydrophobic. This demonstrates that the obtained ZnO-CuS@CC photothermal material possesses wetting properties with a hydrophilic upper layer and a hydrophobic lower layer, successfully preparing the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material.

[0092] Figure 3This diagram illustrates the use of ZnO-CuS@CC photothermal material for catalysis and evaporation. Driven by evaporation at both liquid surfaces and the solar interface, the solution is pumped from the storage tank to the surface of the ZnO-CuS@CC photothermal material via capillary action through a cleanroom cloth. A thin water film forms on the ZnO-CuS@CC photothermal material, and the solution continues to be transferred to the outlet tank on the other side using the cleanroom cloth. This unidirectional conduction process enables the evaporation and concentration of brine, as well as the photocatalytic degradation of organic pollutants.

[0093] Figure 4 The figure shows the evaporation rate and mass loss of the ZnO-CuS@CC photothermal evaporator in 15% concentrated brine. As can be seen from the figure, under one solar radiation, the average evaporation rate of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal evaporator for a unidirectionally conductive 15wt% NaCl solution is 2.47 kg / m³. -2 ·h -1 The results indicate that the ZnO-CuS@CC photothermal evaporator has good photothermal conversion performance and water transport performance. At the same time, its evaporation rate only fluctuated within a small range within 2 hours without a downward trend, indicating that no salt crystals were generated on the surface of the ZnO-CuS@CC photothermal material. This further proves that the evaporator has stability and durability in evaporating high-concentration brine.

[0094] Figure 5 The ZnO-CuS@CC photothermal evaporator demonstrates its photocatalytic degradation performance of organic pollutants. The ZnO-CuS@CC photothermal material features n-type semiconductor ZnO particles attached to p-type semiconductor CuS nanosheets, forming a ZnO-CuS heterostructure, which exhibits good photocatalytic activity for the degradation of Rhodamine B (RhB). As shown in the figure, the ZnO-CuS@CC photothermal evaporator can simultaneously achieve evaporation and photocatalytic degradation of RhB organic pollutants at a concentration of 10 mg / L. After five cycles of evaporation and photocatalysis following adsorption and desorption, the evaporator achieves a degradation efficiency of over 85% for the RhB solution, demonstrating a good dual function of evaporation and photocatalytic degradation of organic pollutants.

[0095] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. An ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, characterized in that, The invention includes a hydrophobic substrate, wherein the hydrophobic substrate is a hydrophobic carbon cloth (CC), and an ultrathin ZnO-CuS hydrophilic layer is grown on the upper surface of the hydrophobic substrate. The ultrathin ZnO-CuS hydrophilic layer includes CuS nanosheets and ZnO nanoparticles attached to the CuS nanosheets. A large number of micropores and cavities are formed on the surface of the ultrathin ZnO-CuS hydrophilic layer, and the presence of micropores and cavities constructs light traps. The thickness of the ultrathin ZnO-CuS hydrophilic layer is 300 nm ± 5 nm.

2. A method for preparing the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material as described in claim 1, characterized in that, Includes the following steps: Prepare a hydrophobic substrate with a single-sided ultrathin copper plating layer; Sodium hydroxide granules and sulfur powder were mixed in DMF, and deionized water was added to prepare a yellow mixed solution. A hydrophobic substrate with a single-sided ultrathin copper plating layer was immersed in a yellow mixed solution. The single-sided ultrathin copper plating layer reacted to generate copper sulfide nanosheets. After rinsing and drying, a hydrophobic substrate with a copper sulfide nanosheet layer was obtained. Zinc oxide was sputtered onto one side of a hydrophobic substrate on which copper sulfide nanosheets are grown to prepare ZnO-CuS@CC photothermal material.

3. The preparation method of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material according to claim 2, characterized in that, The process for preparing the hydrophobic substrate with a single-sided ultrathin copper plating layer is as follows: The cleaned hydrophobic substrate is fixed onto a magnetron sputtering device, a copper target is placed in, argon gas is introduced after vacuuming, and the oxides on the surface of the copper target are pre-sputtered to clean it. Then, sputtering is performed for 5-20 minutes to deposit copper on the hydrophobic carbon cloth, thus preparing a hydrophobic substrate with a single-sided ultrathin copper plating layer.

4. The preparation method of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material according to claim 2, characterized in that, The thickness of the single-sided ultra-thin copper plating layer is 80~100nm.

5. The preparation method of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material according to claim 2, characterized in that, The thickness of the copper sulfide nanosheets is 210~220 nm.

6. The preparation method of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material according to claim 2, characterized in that, The ratio of sodium hydroxide, sulfur powder and DMF is 2g:1g:2mL, and the volume ratio of DMF to deionized water is 1:

15.

7. The preparation method of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material according to claim 2, characterized in that, The process of sputtering zinc oxide onto one side of the hydrophobic substrate on which the copper sulfide nanosheets are grown is as follows: The hydrophobic substrate on which the copper sulfide nanosheets are grown rotates at a speed of 13 r / min. A DC power supply is used to sputter the Zn target, with 30 sccm-50 sccm of argon and 15 sccm-30 sccm of oxygen introduced. The power supply is started under a vacuum of 0.6 Pa, with a current of 0.2 A-0.3 A and a sputtering power of 40 W-80 W. The Zn target surface glows and discharges, and sputtering lasts for 5 min-10 min.

8. The application of the ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material as described in claim 1 in a photothermal evaporator, characterized in that, The photothermal evaporator includes an ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material, a water storage tank and an outlet tank respectively covered with a dust-free cloth. The ultrathin hydrophilic / hydrophobic ZnO-CuS@CC photothermal material serves as a bridge between the water storage tank and the outlet tank and overlaps with the dust-free cloths covering the water storage tank and the outlet tank respectively.

Images