Preparation method and application of super-hydrophobic copper mesh

Abstract

The invention discloses a preparation method of a super-hydrophobic copper mesh, which comprises the following steps: soaking a cleaned red copper mesh in a hydrochloric acid solution, cleaning and drying, placing in a Fe (NO3) 3 solution for reaction, and then cleaning and drying to obtain a Cu2O coating modified copper mesh; and placing the copper wire mesh in a stearic acid (SA) solution for reaction, washing with absolute ethyl alcohol after reaction is finished, and performing vacuum drying and curing to obtain the copper wire mesh. According to the method, a one-step chemical oxidation method is adopted, the Cu2O layer is directly grown on the surface of the copper net in situ by utilizing the Fe < 3 + > solution, the super-hydrophobic characteristic and the photocatalytic activity are successfully integrated into the same material system, the limitation of a traditional single-function material is overcome, and an innovative technical solution is provided for efficient and integrated wastewater remediation. The super-hydrophobic copper mesh prepared by the preparation method disclosed by the invention shows high-efficiency separation capacity and good stability on various oil-water mixtures, and shows excellent photocatalytic Fenton-like catalytic activity. According to the method, the preparation period is remarkably shortened, large-scale preparation is easier, toxic and harmful gas is not generated, and the operation safety is good.

Description

Technical Field

[0001] This invention belongs to the technical field of oily wastewater separation materials, specifically relating to a method for preparing a superhydrophobic copper mesh and its application. Background Technology

[0002] With rapid industrialization and urbanization, oil spills and the discharge of toxic dyes have become major sources of water pollution. Membrane separation technology, due to its high efficiency, ease of operation, low cost, and suitability for industrial-scale applications, has become an ideal solution for wastewater treatment. Traditional membrane materials are typically designed for single pollutants, resulting in limited treatment effectiveness when dealing with complex wastewater compositions. Therefore, developing functional materials that combine high-efficiency oil-water separation and dye degradation capabilities has become a current research hotspot.

[0003] Currently, superhydrophobic copper meshes are widely used in oil-water separation, antifouling, and corrosion prevention. However, existing preparation methods often suffer from problems such as complex processes, high costs, and environmental unfriendliness. For example, Liu et al. used a NaOH and K2S2O8 oxidation solution to form Cu(OH)2 nanoneedle structures on the surface of a copper mesh, followed by modification with 1H,1H,2H,2H-perfluorodecyltriethoxysilane to prepare a superhydrophobic membrane for oil-water separation. Cao et al. used a mixed solution of H2O2 and HNO3 to acid-etch the copper mesh, then impregnated it with AgNO3 solution, and finally modified it with dithiothreitol for hydrophobic modification. Liu et al. used ammonia water to chemically etch the copper mesh, followed by calcination to generate Cu2O on the surface, and finally achieved oil-water separation through stearic acid (SA) modification. These methods generally suffer from problems such as complex process steps, harsh reaction conditions, low efficiency, use of highly corrosive or irritating reagents, and limited functionality.

[0004] Therefore, there is an urgent need to develop a simple, green, and efficient method for preparing copper-based superhydrophobic materials that combines oil-water separation and catalytic degradation functions. Summary of the Invention

[0005] To address the problems of complex process steps, use of irritating reagents, and limited functionality in existing technologies, this invention provides a simple and low-cost method for preparing superhydrophobic SA / Cu2O / copper mesh (CM), and achieves a superhydrophobic copper mesh that combines efficient oil-water separation and photocatalytic Fenton-like dye degradation functions.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical means:

[0007] This invention first discloses a method for preparing a superhydrophobic copper mesh, comprising:

[0008] (1) First, cut the 200 mesh CM into 4 cm × 4 cm sizes, and then use ethanol and water to ultrasonically clean the sample for 15 min in sequence to obtain copper mesh for later use.

[0009] (2) Immerse the copper mesh in 1 M hydrochloric acid solution for 10 min, then rinse with deionized water and dry in a vacuum drying oven at 60℃ to obtain a pretreated copper mesh for later use.

[0010] (3) Take the pretreated copper mesh film and place it in Fe(NO3)3 solution. Then, reflux it for 1 h under constant temperature magnetic stirring in an oil bath at 120℃. After cooling to room temperature, take it out, rinse it with deionized water and then vacuum dry it to obtain a purple-red Cu2O coating modified copper mesh for later use.

[0011] (4) Place the purple-red Cu2O-coated copper mesh in SA solution, let it stand at room temperature (~25℃) for 12 h, take it out, rinse it with anhydrous ethanol and then vacuum dry and solidify it to obtain an SA / Cu2O / CM superhydrophobic film material, namely superhydrophobic copper mesh.

[0012] Further, the Fe(NO3)3 solution in step (3) has a concentration of 15 g / L and is prepared by the following method:

[0013] Pour 100 mL of deionized water into a 250 mL round-bottom flask, weigh 1.5 g of Fe(NO3)3·9H2O and add it to the flask, then shake the flask until all the particles are dissolved.

[0014] Further, the vacuum drying conditions in step (3) are: drying in a vacuum drying oven at 80°C for 2 hours.

[0015] Further, the SA solution in step (4) has a concentration of 0.05 mol / L and is prepared by the following method:

[0016] Weigh 1.28 g SA into 90 mL of ethanol solution and stir magnetically until completely dissolved.

[0017] Further, the vacuum drying and curing conditions in step (4) are: heating and curing in a vacuum drying oven at 80°C for 2 hours.

[0018] The present invention also discloses a superhydrophobic copper mesh prepared according to any of the above preparation methods.

[0019] The present invention also discloses the application of the above-mentioned superhydrophobic copper mesh in the fields of oil-water separation, water treatment and water purification, self-cleaning and corrosion protection, and biomedicine.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. This invention employs a one-step chemical oxidation method, utilizing Fe 3+Solution-induced in-situ growth of a Cu2O layer on the surface of a copper mesh replaces the traditional multi-step chemical reaction or high-temperature calcination process. This method significantly shortens the preparation cycle and is easier to scale up. It does not generate toxic or harmful gases, has good operational safety, and aligns with the development direction of green chemistry.

[0022] 2. This invention successfully integrates superhydrophobic properties and photocatalytic activity into a single material system, overcoming the limitations of traditional single-function materials and providing an innovative technical solution for efficient and integrated wastewater remediation. The prepared SA / Cu2O / CM exhibits high efficiency and good stability for various oil-water mixtures, and demonstrates excellent Fenton-like photocatalytic activity. Attached Figure Description

[0023] Figure 1 The images are scanning electron microscope (SEM) images of (A) the original CM, (B) Cu2O / CM, and (C) SA / Cu2O / CM; the μm unit in the figures represents the scale bar size.

[0024] Figure 2 X-ray diffraction patterns of the original CM, Cu2O / CM, and SA / Cu2O / CM samples;

[0025] Figure 3 The attenuated total reflectance-Fourier transform infrared spectra of the original CM, Cu2O / CM, and SA / Cu2O / CM samples are shown.

[0026] Figure 4 Images of the water contact angles of the original CM, Cu2O / CM, and SA / Cu2O / CM samples;

[0027] Figure 5 (a) represents the separation efficiency and throughput of SA / Cu2O / CM for different oil-water mixtures; (b) represents the cyclic separation stability for dichloromethane and water mixtures.

[0028] Figure 6 (a) shows the UV absorption spectrum and color change of methylene blue (MB) solution under 18 min of illumination; (b) shows the pseudo-first-order kinetic equation for the degradation of MB by SA / Cu2O / CM.

[0029] Figure 7 (a) shows the UV absorption spectrum and color change of Rhodamine B (RhB) solution under 18 min of illumination; (b) shows the pseudo-first-order kinetic equation for the degradation of RhB by SA / Cu2O / CM. Detailed Implementation

[0030] To facilitate understanding of the present invention, a more comprehensive description of the invention will be provided below in conjunction with specific embodiments. Preferred embodiments of the invention are given in the specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0032] Example 1

[0033] A method for preparing a superhydrophobic SA / Cu2O / CM membrane

[0034] (1) First, cut the 200 mesh CM into 4 cm × 4 cm sizes, and then use ethanol and water to ultrasonically clean the sample for 15 min.

[0035] (2) Immerse it in 1 M hydrochloric acid solution for 10 min, then rinse with deionized water and dry in a vacuum drying oven at 60℃.

[0036] (3) Prepare 15 g / L Fe(NO3)3 solution: Pour 100 mL of deionized water into a 250 mL round bottom flask, weigh 1.5 g Fe(NO3)3·9H2O and put it into the flask, shake the flask until all the particles are dissolved.

[0037] (4) Three pretreated copper mesh films were placed in the Fe(NO3)3 solution. After reflux for 1 h under constant temperature magnetic stirring in an oil bath at 120℃, the mixture was cooled to room temperature, rinsed with deionized water, and dried in a vacuum drying oven at 80℃ for 2 h to obtain a purplish-red Cu2O coating modified copper mesh.

[0038] (5) Prepare 0.05 mol / L SA ethanol solution: Weigh 1.28 g stearic acid (SA) into 90 mL ethanol solution, stir magnetically until completely dissolved, and obtain SA solution for later use.

[0039] (6) The purple-red Cu2O-coated copper mesh was immersed in SA solution and left to stand at room temperature (~25℃) for 12 h. The sample was then taken out, rinsed with anhydrous ethanol, and placed in an 80℃ vacuum drying oven for 2 h to heat and cure. The SA / Cu2O / CM superhydrophobic film material was successfully prepared.

[0040] Comparative Example

[0041] Wahid et al. first oxidized and etched a copper mesh with ammonium persulfate solution for 20 min to grow a Cu(OH)2 layer on the surface. Then, they immersed it in sodium sulfide solution for 30 min (sulfidation), removed it, cleaned it, and vacuum-dried it at 150 °C for 2 h to obtain Cu2S / Cu2O / CM. Finally, they immersed it in stearic acid ethanol solution for 5 h to obtain a superhydrophobic SA / Cu2S / Cu2O / CM. Paul et al. annealed the pretreated copper mesh at 500 °C for 4 h to form copper oxide, then immersed it in stearic acid ethanol solution for 2 h, cleaned it, and dried it at 60 °C to obtain a superhydrophobic / superoleophilic copper mesh.

[0042] The aforementioned comparative examples require multiple chemical reactions or high-temperature conditions (annealing at 500°C). The process of this invention is relatively simple, and the superhydrophobic modification of CM can be achieved under relatively mild reaction conditions.

[0043] Application examples

[0044] Wahid et al.'s SA / Cu2S / Cu2O / CM, prepared through a multi-step process, achieved a separation efficiency of 99.6% for dichloromethane and water mixtures, and a degradation rate of 97.2% for Rhodamine B using a Fenton-like reaction (reaction time of 24 min). Paul et al.'s superhydrophobic copper mesh exhibited a separation efficiency of approximately 98% for various oil-water mixtures. This invention not only prepares a superhydrophobic copper mesh through a simple process but also realizes its application in oil-water separation and dye degradation, achieving an oil-water separation efficiency of 99.8% and a Rhodamine B degradation rate of 97.6% (reaction time of 18 min). This invention combines photocatalysis with a Fenton-like reaction, significantly improving the degradation efficiency of organic dyes.

[0045] Experimental Example 1

[0046] Material characterization:

[0047] from Figure 1 It can be seen that the original CM is a three-dimensional mesh structure woven from smooth copper wires with an average diameter of 42 μm. After solvothermal treatment, the substrate surface is covered with densely packed irregular Cu2O crystals, ranging in size from 300 nm to 3.4 μm. After modification with SA, the surface is further transformed into a rose petal-like microstructure composed of copper stearate.

[0048] Figure 2 XRD patterns of the original CM, Cu2O / CM, and SA / Cu2O / CM samples

[0049] The original CM sample exhibited three main diffraction peaks at 43.2°, 50.3°, and 72.2°, corresponding to the (111), (200), and (220) crystal planes of metallic Cu, respectively. In addition to all Cu peaks, the Cu2O / CM sample also showed characteristic diffraction peaks at 36.5° and 42.4°, which correspond to the (111) and (200) crystal planes of Cu2O, indicating that Cu2O was successfully grown on the CM surface.

[0050] Figure 3 ATR-FTIR spectra of the original CM, Cu2O / CM, and SA / Cu2O / CM samples

[0051] according to Figure 3 The results show that the spectrum of pure CM is in the range of 4000-450 cm⁻¹. -1 No obvious absorption peaks were observed within the range, which is consistent with its metallic properties. The Cu2O / CM spectrum is at 504 cm⁻¹. -1 A weak absorption peak appears at 2915 cm⁻¹, which can be attributed to the Cu-O stretching vibration of Cu₂O, indicating that Cu₂O has been successfully formed on the CM surface. Comparative analysis of pure SA and superhydrophobic SA / Cu₂O / CM samples shows that the spectrum of pure SA reaches 2915 cm⁻¹. -1 and 2850 cm -1 The two peaks at 1702 cm⁻¹ correspond to the CH symmetric and asymmetric stretching vibrations of the methyl (CH₃) and methylene (CH₂) groups, respectively. Additionally, at 1702 cm⁻¹... -1 The significant peak at cm⁻¹ can be attributed to the C=O stretching vibration of the carboxyl group. The spectrum of SA / Cu₂O / CM retains all the characteristic peaks of SA, but the C=O peak shifts significantly downward to 1587 cm⁻¹. -1 This displacement indicates that the COO- functional group in SA coordinates with the copper ions in Cu2O, confirming the formation of copper stearate on the Cu2O / CM surface.

[0052] The surface wettability of pure CM, Cu2O / CM, and SA / Cu2O / CM films was evaluated by measuring the contact angle of the film materials in air. The results are as follows: Figure 4 As shown, the water contact angle of pure CM in air is 127.3°, confirming its inherent hydrophobicity. A Cu₂O microstructure was formed on the CM surface via solvothermal oxidation, resulting in micro-nano-scale roughness that increased the water contact angle (WCA) to 136.0°. After further modification with SA solution, water droplets on the sample surface existed as stable spheres, and the WCA was increased to 152.5°, indicating that the prepared SA / Cu₂O / CM film possesses superhydrophobicity. This performance improvement is attributed to the synergistic effect of multi-level roughness and the surface energy reduction of the SA coating.

[0053] Experimental Example 2

[0054] The SA / Cu2O / CM obtained above was applied to oil-water separation and dye degradation, and the specific operation is as follows:

[0055] (1) Oil-water separation experiment

[0056] Different densities of oil were simulated using organic solvents such as dichloromethane, trichloromethane, kerosene, n-hexane, and toluene. 40 mL of oil was mixed with 40 mL of deionized water to obtain different oil-water mixtures, which were then poured uniformly into the upper glass tube, and oil-water separation was performed under gravity alone. Twenty cycles of separation experiments were also conducted on the dichloromethane / water mixture to verify the membrane's reusability.

[0057] Figure 5 (a) Separation efficiency and flux of SA / Cu2O / CM for different oil-water mixtures; (b) Cyclic separation stability for dichloromethane and water mixtures. Based on... Figure 5 The results show that SA / Cu2O / CM can efficiently separate mixtures of dichloromethane, kerosene, n-hexane, toluene, chloroform, and water, with a separation efficiency greater than 99.78% and a throughput of 19800 L·m⁻¹. -2 ·h -1 The above describes the separation process. After 20 cycles of separation of a dichloromethane and water mixture, the separation efficiency remained above 99.48%, and the separation flux remained at 22420 L·m⁻¹. -2 ·h -1 .

[0058] (2) Experiment on catalytic degradation of dyes

[0059] Prepare a 10 mg / L solution of methylene blue (MB) and rhodamine B (RhB) dye at pH 2. Add 0.5 g of the membrane and 50 μL of H2O2 to 100 mL of the dye solution. Conduct a catalytic experiment at 28 °C under 300 W xenon lamp irradiation at 300 rpm. Take 2 mL samples from the aqueous solution every 3 min and measure the absorbance of the MB and RhB solutions at 664 nm and 554 nm using a UV-Vis spectrophotometer.

[0060] in, Figure 6 (a) The UV absorption spectrum and color change of MB solution under 18 min of illumination; (b) The pseudo-first-order kinetic equation for the degradation of MB by SA / Cu2O / CM. Figure 7 (a) The UV absorption spectrum and color change of the RhB solution under 18 min of illumination; (b) The pseudo-first-order kinetic equation for the degradation of RhB by SA / Cu2O / CM. Figure 6 and Figure 7The results showed that the maximum absorbance values ​​of both MB and RhB solutions gradually decreased with increasing illumination time. The degradation efficiencies of SA / Cu₂O / CM on MB and RhB solutions within 18 min were 95.42% and 97.13%, respectively, and the degradation process conformed to a pseudo-first-order kinetic equation. The degradation rate constants for MB and RhB solutions were 0.1742 and 0.2067 min, respectively. -1 .

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention. Including but not limited to: (1) other oxidants such as hydrogen peroxide can be used to replace Fe. 3+ (2) The hydrophobic modifier can be replaced with other long-chain fatty acids (such as thiols, polydimethylsiloxane, etc.); (3) The substrate can be replaced with stainless steel mesh, cotton cloth, etc.

Claims

1. A method for preparing a superhydrophobic copper mesh, comprising: (1) First, cut the 200-mesh copper mesh into 4 cm × 4 cm pieces, and then clean it with ethanol and water by ultrasonic cleaning for 15 min each time to obtain copper mesh sheets for later use. (2) Immerse the copper mesh in hydrochloric acid solution, then rinse with deionized water and dry in a vacuum drying oven at 60°C to obtain a pretreated copper mesh for later use. (3) Take the pretreated copper mesh film and place it in Fe(NO3)3 solution. Stir it magnetically and reflux it under constant temperature oil bath conditions. After cooling to room temperature, take it out, rinse it with deionized water and vacuum dry it to obtain a purple-red Cu2O coating modified copper mesh for later use. (4) The purple-red Cu2O-coated copper mesh was placed in stearic acid solution, left to stand at room temperature for 12 h, then removed, rinsed with anhydrous ethanol and vacuum dried to obtain a superhydrophobic copper mesh.

2. The preparation method according to claim 1, wherein: In step (2), the hydrochloric acid concentration is 1 M and the immersion time is 10 min.

3. The preparation method according to claim 1, wherein: The constant temperature oil bath temperature in step (3) is 120 ℃; The condensation reflux time is 1 hour.

4. The preparation method according to claim 1, wherein: The Fe(NO3)3 solution in step (3) has a concentration of 15 g / L and is prepared by the following method: Pour 100 mL of deionized water into a 250 mL round-bottom flask, weigh 1.5 g of Fe(NO3)3·9H2O and add it to the flask, then shake the flask until all the particles are dissolved.

5. The preparation method according to claim 1, wherein: The vacuum drying conditions in step (3) are: drying in a vacuum drying oven at 80℃ for 2 hours.

6. The preparation method according to claim 1, wherein: The SA solution in step (4) has a concentration of 0.05 mol / L and is prepared by the following method: Weigh 1.28 g of stearic acid into 90 mL of ethanol solution and stir magnetically until completely dissolved.

7. The preparation method according to claim 1, wherein: The vacuum drying and curing conditions in step (4) are: heating and curing in a vacuum drying oven at 80℃ for 2 hours.

8. A superhydrophobic copper mesh prepared by any one of the preparation methods according to claims 1 to 7.

9. The application of the superhydrophobic copper mesh according to claim 8 in the fields of oil-water separation, water treatment and water purification, self-cleaning and corrosion protection, and biomedicine.

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