Three-dimensional short carbon fiber foam loaded Sb2S3 composite material, preparation method and application thereof

Abstract

The application belongs to the field of carbon fiber materials and environmental protection, and discloses a three-dimensional chopped carbon fiber foam loaded Sb2S3 composite material, a preparation method and application thereof. In the composite material, Sb2S3 nanoparticles are loaded on the surface and inside of the three-dimensional chopped carbon fiber foam through a one-step method. When the composite material is used for treating dye wastewater, due to the excellent photoelectrochemical properties of the Sb2S3 nanoparticles and the synergistic effect between the Sb2S3 nanoparticles and the carbon fiber, the composite material has good performance in adsorbing, photocatalyzing and electrocatalyzing the degradation of the dye wastewater. In addition, the three-dimensional chopped carbon fiber foam has large pores and a large surface area, excellent mechanical strength and recyclability, and can be efficiently used and repeatedly used in practical applications.

Description

Technical Field

[0001] This invention relates to the fields of carbon fiber materials and environmental protection, and in particular to a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material, its preparation method, and its application. Background Technology

[0002] Methyl orange, crystal violet, and methylene blue dyes are widely used in the textile, printing, cosmetic, and pharmaceutical industries. The azo groups and phenyl groups present in dye molecules exhibit chemical stability and low degradability, but their toxicity to ecosystems makes them a key focus of wastewater treatment research in the environmental field. Current treatment methods for dye wastewater include membrane filtration, catalytic oxidation, adsorption, microbial treatment, photocatalysis, and electrocatalysis. Carbon materials such as graphene, activated carbon, carbon nanotubes, and nanoporous carbon possess excellent mechanical, electrical properties, and chemical stability, making them ideal for adsorbing and degrading organic dye molecules. However, current research addresses issues such as material agglomeration, structural collapse and deformation, and the inability to recycle them. Patent CN115138342B applies porous aerogels containing polyamino-3D graphene to wastewater treatment, which can solve the problem of reduced specific surface area caused by material agglomeration. However, its strength and toughness still cannot meet the requirements for use and recycling in complex and harsh natural environments in practical applications.

[0003] Carbon fiber is a carbon material prepared by high-temperature carbonization of carbon fiber precursor, possessing characteristics such as chemical stability, high specific strength, fatigue resistance, high electrical conductivity, corrosion resistance, lightweight, and non-biotoxicity. High-performance carbon fiber can be used in sports and leisure products, aerospace products, medical devices, musical instruments, wind power generation, transportation, and other industrial components. Using carbon fiber as a supporting material to construct self-supporting three-dimensional carbon fiber materials can compensate for the reduced strength and toughness of nanomaterials. Short-cut carbon fiber originates from the precise cutting of high-quality continuous carbon fiber bundles, with controllable length. It retains the good mechanical strength, electrochemical conductivity, and excellent modifiability of carbon fiber, and has the advantages of shorter dimensions, easier construction into three-dimensional structures, easier surface treatment, and high loading capacity for nanoparticles, resulting in superior performance in dye wastewater treatment.

[0004] Commercially available chopped carbon fibers (BCCFs) often have sizing agents on their surface, which alters the surface structure and chemical functional groups of the fibers, affecting their adsorption performance and limiting the adhesion and synergistic effects of nanoparticles. However, unsizing BCCFs suffer from aggregation, hindering their self-assembly into three-dimensional structures for application in dye wastewater treatment. Therefore, dispersing unsizing BCCFs and constructing them into self-supporting three-dimensional structures is a key research focus. Three-dimensional chopped carbon fiber materials possess a larger specific surface area, excellent electrical conductivity and mechanical properties, and can effectively adsorb small molecules as adsorbents or as supporting materials to load other nanomaterials, thereby enhancing catalytic degradation efficiency. Therefore, designing three-dimensional chopped carbon fiber composites with high specific surface area, stable structure, and high nanomaterial loading rates can fully leverage the strength advantages of carbon fibers and achieve their recycling in practical wastewater treatment. Summary of the Invention

[0005] This invention addresses the many shortcomings of existing technologies by providing a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material, its preparation method, and its applications.

[0006] The main concept of this invention is as follows:

[0007] Unsized chopped carbon fibers suffer from fiber aggregation, hindering their self-assembly into a three-dimensional structure for application in dye wastewater treatment. Therefore, the inventors opted for surface treatment and special dispersion of the unsized chopped carbon fibers. The dispersed fibers were then attached and embedded into the surface and interior of a three-dimensional foam template material using external force. The fibers were then compacted by pressing, and the original foam template was removed using a hydrothermal method, successfully constructing a self-supporting three-dimensional foam structure from the chopped carbon fibers.

[0008] Three-dimensional chopped carbon fiber foam materials possess a larger specific surface area, excellent electrical conductivity, and mechanical properties. They can effectively adsorb small molecules as adsorbents or act as supporting materials to load other nanomaterials, achieving synergistic effects and improving catalytic degradation efficiency, thus enabling practical recycling. Sb₂S₃ nanoparticles exhibit excellent photochemical and electrochemical properties, making them widely applicable in the photocatalytic and electrocatalytic degradation of dye molecules. By loading Sb₂S₃ nanoparticles onto the surface and interior of three-dimensional chopped carbon fiber foam using a one-step method, the high nanoparticle loading rate, full exposure of catalytically active sites, and synergistic effect with the three-dimensional chopped carbon fiber foam result in a composite material with excellent adsorption, photocatalytic, and electrocatalytic degradation performance of dye wastewater. Furthermore, the large pore size and surface area of ​​the three-dimensional chopped carbon fiber foam, along with its excellent mechanical strength and recyclability, enable practical recycling.

[0009] The specific technical solution of this invention is as follows:

[0010] A three-dimensional chopped carbon fiber foam-loaded Sb2S3 composite material, wherein the percentage of Sb2S3 loaded to the total mass of the three-dimensional chopped carbon fiber foam, i.e., the loading rate, is 30-80%, with an optimal loading rate of 50%.

[0011] The three-dimensional chopped carbon fiber foam used is obtained by cleaning and surface treating chopped carbon fibers, mixing them with foam, and then ultrasonically extruding and hydrothermally treating them.

[0012] The chopped carbon fibers are chemically treated, unsized pure carbon fibers, and the pure carbon fibers are selected from one or more of polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, viscose-based carbon fibers, and vapor-grown carbon fibers.

[0013] The chopped carbon fibers have a diameter of 1μm–15μm and a length of 0.5mm–2mm.

[0014] The inventors further provided a method for preparing the above-mentioned three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material, the specific steps of which are as follows:

[0015] (1) After cleaning and surface treatment of short-cut carbon fibers, they are mixed with foam, ultrasonically extruded, and hydrothermally treated to prepare three-dimensional short-cut carbon fiber foam.

[0016] (2) Three-dimensional short-cut carbon fiber foam was mixed with precursor molecules for preparing Sb2S3 nanoparticles and stirred to prepare three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material.

[0017] More specific steps (1) include:

[0018] A1. Clean and chemically treat the surface of unsized chopped carbon fibers, wash with deionized water and then dry.

[0019] A2. The short-cut carbon fibers treated according to step A1 are ultrasonically dispersed in an aqueous solution at a concentration of 1–4 g / L.

[0020] The above aqueous solution also contains one or more of cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethyl cellulose, cellulose acetate, cellulose triacetate, and cellulose acetate butyrate; preferably, the aqueous solution is an aqueous solution of cellulose, carboxymethyl cellulose, or hydroxyethyl cellulose with a concentration of 0.5–6 g / L.

[0021] A3. Place a piece of foam material cut to a certain size in 50 mL of the dispersion obtained in step A2, and stir magnetically to obtain a material with short-cut carbon fibers inserted on the surface and inside the foam.

[0022] A4. Press the material obtained in step A3 under the tablet press;

[0023] A5. The material obtained in step A4 is placed in a hydrothermal reactor. After the hydrothermal reaction, the foam disappears, and three-dimensional short-cut carbon fiber foam is obtained.

[0024] Among them, the short-cut carbon fiber mentioned in step A1 is chemically treated, unsized pure carbon fiber;

[0025] The pure carbon fiber is selected from one or more of polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, viscose-based carbon fiber, and vapor-grown carbon fiber; the chopped carbon fiber has a diameter of 1μm–15μm and a length of 0.5mm–2mm.

[0026] The chopped carbon fiber cleaning process involves ultrasonic cleaning using one or a mixture of acetone, anhydrous ethanol, methanol, ethylene glycol, diethyl ether, dichloromethane, cyclohexane, and N,N-dimethylformamide. The ultrasonic cleaner has a minimum power of 1000W, and acetone and anhydrous ethanol are preferred. The cleaning is performed three times each, followed by natural air drying to remove oil and impurities from the surface of the chopped carbon fiber.

[0027] Chemical treatment includes acid treatment, oxidation treatment, or surface modification treatment, with a mixed solution of concentrated sulfuric acid and hydrogen peroxide being preferred.

[0028] Hydrogen peroxide (30%, AR) was added to concentrated sulfuric acid (98%) (volume ratio 3:7). The temperature of the mixed solution rose sharply. After mixing evenly, the surface-cleaned short-cut carbon fibers were placed in the mixed solution and soaked for 20 minutes. The soaked short-cut carbon fibers were then transferred to a beaker and rinsed three times with deionized water. It was observed that the surface of the short-cut carbon fibers was hydrophilic and dispersed evenly in deionized water without agglomeration.

[0029] The above-mentioned mixed solution of hydrogen peroxide and concentrated sulfuric acid has strong oxidizing properties, which can remove organic matter from the short-cut carbon fibers. Moreover, the surface of the short-cut carbon fibers treated with it will have hydroxyl groups, thus making them highly hydrophilic.

[0030] Furthermore, the short-cut carbon fibers treated according to step A1 are ultrasonically dispersed in an aqueous solution. Preferably, one or more of cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethyl cellulose, cellulose acetate, cellulose triacetate, and cellulose acetate butyrate are added to the aqueous solution, which can effectively increase the dispersibility of the short-cut carbon fibers. Moreover, the above-mentioned cellulose can be more easily removed during subsequent processing without affecting the surface structure and functional groups of the short-cut carbon fibers.

[0031] Furthermore, the foam material selected in step A3 is one of polyethylene foam, polystyrene foam, polypropylene foam, or melamine foam, with melamine foam being preferred. These foams are primarily composed of carbon or nitrogen, possessing large porosity and a certain strength. At room temperature, they can act as templates to allow chopped carbon fibers to adhere to the surface and embed themselves within. The foam size ranges from 0.5cm × 0.5cm × 1mm to 2cm × 2cm × 5mm. After immersing the foam in the dispersion at the above ratio, it is stirred with a magnetic stirrer at 1000 rpm for 0.5h–2h until the chopped carbon fibers are adhered and embedded in the surface and interior of the foam material. After approximately 0.5h of stirring, a foam composite with surface-attached and internally embedded chopped carbon fibers is obtained. As the stirring time increases, the amount embedded in the foam surface and interior increases. However, after 2h, the foam surface is essentially completely covered with chopped carbon fibers, and the amount of chopped carbon fibers adhering to the foam no longer increases significantly, at which point stirring can be stopped.

[0032] Furthermore, in step A4, the pressure of the press is 5–22 MPa, and the pressing time is 30 s–10 min. Pressing causes the composite material formed by the attachment of chopped carbon fibers and the intercalation of the foam substrate to deform under pressure, making the chopped carbon fibers interlock more densely and preventing structural loosening.

[0033] In step A5, the hydrothermal reaction temperature is 150–250℃, and the reaction time is 8–24 hours. After the reaction, the foam material disappears. The foam template decomposes into small molecules after being subjected to high temperature and high pressure chemical treatment, and the main skeleton structure disappears, but the intercalated short-cut carbon fibers are retained, so that the short-cut carbon fibers form a dense three-dimensional foam structure without structural loosening.

[0034] The self-assembled three-dimensional chopped carbon fiber foam was washed three times with deionized water and then dried in a drying oven at 60°C.

[0035] Step (2) above specifically includes:

[0036] B1. Place the three-dimensional chopped carbon fiber foam obtained in step A5 into ethylenediamine, with the mass ratio of chopped carbon fiber to ethylenediamine being 0.05–0.07 g: 20 mL;

[0037] B2. Add 0.5–2 g of the precursor ethyl xanthate to the B1 solution and stir at room temperature for 2–5 days;

[0038] During the above process, a reddish-brown solid appears in the solution. The solid particles are deposited on the surface of the chopped carbon fibers and adhere to the surface and interior of the three-dimensional chopped carbon fiber foam.

[0039] B3. The composite material obtained in B2 is washed three times by soaking in deionized water and anhydrous ethanol, and then dried in a drying oven at 40°C to obtain the target composite material.

[0040] Composite materials can be characterized using X-ray photoelectron spectroscopy (XPS). Figure 1 X-ray photoelectron spectra of C1s, N1s, Sb3d and S2p show that the addition of cellulose and other substances in the early stage does not affect the surface composition and structure of the short-cut carbon fibers, and the deposited particles are Sb2S3 nanomaterials.

[0041] In the aforementioned three-dimensional chopped carbon fiber foam-supported Sb₂S₃ composite material, Sb₂S₃ is deposited on the surface of the chopped carbon fibers as nanoparticles with a particle size of 10–50 nm (average particle size 30 nm) through a solvation reaction of precursor molecules. The three-dimensional chopped carbon fiber foam has a large Sb₂S₃ loading rate, with a large number of Sb₂S₃ particles dispersed both on its surface and inside. The percentage of Sb₂S₃ particles in the total mass of the three-dimensional chopped carbon fiber foam, i.e., the loading rate, is 30–80%, with an optimal loading rate of 50%.

[0042] Using three-dimensional chopped carbon fiber foam as a support material can prevent the aggregation of high-load Sb2S3 nanoparticles, maximizing the exposure of the catalytic active sites of the Sb2S3 nanoparticles and allowing them to work synergistically to improve the efficiency of photocatalytic and electrocatalytic degradation of dye molecules in the composite material. After loading Sb2S3 nanoparticles onto three-dimensional chopped carbon fiber foam, the catalytic degradation efficiency of methyl orange dye molecules was significantly improved, with the complete catalytic degradation time shortened from 9.5 h to 4 h, representing a 36.2% increase in degradation efficiency. The three-dimensional chopped carbon fiber foam-loaded Sb2S3 composite material exhibits excellent recyclability, with the degradation efficiency decreasing by only 5.2% after six cycles.

[0043] The beneficial effects of this invention are as follows:

[0044] 1. This invention prepares recyclable three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite materials. The preparation process is simple and the production conditions are mild.

[0045] 2. The three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material possesses good mechanical strength and can be self-supporting as an independent adsorbent, photocatalyst, and electrocatalyst, facilitating practical operation and subsequent recycling. The three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material can be used as an adsorbent because the surface-treated short-cut carbon fibers have more functional groups, making it easier to adsorb dye molecules. Excellent adsorption performance is also a prerequisite for photocatalytic and electrocatalytic performance. The three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material can be used as a photocatalyst because Sb2S3 nanomaterials themselves are excellent semiconductor photocatalysts. The three-dimensional short-cut carbon fiber foam, as a supporting material, can prevent the highly loaded Sb2S3 nanoparticles from agglomerating, exposing photocatalytic active sites and improving the photocatalytic degradation effect of dye molecules. When used as an electrocatalyst, the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material, in addition to preventing Sb2S3 nanoparticle agglomeration, also has the advantage of good conductivity, allowing the loaded Sb2S3 nanoparticles to undergo redox reactions under voltage, achieving the effect of electrocatalytic degradation of dye molecules.

[0046] 3. Three-dimensional short-cut carbon fiber foam retains the excellent mechanical properties and electrical conductivity of carbon fiber. The network structure increases the contact area with the test liquid, thereby improving the adsorption effect and catalytic efficiency.

[0047] 4. By depositing Sb2S3 nanoparticles on the surface and interior of three-dimensional chopped carbon fiber foam in one step using a simple in-situ method, the catalytic active sites of the nanoparticles can be fully exposed and they can work synergistically with the chopped carbon fibers to give full play to their excellent photocatalytic and electrocatalytic performance. Attached Figure Description

[0048] Figure 1 X-ray photoelectron spectroscopy (XPS) of C1s, N1s, Sb3d, and S2p of a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite.

[0049] Figure 2 Scanning electron microscope (SEM) images (A) and (B) of a single chopped carbon fiber, respectively, of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 1 of this invention.

[0050] Figure 3 The UV-Vis absorption spectrum (A) and degradation rate graph (B) of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 1 of this invention for the electrodegradation of methyl orange solution are shown. (The inset is a digital photograph comparison of the fading of methyl orange solution over time).

[0051] Figure 4The images shown are scanning electron microscope (SEM) images (A) of the three-dimensional short-cut carbon fiber foam prepared in Comparative Example 1 of the present invention and (B) of a single short-cut carbon fiber.

[0052] Figure 5 The UV-Vis absorption spectrum (A) and degradation rate spectrum (B) of the three-dimensional short-cut carbon fiber foam electrodegradation methyl orange solution prepared in Comparative Example 1 of this invention are shown.

[0053] Figure 6 The UV-Vis absorption spectra of three dye solutions (methyl orange, crystal violet, and methylene blue) are shown in (A), and the UV-Vis absorption spectra of the electrodegradable mixed dye solution (a mixed solution of methyl orange, crystal violet, and methylene blue) of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 2 of this invention are shown in (B) (the inset is a digital photo comparison of the fading of the mixed dye).

[0054] Figure 7 The UV-Vis absorption spectrum (A) and degradation rate diagram (B) of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 3 of this invention are shown.

[0055] Figure 8 The graph shows the cyclic performance test results of electrodegradation of methyl orange solution by the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 4 of this invention. Detailed Implementation

[0056] To better understand the present invention, the following embodiments further illustrate the content of the present invention. The present invention described herein is only for explaining the present invention and is not intended to limit the present invention.

[0057] The electrocatalytic tests in the following examples and comparative examples were performed using an electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd., model CHI760E). A platinum sheet electrode was used as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The prepared three-dimensional chopped carbon fiber foam-supported Sb₂S₃ composite material and the three-dimensional chopped carbon fiber foam were fixed with electrode clamps as the working electrodes. A three-electrode system was constructed using a 50 mL beaker and a perforated polytetrafluoroethylene (PTFE) cover. The three electrodes were inserted into the holes in the cover and immersed in the solution in the beaker. The working voltage measured at room temperature was compared with that of a saturated calomel electrode (SCE). A 0.1 mol·L⁻¹ solution was used. -1 A 16 mg / L solution of methyl orange and a mixed dye solution (a mixture of methyl orange, crystal violet, and methylene blue) was prepared using PBS solution (pH=7) (a mixture of disodium hydrogen phosphate and sodium dihydrogen phosphate) for electrochemical degradation experiments. The applied voltage for the electrocatalytic degradation experiment was 2.4 V (vs. SCE). Dye solution samples were taken at different test times, and the absorbance was measured using a UV-Vis spectrophotometer to calculate the degradation rate and analyze the electrocatalytic performance.

[0058] The photocatalytic testing in the following examples was conducted using a photochemical reactor (Nanjing Xujiang Electromechanical Plant, model XPA). The specific steps are as follows: The prepared three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material was added to the target degradation product (50 mL crystal violet solution, concentration 16 mg / L). After initial sonication or stirring in the dark, the sample was placed in a dark room for static adsorption. The adsorbed sample was then transferred to a visible light photocatalytic reactor. The circulating water pump was turned on, the light source was adjusted to a 500W xenon lamp, and the filter (wavelength range 200–800 nm) was removed. The reaction time was recorded. Crystal violet solution was sampled every 1 hour or 30 minutes, and the absorbance of the degraded crystal violet solution was measured using a UV-Vis spectrophotometer. The degradation rate was calculated, and the photocatalytic performance was analyzed.

[0059] Wherein, electrocatalytic / photocatalytic degradation rate % = (A0 – A) / A0 = 1 – A / A0 = 1 – C / C0

[0060] C0, the initial concentration of the dye solution;

[0061] C, the concentration of the dye solution after t min;

[0062] A0, the absorbance of the initial dye solution at the wavelength of maximum absorption;

[0063] A, the absorbance of the dye solution at the maximum absorption wavelength after t min.

[0064] Example 1

[0065] The preparation of a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material and its application in electrocatalytic wastewater treatment includes the following steps:

[0066] 0.0700g of unsized polyacrylonitrile-based short-cut carbon fibers with a diameter of 7.5μm and a length of 1mm were ultrasonically cleaned three times with acetone and anhydrous ethanol in an ultrasonic cleaner with a power of 1000W and then air-dried.

[0067] Soak it in a 20 mL solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 7:3 for 20 min, then transfer it to a beaker and rinse it three times with deionized water. It can be observed that the surface of the short-cut carbon fiber is hydrophilic and it is uniformly dispersed in deionized water without agglomeration.

[0068] The cleaned and dried chopped carbon fibers were dispersed in 50 mL of an aqueous solution containing 0.2 g of carboxymethyl cellulose (the concentration of carboxymethyl cellulose was 4 g / L), and the concentration of the chopped carbon fibers dispersed in the solution was 1.4 g / L.

[0069] Melamine foam with dimensions of 1cm×1cm×1mm was placed in the above-mentioned chopped carbon fiber dispersion. After stirring with a magnetic stirrer at 1000rpm for 1 hour, the foam with chopped carbon fibers embedded on the surface and inside was transferred to a press and pressed at a pressure of 15MPa for 1 minute.

[0070] The compressed material was transferred to a hydrothermal reactor and subjected to a hydrothermal reaction at 180°C for 10 hours. After the reaction, the foam disappeared, yielding a self-supporting three-dimensional chopped carbon fiber foam with dimensions approximately 1 cm × 1 cm × 1 mm. The obtained self-supporting three-dimensional chopped carbon fiber foam was then washed three times with deionized water and dried in a drying oven at 60°C.

[0071] The dried self-supporting three-dimensional chopped carbon fiber foam was placed in 20 mL of ethylenediamine, and 0.8 g of antimony ethyl xanthate was added. After stirring at room temperature for three days, a reddish-brown precipitate adhered to the surface and interior of the three-dimensional chopped carbon fiber foam. The foam was then washed three times with deionized water and anhydrous ethanol, and finally dried in a drying oven at 40 °C. Testing showed that the loading rate of the three-dimensional chopped carbon fiber foam-loaded Sb2S3 composite material obtained at this time was 53%.

[0072] Figure 1 The X-ray photoelectron spectroscopy (XPS) spectra of C1s, N1s, Sb3d, and S2p of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material obtained above are shown. Figure 1 (AB) It is known that the addition of substances such as cellulose in the early stages does not affect the surface composition and structure of chopped carbon fibers. The C1s phase of the chopped carbon fiber foam splits into four peaks at 284.75 eV, 285.0 eV, 286.5 eV, and 289.2 eV, corresponding to the C=C, C=C, CO, and O=CO functional groups, respectively. Among them, the C=C bond and the C=C bond represent the sp bonds of the chopped carbon fiber. 2 and sp 3 Hybridized carbon atom structure. Its low-strength oxygen-containing functional groups also verify the chemical stability of the short-cut carbon fiber foam. The N 1s peak splits into pyridine-N (398.59 eV), pyrrole-N (400.15 eV), quaternary ammonium salt-N (401.1 eV), and oxide-N (402 eV). From Figure 1 (CD) confirms that the deposited particles are Sb2S3 nanoparticles, Sb3d 5 / 2 and Sb 3d 3 / 2 The binding energies are located at 530.2 eV and 539.5 eV, respectively, and the S2p peak splits into S2p peaks. 1 / 2 and S2p 3 / 2 The corresponding peak positions are 161.9 eV and 163.1 eV, respectively.

[0073] Figure 2Scanning electron microscope (SEM) images (A) and (B) magnified images of a single chopped carbon fiber in the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in this embodiment. Figure 2 It can be seen that after loading Sb2S3 nanoparticles, the diameter of the chopped carbon fibers is about 7.5 μm, and their size and morphology do not change significantly. The chopped carbon fibers randomly cross and stack to form a three-dimensional network structure. The surface of the chopped carbon fibers is loaded with Sb2S3 nanoparticles with a size range of 10–50 nm (average particle size 30 nm).

[0074] Figure 3 The UV-Vis absorption spectrum (A) of the electrodegradation of methyl orange solution using the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared for this embodiment, clamped on an electrode clip as the working electrode of a three-electrode system (implementation voltage 2.4V), is shown (with insets showing digital photographs comparing the fading of the methyl orange solution over time) and the degradation rate (B). Figure 3 (A) shows that as degradation time increases, the absorbance at the maximum absorption wavelength of methyl orange (465 nm) gradually decreases, indicating that the chromogenic groups of the dye are destroyed, consistent with the gradual lightening of the color of the methyl orange solution to colorless in the inset diagram. From Figure 3 (B) It can be seen that the degradation rate of methyl orange by the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material can reach 97.9% in 4 hours, which has a high degradation efficiency.

[0075] Comparative Example 1

[0076] The preparation process of the control group three-dimensional short-cut carbon fiber foam is the same as that of Example 1, except that Sb2S3 nanoparticles are not loaded.

[0077] The three-dimensional short-cut carbon fiber foam prepared in Comparative Example 1 was used as the working electrode. The voltage of the three-electrode system was set to 2.4V to carry out electrocatalytic degradation experiments on methyl orange solution.

[0078] Figure 4 Scanning electron microscope (SEM) images (A) of the three-dimensional chopped carbon fiber foam prepared for this comparative example and (B) of a single chopped carbon fiber are shown. Figure 4 It can be seen that the surface of the chopped carbon fibers is smooth, with no obvious impurities attached, and the diameter is about 7.5 μm. The chopped carbon fibers are randomly stacked and cross each other to form a three-dimensional network structure, forming a three-dimensional chopped carbon fiber foam.

[0079] Figure 5 The images show the UV-Vis absorption spectrum (A) and degradation rate (B) of the three-dimensional short-cut carbon fiber foam electrodegradation methyl orange solution prepared in Comparative Example 1 of this invention. Figure 5It can be seen that as the degradation time increases, the absorbance at the maximum absorption wavelength of methyl orange (465 nm) gradually decreases, indicating that the chromogenic groups of the dye are destroyed. The degradation rate of methyl orange by three-dimensional chopped carbon fiber foam is only 62.5% after 4 hours, but the degradation rate can reach 98.8% after extending the time to 9.5 hours.

[0080] Comparing the data from Comparative Example 1 and Example 1 reveals that the three-dimensional chopped carbon fiber foam possesses a certain ability to adsorb and degrade methyl orange dye molecules, but the complete degradation of the dye molecules requires a relatively long time. However, after loading Sb2S3 nanoparticles onto the three-dimensional chopped carbon fiber foam, as shown in Example 1, the electrocatalytic degradation effect of methyl orange dye molecules is significantly improved, and the degradation time is shortened by nearly half. The results indicate that the three-dimensional chopped carbon fiber foam can effectively degrade methyl orange, and the addition of Sb2S3 nanomaterials can synergistically improve the degradation efficiency.

[0081] Example 2

[0082] The preparation of a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material and its application in electrocatalytic wastewater treatment includes the following steps:

[0083] 0.1000g of unsized pitch-based short-cut carbon fibers (5μm in diameter and 1.5mm in length) were ultrasonically cleaned three times with acetone and anhydrous ethanol using a 1200W ultrasonic cleaner and then air-dried. They were then immersed in a 20mL solution of concentrated sulfuric acid and hydrogen peroxide (7:3 volume ratio) for 20 minutes, transferred to a beaker, and rinsed three times with deionized water. The results showed that the short-cut carbon fibers were hydrophilic on the surface and uniformly dispersed in the deionized water without agglomeration.

[0084] The cleaned and dried short-cut carbon fibers were dispersed in 50 mL of an aqueous solution containing 0.25 g of cellulose (cellulose concentration of 5 g / L), and the concentration of the short-cut carbon fibers dispersed in the solution was 2 g / L.

[0085] Melamine foam with dimensions of 1.5cm×1.5cm×2mm was placed in the above-mentioned chopped carbon fiber dispersion and stirred for 1.5 hours with a magnetic stirrer at a speed of 1000 rpm. The foam with chopped carbon fibers embedded on the surface and inside was then transferred to a press and pressed at a pressure of 10 MPa for 5 minutes.

[0086] The compressed material was transferred to a hydrothermal reactor and subjected to a hydrothermal reaction at 200°C for 8 hours. After the reaction, the foam disappeared, yielding a self-supporting three-dimensional chopped carbon fiber foam with dimensions approximately 1.5cm × 1.5cm × 2mm. The self-assembled three-dimensional chopped carbon fiber foam was then washed three times with deionized water and dried in a drying oven at 60°C.

[0087] The dried self-supporting three-dimensional chopped carbon fiber foam was placed in 30 mL of ethylenediamine, and 1.0 g of antimony ethyl xanthate was added. After stirring for four days, a reddish-brown precipitate adhered to the surface and interior of the three-dimensional chopped carbon fiber foam. The foam was then washed three times with deionized water and anhydrous ethanol, and finally dried in a drying oven at 40°C. Testing showed that the loading rate of the three-dimensional chopped carbon fiber foam-loaded Sb2S3 composite material obtained at this time was 46%.

[0088] The three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 2 was clamped onto an electrode holder as the working electrode of a three-electrode system. The three-electrode system was set with a voltage of 2.4V to conduct electrocatalytic degradation experiments on a mixed solution of methyl orange, crystal violet, and methylene blue.

[0089] Figure 6 (A) is the UV-Vis absorption spectrum of a mixed solution of methyl orange, crystal violet, and methylene blue (mixed in a volume ratio of 1:1:1). Figure 6 (B) is the UV-Vis absorption spectrum of the electrodegradable mixed dye solution (a mixed solution of methyl orange, crystal violet and methylene blue) of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 2 of the present invention (inset is a digital photo comparison of the fading of the mixed dye).

[0090] Depend on Figure 6 (A) indicates that the wavelengths of the UV-Vis absorption peaks of methyl orange are 272.5 and 465 nm, those of crystal violet are 248, 301, 544, and 584 nm, and those of methylene blue are 247, 293, 614, and 664 nm. Figure 6 (B) It is known that, using the three-dimensional chopped carbon fiber foam-supported Sb2S3 composite material as the working electrode, the absorbance values ​​of the characteristic peaks of the mixed solution of methyl orange, crystal violet, and methylene blue decreased to varying degrees with time, indicating that the chromogenic groups of the mixed dyes were destroyed, consistent with the gradual lightening of the color of the mixed dye solution in the inner inset. After 5 hours of degradation, the mixed dye solution was degraded into a colorless solution. This demonstrates that the three-dimensional chopped carbon fiber foam-supported Sb2S3 composite material can not only degrade methyl orange solution but also has a good degradation effect on mixed dyes, showing promising application prospects in the field of practical wastewater treatment.

[0091] Example 3

[0092] The preparation of a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material and its application in photocatalytic wastewater treatment includes the following steps:

[0093] 0.1500g of unsized pitch-based short-cut carbon fibers (8μm in diameter and 0.5mm in length) were ultrasonically cleaned three times with acetone and anhydrous ethanol using a 1000W ultrasonic cleaner and then air-dried. They were then immersed in a 20mL solution of concentrated sulfuric acid and hydrogen peroxide (7:3 volume ratio) for 20 minutes, transferred to a beaker, and rinsed three times with deionized water. It was observed that the surface of the short-cut carbon fibers was hydrophilic and uniformly dispersed in deionized water without agglomeration.

[0094] The cleaned and dried chopped carbon fibers were dispersed in 50 mL of an aqueous solution containing 0.3 g of hydroxyethyl cellulose (the concentration of hydroxyethyl cellulose was 6 g / L), and the concentration of the chopped carbon fibers dispersed in the solution was 3 g / L.

[0095] Melamine foam with dimensions of 2cm×2cm×3mm was placed in the above-mentioned chopped carbon fiber dispersion. After stirring with a magnetic stirrer at 1000rpm for 2 hours, the foam with chopped carbon fibers embedded on the surface and inside was transferred to a press and pressed at a pressure of 18MPa for 1 minute.

[0096] The compressed material was transferred to a hydrothermal reactor and subjected to a hydrothermal reaction at 220°C for 8 hours. After the foam disappeared, a self-supporting three-dimensional chopped carbon fiber foam with dimensions approximately 2cm × 2cm × 3mm was obtained. The self-assembled three-dimensional chopped carbon fiber foam was washed three times with deionized water and then dried in a drying oven at 60°C.

[0097] The dried self-supporting three-dimensional chopped carbon fiber foam was placed in 50 mL of ethylenediamine, and 2.5 g of antimony ethyl xanthate was added. After stirring for three days, a reddish-brown precipitate adhered to the surface and interior of the three-dimensional chopped carbon fiber foam. The foam was then washed three times with deionized water and anhydrous ethanol, and finally dried in a drying oven at 40 °C. The loading rate of the three-dimensional chopped carbon fiber foam-loaded Sb2S3 composite material obtained at this time was 77%.

[0098] The three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in Example 3 was subjected to visible light photocatalysis testing of crystal violet. The test results are as follows: Figure 7 As shown, by Figure 7 It can be seen that as the reaction time increases, the absorbance of the characteristic absorption peak of crystal violet gradually decreases, and a degradation rate of 93% can be achieved in 3.5 hours, which shows the excellent photocatalytic performance of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material.

[0099] Example 4

[0100] The preparation of a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material and its application in electrocatalytic wastewater treatment includes the following steps:

[0101] 0.200g of unsized polyacrylonitrile-based chopped carbon fibers (10μm in diameter and 2mm in length) were ultrasonically cleaned three times with acetone and anhydrous ethanol using a 1200W ultrasonic cleaner and then air-dried. The fibers were then immersed in a 20mL solution of concentrated sulfuric acid and hydrogen peroxide (7:3 volume ratio) for 20 minutes, transferred to a beaker, and rinsed three times with deionized water. The results showed that the chopped carbon fibers were hydrophilic on the surface and uniformly dispersed in the deionized water without agglomeration.

[0102] The cleaned and dried chopped carbon fibers were dispersed in 50 mL of an aqueous solution containing 0.3 g of cellulose (cellulose concentration of 6 g / L), and the concentration of the chopped carbon fibers dispersed in the solution was 4 g / L.

[0103] Melamine foam with dimensions of 1.5cm×1.5cm×1mm was placed in the above-mentioned chopped carbon fiber dispersion and stirred for 2 hours with a magnetic stirrer at 1000rpm. The foam with chopped carbon fibers embedded on the surface and inside was then transferred to a press and pressed at a pressure of 20MPa for 1 minute.

[0104] The compressed material was transferred to a hydrothermal reactor and subjected to a hydrothermal reaction at 240°C for 10 hours. After the foam disappeared, a self-supporting three-dimensional chopped carbon fiber foam with dimensions approximately 1.5cm × 1.5cm × 1mm was obtained. The self-assembled three-dimensional chopped carbon fiber foam was washed three times with deionized water and then dried in a drying oven at 60°C.

[0105] The dried self-supporting three-dimensional chopped carbon fiber foam was placed in 70 mL of ethylenediamine, and 2.2 g of antimony ethyl xanthate was added. After stirring for four days, a reddish-brown precipitate adhered to the surface and interior of the three-dimensional chopped carbon fiber foam. The foam was then washed three times with deionized water and anhydrous ethanol, and finally dried in a drying oven at 40 °C. The loading rate of the three-dimensional chopped carbon fiber foam-loaded Sb2S3 composite material obtained at this time was 50%.

[0106] Figure 8 Cyclic performance test results of electrodegradation of methyl orange solution using a three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material prepared in this embodiment. Figure 8 It can be seen that as the number of electrodegradation cycles of methyl orange increases, the electrodegradation efficiency of the composite material for 4 hours gradually decreases from 98%, until the degradation rate reaches 92.8% after the sixth cycle of electrodegradation of methyl orange for 4 hours. That is, the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material has excellent recyclability, and the electrodegradation efficiency only decreases by 5.2% after 6 cycles, still showing excellent electrodegradation effect.

[0107] For those skilled in the art, the specific embodiments are merely illustrative descriptions of the present invention. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A three-dimensional chopped carbon fiber foam-supported Sb2S3 composite material, characterized in that: The percentage of Sb2S3 loaded in the total mass of the three-dimensional chopped carbon fiber foam, i.e., the loading rate, is 30-80%. The three-dimensional short-cut carbon fiber foam used is obtained by washing and chemically treating short-cut carbon fibers, mixing them with foam, and then ultrasonically extruding and hydrothermally treating them; the chemical treatment is an oxidation treatment. The chopped carbon fibers are unsized pure carbon fibers, and the pure carbon fibers are selected from one or more of polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, viscose-based carbon fibers, and vapor-grown carbon fibers; the chopped carbon fibers have a diameter of 1 µm-15 µm and a length of 0.5 mm-2 mm. The selected foam is one of polyethylene foam, polystyrene foam, polypropylene foam, or melamine foam; the hydrothermal reaction temperature is 150-250 ℃, and the reaction time is 8-24 h.

2. The three-dimensional short-cut carbon fiber foam-loaded Sb2S3 composite material according to claim 1, characterized in that: The percentage of Sb2S3 loaded in the three-dimensional chopped carbon fiber foam is 50%.

3. The method for preparing the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 1, characterized in that, The specific steps are as follows: (1) After cleaning and chemically treating the short carbon fibers, they are mixed with foam, ultrasonically extruded, and hydrothermally treated to prepare three-dimensional short carbon fiber foam; (2) Three-dimensional short-cut carbon fiber foam is mixed with raw materials for preparing Sb2S3 nanoparticles and stirred to prepare three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material.

4. The method for preparing the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 3, characterized in that, Step (1) specifically includes: A1. Clean and chemically treat the surface of the short-cut carbon fibers, wash with deionized water and then dry; A2. The short-cut carbon fibers treated according to step A1 are ultrasonically dispersed in an aqueous solution, and the concentration of the short-cut carbon fibers dispersed therein is 1-4 g / L; A3. Place a piece of foam material cut to a certain size in 50 mL of the dispersion obtained in step A2, and stir magnetically to obtain a material with short-cut carbon fibers inserted on the surface and inside the foam. A4. Press the material obtained in step A3 under a press; A5. The material obtained in step A4 is placed in a hydrothermal reactor. After the hydrothermal reaction, the foam disappears, and three-dimensional short-cut carbon fiber foam is obtained.

5. The method for preparing the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 4, characterized in that, The short-cut carbon fibers mentioned in step A1 are unsized pure carbon fibers; the pure carbon fibers are selected from one or more of polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, viscose-based carbon fibers, and vapor-grown carbon fibers; the short-cut carbon fibers have a diameter of 1µm-15µm and a length of 0.5 mm-2 mm; the carbon fiber cleaning refers to ultrasonic cleaning using one or a mixture of acetone, anhydrous ethanol, methanol, ethylene glycol, diethyl ether, dichloromethane, cyclohexane, and N,N-dimethylformamide, with a minimum power of 1000 W for the ultrasonic cleaner, followed by natural air drying; the chemical treatment is an oxidation treatment.

6. The method for preparing the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 4, characterized in that, The aqueous solution of A2 also contains one or more of cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethyl cellulose, cellulose acetate, cellulose triacetate, and cellulose acetate butyrate; the concentration is 0.5-6 g / L.

7. The method for preparing the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 4, characterized in that, The foam material selected in step A3 is one of polyethylene foam, polystyrene foam, polypropylene foam, or melamine foam, with a foam size range of 0.5cm×0.5cm×1mm-2cm×2cm×5mm. The foam is soaked in the dispersion solution according to the ratio and then stirred with a magnetic stirrer at 1000 rpm for 0.5 h-2 h until the short carbon fibers are attached and embedded in the surface and interior of the foam material. The pressure of the press mentioned in step A4 is 5-22 MPa, and the pressing time is 30s-10min; In step A5, the hydrothermal reaction temperature is 150-250 ℃, and the reaction time is 8-24 h.

8. The method for preparing the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 5, 6, or 7, characterized in that, In step A1, the carbon fiber is cleaned three times with acetone and anhydrous ethanol respectively. The chemical treatment is carried out using a mixed solution of concentrated sulfuric acid and hydrogen peroxide. Specifically, hydrogen peroxide is added to concentrated sulfuric acid at a volume ratio of 3:

7. The surface-cleaned chopped carbon fiber is then immersed in the mixed solution for 20 minutes. In step A2, the aqueous solution is an aqueous solution of cellulose, carboxymethyl cellulose, or hydroxyethyl cellulose. In step A3, the selected foam material is melamine foam.

9. The method for preparing the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 4, characterized in that, Step (2) includes: B1. Place the three-dimensional chopped carbon fiber foam obtained in step A5 into ethylenediamine, with the mass ratio of chopped carbon fiber to ethylenediamine being 0.05-0.07 g: 20 mL; B2. Add 0.5-2 g of the precursor ethyl antimony xanthate to the B1 solution and stir at room temperature for 2-5 days; B3. The composite material obtained in B2 is washed three times by soaking in deionized water and anhydrous ethanol, and then dried in a drying oven at 40 °C to obtain the target composite material.

10. The application of the three-dimensional short-cut carbon fiber foam-supported Sb2S3 composite material according to claim 1 or 2 in the treatment of dye wastewater.

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