A sodium alginate / prussian blue hydrogel carbon cloth composite material, a preparation method and application thereof
The sodium alginate/Prussian blue hydrogel carbon cloth composite material solves the problems of easy leaching, aggregation and difficulty in recycling of metal ions in Prussian blue analog catalysts in water treatment, and achieves efficient and stable catalytic degradation effect, which is suitable for the deep purification of fluoroquinolone antibiotics in water.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGXI UNIV
- Filing Date
- 2026-04-30
- Publication Date
- 2026-05-29
AI Technical Summary
Existing Prussian blue analogue catalysts have problems in water treatment, such as easy leaching of metal ions, easy aggregation of nanocatalysts, difficulty in recycling and forming, which leads to the risk of secondary pollution and difficulty in scaling up in practical applications.
Cobalt-iron Prussian blue analog nanoparticles were prepared by microwave hydrothermal method using sodium alginate/Prussian blue hydrogel carbon cloth composite material. The sodium alginate hydrogel layer was used to physically embed and chemically anchor the nanoparticles, forming a stable composite material. Combined with a carbon cloth substrate, this enabled the preparation of a self-supporting catalyst.
It significantly improves catalytic activity and structural stability, greatly reduces the amount of metal ion leaching, and achieves a degradation efficiency of 91.2% for fluoroquinolone antibiotics under visible light. It also maintains good performance within the pH range of 2-11, and can maintain a removal rate of over 70% after 10 cycles. It is highly adaptable and suitable for actual water treatment.
Smart Images
Figure CN122098697A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of water treatment technology, specifically relating to a sodium alginate / Prussian blue hydrogel carbon cloth composite material, its preparation method, and its application. Background Technology
[0002] Fluoroquinolone antibiotics are widely detected in aquatic environments and have become a major challenge in environmental remediation due to their strong biotoxicity and resistance gene induction capabilities. Traditional water treatment processes such as biodegradation, adsorption, and membrane separation have limited effectiveness in removing these antibiotics and are insufficient for achieving deep purification. Therefore, advanced oxidation technologies based on persulfate activation are gradually becoming a research focus due to their strong oxidizing power and wide applicability.
[0003] In the persulfate activation process, the design and construction of heterogeneous catalysts are crucial. Prussian blue analogues (PBAs) are considered promising heterogeneous catalysts due to their tunable electronic structure and abundant active sites. However, existing PBA-based catalytic materials still have the following problems and shortcomings in practical applications:
[0004] First, metal ions are easily leached, posing a high risk of secondary pollution. During the reaction process, PBAs materials, especially those containing metal ions such as cobalt and iron, are easily dissolved, which not only leads to a decrease in catalyst activity and structural instability, but may also cause secondary environmental risks, severely restricting their application in actual water treatment.
[0005] Secondly, nanocatalysts are prone to agglomeration and are difficult to recycle. Powdered PBAs are prone to agglomeration in the aqueous phase, reducing the exposure of effective active sites; at the same time, powdered catalysts are difficult to separate effectively from the reaction system, resulting in high recycling costs and poor recyclability, which makes it difficult to meet the requirements of green and sustainable development.
[0006] Furthermore, catalyst molding is difficult, making it hard to adapt to the needs of engineering applications. Existing research mainly focuses on the performance optimization of powdered catalysts, lacking research on the design and preparation of molding materials for practical water treatment engineering applications. This results in catalytic materials being difficult to directly adapt to existing water treatment engineering processes, creating a significant gap between laboratory research and large-scale application.
[0007] Therefore, developing a structurally stable, highly catalytically active, recyclable, and environmentally friendly self-supporting composite catalytic material is of great significance for promoting the practical engineering application of advanced oxidation technologies based on persulfate activation. Summary of the Invention
[0008] In view of the above, it is necessary to provide a structurally stable, highly catalytically active, recyclable, and environmentally friendly self-supporting composite catalytic material, its preparation method, and its application.
[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows.
[0010] A sodium alginate / Prussian blue hydrogel carbon cloth composite material, comprising:
[0011] Carbon cloth substrate.
[0012] A sodium alginate hydrogel layer is attached to the surface of the carbon cloth substrate, the sodium alginate hydrogel layer being formed by calcium ion cross-linking and curing.
[0013] And Prussian blue analog nanoparticles dispersed within the sodium alginate hydrogel layer, wherein the Prussian blue analog nanoparticles are immobilized in the sodium alginate hydrogel layer through a dual action of physical encapsulation and chemical anchoring.
[0014] In this invention, the Prussian blue analog nanoparticles are cobalt-iron Prussian blue analog nanoparticles, and the Prussian blue analog nanoparticles have a hollow cubic structure.
[0015] In this invention, the mass ratio of the Prussian blue analog nanoparticles to sodium alginate is 1:4.
[0016] The present invention also proposes a method for preparing the sodium alginate / Prussian blue hydrogel carbon cloth composite material as described above, comprising the following steps.
[0017] S1. Prussian blue analog nanoparticles were prepared by microwave hydrothermal method.
[0018] S2. Disperse the Prussian blue analog nanoparticles obtained in step S1 in a sodium alginate solution to obtain a dispersion.
[0019] S3. Immerse the carbon cloth substrate in the dispersion of step S2 for impregnation loading.
[0020] S4. The carbon fabric treated in step S3 is cross-linked and cured in a calcium salt solution, and then washed and dried to obtain the sodium alginate / Prussian blue hydrogel carbon fabric composite material.
[0021] In this invention, further, in step S1, the metal source used in the microwave hydrothermal method includes K3Fe(CN)6 and Co(NO3)2, the reaction temperature is 70-90℃, and the reaction time is 2-6 hours.
[0022] In this invention, further, in step S1, the temperature of the microwave hydrothermal reaction is 80°C and the reaction time is 4 hours.
[0023] In this invention, further, in step S4, the calcium salt solution is a CaCl2 solution with a mass concentration of 3%-8%, and the cross-linking curing time is 2-6 hours.
[0024] In this invention, further, in step S4, the calcium salt solution is a CaCl2 solution with a mass concentration of 5%, and the crosslinking curing time is 4 hours.
[0025] The present invention also proposes the application of the sodium alginate / Prussian blue hydrogel carbon cloth composite material as described above in the use of activated persulfate for the degradation of organic pollutants in water.
[0026] In this invention, the organic pollutant is a fluoroquinolone antibiotic, and the degradation is carried out under visible light irradiation.
[0027] Compared with the prior art, the present invention has at least the following beneficial effects: 1. Significantly enhanced catalytic activity. Targeting moxifloxacin as the pollutant, under visible light irradiation, the material of this invention can achieve a degradation efficiency of 91.2% within 30 minutes, with a reaction rate constant of 0.45034 min. -1 Compared with similar catalysts reported in recent years, its overall performance is superior to most existing catalysts.
[0028] 2. Stable structure and recyclable. This invention significantly improves the structural stability of the material through the dual immobilization of Prussian blue analog nanoparticles via a sodium alginate gel network. Metal ion leaching tests show that the leaching amounts of Fe and Co in the control system without the sodium alginate layer are 2.58 times and 4.50 times that of the system in this invention, respectively, fully demonstrating that the sodium alginate hydrogel network effectively inhibits the dissolution of active metal components. Ten consecutive cycles of use experiments show that the removal rate of moxifloxacin remains above 70% in the first seven cycles, demonstrating that the material possesses both excellent catalytic efficiency and environmental friendliness.
[0029] 3. Strong environmental adaptability. The material of this invention maintains a degradation efficiency of over 85.0% within a wide pH range of 2-11, and exhibits good tolerance to various actual water bodies and coexisting ions, demonstrating potential for practical application.
[0030] 4. Significantly improved hydrophilicity and mass transfer efficiency. Contact angle tests show that the water contact angle on the original carbon cloth surface is 136.43°, exhibiting hydrophobic properties. However, water droplets on the surface of the composite material of this invention are rapidly absorbed, exhibiting superhydrophilicity. This facilitates the wetting and penetration of the reaction medium on the material surface, promoting mass transfer of reactants to active sites. Furthermore, this invention uses a microwave hydrothermal method instead of the traditional oven heating method, shortening the synthesis cycle by more than 80% and effectively avoiding the formation of the second phase, Prussian blue. The product has high purity and stable quality, which is beneficial for large-scale production. Attached Figure Description
[0031] Figure 1This is a comparison chart of the adsorption and degradation performance of different systems for moxifloxacin in embodiments of the present invention; wherein, Figure 1 (a) is a comparison of the dark adsorption performance of moxifloxacin for different systems. Figure 1 (b) shows the degradation performance curves of different systems under visible light irradiation. Figure 1 (c) is a comparison of the final degradation rate and reaction rate constant of different systems with and without visible light irradiation. Figure 1 (d) is a comparison of the persulfate activation efficiency of different systems with and without visible light irradiation.
[0032] Figure 2 The images show structural characterization diagrams of Prussian blue analog nanoparticles prepared under different hydrothermal times and heating methods in embodiments of the present invention; wherein, Figure 2 (a) is the full XRD spectrum. Figure 2 (b) is a magnified XRD pattern. Figure 2 (c) is another locally magnified XRD pattern. Figure 2 (d) is the FTIR spectrum.
[0033] Figure 3 These are scanning electron microscope (SEM) images of Prussian blue analog nanoparticles prepared at different hydrothermal times in embodiments of the present invention; wherein, Figure 3 (a) is a SEM image of PBAs-2. Figure 3 (b) is the SEM image of PBAs-4. Figure 3 (c) is a SEM image of PBAs-6.
[0034] Figure 4 This is a comparison of the catalytic performance of Prussian blue analog nanoparticles prepared at different hydrothermal times in the embodiments of the present invention; wherein, Figure 4 (a) is a graph showing the degradation performance of moxifloxacin for different samples in the Vis / PMS system. Figure 4 (b) is a comparison chart of the corresponding degradation rate constants.
[0035] Figure 5 The images shown are XRD and FTIR spectra of Prussian blue analog nanoparticles prepared with different hydrothermal times and heating methods in this embodiment of the invention; wherein, Figure 5 (a) shows the XRD patterns of PBAs-2, PBAs-4, PBAs-6, PBAs-8, and PBAs-24. Figure 5 (b) is a magnified view of a portion of the image. Figure 5 (c) is another enlarged view of the area. Figure 5 (d) is the FTIR spectrum.
[0036] Figure 6 This is a comparison of the degradation performance of Prussian blue analog nanoparticles prepared at different hydrothermal times in this invention embodiment; wherein, Figure 6 (a) is a graph showing the degradation performance of moxifloxacin for different samples in the Vis / PMS system. Figure 6 (b) is a comparison chart of the corresponding degradation rate constants.
[0037] Figure 7 This is a graph showing the effect of different mass ratios of Prussian blue analog nanoparticles to sodium alginate on the catalytic performance of the composite material in the embodiments of the present invention; wherein, Figure 7 (a) shows the degradation performance curves at different mass ratios. Figure 7 (b) is a comparison chart of the corresponding reaction rate constants.
[0038] Figure 8 This is a scanning electron microscope cross-sectional image of the sodium alginate / Prussian blue hydrogel carbon cloth composite material prepared in the embodiments of the present invention.
[0039] Figure 9 This is a comparison chart of the metal ion leaching amounts between the sodium alginate / Prussian blue hydrogel carbon cloth composite material and the control material in the embodiments of the present invention.
[0040] Figure 10 This is a comparison diagram of the surface wettability of the original carbon cloth and the sodium alginate / Prussian blue hydrogel carbon cloth composite material in an embodiment of the present invention; wherein, Figure 10 (a) is a water contact angle test diagram of the original carbon cloth (contact angle 136.43°). Figure 10 (b) is a diagram showing the contact state of water droplets on the surface of the composite material at 0s. Figure 10 (c) shows the spreading state of water droplets on the surface of the composite material at 1 second. Figure 10 (d) shows the fully spread state of water droplets on the surface of the composite material at 2s, indicating that the composite material exhibits superhydrophilicity.
[0041] Figure 11 The images show the XRD patterns of Prussian blue analog nanoparticles prepared by different hydrothermal times and heating methods in this invention embodiment; wherein, Figure 11 (a) shows the full XRD spectra of PBAs-2, PBAs-4, PBAs-6, PBAs-8, and PBAs-24. Figure 11 (b) is a magnified view of the part.
[0042] Figure 12 The images show the X-ray photoelectron spectroscopy (XPS) analysis of the sodium alginate / Prussian blue hydrogel carbon cloth composite material and the control material in this embodiment of the invention; wherein, Figure 12 (a) is the XPS spectrum of Fe 2p. Figure 12 (b) is the XPS spectrum of Co 2p. Figure 12 (c) is a comparison diagram of the changes in the valence state of Fe before and after the reaction. Figure 12 (d) is a comparison diagram of the changes in the valence state of Co before and after the reaction.
[0043] Figure 13 This diagram illustrates the influence of different environmental factors on the catalytic degradation performance of the sodium alginate / Prussian blue hydrogel carbon cloth composite material in this invention embodiment; wherein, Figure 13 (a) shows the degradation effect under different pH conditions. Figure 13 (b) shows the degradation effect in different actual water bodies. Figure 13 (c) shows the degradation effect under different pollutants.
[0044] Figure 14 This is a radar diagram showing the effects of common coexisting ions in water and different humic acid concentrations on the catalytic degradation of moxifloxacin by sodium alginate / Prussian blue hydrogel carbon cloth composite material in an embodiment of the present invention.
[0045] Figure 15 This is a test diagram of the cyclic stability of the sodium alginate / Prussian blue hydrogel carbon cloth composite material in an embodiment of the present invention. Detailed Implementation
[0046] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0047] Example 1: Preparation of CoFe-PBAs nanoparticles.
[0048] Weigh 4.0 g of polyvinylpyrrolidone (PVP) and dissolve it in 40 mL of 0.1 M hydrochloric acid solution, stirring thoroughly until completely dissolved. Divide the resulting solution into two equal portions, labeled A and B, each with a volume of 20 mL. Add 65 mg of K3Fe(CN)6 to solution A and 70 mg of Co(NO3)2 to solution B, stirring until completely dissolved. At room temperature, slowly pour solution A into solution B, stirring continuously for 30 min to allow for complete reaction. Then transfer the mixture to a 100 mL polytetrafluoroethylene reaction vessel, seal it, and place it in a microwave hydrothermal synthesis apparatus, heating it at 80 °C for 4 h. After the reaction vessel cools, the product is separated by centrifugation, washed three times with anhydrous ethanol, and dried in a 60 °C vacuum drying oven for 24 h to obtain CoFe-PBAs nanoparticles, labeled PBAs-4.
[0049] To investigate the effect of hydrothermal time on the structure and properties of the products, the microwave hydrothermal reaction time was controlled at 2 h, 6 h, and 8 h, respectively, and the resulting products were labeled as PBAs-2, PBAs-6, and PBAs-8, respectively. In addition, under the same reaction conditions, a conventional oven was used to heat the product at 80 °C for 24 h, and the resulting sample was labeled as PBAs-24, serving as a control sample.
[0050] Example 2: Preparation of sodium alginate / Prussian blue hydrogel carbon cloth composite material.
[0051] (1) Preparation of sodium alginate hydrogel precursor solution: Sodium alginate (SA) was dissolved in deionized water to prepare an SA solution with a concentration of 0.8 wt%. PBAs-4 nanoparticles prepared in Example 1 were added to the SA solution at a mass ratio of CoFe-PBAs nanoparticles to SA of 1:4. The mixture was ultrasonically dispersed for 30 min to ensure that the PBAs nanoparticles were uniformly dispersed in the SA matrix, thus obtaining a PBAs / SA mixed dispersion.
[0052] (2) Pretreatment of carbon cloth substrate: Cut carbon cloth (CC) to a suitable size, and clean it with acetone, anhydrous ethanol and deionized water for 15 minutes each to remove surface oil and impurities. Dry it at 60°C for later use.
[0053] (3) Impregnation loading: The pretreated carbon cloth is immersed in the above PBAs / SA mixed dispersion for 2.5 hours. During the impregnation process, the room temperature (25±2℃) is maintained. The mixture is left to stand so that the SA molecular chains can fully penetrate and adsorb onto the surface of the carbon cloth fibers.
[0054] (4) In-situ crosslinking and curing: Take out the impregnated carbon cloth and immerse it in a 5% CaCl2 solution for crosslinking and curing for 4 hours, so that the SA molecular chains are crosslinked with Ca. 2+ An ionic cross-linking reaction occurs, forming a three-dimensional hydrogel network structure that encapsulates and anchors PBA nanoparticles within it.
[0055] (5) Post-treatment: Remove the composite material and rinse it repeatedly with deionized water to remove uncrosslinked Ca on the surface. 2+ The loosely attached PBA nanoparticles were naturally dried at room temperature to obtain the sodium alginate / Prussian blue hydrogel carbon cloth composite material, labeled as PBA@SA / CC.
[0056] For comparative studies, the following control materials were also prepared in this embodiment: (1) PBAs / CC: PBA nanoparticles were directly loaded onto the surface of carbon cloth by impregnation and drying without the use of sodium alginate; (2) PBAs+SA / CC: PBA nanoparticles were physically mixed with SA solution, impregnated and loaded onto carbon cloth, and dried and cured at 60°C (without Ca2+). 2+(3) SA / CC: Only SA hydrogel layer is loaded, without PBA nanoparticles; (4) PBA@SA hydrogel block: PBA / SA mixed dispersion is directly injected into calcium salt solution for cross-linking and solidification to form hydrogel block, which is then crushed and used.
[0057] Example 3: Characterization of the phase and crystal structure of the catalytic material.
[0058] X-ray diffraction (XRD) was used to analyze the phase composition of the PBA nanoparticles prepared under different hydrothermal times and heating methods in Example 1. Figure 5 As shown in (a), the XRD diffraction peak positions of PBAs-2 to PBAs-8 prepared by microwave hydrothermal method are completely consistent and match well with the CoFe-PBAs standard card (JCPDF#86-0502), further verifying the phase structure uniformity of the products prepared by microwave hydrothermal method; while PBAs-24 (conventional oven method) has the same main peak, but weak impurity peaks are visible in the full spectrum, which is inconsistent with the subsequent local magnification image ( Figure 5 (b) and Figure 5 (c)) matches the characteristics of the second phase PB. Figure 2 (a) to Figure 2 As shown in (c), the XRD diffraction peak positions of PBAs-2, PBAs-4, PBAs-6, PBAs-8 and PBAs-24 are basically consistent, and all of them are consistent with the standard card JCPDF#86-0502 of CoFe-PBAs, indicating that the CoFe-PBAs structure was successfully synthesized in all samples.
[0059] Further analysis revealed that the product from the conventional 24-hour hydrothermal drying oven (PBAs-24) exhibited a new diffraction shoulder peak to the right of the corresponding diffraction peak (e.g., Figure 5 (b) Figure 5 (c) Figure 11 (a) and Figure 11 (b) shows that the peaks matched those of Prussian blue (PB). This indicates that during the long reaction period of the conventional hydrothermal method, some of the initially formed CoFe-PBA structures may have undergone transformation or decomposition, leading to the formation of the second phase PB. In contrast, no such impurity peak was observed in the products of the microwave hydrothermal method at any time (PBAs-2 to PBAAs-8), proving that the microwave hydrothermal method can effectively suppress the formation of the second phase and ensure product purity.
[0060] The sample was analyzed using Fourier transform infrared spectroscopy (FTIR), and the results are as follows: Figure 2 (d) and Figure 5As shown in (d), the sample prepared by the microwave hydrothermal method (PBAs-4) exhibited cyano vibration peaks related to both Fe-CN and Co-CN, while the sample prepared by the conventional method (PBAs-24) only showed cyano vibration peaks related to Fe. This result indicates that the microwave hydrothermal method can achieve effective cobalt ion doping and successfully construct a bimetallic structure, while the conventional hydrothermal method is difficult to achieve the same degree of bimetallic doping.
[0061] Example 4: Microstructure characterization of catalytic materials.
[0062] The morphology of PBA nanoparticles prepared for different microwave hydrothermal times was observed using scanning electron microscopy (SEM), and the results are as follows: Figure 3 As shown. When the reaction time is 2 hours ( Figure 3 (a)) PBA particles are uniformly square-shaped with relatively smooth surfaces; when the reaction time is extended to 4 hours ( Figure 3 (b) The particle morphology evolved into a hollow cubic structure with sharp edges and internal cavities, significantly increasing the specific surface area, which is beneficial for exposing more active sites and enhancing mass transfer efficiency; further extending the reaction time to 6 hours ( Figure 3 (c) The particle morphology maintained its hollow cubic structure without significant change. This result indicates that a microwave hydrothermal reaction of 4 hours is the optimal condition for forming a complete hollow cubic structure.
[0063] Example 5: Characterization of the microstructure and surface properties of composite materials.
[0064] The cross-sectional morphology of the PBAs@SA / CC composite material prepared in Example 2 was observed using scanning electron microscopy (SEM), and the results are as follows: Figure 8 As shown in the figure, a three-layer structure can be clearly observed: the bottom layer is a carbon fiber substrate, the middle layer is a sodium alginate hydrogel layer, and the top layer is PBA nanoparticles uniformly dispersed in the gel layer. This structural feature fully demonstrates that the present invention has successfully constructed a three-layer composite structure of "carbon fiber substrate-sodium alginate hydrogel layer-PBAs nanoparticles".
[0065] The surface wettability of the original carbon cloth and the PBAs@SA / CC composite material prepared in Example 2 was tested using an optical contact angle meter. Figure 10 As shown in (a), the water contact angle of the original carbon cloth surface is 136.43°, exhibiting typical hydrophobic properties. Figure 10 (b) to Figure 10As shown in (d), water droplets on the surface of the PBAs@SA / CC composite material contacted at 0 s, began to spread at 1 s, and were rapidly and completely absorbed at 2 s, with the contact angle approaching 0°, exhibiting superhydrophilicity. This result indicates that the introduction of sodium alginate significantly improves the hydrophilicity of the carbon cloth substrate, facilitating the wetting and penetration of the aqueous reaction medium on the material surface, promoting mass transfer of reactants to active sites, and thus enhancing the efficiency of the heterogeneous catalytic degradation process.
[0066] Example 6: Catalytic performance test of composite material.
[0067] The catalytic activity of the PBAs@SA / CC composite material prepared in this invention was evaluated using moxifloxacin (MOX) as the target pollutant. Test conditions: initial MOX concentration was 10 mg / L, and the composite material application area was 3 cm × 4 cm (approximately 12 cm²). 2 The PMS concentration was 1 mmol / L, and the reaction was carried out under visible light irradiation (λ>420nm) in a 100 mL volume in a constant temperature shaker. The MOX concentration was measured by taking samples at regular intervals.
[0068] First, the dark adsorption performance of different materials for MOX was investigated, and the results are as follows: Figure 1 As shown in (a), the adsorption rate of MOX by PBAs@SA / CC is approximately 19.8%, which is superior to that of control materials such as SA / CC and pure CC. This result indicates that the introduction of PBAs enhances the material's ability to enrich the target pollutant.
[0069] Further investigation was conducted into the degradation performance of MOX by different catalytic systems with and without visible light irradiation. The results are as follows: Figure 1 (b) to Figure 1 As shown in (d), under visible light irradiation, the PBAs@SA / CC / PMS system can achieve a MOX degradation efficiency of 91.2% within 30 min, with a reaction rate constant of 0.45034 min. -1 The degradation efficiency was significantly better than that under light-free conditions. Furthermore, the degradation efficiency of the PBAs@SA / CC / PMS system was significantly higher than that of the PBAs / CC / PMS system and the PBAs@SA hydrogel bulk / PMS system, demonstrating the synergistic effect of the sodium alginate hydrogel layer and the carbon cloth substrate on improving catalytic performance.
[0070] Example 7: Comparison of catalytic performance of PBAs at different hydrothermal times.
[0071] PBA nanoparticles (PBAs-2, PBAAs-4, PBAAs-6, PBAAs-8) prepared at different hydrothermal times in Example 1, and PBAAs-24 prepared by conventional oven heating, were used to prepare corresponding PBA@SA / CC composite materials according to the method in Example 2. Their degradation performance against MOX was tested according to the conditions in Example 6. The results are as follows: Figure 4 and Figure 6 As shown.
[0072] from Figure 4 (a) Figure 4 (b) and Figure 6 (a) Figure 6 (b) It can be seen that in this series of comparative experiments, PBAs-4 exhibited the best degradation effect, achieving a MOX degradation rate of 86.0% within 30 min. Due to insufficient reaction time, PBAs-2 particles did not form a complete hollow structure, resulting in insufficient exposure of active sites. Although PBAs-6 and PBAs-8 maintained a hollow structure, further extending the reaction time had limited effect on improving catalytic performance, and even slightly reduced it. PBAs-24, prepared by conventional oven heating, showed significantly lower catalytic performance than PBAs-4 due to the presence of a second phase (PB) and insufficient Co doping. These results indicate that a microwave hydrothermal reaction of 4 h is the optimal condition for preparing highly catalytically active PBAs.
[0073] Example 8: Optimization of preparation conditions (PBAs / SA mass ratio).
[0074] The effect of the PBA to SA mass ratio on the catalytic performance of the composite material was investigated. PBA@SA / CC composite materials were prepared according to the method of Example 2 with PBA to SA mass ratios of 1:2, 1:4, and 1:6, respectively, and their MOX degradation performance was tested according to the conditions of Example 6. The results are as follows: Figure 7 As shown.
[0075] from Figure 7 (a) and Figure 7 (b) It can be seen that the composite material exhibits the best MOX degradation effect when the mass ratio of PBAs to SA is 1:4. When the mass ratio is too low (1:6), the PBA loading is insufficient, resulting in fewer active sites; when the mass ratio is too high (1:2), the PBAs are unevenly dispersed in the SA matrix and are prone to aggregation, which reduces the catalytic efficiency. This result indicates that a mass ratio of PBAs to SA of 1:4 is the optimal ratio.
[0076] Example 9: Optimization of preparation conditions (SA concentration, crosslinking time and calcium source).
[0077] The effect of SA concentration on the catalytic performance of the composite material was investigated. PBAs@SA / CC composite materials were prepared according to the method of Example 2 with SA concentrations of 0.6 wt%, 0.8 wt%, and 1.0 wt%, respectively, and their MOX degradation performance was tested under the conditions of Example 6. The results showed that the composite material exhibited the best catalytic performance when the SA concentration was 0.8 wt%. Too low a SA concentration resulted in an incomplete gel network, while too high a concentration may have hindered mass transfer.
[0078] The effect of crosslinking time on the stability of the composite material was investigated. PBAs@SA / CC composite materials were prepared according to the method in Example 2 with crosslinking curing times of 1 h, 2 h, 4 h, and 8 h, respectively, and their metal ion leaching amount and catalytic activity were tested. The results showed that the material structure was most stable and the metal ion leaching amount was lowest when the crosslinking time was 4 h; when the crosslinking time was too short, the gel network was not fully formed, and when the crosslinking time was too long, the performance improvement was limited.
[0079] The effects of different calcium sources on the properties of the composite materials were investigated. PBAs@SA / CC composite materials were prepared according to the method in Example 2 using CaCl2, calcium gluconate, and Ca(NO3)2 as crosslinking agents, respectively, and their catalytic activity and gel layer integrity were tested. The results showed that CaCl2 had the best crosslinking effect, forming the densest gel network.
[0080] Example 10: Metal ion leaching test of the material.
[0081] Metal ion leaching tests were performed on the PBAs@SA / CC composite material prepared in Example 2 and the control material PBAs / CC. The materials were placed in the reaction system, and after reacting for 30 min, the supernatant was collected, and the leaching amounts of Fe and Co were determined using inductively coupled plasma optical emission spectrometry (ICP-OES).
[0082] The results are as follows Figure 9 As shown, the leaching amounts of Fe and Co in the PBAs / CC / PMS system were 2.58 times and 4.50 times that of the PBAs@SA / CC / PMS system, respectively. This result fully demonstrates that the three-dimensional hydrogel network formed by sodium alginate effectively inhibits the dissolution of active metal components (especially Co) during the catalytic process through a dual immobilization mechanism of physical embedding and chemical anchoring. This not only helps maintain the long-term structural stability of the catalyst but also significantly reduces the secondary environmental risk.
[0083] Example 11: XPS analysis of materials.
[0084] To further verify the chemical anchoring effect of sodium alginate on PBAs, X-ray photoelectron spectroscopy (XPS) analysis was performed on the PBAs@SA / CC composite material before and after the reaction, as well as the control material PBAs / CC. The results are as follows: Figure 12 As shown.
[0085] like Figure 12 (a) and Figure 12 As shown in (b), the electronic binding energies of Fe 2p and Co 2p in PBAs@SA / CC have shifted to a certain extent compared to PBAs / CC, moving towards higher binding energies. This provides strong evidence for the possible coordination interaction between the carboxylate groups in sodium alginate and the Fe and Co metal sites in PBAs. Figure 12 (c) and Figure 12 As shown in (d), the valence states of Fe and Co in the PBAs@SA / CC sample changed little after the reaction, while the valence states of metal ions in the PBAs / CC sample changed significantly. This result provides evidence at the molecular level for the "chemical anchoring" mechanism between sodium alginate and PBAs.
[0086] Example 12: pH adaptability test of materials.
[0087] The degradation performance of PBAs@SA / CC composites on MOX under different pH conditions was investigated. The pH of the reaction system was adjusted to the range of 2-11 using HCl or NaOH solution, and other conditions were the same as in Example 6. The results are as follows. Figure 13 As shown in (a), the MOX removal rate of the PBAs@SA / CC / PMS / Vis system reached over 85.0% within a wide pH range of 2-11. This result demonstrates that the material of this invention exhibits excellent pH adaptability and maintains good catalytic performance under varying acidity and alkalinity conditions.
[0088] Example 13: Test of the material's adaptability to actual water bodies.
[0089] The degradation performance of PBAs@SA / CC composites in different real water bodies was investigated. MOX solutions were prepared using tap water, river water, and wastewater effluent as reaction media, with other conditions the same as in Example 6. The results are as follows: Figure 13 As shown in (b), the removal rate of MOX by the PBAs@SA / CC / PMS / Vis system remained above 80% in different actual water bodies, indicating that the material has good potential for practical application.
[0090] Example 14: Broad spectrum test of materials.
[0091] The degradation performance of PBAs@SA / CC composites on other fluoroquinolone antibiotics was investigated. Ciprofloxacin and ofloxacin were used as target pollutants, and other conditions were the same as in Example 6. The results are as follows. Figure 13 As shown in (c), the PBAs@SA / CC / PMS / Vis system achieved a degradation rate of over 85% for ciprofloxacin and ofloxacin within 30 min, demonstrating that the material has a good degradation effect on a variety of fluoroquinolone antibiotics and exhibits good broad-spectrum activity.
[0092] Example 15: Test of the material's tolerance to coexisting ions.
[0093] The effects of common coexisting ions in water and different concentrations of humic acid (HA) on the MOX degradation performance of PBAs@SA / CC composites were investigated. Different concentrations of Cl- were added to the reaction system. -HCO3 - NO3 - CO3 2- SO4 2- And different concentrations of HA, other conditions were the same as in Example 6. Results are as follows: Figure 14 As shown, except for NO3 - and CO3 2- Apart from the presence of other coexisting ions, the effects on the catalytic performance of the system are minimal, with the degradation efficiency decreasing by less than 10%. This result indicates that the material of this invention has good tolerance to common coexisting ions in water.
[0094] Example 16: Stability test of material recycling.
[0095] Cyclic stability tests were conducted on the PBAs@SA / CC composite material. After each reaction, the material was removed from the reaction system, rinsed with deionized water, and directly added to the next reaction. Other conditions were the same as in Example 6, and a total of 10 cycles were performed. The results are as follows: Figure 15 As shown, in the first seven cycles of the experiment, the removal rate of MOX by this system remained above 70%, demonstrating the material's good potential for reusability. This result is consistent with... Figure 9 The low metal ion leaching rates shown corroborate each other, proving that the sodium alginate hydrogel network effectively inhibits the loss of PBAs and ensures the long-term structural stability of the material.
[0096] The above embodiments only illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention.
Claims
1. A sodium alginate / Prussian blue hydrogel carbon cloth composite material, characterized in that, include: Carbon cloth substrate; A sodium alginate hydrogel layer is attached to the surface of the carbon cloth substrate, and the sodium alginate hydrogel layer is formed by calcium ion cross-linking and curing. And Prussian blue analog nanoparticles dispersed within the sodium alginate hydrogel layer, wherein the Prussian blue analog nanoparticles are immobilized in the sodium alginate hydrogel layer through a dual action of physical encapsulation and chemical anchoring.
2. The composite material according to claim 1, characterized in that, The Prussian blue analog nanoparticles are cobalt-iron Prussian blue analog nanoparticles, and the Prussian blue analog nanoparticles have a hollow cubic structure.
3. The composite material according to claim 1, characterized in that, The mass ratio of the Prussian blue analog nanoparticles to sodium alginate is 1:
4.
4. A method for preparing a sodium alginate / Prussian blue hydrogel carbon cloth composite material as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Prussian blue analog nanoparticles were prepared by microwave hydrothermal method. S2. Disperse the Prussian blue analog nanoparticles obtained in step S1 in a sodium alginate solution to obtain a dispersion. S3. Immerse the carbon cloth substrate in the dispersion of step S2 for impregnation and loading. S4. The carbon fabric treated in step S3 is cross-linked and cured in a calcium salt solution, and then washed and dried to obtain the sodium alginate / Prussian blue hydrogel carbon fabric composite material.
5. The preparation method according to claim 4, characterized in that, In step S1, the metal source used in the microwave hydrothermal method includes K3Fe(CN)6 and Co(NO3)2, the reaction temperature is 70-90℃, and the reaction time is 2-6 hours.
6. The preparation method according to claim 5, characterized in that, In step S1, the temperature of the microwave hydrothermal reaction is 80°C and the reaction time is 4 hours.
7. The preparation method according to claim 4, characterized in that, In step S4, the calcium salt solution is a CaCl2 solution with a mass concentration of 3%-8%, and the cross-linking curing time is 2-6 hours.
8. The preparation method according to claim 7, characterized in that, In step S4, the calcium salt solution is a 5% CaCl2 solution by mass, and the cross-linking curing time is 4 hours.
9. The application of a sodium alginate / Prussian blue hydrogel carbon cloth composite material as described in any one of claims 1-3 in the use of activated persulfate for the degradation of organic pollutants in water.
10. The application according to claim 9, characterized in that, The organic pollutant is a fluoroquinolone antibiotic, and the degradation is carried out under visible light irradiation.