A cobalt-based fenton catalyst, a preparation method and application thereof

Abstract

The application discloses a cobalt-based Fenton-like catalyst and a preparation method and application thereof. The catalyst is prepared by the following steps: taking pyrrole as a monomer, dimethoxymethane as a crosslinking agent, methanesulfonic acid as a polymerization catalyst and a sulfonating agent, polymerizing by Friedel-Crafts alkylation to obtain a methanesulfonyl functionalized super-crosslinked polymer precursor, and then performing ultrasonic-assisted impregnation to load cobalt salt and high-temperature calcination. The active component of the catalyst is Co9S8 and elemental Co dual phases, which are highly dispersed in a porous carbon carrier in nanoscale, and no external sulfur source is needed. The phase controllable transformation is realized by adjusting the amount of the cobalt salt. The catalyst is used for Fenton-like reaction, and can quickly degrade a plurality of refractory organic pollutants such as sertraline, tetracycline, sulfamethoxazole and rhodamine B in the presence of PMS, and the removal rate reaches 100%. The catalyst has the advantages of simple preparation, high activity, good stability and wide application.

Description

Technical Field

[0001] This invention relates to the fields of water treatment technology and Fenton-like catalytic materials, specifically to a cobalt-based Fenton-like catalyst, its preparation method and application, which is particularly suitable for the efficient catalytic degradation of recalcitrant organic pollutants (especially the antidepressant sertraline). Background Technology

[0002] With the rapid development of the pharmaceutical industry, antidepressants are widely used in clinical treatment, and their residues in the aquatic environment have become a typical emerging pollutant. Sertraline, as a commonly used selective antidepressant in clinical practice... Reuptake inhibitors, characterized by their stable chemical structure and poor biodegradability, are difficult to remove effectively using conventional wastewater treatment processes and are frequently detected in various water bodies. These pollutants can cause endocrine disruption and genotoxicity in aquatic organisms and can accumulate along the food chain, thus threatening human health. Therefore, developing efficient and stable sertraline degradation technologies is of significant practical importance.

[0003] Advanced oxidation processes are one of the core technologies for degrading recalcitrant organic pollutants in water. Among these, heterogeneous Fenton reactions effectively overcome the shortcomings of traditional homogeneous Fenton reactions, such as narrow pH application range, large iron sludge production, and difficulty in catalyst recovery. In recent years, cobalt-based catalysts have gained attention due to the presence of cobalt species (…). It exhibits excellent activation ability for persulfate (PMS), and can efficiently generate strong oxidizing active species such as sulfate radicals, thus demonstrating good catalytic performance in Fenton-like reactions.

[0004] However, existing cobalt-based Fenton catalysts still have significant shortcomings. For example, the active components are prone to aggregation, have a small specific surface area, and insufficient exposure of active sites, resulting in low degradation efficiency and slow reaction rates for organic pollutants. The catalysts also exhibit poor structural stability, making them susceptible to cobalt leaching, which not only reduces cycle life but also easily causes secondary metal pollution. Furthermore, the preparation processes of some catalysts are complex and costly, making it difficult to meet the application requirements of practical wastewater treatment.

[0005] In recent years, metal-organic framework (MOF)-derived materials have attracted attention in the Fenton-like field due to their high specific surface area and tunable structure. For example, some studies have used... Using an external sulfur source as a precursor, a solvent was used for thermal sulfidation followed by high-temperature calcination to prepare a product. The catalyst was used to degrade sulfonamide antibiotics using PMS-based Fenton catalysts (see: Research on the Degradation of Active Drugs in Water by Metal-Organic Framework-Based Fenton Catalysts, Chapter 4). Although this scheme achieved effective degradation of sulfonamide drugs, it still has the following shortcomings: (1) The use of an external sulfur source (such as thioacetamide) increases the cost of raw materials and process steps; (2) The product is a single product. Phase, the active components are relatively simple; (3) with As a precursor, the preparation process involves organic solvents, which results in high costs and requires improvement in environmental friendliness.

[0006] In summary, there are few reports on highly efficient cobalt-based Fenton catalysts specifically designed for the degradation of the antidepressant sertraline. Therefore, developing a cobalt-based Fenton catalyst with a simple preparation process, no need for an external sulfur source, good dispersibility of active components, high catalytic activity, and excellent stability to achieve efficient and rapid degradation of sertraline has become an urgent technical challenge in this field. Summary of the Invention

[0007] Therefore, the present invention aims to provide a cobalt-based Fenton catalyst, its preparation method and application, in order to solve the technical problems of existing cobalt-based Fenton catalysts, such as easy agglomeration of active components, the need for external sulfur source in the preparation process, and poor degradation effect on refractory antidepressant drugs such as sertraline.

[0008] A first aspect of the present invention provides a method for preparing a cobalt-based Fenton catalyst, comprising the following steps: Using pyrrole as a monomer, dimethoxymethane as a crosslinking agent, and methanesulfonic acid as both a polymerization catalyst and a sulfonating agent, the polymerization process... Alkylation polymerization reaction was used to prepare methanesulfonyl-functionalized pyrrole-based hypercrosslinked polymer precursors; The precursor was dispersed in a solvent, a cobalt salt solution was added, and the mixture was ultrasonically impregnated and dried to obtain a cobalt ion-loaded precursor. The cobalt-loaded precursor was calcined at high temperature under an inert atmosphere, and the cobalt-based Fenton catalyst was obtained after cooling. The preparation process does not require an external sulfur source; the sulfur source comes from the methanesulfonyl group introduced by grafting methanesulfonic acid in step (1).

[0009] Compared with the prior art, the present invention has the following beneficial effects: a) Simple process, no external sulfur source required Using methanesulfonic acid as both a catalyst and a sulfonating agent, methanesulfonyl groups are introduced in one step while constructing the hypercrosslinked polymer, serving as a self-supplying sulfur source during the high-temperature calcination process. This eliminates the need for an external sulfur source, significantly reducing raw material costs and process complexity.

[0010] b) The active components are highly dispersed and exhibit excellent stability. Using methanesulfonyl-functionalized pyrrole-based hypercrosslinked polymer as a precursor, the active components (Co9S8 and elemental Co) are uniformly dispersed in a porous carbon support as nano-sized particles after ultrasonic-assisted impregnation with a cobalt source and calcination, effectively inhibiting agglomeration and exhibiting excellent cycle stability.

[0011] c) Excellent degradation performance The catalyst exhibits excellent catalytic degradation activity for recalcitrant organic pollutants such as sertraline. Under the conditions of catalyst dosage of 0.05 g / L and PMS dosage of 1 mmol / L, the degradation rate of sertraline can reach 100% within 9-10 minutes, which is significantly better than the existing technology.

[0012] Based on the above technical solution, the present invention can be further improved as follows: Further: the molar ratio of pyrrole, dimethoxymethane and methanesulfonic acid is 1:1~3:1~6.

[0013] Preferably, the molar ratio of pyrrole, dimethoxymethane and methanesulfonic acid is 1:2:2.

[0014] Compared with the existing technology, the beneficial effects of adopting the above-mentioned further technical solution are as follows: By using the above molar ratio range, the degree of crosslinking and sulfonation of the polymer can be effectively controlled, the pore structure and sulfur content of the carbon support can be optimized, and an ideal platform can be provided for the efficient loading and uniform dispersion of the subsequent cobalt active components.

[0015] Based on the above technical solution, the present invention can be further improved as follows: Furthermore: the aforementioned The alkylation polymerization reaction is carried out in stages. The first stage reaction temperature is 45~65 ℃ and the time is 4~6 h, while the second stage reaction temperature is 70~90 ℃ and the time is 15~30 h.

[0016] Compared with the existing technology, the beneficial effects of adopting the above-mentioned further technical solution are as follows: The segmented reaction can effectively control the polymerization rate and crosslinking degree, and obtain polymer precursors with high specific surface area, abundant hierarchical channels and uniform distribution of methanesulfonyl groups, thus providing an ideal carbon support for the efficient loading and uniform dispersion of subsequent active components.

[0017] Based on the above technical solution, the present invention can be further improved as follows: Further: the mass ratio of the methanesulfonyl functionalized pyrrole hypercrosslinked polymer precursor to the cobalt salt is 1:0.13~1.2.

[0018] Preferably, the mass ratio of the methanesulfonyl functionalized pyrrole hypercrosslinked polymer precursor to the cobalt salt is 1:0.9.

[0019] Compared with the existing technology, the beneficial effects of adopting the above-mentioned further technical solution are as follows: By controlling the mass ratio of precursor to cobalt salt within the range of 1:0.13 to 1.2, the active phase of the catalyst can be precisely controlled from a single Co9S8 phase to a Co / Co9S8 dual phase, thereby optimizing the interfacial electron transport and cobalt ion regeneration efficiency and significantly improving Fenton-like catalytic activity.

[0020] Based on the above technical solution, the present invention can be further improved as follows: Furthermore, the high-temperature calcination temperature is 500~800 ℃, the calcination time is 2~5 h, and the heating rate is 2~10 ℃ / min.

[0021] Compared with the existing technology, the beneficial effects of adopting the above-mentioned further technical solution are as follows: The above-mentioned high-temperature calcination conditions can precisely control the crystal phase transformation and nanoscale uniform dispersion of the active components, forming a Co / Co9S8 dual-phase structure with significant synergistic catalytic effect, thereby significantly improving the degradation rate of Fenton-like reactions and the stability of catalyst structure.

[0022] The present invention also provides a cobalt-based Fenton catalyst, which is prepared by the aforementioned method. The active component of the catalyst is a two-phase mixture of Co9S8 and elemental Co, and the active component is uniformly dispersed at the nanoscale in a porous carbon support.

[0023] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows: This invention uses methanesulfonic acid as both a polymerization catalyst and a sulfonating agent, through... Alkylation polymerization yields methanesulfonyl-functionalized hypercrosslinked polymer precursors in a single step, achieving in-situ self-sufficiency of sulfur without the need for an external sulfur source. The preparation process is simple, low-cost, and easily scaled up. Leveraging a three-dimensional carbon network framework constructed by covalent bonds, the catalyst remains structurally stable and does not collapse during high-temperature calcination and Fenton-like reactions. The active component Co9S8 and elemental Co are uniformly dispersed at the nanoscale in the porous carbon support, effectively inhibiting the aggregation and loss of the active component. More importantly, by controlling the amount of cobalt salt added, a Co / Co9S8 biphase symbiotic structure can be formed, with elemental Co acting as an electron donor to accelerate the reaction. The in-situ regeneration and the synergistic enhancement of electron transport at the two-phase interface enable the catalyst to achieve a 100% removal rate for recalcitrant organic pollutants such as sertraline. It also exhibits broad-spectrum and highly efficient catalytic degradation performance for tetracycline, sulfamethoxazole, and various dyes. With high activity, high stability, and wide pH adaptability, it has outstanding application prospects in the field of advanced treatment of complex organic wastewater.

[0024] The present invention also provides an application of the cobalt-based Fenton-like catalyst in the degradation of sertraline, wherein the catalyst and persulfate are added to wastewater containing sertraline to carry out a Fenton-like reaction, wherein the catalyst dosage is 0.01~0.06 g / L, the persulfate dosage is 0.2~1 mmol / L, and the reaction time is 1~20 min.

[0025] Preferably, the antibiotic contaminant is selected from tetracycline and sulfamethoxazole, and the dye contaminant is selected from rhodamine B, methylene blue, Congo red, and methyl orange.

[0026] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows: Using methanesulfonic acid as both a polymerization catalyst and a sulfonating agent, a one-step Friedel-Crafts alkylation reaction was employed to prepare methanesulfonyl-functionalized pyrrole-based hypercrosslinked polymer precursors. This method achieves in-situ self-sufficiency of sulfur during high-temperature calcination without the need for an external sulfur source, resulting in a simple, low-cost, and environmentally friendly process. In the prepared catalyst, Co9S8 and elemental Co are uniformly dispersed at the nanoscale within a covalently bonded porous carbon framework, overcoming the shortcomings of traditional MOF-derived supports such as easy collapse and agglomeration and loss of active components, significantly improving structural stability and accessibility of active sites. This catalyst requires only a dosage of 0.05 g / L and a persulfate concentration of 1.0 g / L. Under the condition of mmol / L, sertraline can be completely degraded within 9-10 minutes. At the same time, it shows a high removal rate of more than 97% for antibiotics (tetracycline, sulfamethoxazole) and various dyes (rhodamine B, methylene blue, etc.). It has outstanding advantages such as fast reaction rate, thorough degradation and broad-spectrum applicability, providing an efficient and stable catalytic solution for the deep treatment of recalcitrant organic wastewater.

[0027] Based on the above technical solution, the present invention can be further improved as follows: Furthermore, the catalyst dosage is 0.05 g / L, and the persulfate dosage is 1 mmol / L.

[0028] Compared with the existing technology, the beneficial effects of adopting the above-mentioned further technical solution are as follows: Using this optimized dosage, 100% complete degradation of sertraline can be achieved within 9 minutes, significantly improving catalytic efficiency and reaction rate.

[0029] Based on the above technical solution, the present invention can be further improved as follows: Furthermore, the reaction time is 9-10 minutes.

[0030] Compared with the existing technology, the beneficial effects of adopting the above-mentioned further technical solution are as follows: This invention can achieve complete degradation of sertraline in a shorter time (100% degradation rate), significantly improving the efficiency of Fenton-like reactions.

[0031] Based on the above technical solution, the present invention can be further improved as follows: Furthermore, the Fenton-like reaction temperature is 20~30℃.

[0032] Compared with the existing technology, the beneficial effects of adopting the above-mentioned further technical solution are as follows: This invention maintains highly efficient catalytic degradation performance under normal temperature conditions. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 These are X-ray powder diffraction (XRD) patterns of cobalt-based Fenton catalysts with different cobalt salt mass ratios prepared in Examples 1-6 of this invention.

[0035] Figure 2 These are Fourier transform infrared (FTIR) spectra of cobalt-based Fenton catalysts with different cobalt salt mass ratios prepared in Examples 1-6 of this invention.

[0036] Figure 3 This is the cobalt-based Fenton catalyst (C) prepared in Example 5 of the present invention. Py-HCP Scanning electron microscope (SEM) images and elemental distribution diagrams of -Co / Co9S8-7; where a is the overall morphology at 20.00 KX magnification, b is the surface framework structure at 50.00 KX magnification, c is the high-magnification morphology at 100.00 KX magnification, and d~g are the EDS energy distribution diagrams of C, Co, S, and N elements, respectively. Detailed Implementation

[0037] The following description is based on specific embodiments.

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the present invention.

[0039] In this invention, unless otherwise specified, all equipment and raw materials are available from the market or commonly used in the industry. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0040] I. Catalyst Preparation Examples Example 1

[0041] This embodiment uses a metal-free catalyst. The prepared comparative example.

[0042] Add 0.01 mol pyrrole and 40 mL of [unspecified substance] to a 250 mL three-necked flask. (DCE) was stirred until completely dissolved. Then, 0.02 mol of dimethoxymethane (FDA) and 1 mL of methanesulfonic acid were added sequentially, and the mixture was reacted at 50 °C for 5 h, then heated to 80 °C and reacted for another 19 h. After the reaction was completed, the mixture was extracted with methanol as solvent using a Soxhlet extractor for 24 h to remove impurities. The product was then vacuum dried at 80 °C for 24 h to obtain a dark gray methanesulfonyl functionalized pyrrole hypercrosslinked polymer precursor.

[0043] 1.0 g of the above precursor was weighed and placed in a tube furnace. Under a nitrogen atmosphere, the temperature was increased to 700 °C at a heating rate of 5 °C / min and calcined for 4 h. The calcined sample was then naturally cooled to room temperature. The resulting sample was washed three times with deionized water and then vacuum dried at 80 °C for 24 h to obtain the metal-free catalyst, denoted as [catalyst name missing]. . Example 2

[0044] This embodiment describes a catalyst. And its preparation method.

[0045] Add 0.01 mol pyrrole and 40 mL of [unspecified substance] to a 250 mL three-necked flask. (DCE) was stirred until completely dissolved, and 0.02 mol of dimethoxymethane (FDA) and 1 mL of methanesulfonic acid were added sequentially. The mixture was reacted at 50 °C for 5 h, and then the temperature was raised to 80 °C for another 19 h. After the reaction was completed, impurities were removed using a Soxhlet extractor, and the mixture was dried under vacuum at 80 °C for 24 h to obtain a dark gray methanesulfonyl functionalized pyrrole hypercrosslinked polymer precursor.

[0046] Add 20 mL of deionized water and 0.130 g (1 mmol) to a 50 mL beaker. The mixture was prepared by sonication for 60 min with 1 g of the aforementioned precursor, followed by drying of the resulting suspension at 80 °C for 24 h. The resulting black blocky solid was ground and calcined in a tube furnace at 700 °C for 4 h under nitrogen atmosphere with a heating rate of 5 °C / min. After natural cooling to room temperature, the product was washed three times with deionized water and then vacuum dried at 80 °C for 24 h to obtain the black catalyst, denoted as […]. In this embodiment, the mass ratio of the precursor to CoCl2 is 1:0.13. Example 3

[0047] This embodiment describes catalyst C. Py-HCP -Co / Co9S8-3 and its preparation.

[0048] The difference from Example 2 is that the amount of CoCl2 added is 0.390 g (3 mmol), and the mass ratio of precursor to CoCl2 is 1:0.39. The remaining steps are the same, yielding a black catalyst, denoted as C. Py-HCP -Co / Co9S8-3. Example 4

[0049] This embodiment describes catalyst C. Py-HCP -Co / Co9S8-5 and its preparation.

[0050] The difference from Example 2 is that the amount of CoCl2 added is 0.650 g (5 mmol), and the mass ratio of precursor to CoCl2 is 1:0.65. The remaining steps are the same, yielding a black catalyst, denoted as C. Py-HCP -Co / Co9S8-5. Example 5

[0051] This embodiment describes catalyst C. Py-HCP -Co / Co9S8-7 and its preparation.

[0052] The difference from Example 2 is that the amount of CoCl2 added is 0.910 g (7 mmol), and the mass ratio of precursor to CoCl2 is 1:0.91. The remaining steps are the same, yielding a black catalyst, denoted as C. Py-HCP-Co / Co9S8-7. Example 6

[0053] This embodiment describes catalyst C. Py-HCP -Co / Co9S8-9 and its preparation.

[0054] The difference from Example 2 is that the amount of CoCl2 added is 1.2 g (9 mmol), and the mass ratio of precursor to CoCl2 is 1:1.2. The remaining steps are the same, yielding a black catalyst, denoted as C. Py-HCP -Co / Co9S8-9.

[0055] II. Catalyst Characterization 2.1 X-ray diffraction (XRD) analysis The catalysts prepared in Examples 1–6 were characterized by X-ray powder diffraction using Cu Kα rays (λ = 0.15406 nm) with a scanning range of 2θ = 10°–90°. The results are as follows: Figure 1 As shown.

[0056] Pure C Py-HCP The support exhibits a significant broadened diffraction peak near 2θ = 25°, which can be attributed to the (002) crystal plane of graphitized carbon. When 1.0 mmol of [a specific substance] is added to the system... At that time, the obtained catalyst It exhibits a single Co9S8 crystal phase, with diffraction peaks at 2θ = 15.4°, 29.8°, 31.2°, 40.6°, 47.6°, and 54.7° corresponding to Co9S8 (…). The (111), (311), (222), (420), (511), and (531) crystal planes of the cobalt salt were observed. As the amount of cobalt salt increased to 3 mmol, 5 mmol, and 7 mmol, the catalyst phase gradually changed from a single Co9S8 to a two-phase structure where metallic cobalt (Co) and Co9S8 coexisted. Except for the characteristic diffraction peaks of Co9S8 remaining unchanged, new diffraction peaks appearing at 2θ = 44.3°, 51.6°, 76.0°, and 92.4° were attributed to elemental Co (Co9S8). The (111), (200), (220) and (311) crystal planes of Co. When the amount of cobalt salt is increased to 9 mmol, the diffraction peak intensity of elemental Co further increases.

[0057] The above results indicate that the catalyst phase can be controllably transformed from a single Co9S8 phase to a Co / Co9S8 dual phase by adjusting the amount of cobalt salt added. When the sulfur source (from methanesulfonyl group) reaches coordination saturation, excess cobalt ions are converted into elemental Co under in-situ reduction of the carbon matrix, forming a tightly coupled composite structure of two phases.

[0058] 2.2 Fourier Transform Infrared Spectroscopy (FTIR) Analysis The catalysts prepared in Examples 1-6 were subjected to FTIR testing using the KBr pellet method, and the results are as follows: Figure 2 As shown, the infrared spectra of each catalyst exhibit highly similar overall characteristics. (Based on C...) Py-HCP Taking Co / Co9S8-7 as an example, in The broad absorption peak at this point is attributed to the stretching vibration of hydroxyl (OH) groups on the surface of adsorbed water or catalyst. The nearby weak absorption peak corresponds to the stretching vibration of aliphatic CH bonds; The characteristic peak at this location is the imine (C=N) stretching vibration peak, indicating that the material contains nitrogen functional groups; The nearby absorption peaks correspond to the pyrrole ring. Bond stretching vibrations further confirmed the presence of nitrogen-containing heterocyclic structures in the material; and The nearby absorption peaks correspond to sulfonyl groups, respectively. The symmetric and asymmetric stretching vibrations confirmed the successful introduction of sulfur into the material after methanesulfonic acid sulfonation.

[0059] 2.3 Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis The catalyst C prepared in Example 5 Py-HCP The morphology of -Co / Co9S8-7 was characterized by SEM and the elemental distribution by EDS. The results are as follows: Figure 3 As shown. Figure 3 Figure a (20.00 KX magnification) shows that the catalytic material is mainly composed of irregular blocky and sheet-like carbon supports, with loose and porous stacked structures formed between the sheets. Figure 3 Image b (50.00 KX magnification) clearly shows the finely interwoven network and linear framework structure grown on the carbon support surface, with irregular particles of hundreds of nanometers visible in some areas, corresponding to the cobalt-based active components loaded on it. Figure 3 Image c (100.00 KX high magnification) shows the mesopores and macropores of the wrinkled two-dimensional sheet network carbon support. The cobalt-based active components are uniformly attached to the sheet surface in the form of nano-sized particles without obvious agglomeration.

[0060] EDS mapping results ( Figure 3 The DG diagram shows that C forms a continuous carbon framework, while Co, S, and N elements exhibit highly uniform distribution. The distribution of Co and S elements is highly matched, indicating that the cobalt-based active components (…) The uniform dispersion of elemental Co on the carbon support effectively avoids the problem of active site masking caused by agglomeration. Simultaneously, the uniform distribution of nitrogen, derived from the introduction of pyrrole monomers, synergistically optimizes the electronic structure of the carbon support, further enhancing electron transfer and pollutant adsorption capabilities. This morphological characteristic, combining high specific surface area, multidimensional porous structure, and highly dispersed active components, can efficiently promote substrate adsorption, electron transfer, and intermediate product conversion, significantly improving Fenton-like reaction kinetics and pollutant degradation efficiency, providing structural support for the rapid and deep degradation of recalcitrant drugs such as sertraline.

[0061] III. Catalyst Performance Evaluation 3.1 Sertraline Degradation Experiment (Comparison of Examples 1-6) At room temperature, 100 mL of sertraline-simulated wastewater with a concentration of 10 mg / L was added to a 250 mL beaker, along with 5 mg of catalyst (0.05 g / L). A Fenton-like reaction was initiated by adding 1.0 mM persulfate (PMS) under magnetic stirring. After a certain reaction time, samples were taken, and the residual concentration of sertraline was determined by high-performance liquid chromatography (HPLC). The degradation rate was calculated. The results are shown in Table 1.

[0062] Table 1. Degradation performance of sertraline by different catalysts

[0063] As can be seen from Table 1, undoped metals The support exhibited only weak adsorption and degradation capabilities; the degradation efficiency was significantly improved after loading cobalt species. With increasing cobalt salt content, the catalyst gradually transformed from a single Co9S8 phase to a coexisting Co and Co9S8 two-phase structure, and the catalytic degradation rate showed a trend of first increasing and then decreasing. The C9S8 catalyst prepared in Example 5 showed the following characteristics: Py-HCP -Co / Co9S8-7 achieved complete degradation of sertraline within 10 minutes, exhibiting optimal catalytic activity. When the amount of cobalt salt was further increased to that in Example 6, the excess metal active component underwent local agglomeration, obscuring some active sites and resulting in a slight decrease in catalytic activity.

[0064] 3.2 Effect of catalyst dosage on degradation efficiency Using the catalyst prepared in Example 5 as the research object, with a fixed PMS addition amount of 1.0 mmol / L and a reaction time of 9 min, the effect of catalyst addition on sertraline degradation rate was investigated. The results are shown in Table 2.

[0065] Table 2 Effect of catalyst dosage on sertraline degradation rate Catalyst dosage (g / L) Reaction time (min) Degradation rate (%) 0.01 9 61.0 0.02 9 84.4 0.03 9 83.5 0.04 9 92.1 0.05 9 100.0 0.06 9 91.0 As shown in Table 2, the catalyst dosage range of 0.01–0.06 g / L positively promotes the degradation of sertraline. The removal rate reaches 100.0% when the dosage is 0.05 g / L, and the optimal dosage is determined to be 0.05 g / L.

[0066] 3.3 Effect of PMS dosage on degradation efficiency With a fixed catalyst dosage of 0.05 g / L (Example 5) and a reaction time of 9 min, the effect of PMS dosage on the degradation rate of sertraline was investigated. The results are shown in Table 3.

[0067] Table 3 Effect of PMS dosage on sertraline degradation rate PMS dosage (mmol / L) Reaction time (min) Degradation rate (%) 0.0 9 14.7 0.2 9 57.9 0.4 9 60.3 0.6 9 77.5 0.8 9 82.8 1.0 9 100.0 As shown in Table 3, PMS significantly promoted the degradation of sertraline within the range of 0–1.0 mmol / L. Without PMS, the degradation rate was only 14.7%, indicating that the adsorption and oxidation capacity of the catalyst itself was limited. The degradation rate gradually increased with increasing PMS dosage, and when the PMS dosage was 1.0 mmol / L, sertraline was completely removed within 9 minutes. The optimal PMS dosage was determined to be 1.0 mmol / L.

[0068] 3.4 Degradation performance of catalysts for different organic pollutants Using the catalyst prepared in Example 5 as the research object, its degradation performance on different types of organic pollutants was investigated under optimal reaction conditions (catalyst dosage 0.05 g / L, PMS dosage 1.0 mmol / L, room temperature). The initial concentration of pollutants was 20 mg / L, and the results are shown in Table 4.

[0069] Table 4. Degradation performance of catalysts for different organic pollutants Pollutant type (20 mg / L) Degradation time (min) Degradation rate (%) Sertraline 9 100.0 Methylene blue 20 98.0 Congo Red 20 98.5 Methyl orange 20 97.0 Rhodamine B 15 100.0 Sulfamethoxazole 15 100.0 tetracycline 15 100.0 As shown in Table 4, the cobalt-based Fenton catalyst provided by this invention exhibits excellent catalytic degradation activity for a variety of recalcitrant organic pollutants and has broad applicability.

[0070] In summary, the cobalt-based Fenton catalyst and its preparation method provided by this invention have the following beneficial effects: Using methanesulfonic acid, which functions as both a polymerization catalyst and an in-situ sulfonating agent, methanesulfonyl functionalized support precursors can be prepared in one step without the need for an external sulfur source. The preparation process is simple, the raw material cost is low, and the reaction conditions are mild and controllable, making it a potential for industrial scale-up.

[0071] By adjusting the amount of cobalt salt added, the catalyst phase can be controllably transformed from a single Co9S8 phase to a Co / Co9S8 dual-phase phase. The Co / Co9S8 dual-phase structure can construct efficient interfacial electron transport channels, and elemental Co can accelerate the transformation of Co...3+ To Co 2+ The reduction and regeneration significantly improves the activation efficiency and reaction kinetics of PMS, resulting in a degradation effect far superior to that of single-phase catalysts.

[0072] The active components are highly uniformly dispersed in the porous carbon support at the nanoscale. The carbon matrix effectively anchors and blocks the active particles, which can significantly inhibit the aggregation and loss of active particles, thus enabling the catalyst to exhibit excellent structural stability and recyclability.

[0073] This catalyst not only exhibits highly efficient and rapid catalytic degradation capabilities for refractory antidepressants such as sertraline, but also demonstrates excellent degradation effects on typical antibiotics such as tetracycline and sulfamethoxazole, as well as dye pollutants such as rhodamine B and methylene blue, thus possessing broad-spectrum applicability.

[0074] In the description of this invention, it should be understood that "-" and "~" represent a range between two values, and this range includes the endpoints. For example, "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0075] In the description of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0076] In the description of the invention, the numerical values ​​of time, temperature, ratio, and mass involved can be based on actual measurements, standard equipment parameters, simplified rounding results, or within an acceptable error range, ensuring the practicality and repeatability of the invention.

[0077] In the description of this invention, the terms “about” or “approximately” are used to express approximate values ​​or ranges, allowing for a certain degree of error to ensure the flexibility and practicality of the description, while remaining within an acceptable range of error, with the maximum error not exceeding 10% of the corresponding value or range.

[0078] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a cobalt-based Fenton catalyst, characterized in that, Includes the following steps: Using pyrrole as a monomer, dimethoxymethane as a crosslinking agent, and methanesulfonic acid as both a polymerization catalyst and a sulfonating agent, the polymerization process... Alkylation polymerization reaction was used to prepare methanesulfonyl-functionalized pyrrole-based hypercrosslinked polymer precursors; The precursor was dispersed in a solvent, a cobalt salt solution was added, and the mixture was ultrasonically impregnated and dried to obtain a cobalt ion-loaded precursor. The cobalt-loaded precursor was calcined at high temperature under an inert atmosphere, and the cobalt-based Fenton catalyst was obtained after cooling. The preparation process does not require an external sulfur source; the sulfur source comes from the methanesulfonyl group introduced by grafting methanesulfonic acid in step (1).

2. The method according to claim 1, characterized in that, The molar ratio of pyrrole, dimethoxymethane and methanesulfonic acid is 1:1~3:1~6.

3. The method according to claim 1, characterized in that, The The alkylation polymerization reaction is carried out in stages. The first stage reaction temperature is 45~65 ℃ and the time is 4~6 h, while the second stage reaction temperature is 70~90 ℃ and the time is 15~30 h.

4. The method according to claim 1, characterized in that, The mass ratio of the methanesulfonyl-functionalized pyrrole-based hypercrosslinked polymer precursor to the cobalt salt is 1:0.13~1.

2.

5. The method according to claim 1, characterized in that, The high-temperature calcination temperature is 500~800 ℃, the calcination time is 2~5 h, and the heating rate is 2~10 ℃ / min.

6. A cobalt-based Fenton catalyst, characterized in that, The catalyst is prepared by any one of claims 1 to 5, wherein the active component is a two-phase mixture of Co9S8 and elemental Co, and the active component is uniformly dispersed in a porous carbon support at a nanoscale height.

7. The application of a cobalt-based Fenton catalyst as described in claim 6 in the degradation of sertraline, characterized in that: The catalyst and persulfate were added to sertraline-containing wastewater to carry out a Fenton-like reaction, wherein the catalyst dosage was 0.01~0.06 g / L, the persulfate dosage was 0.2~1 mmol / L, and the reaction time was 1~20 min.

8. The application according to claim 7, characterized in that, The catalyst dosage is 0.05 g / L, and the persulfate dosage is 1 mmol / L.

9. The application according to claim 7, characterized in that, The reaction time is 9-10 minutes.

10. The application according to claim 7, characterized in that, The Fenton-like reaction temperature is 20~30℃.

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