Preparation method and application of Co and N loaded Ti3AlC2 composite catalyst

Abstract

The invention relates to the technical field of organic pollutant removal application, and particularly discloses a preparation method and application of a Co and N loaded Ti3Al C2 composite catalyst, and the preparation method comprises the step of successfully doping N and Co into the surface of Ti3Al C2 to synthesize a Co-N-Ti3Al C2 composite material by adopting a simple hydrothermal combined high-temperature carbonization method. Compared with a double combination of the materials, the Co-N-Ti3Al C2 has higher PMS activation and sulfonamide isoxazole (S IZ) degradation capability, and 98.6% of S IZ simulation wastewater with the concentration of 10 mg / L can be removed within 30 minutes by combining the Co-N-Ti3Al C2 with a PMS system. The high catalytic activity of the material is attributed to the strong interaction between pyridine N and Co atoms on the surface of Ti3AlC2, and meanwhile, the strong interaction is also beneficial for inhibiting leaching of Co ions in the material. The Co-N-Ti3Al C2 composite material has the advantages that the Co-N-Ti3Al C2 composite material is high in interference resistance, high in activity in natural water and high in practical applicability.

Description

Technical Field

[0001] This invention belongs to the field of organic pollutant removal application technology, specifically relating to a method for preparing a Co and N supported Ti3AlC2 composite catalyst and its application. Background Technology

[0002] In recent years, sulfonamides have been widely used to treat diseases such as urinary tract infections in humans and animals, representing a typical example of antibiotic therapy. The widespread use of sulfonamides across various fields, coupled with their persistent degradation characteristics, has led to a large influx of these drugs into the ecosystem. According to the International Agency for Research on Cancer (IARC), some sulfonamide antibiotics (such as SIZ, sulfafuran, and sulfadiazine) are carcinogenic, and long-term exposure to sulfonamides poses health threats. Among sulfonamides, SIZ is a weakly acidic substance where oxazole replaces sulfonamide, exhibiting poor biodegradability. Furthermore, its residues in water bodies can cause allergic reactions and endocrine disorders in animals. Current traditional water treatment methods struggle to completely remove SIZ, and also suffer from limitations such as poor degradation efficiency, highly toxic degradation byproducts, and high treatment costs. Therefore, seeking new methods to promote the effective degradation of sulfonamides is of great significance.

[0003] Among existing technologies, advanced oxidation processes based on peroxymonosulfate (PMS) (SR-AOPs) are one of the most promising processes for treating recalcitrant organic pollutants.

[0004] Among the many activation methods for PMS, the method of activating PMS using transition metal ions (such as Co2+, Fe2+, Mn2+, Cr3+ and V3+) has attracted widespread attention due to its high efficiency and ease of operation.

[0005] Co2+ has a high standard redox potential (1.92V) and is considered the most efficient catalyst among transition metals. However, Co2+ is genotoxic and carcinogenic, and excessive exposure to high doses of Co2+ may cause health problems such as asthma, pneumonia, and cardiomyopathy.

[0006] To overcome the drawback of excessive Co2+ entering the water body in the Co2+-PMS system, researchers have developed supported heterogeneous cobalt-based catalysts. Compared with homogeneous catalysts, heterogeneous catalysts significantly reduce the amount of Co2+ entering the water body and have advantages such as reusability, insolubility in water, and ease of transportation, representing a major trend in transition metal development. Currently reported common cobalt supports include metal oxides, carbon materials, and clay minerals. Among these, carbon materials have become a common choice for transition metal heterogeneous catalyst substrates due to their large specific surface area and abundant surface active groups. However, in the SR-AOPs process, the active groups on the surface of carbon materials are easily oxidized by free radicals generated by the system, and the carbon network is also easily oxidized to generate soluble organic matter that enters the water, resulting in poor stability.

[0007] Meanwhile, the traditional preparation process of catalytic composite materials is relatively complex and costly.

[0008] In summary, this invention provides a novel method for preparing composite materials, which are then used to activate peroxymonosulfate to generate ROS for the degradation of persistent organic pollutants. This method is significant for the degradation and removal of organic pollutants in natural water bodies and wastewater, and has certain implications for the recycling and utilization of global water resources. Summary of the Invention

[0009] The purpose of this invention is to provide a Co and N-loaded Ti3AlC2 composite material and its preparation method, in order to solve the problems in the above-mentioned background technology, where it is difficult to activate peroxymonosulfate to generate ROS to degrade persistent organic pollutants in current traditional water treatment methods, and there are also limitations such as poor degradation efficiency, high toxicity of degradation by-products, and high treatment costs.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A method for preparing a Co- and N-supported Ti3AlC2 composite catalyst includes the following steps:

[0012] 1) Dissolve 0.9g Ti3AlC2, 0.6g organic nitrogen compound and 0.1-0.4g cobalt-based compound in 100mL deionized water and stir magnetically for 2h to ensure complete dissolution. The mass ratio of Ti3AlC2:organic nitrogen compound:cobalt-based compound is 9:6:(1-4).

[0013] 2) Transfer the solution from step 1) to a 100 mL polytetrafluoroethylene reactor, and then transfer the reactor to an oven at 120℃-170℃ for 12-24 hours.

[0014] 3) After the hydrothermal reaction is completed and cooled to room temperature, the mixture obtained in step 2) is filtered and repeatedly washed with deionized water until the filtrate is neutral before collecting the solid product.

[0015] 4) The solid product obtained in step 3) was dried overnight in a vacuum drying oven at 80°C, ground, and then collected to obtain the precursor material;

[0016] 5) Place the precursor material obtained in step 4) under a nitrogen atmosphere at 700-900℃ for 2-4 hours, with a heating rate of 5℃ / min, and obtain the finished product after calcination.

[0017] Preferably, the organic nitrogen compound in step 1) is one of melamine, urea, and amino acids.

[0018] Preferably, the cobalt-based compound in step 1) is one of cobalt acetate, cobalt nitrate, and cobalt chloride.

[0019] Preferably, the mass of the cobalt-based compound in step 1) is one of 0.1g, 0.2g, or 0.4g.

[0020] Preferably, the oven temperature in step 2) is one of 120°C, 150°C, and 170°C.

[0021] Preferably, the heating time of the oven in step 2) is one of 12 hours, 18 hours, or 24 hours.

[0022] Preferably, the heating of the precursor material in step 5) is one of 2 hours, 3 hours, or 4 hours.

[0023] An application of a Co-N supported Ti3AlC2 composite catalyst for removing organic pollutants from water is disclosed. The Ti3AlC2 composite catalyst is placed in wastewater containing organic pollutants, and peroxymonosulfate is added to the wastewater. The active sites on the surface of the Co-N-Ti3AlC2 material catalyze the peroxymonosulfate to generate an oxidizing active substance. Under the action of external force, the oxidizing active substance comes into full contact with the organic pollutants, thereby achieving the removal of organic pollutants.

[0024] Preferably, the organic pollutants include SIZ, sulfamethoxazole, sulfadiazine, rhodamine B, and atrazine, and the dosage of peroxymonosulfate is 0.4, 0.5, or 0.6 g / L.

[0025] The dosage of Co-N-Ti3AlC2 composite material is 0.4, 0.5, and 0.6 g / L.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention directly utilizes Ti3AlC2 as a substrate to prepare the catalyst, effectively avoiding the environmental damage and high costs associated with Al layer etching. Simultaneously, the Ti3AlC2-based catalyst possesses strong antioxidant capacity and high catalytic activity. Furthermore, the successful incorporation of nitrogen increases the active sites on the Ti3AlC2 surface, and the synergistic effect of Co-N elements enhances the catalytic activity and stability of the material. The Co-N-Ti3AlC2+PMS system exhibits good resistance to anion interference and maintains good activity in natural water bodies. Moreover, the catalyst demonstrates excellent reusability, significantly reducing its economic cost.

[0028] There is a synergistic effect among Co, N, and Ti3AlC2. The synthesized Co-N-Ti3AlC2 exhibits higher PMS activation ability and SIZ degradation ability compared with Co-Ti3AlC2 and N-Ti3AlC2.

[0029] In summary, this invention synthesizes a Co, N co-doped Ti3AlC2 catalyst using a simple method, reducing preparation costs. It also demonstrates good potential in activating PMS to degrade SIZ, providing a possible method for degrading and removing organic pollutants from natural water bodies and wastewater, and is significant for the recycling and utilization of global water resources. Attached Figure Description

[0030] Figure 1 Synthesis process of Co-N-Ti3AlC2.

[0031] Figure 2 (a) SEM image of Ti3AlC2; (b, c) SEM image of Co-N-Ti3AlC2; (d, e) TEM image of Co-N-Ti3AlC2; (f) HRTEM image of Co-N-Ti3AlC2; (gk) Mapping image of Co-N-Ti3AlC2.

[0032] Figure 3 (a) XRD spectra of Ti3AlC2, Co-Ti3AlC2 and Co-N-Ti3AlC2; (b) FT-IR spectra.

[0033] Figure 4 X-ray photoelectron spectra of Co-N-Ti3AlC2: (a) total XPS spectrum; (b) high-resolution XPS spectrum of C1s; (c) N1s; (d) Co 2p; (e) Al 2p; (f) Ti 2p.

[0034] Figure 5 (a) Effects of different catalysts on the SIZ degradation performance of activated PMS; (b) First-order reaction rate constants of SIZ degradation by activated PMS with different catalysts; Interfering factors: (c) Catalyst dosage, (d) PMS dosage, (e) pH value, (f) Effects of coexisting anions on SIZ degradation efficiency; (g) Degradation efficiency of the Co-N-Ti3AlC2+PMS system for different target pollutants; (h) Changes in degradation performance of the Co-N-Ti3AlC2+PMS system under 4 cycles; (i) Effects of the Co-N-Ti3AlC2+PMS system on SIZ degradation under different water quality conditions. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0036] Example 1:

[0037] Preparation method of Co-N-Ti3AlC2

[0038] (1) Dissolve 0.9g Ti3AlC2, 0.6g melamine and 0.4g cobalt acetate in 100mL deionized water and stir magnetically for 2h to ensure complete dissolution;

[0039] (2) Transfer the solution from step (1) to a 100 mL polytetrafluoroethylene reactor, and then transfer the reactor to an oven at 170 °C for 12 h.

[0040] (3) After the hydrothermal reaction is completed and cooled to room temperature, the mixture after the reaction in step (2) is filtered and repeatedly washed with deionized water until the filtrate is neutral before collecting the solid product.

[0041] (4) The solid product obtained in step (3) was placed in a vacuum drying oven at 80°C and dried overnight. After grinding, the precursor material was collected.

[0042] (5) The precursor material obtained in step (4) is placed in a nitrogen atmosphere at 700℃ and calcined for 2 hours at a heating rate of 5℃ / min. The finished product is obtained after calcination.

[0043] Example 2:

[0044] Preparation method of Co-N-Ti3AlC2;

[0045] (1) Dissolve 0.9g Ti3AlC2, 0.6g urea and 0.4g cobalt acetate in 100mL deionized water and stir magnetically for 2h to ensure complete dissolution;

[0046] (2) Transfer the solution from step (1) to a 100 mL polytetrafluoroethylene reactor, and then transfer the reactor to an oven at 120 °C for 24 h.

[0047] (3) After the hydrothermal reaction is completed and cooled to room temperature, the mixture after the reaction in step (2) is filtered and repeatedly washed with deionized water until the filtrate is neutral before collecting the solid product.

[0048] (4) The solid product obtained in step (3) was placed in a vacuum drying oven at 80°C and dried overnight. After grinding, the precursor material was collected.

[0049] (5) The precursor material obtained in step (4) is placed in a nitrogen atmosphere at 700℃ and calcined for 2 hours at a heating rate of 5℃ / min. The finished product is obtained after calcination.

[0050] Example 3:

[0051] Preparation method of Co-N-Ti3AlC2

[0052] (1) Dissolve 0.9g Ti3AlC2, 0.6g glycine and 0.4g cobalt acetate in 100mL deionized water and stir magnetically for 2h to ensure complete dissolution;

[0053] (2) Transfer the solution from step (1) to a 100 mL polytetrafluoroethylene reactor, and then transfer the reactor to an oven at 150 °C for 18 h.

[0054] (3) After the hydrothermal reaction is completed and cooled to room temperature, the mixture after the reaction in step (2) is filtered and repeatedly washed with deionized water until the filtrate is neutral before collecting the solid product.

[0055] (4) The solid product obtained in step (3) was placed in a vacuum drying oven at 80°C and dried overnight. After grinding, the precursor material was collected.

[0056] (5) The precursor material obtained in step (4) is placed in a nitrogen atmosphere at 800℃ and calcined for 2 hours at a heating rate of 5℃ / min. The finished product is obtained after calcination.

[0057] Example 4:

[0058] Preparation method of Co-N-Ti3AlC2;

[0059] (1) Dissolve 0.9g Ti3AlC2, 0.6g melamine and 0.2g cobalt chloride in 100mL deionized water and stir magnetically for 2h to ensure complete dissolution;

[0060] (2) Transfer the solution from step (1) to a 100 mL polytetrafluoroethylene reactor, and then transfer the reactor to an oven at 170 °C for 12 h.

[0061] (3) After the hydrothermal reaction is completed and cooled to room temperature, the mixture after the reaction in step (2) is filtered and repeatedly washed with deionized water until the filtrate is neutral before collecting the solid product.

[0062] (4) The solid product obtained in step (3) was placed in a vacuum drying oven at 80°C and dried overnight. After grinding, the precursor material was collected.

[0063] (5) The precursor material obtained in step (4) is placed in a nitrogen atmosphere at 900℃ and calcined for 2 hours at a heating rate of 5℃ / min. The finished product is obtained after calcination.

[0064] According to the content of Implementation 1 and the attached diagram;

[0065] Figure 2 Comparison of Co and N doped Ti3AlC2 before ( Figure 2 a) after ( Figure 2 SEM images b and c) show that Co-N-Ti3AlC2 exhibits a more pronounced layered morphology compared to the original Ti3AlC2. In addition, the surface of Co-N-Ti3AlC2 is covered with a layer of villous material, which, according to relevant literature, is likely TiO2 nanowires formed by the oxidation of the material. The presence of TiO2 nanowires can increase the specific surface area of ​​the material, providing more attachment sites for metallic Co, and also improving the material's charge conductivity. To further investigate the elemental mapping within the material's microstructure, Figure 2 TEM images of Co-N-Ti3AlC2 shown in d and e reveal the layered structure of the material. A lattice spacing of 0.2 nm was also observed. Figure 2 f), corresponding to the (111) crystal plane of Co. HAADF-EDS of Co-N-Ti3AlC2 ( Figure 2 The gk indicates that Co and N elements are uniformly distributed on the surface of the material.

[0066] Figure 3 Figure a shows the XRD pattern of the Co-N-Ti3AlC2 composite material prepared in this embodiment. Compared with the original Ti3AlC2 material, a small diffraction peak appears at 44.1° after Co doping, which is attributed to Co. 0 The absence of cobalt nitride, cobalt carbide, and cobalt oxide signals in Co-N-Ti3AlC2 confirms that the Ti3AlC2 material is loaded with pure metallic Co particles. This is because, during the high-temperature carbonization process, Ti3AlC2 acts as a reducing agent to reduce the Co-based components. The resulting metallic cobalt particles, in turn, can catalyze the graphitization of amorphous carbon. The broad diffraction peaks observed in the Co-N-Ti3AlC2 composite material at 26° to 30° confirm the presence of graphitized carbon nitride, indicating successful N doping.

[0067] Figure 3 b shows the FT-IR spectrum of the Co-N-Ti3AlC2 composite material prepared in this embodiment. 3446cm -1 and 3643cm -1The absorption peak at 1630 cm⁻¹ is attributed to -OH groups, and the -OH content on the Co-N-Ti3AlC₂ surface is significantly higher than that on the Co-Ti3AlC₂ and Ti3AlC₂ materials. -1 The absorption peak at 580 cm⁻¹ is attributed to the C=C vibration of the carbon layer in the material or the C=C=N vibration after N doping. -1 The absorption peaks at the left and right positions may be attributed to the metallic stretching vibration of Co.

[0068] To clearly characterize the chemical composition and valence of the synthesized Co-N-Ti3AlC2 composite material, XPS characterization analysis was performed. Figure 4 As shown in Figure a, the Co-N-Ti3AlC2 material contains C, N, Co, Al, Ti, and O elements. Figure 4 b shows the C1s spectrum of the Co-N-Ti3AlC2 material, where the four spectral peaks at 281.3 eV, 284.6 eV, 285.7 eV, and 287.2 eV correspond to the C-Ti bond, sp bond, and sp bond, respectively. 2 Hybridized graphite carbon (C-Csp) 2 ), sp 3 Hybrid diamond-like carbon (CC sp) 3 ) and CO / CN bonds. N 1s spectrum of Co-N-Ti3AlC2 material ( Figure 4 c) shows five N-bond configurations at 397.6 eV, 398.6 eV, 399.5 eV, 400.8 eV, and 403.8 eV, representing pyridine N, Co-N, and other bond configurations, respectively. x , pyrrole N, graphite N and N oxide. Figure 4 d shows the Co 2p on the surface of the Co-N-Ti3AlC2 material. 3 / 2 The spin orbital has three components, namely the metallic Co 0 (778.6 eV), N-coordinated Co species (780.8 eV) and Co 2p 1 / 2 (796.9 eV), in addition to the two spectral peaks at 785.6 eV and 803.8 eV, which are Co. 2+ The satellite peaks. Among them, the spectral peak at 780.8 eV originates from the surface Co. 2+ The strong coordination with electronegative N atoms, along with the peak intensity at this location, indicates a stronger electronic interaction between the N-doped material and metallic Co. This will promote the migration of electrons from N atoms to Co, thereby promoting PMS activation. Figure 4 In f, 455.8 eV, 458.9 eV, 461.2 eV, and 464.2 eV correspond to Ti, respectively. 2+ 2p 3 / 2 、Ti 4+ -O 2p 3 / 2、Ti 2+ 2p 1 / 2 、Ti 4+ -O 2p 1 / 2 The presence of a large number of Ti atoms in the material can accelerate the transport of electrons inside the material.

[0069] To further verify this, the following experiment was conducted;

[0070] Experimental Example 1

[0071] The removal of SIZ from the wastewater was carried out using Co-N-Ti3AlC2 prepared in Example 1, as detailed below:

[0072] 50 mL of the target solution containing SIZ was placed in a 100 mL Erlenmeyer flask, and catalyst powder and PMS were added. The flask was then placed in a constant-temperature shaker, with the reaction temperature set at 25 °C and the stirring speed at 150 rpm. Every 5 min, 2 mL of water was taken from the Erlenmeyer flask using a syringe, filtered through a 0.22 μm nylon 66 needle filter, and transferred to a quartz cuvette. The solution concentration was measured at 264 nm using a UV spectrophotometer. The total reaction time was 30 min. Simultaneously, to investigate the importance of N-doping and Co-doping in the preparation of Co-N-Ti3AlC2 composite materials, the degradation performance of sulfamethoxazole in N-Ti3AlC2, Co-Ti3AlC2, and Co-N-Ti3AlC2 combined with PMS was compared. The results are as follows: Figure 5 a, b. In the system containing only Co-N-Ti3AlC2 material, less than 2% of SIZ was adsorbed within 30 minutes, and the adsorption effect was negligible. PMS alone also had limited degradation capacity for SIZ, removing no more than 18% of SIZ within 30 minutes. Among the various materials, the Co-N-Ti3AlC2+PMS system exhibited the highest SIZ degradation efficiency, achieving a removal rate of 98.6% within 30 minutes, while the Co-Ti3AlC2+PMS system only achieved a removal rate of 61.1%, and the N-Ti3AlC2+PMS system performed even worse, with a SIZ removal rate of less than 1%. Simultaneously, the reaction rate of the Co-Ti3AlC2+PMS system reached 0.1539 min. -1 The values ​​were 4.13 times and 14.02 times higher than those of the Co-Ti3AlC2+PMS system (0.03721) and the N-Ti3AlC2+PMS system (0.01097), respectively, which proves that Co and N doping play an important role in improving the activation performance of Ti3AlC2 materials for PMS.

[0073] Experiment Example 2

[0074] The Co-N-Ti3AlC2 prepared in Example 1 was used to conduct anti-interference experiments under different influencing factors, as detailed below:

[0075] (1) Effect of catalyst dosage on the reaction

[0076] The degradation capacity of Co-N-Ti3AlC2 for SIZ was evaluated by selecting dosages of 0.4, 0.5, and 0.6 g / L, respectively. Figure 5 As shown in c, with the increase of catalyst dosage, the degradation rate increased from 96.05% and 97.58% to 98.48%, respectively, and the reaction rates were 0.1149, 0.1409, and 0.1671 min respectively. -1 The degradation rate and reaction rate of SIZ both increase accordingly. Increasing the amount of catalyst increases the number of active sites in the reaction system, thereby accelerating the electron transfer rate and enhancing the degradation ability of the target pollutant.

[0077] (2) Effect of PMS dosage on the reaction

[0078] Further research was conducted using PMS dosages of 0.4, 0.5, and 0.6 g / L. The results are as follows: Figure 5 As shown in d, when the PMS dosage increased from 0.4 g / L to 0.5 g / L, the degradation rate and degradation percentage of SIZ in the system both improved, increasing from 95.03% and 0.1123 min, respectively. -1 Increased to 98.56% and 0.1539 min -1 This is because as the PMS concentration increases, the amount of ROS generated in the system also increases, thereby increasing the reaction rate. However, when the PMS dosage continues to increase to 0.6 g / L, the degradation rate and degradation percentage of SIZ actually decrease, from 98.56% and 0.1539 min, respectively. -1 It decreased to 97.58% and 0.1409 min. -1 This may be because, on the one hand, the catalyst has a limited number of active sites, and its activation rate of PMS has reached its maximum. On the other hand, excessive PMS entering the catalytic system will lower the pH of the reaction solution, thereby inhibiting the catalytic process.

[0079] (3) Effect of pH on the reaction

[0080] The initial state of the SIZ solution is a slightly acidic environment. For example... Figure 5As shown in Figure e, the Co-N-Ti3AlC2+PMS system exhibits good activity within a pH range of 5-9. However, under highly acidic conditions (pH=3), the reaction is significantly inhibited, with the degradation rate decreasing from 98.56% under neutral conditions to 65.67%. However, given the already low initial pH of the SIZ solution, the main reason for the inhibition of the reaction at pH=3 may not be H+. + The interference is not due to the presence of chlorine ions introduced during pH adjustment with HCl, but rather to the adverse effects of these ions. Excessively high pH also inhibits catalytic activity; when the solution pH reached 11, the degradation rate of SIZ decreased to 63.69%. This is likely because at pH = 11, PMS primarily exists as HSO₅ in solution. 2- The existence of SO4· in this form is therefore detrimental to SO4· - The generation of .

[0081] (4) Effect of coexisting anions on the reaction

[0082] like Figure 5 As shown in f, Cl was investigated. - HCO3 - / CO3 2- SO4 2- and HPO4 2- / H2PO4 - The degradation effects on SIZ showed final degradation rates of 56.56%, 50.36%, 95.58%, and 95.8%, respectively. Among these, SO4... 2- and HPO4 2- / H2PO4 - It has almost no effect on the reaction, while Cl - and HCO3 - / CO3 2- It inhibited the degradation of SIZ during the process, reducing the degradation rate by nearly half and also significantly decreasing the reaction rate (0.03728 min). -1 0.02915min -1 ).

[0083] Experimental Example 3

[0084] The practical application capabilities of Co-N-Ti3AlC2 prepared in Example 1 were explored, as detailed below:

[0085] (1) Treatment effect of Co-N-Ti3AlC2+PMS system on different pollutants

[0086] Two other sulfonamide pollutants (SMX, SM2), as well as the dye RHB and the pesticide ATZ, were selected as target pollutants for degradation reactions. For example... Figure 5As shown in g. For dye RhB, 100% removal was achieved within 5 minutes. For the other two types of sulfonamides, the degradation rates after 30 minutes were: SMX: 93.29% and SM2: 79.27%. The Co-N-Ti3AlC2+PMS system showed the worst degradation efficiency for pesticide ATZ, removing only 60% within 30 minutes. In summary, Co-N-Ti3AlC2 material-activated PMS is highly applicable for degrading organic pollutants. Furthermore, the Co-N-Ti3AlC2+PMS system exhibits excellent performance in degrading sulfonamide pollutants.

[0087] (2) Stability test of Co-N-Ti3AlC2+PMS system

[0088] Experimental results are as follows Figure 5 As shown in h, after four cycles, the removal rate of SIZ by the system still reached 87.6%, indicating that the catalyst has good stability. The main reason for the performance decline after multiple cycles is the precipitation of Co from the material. Simultaneously, the concentration of Co ions leached from the catalyst into the solution was measured, and it was found that the concentration of Co ions in the solution after the reaction was 0.693 mg / L, less than 1 mg / L, which meets the Chinese Industrial Wastewater Discharge Standard (GB 25467-2010).

[0089] (3) Treatment capacity of the Co-N-Ti3AlC2+PMS system in natural water bodies

[0090] To investigate the effectiveness of the Co-N-Ti3AlC2+PMS system in practical applications, tap water and surface water (Zehu Lake water from Yunnan University) were used instead of the laboratory's deionized water to prepare solutions of the target pollutants. Tap water and natural water bodies contain various ions that interfere with the generation of free radicals, while humic acid in surface water also interferes with the reaction process. The results are as follows... Figure 5 As shown in Figure i, after 30 minutes, the removal rates of SIZ in tap water and surface water were 75.53% and 72.7%, respectively. The SIZ removal efficiency decreased compared with that in pure water, but it still maintained a high degradation rate. This result proves that the Co-N-Ti3AlC2+PMS system has good anti-interference ability for natural water quality and is of great significance for its practical application.

[0091] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0092] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a Co- and N-supported Ti3AlC2 composite catalyst, characterized in that: The preparation of the catalyst includes the following steps: 1) Dissolve 0.9g Ti3AlC2, 0.6g organic nitrogen compound and 0.1-0.4g cobalt-based compound in 100mL deionized water and stir magnetically for 2h to ensure complete dissolution. The mass ratio of Ti3AlC2:organic nitrogen compound:cobalt-based compound is 9:6:(1-4). 2) Transfer the solution from step 1) to a 100 mL polytetrafluoroethylene reactor, and then transfer the reactor to an oven at 120℃-170℃ for 12-24 hours. 3) After the hydrothermal reaction is completed and cooled to room temperature, the mixture obtained in step 2) is filtered and repeatedly washed with deionized water until the filtrate is neutral before collecting the solid product. 4) The solid product obtained in step 3) was dried overnight in a vacuum drying oven at 80°C, ground, and then collected to obtain the precursor material; 5) Place the precursor material obtained in step 4) under a nitrogen atmosphere at 700-900℃ for 2-4 hours, with a heating rate of 5℃ / min, and obtain the finished product after calcination.

2. The method for preparing a Co, N-supported Ti3AlC2 composite catalyst as described in claim 1, characterized in that, The organic nitrogen compound in step 1) is one of melamine, urea, or amino acids.

3. The method for preparing a Co, N-supported Ti3AlC2 composite catalyst as described in claim 1, characterized in that, The cobalt-based compound in step 1) is one of cobalt acetate, cobalt nitrate, and cobalt chloride.

4. The method for preparing a Co, N-supported Ti3AlC2 composite catalyst as described in claim 1, characterized in that, The mass of the cobalt-based compound in step 1) is one of 0.1g, 0.2g, or 0.4g.

5. The method for preparing a Co- and N-supported Ti3AlC2 composite catalyst as described in claim 1, characterized in that, The oven temperature in step 2) is one of 120℃, 150℃, or 170℃.

6. The method for preparing a Co, N-supported Ti3AlC2 composite catalyst as described in claim 1, characterized in that, The heating time of the oven in step 2) is one of 12 hours, 18 hours, or 24 hours.

7. The method for preparing a Co, N-supported Ti3AlC2 composite catalyst as described in claim 1, characterized in that, In step 5), the heating temperature of the precursor material is one of 700℃, 800℃, and 900℃.

8. The method for preparing a Co, N-supported Ti3AlC2 composite catalyst as described in claim 1, characterized in that, In step 5), the precursor material is heated for one of three hours: 2 hours, 3 hours, or 4 hours.

9. An application of a Co, N-supported Ti3AlC2 composite catalyst for removing organic pollutants from water, characterized in that, The Ti3AlC2 composite catalyst obtained by any of the preparation methods described in claims 1-8 is placed in wastewater containing organic pollutants, and peroxymonosulfate is added to the wastewater. The active sites on the surface of the Co-N-Ti3AlC2 material catalyze the peroxymonosulfate to generate oxidizing active substances. Under the action of external force, the oxidizing active substances come into full contact with the organic pollutants, thereby achieving the removal of organic pollutants.

10. The application of the Co, N-supported Ti3AlC2 composite catalyst as described in claim 9 for removing organic pollutants from water, characterized in that, The organic pollutants include SIZ, sulfamethoxazole, sulfadiazine, rhodamine B, and atrazine. The dosage of peroxymonosulfate is 0.4, 0.5, and 0.6 g / L, and the dosage of Co-N-Ti3AlC2 composite material is 0.4, 0.5, and 0.6 g / L.

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