Iron diselenide-Mxene composite catalyst, preparation method thereof and application of iron diselenide-Mxene composite catalyst in tetracycline degradation

Abstract

The invention provides an iron diselenide-Mxene composite catalyst, a preparation method thereof and application of the iron diselenide-Mxene composite catalyst in tetracycline degradation, and belongs to the technical field of wastewater treatment. According to the flower-shaped FeSe2-Ti3C2Tx heterojunction and the preparation method of the flower-shaped FeSe2-Ti3C2Tx heterojunction, the selenide FeSe2 is prepared by adopting transition metal Fe and is loaded on the Ti3C2Tx Mxene layer, the flower-shaped FeSe2-Ti3C2Tx heterojunction is constructed through a simple one-step solvothermal reaction, and the method not only greatly reduces metal leaching, but also can enhance charge migration and dispersion of active sites of the catalyst. The prepared composite catalyst can achieve 95% of high TC degradation efficiency within 24 minutes of catalytic reaction, an FT / PMS / Vis system constructed by the method has very high external interference resistance and shows circulation universality, and activation energy barriers of PMS can be reduced by constructing FT heterojunction.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to an iron diselenide-Mxene composite catalyst and a preparation method thereof and application thereof in degrading tetracycline. Background Art

[0002] In the past few decades, broad-spectrum antibiotics have been widely used in many fields such as human health, animal husbandry and aquaculture. For example, after the use of tetracycline (TC), more than 75% of the active precursors and secondary metabolites will inevitably enter the sewage treatment plant. Due to the long half-life and low biodegradation efficiency of antibiotics, traditional wastewater treatment methods such as biological treatment, chemical oxidation and adsorption can only eliminate part of the antibiotic residues in the water. In addition, these methods often face problems such as low removal rate, high risk of secondary pollution and high maintenance costs. Therefore, the development of an innovative, environmentally sustainable and economically feasible technology for the treatment of tetracycline residues in wastewater is crucial to meet the above challenges.

[0003] The peroxymonosulfate-based advanced oxidation process (PMS-AOP) has strong oxidation ability and high degradation efficiency, and is an effective method for treating antibiotic wastewater. . OH) compared to sulfate (SO4 ·- ) shows a stronger redox potential E 0 (SO4 ·- / SO4 2- )=+2.50-+3.10V NHE , long half-life (30-40 μs), and wider reaction range (pH 2-9), making them ideal for wastewater treatment. Among the different PMS activation methods, transition metal-based PMS activation methods are favored due to their simplicity, high reproducibility, and low energy consumption. However, the reported transition metal catalysts still face problems such as insufficient dispersion, few active sites, and metal ion leaching. Summary of the invention

[0004] The object of the present invention is to provide an iron diselenide-Mxene composite catalyst and a preparation method thereof and application in the degradation of tetracycline. The iron diselenide-Mxene composite catalyst has the characteristics of high specific surface area (many active sites), efficient charge migration, higher PMS activation efficiency and low metal ion leaching.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing an iron diselenide-Mxene composite catalyst, comprising the following steps:

[0007] mixing the iron salt and the first solvent to obtain an iron-containing solution;

[0008] Ti3C2T x , Se powder and a second solvent are mixed to obtain a selenium-containing dispersion;

[0009] The iron-containing solution is mixed with the selenium-containing dispersion, and a solvent thermal reaction is carried out to obtain an iron diselenide-Mxene composite catalyst.

[0010] Preferably, the iron salt comprises ferric chloride; and the first solvent comprises ethanolamine.

[0011] Preferably, the molar ratio of the iron salt to the Se powder is 1:1-3.

[0012] Preferably, in the iron diselenide-Mxene composite catalyst, iron diselenide and Ti3C2T x The mass ratio is 1.07:0.01~0.07.

[0013] Preferably, the second solvent comprises ethanolamine.

[0014] Preferably, the temperature of the solvent thermal reaction is 120-180° C. and the time is 8-12 hours.

[0015] The invention provides an iron diselenide-Mxene composite catalyst prepared by the preparation method described in the technical scheme.

[0016] The present invention provides application of the iron diselenide-Mxene composite catalyst described in the above technical solution in degrading tetracycline.

[0017] Preferably, the application method comprises: mixing the iron diselenide-Mxene composite catalyst, a tetracycline-containing solution and peroxymonosulfate, and degrading the obtained mixed solution.

[0018] The present invention provides a method for preparing an iron diselenide-MXene composite catalyst, using transition metal Fe to prepare selenide FeSe2 and loading it onto Ti3C2T x Flower-like FeSe2-Ti3C2T3O3 was constructed on Mxene layer via a simple one-step solvothermal reaction. x Heterojunction, FeSe2 presents an irregular flake structure, self-assembles into a flower ball shape and tightly adheres to Ti3C2T x surface, while Ti3C2T x It presents a typical accordion-like structure, with FeSe2 evenly distributed in Ti3C2T x Surface, Ti3C2T xThe unique layered structure can increase the specific surface area of ​​the catalyst and provide more active sites. In the process of transition metal activation of PMS, the redox cycle rate of metal ions between different valence states directly determines the catalytic activity, and the electronic structure of selenium enables it to form covalent transition metal selenides, thereby converting the metal from an oxidized state to a reduced state. The present invention forms iron diselenide through the synergistic effect between Se and the transition metal Fe, which can effectively improve the activation efficiency of PMS. In addition, the formation of iron diselenide can also inhibit metal leaching during the catalytic process.

[0019] The number of active sites on the surface of transition metal selenides and the mobility of photogenerated charges are key factors in the activation of PMS. x A heterojunction is formed on the surface, and the transition metal is fixed by chemical action to solve the problem of metal leaching. At the same time, the recombination of electron-hole pairs can be effectively suppressed. Therefore, the method of the present invention not only greatly reduces metal leaching, but also enhances the charge migration and dispersion of the catalyst active sites. The iron diselenide-Mxene composite catalyst prepared by the present invention has the characteristics of high specific surface area, efficient charge migration, higher PMS activation efficiency and low metal ion leaching, and can improve the dispersibility of the catalyst to expose more active sites and reduce metal ion leaching, which is of great significance for improving the catalytic efficiency and effective recovery rate of transition metal activated PMS for water treatment and antibacterial agent removal.

[0020] The results of the embodiment show that the composite catalyst prepared by the present invention can achieve a high TC degradation efficiency of 95% within 24 minutes of catalytic reaction, proving that FeSe2-Ti3C2T x There are abundant active sites and excellent interfacial electron transport between heterojunctions. The FT / PMS / Vis system has strong resistance to external interference and exhibits cyclic versatility. The construction of FT heterojunction can reduce the activation energy barrier of PMS, making the catalytic reaction process easier to occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Among them, (a) FeSe2, (b) Ti3C2T x and (c, d) FESEM images of FT-3%; (e) HRTEM image of FT-3%;

[0022] Figure 2 (a) XRD patterns of different samples; (b) FT-IR spectra; (c) C1s; (d) Ti2p; (e) Fe2p and (f) Se3d XPS high-resolution spectra;

[0023] Figure 3 for FeSe2 and different FeSe2 / Ti3C2T x UV-visible spectra of the composite catalyst;

[0024] Figure 4 FeSe2 / Ti3C2T prepared in Example 2 x XRD comparison chart before and after use;

[0025] Figure 5 (a) The degradation effect of TC under different conditions; (b) Ti3C2T with different doping amounts x TC degradation characteristics of different photocatalysts: 0.2 g / L; TC solution: 20 mg / L, 50 mL, pH = 5.8, visible light irradiation at room temperature); In the PMS / Vis system, the effects of (c) initial pH, (d) PMS and (e) FT-3% catalyst dosage on TC degradation; (f) Cl - 、(g)HCO3 - 、(h)NO3 - and (i) H2PO4 - Effect of coexisting anions on TC degradation by FT-3% catalyst;

[0026] Figure 6 In the figure, (a) the effect of the corresponding apparent rate constants on TC degradation under different conditions; (b) the comparison of TC degradation under different concentrations;

[0027] Figure 7 (a) different water sources; (b) degradation rates of different pollutants; (c) stability in the cycle experiment; (d) leaching rate of metal ions by FT-3%. DETAILED DESCRIPTION

[0028] In the present invention, unless otherwise specified, the required raw materials or reagents are commercially available products well known to those skilled in the art.

[0029] The present invention provides a method for preparing an iron diselenide-Mxene composite catalyst, comprising the following steps:

[0030] mixing the iron salt and the first solvent to obtain an iron-containing solution;

[0031] Ti3C2T x , Se powder and a second solvent are mixed to obtain a selenium-containing dispersion;

[0032] The iron-containing solution is mixed with the selenium-containing dispersion, and a solvent thermal reaction is carried out to obtain an iron diselenide-Mxene composite catalyst.

[0033] In the present invention, the iron salt preferably includes ferric chloride, more preferably FeCl2·4H2O; the first solvent is preferably ethanolamine; and the usage ratio of the first solvent to the iron salt is preferably 30 mL:1.0 g.

[0034] In the present invention, the molar ratio of the iron salt to the Se powder is preferably 1:1-3, more preferably 1:1.

[0035] In the present invention, in the iron diselenide-Mxene composite catalyst, iron diselenide and Ti3C2T x The mass ratio is 1.07:0.01 to 0.07, and more preferably 1.07:0.03 to 0.05.

[0036] In the present invention, the second solvent is preferably ethanolamine; the usage ratio of the second solvent to Se powder is preferably 30 mL: 0.3-0.4 g.

[0037] In the present invention, iron salt is preferably added to the first solvent and stirred for 30 minutes to obtain an iron-containing solution, and Se powder and Ti3C2T3O4 are added to the second solvent. x (commercially available), stirred for 30 min to obtain a selenium-containing dispersion, poured the selenium-containing dispersion into the iron-containing solution under magnetic stirring, stirred for 30 min, and then transferred the mixture into a 100 mL polytetrafluoroethylene autoclave for a solvothermal reaction. The present invention has no particular limitation on the stirring, and the materials can be uniformly mixed according to a process well known in the art.

[0038] In the present invention, the temperature of the solvothermal reaction is preferably 120-180° C., more preferably 160° C., and the time is preferably 8-12 h, more preferably 12 h.

[0039] After the solvothermal reaction is completed, the present invention preferably centrifuges the obtained product, washes it with water and anhydrous ethanol for multiple times, and dries it at 60° C. for 8 h to obtain an iron diselenide-Mxene composite catalyst.

[0040] The invention provides an iron diselenide-Mxene composite catalyst prepared by the preparation method described in the technical scheme.

[0041] The present invention provides application of the iron diselenide-Mxene composite catalyst described in the above technical solution in degrading tetracycline.

[0042] In the present invention, the application method preferably comprises: mixing the iron diselenide-Mxene composite catalyst, a tetracycline-containing solution and peroxymonosulfate, and degrading the obtained mixed solution.

[0043] The present invention preferably uses a tetracycline-containing solution as simulated wastewater.

[0044] In the present invention, the dosage ratio of the iron diselenide-Mxene composite catalyst to the tetracycline-containing solution is preferably 10-30 mg:50 mL, more preferably 10 mg:50 mL, and the concentration of the tetracycline-containing solution is 10-40 mg / L, more preferably 20 mg / L.

[0045] In the present invention, the peroxymonosulfate is preferably potassium hydrogen persulfate; the concentration of the peroxymonosulfate in the mixed solution is 1 mmol / L.

[0046] The present invention has no particular limitation on the degradation time, which can be adjusted according to actual wastewater treatment needs.

[0047] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0048] Example 1

[0049] Add 1.0 g FeCl2·4H2O to 30 mL ethanolamine and stir for 30 min to obtain an iron-containing solution. Add 0.4 g Se powder and 10.7 mg Ti3C2T x , stirred for 30 min to obtain a selenium-containing dispersion. Under magnetic stirring, the selenium-containing dispersion was poured into the iron-containing solution. After stirring for 30 min, the mixed solution was transferred to a 100 mL polytetrafluoroethylene high-pressure reactor and reacted at 160 ° C for 12 h. The obtained product was centrifuged, washed with deionized water and anhydrous ethanol for multiple times, and dried at 60 ° C for 8 h to obtain FeSe2 / Ti3C2T x Composite catalyst, wherein iron diselenide and Ti3C2T x The mass ratio is 1.07:0.01 and is named FT-1%.

[0050] Example 2

[0051] The only difference from Example 1 is that Ti3C2T x The addition amount is 32.1 mg, iron diselenide and Ti3C2T x The mass ratio of is 1.07:0.03, and the obtained catalyst is named FT-3%.

[0052] Example 3

[0053] The only difference from Example 1 is that Ti3C2T x The addition amount is 53.4 mg, iron diselenide and Ti3C2T x The mass ratio of is 1.07:0.05, and the obtained catalyst is named FT-5%.

[0054] Comparative Example 1

[0055] The only difference from Example 1 is that no Ti3C2T is added x , FeSe2 is obtained, which can be recorded as FT-0%.

[0056] Characterization and performance testing

[0057] 1) Field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) were used to analyze the FeSe2 and raw material Ti3C2T in Comparative Example 1. x and the morphology of different FT samples.

[0058] Figure 1 Among them, (a) FeSe2, (b) Ti3C2T x and (c, d) FESEM images of FT-3%; (e) HRTEM image of FT-3%.

[0059] like Figure 1 As shown in a and b, FeSe2 has an irregular flake structure, while Ti3C2T x The typical accordion-like structure is formed. The FeSe2 flakes will self-assemble into a flower ball shape and tightly adhere to the Ti3C2T x surface( Figure 1 c and d), thereby increasing the specific surface area and light absorption rate during the catalytic process. FeSe2 / Ti3C2T x HRTEM images of the composite materials ( Figure 1 Figure e) shows that FeSe2(111) and Ti3C2T x The plane spacing d values ​​of (105) are 0.256 and 0.224 nm, respectively.

[0060] 2) XRD analysis was used to study the crystal structure of the prepared samples:

[0061] Figure 2 (a) XRD patterns of different samples; (b) FT-IR spectra; (c) C1s; (d) Ti2p; (e) Fe2p and (f) Se3d XPS high-resolution spectra.

[0062] exist Figure 2 In a, the prominent XRD diffraction peaks at 31.3°, 35.0°, 36.6°, and 48.4° correspond to the (002), (111), (012), and (121) planes of FeSe2 (PDF#74-0247), respectively. The XRD patterns of FT-1%, FT-3%, and FT-5% materials are very similar to those of FeSe2, which indicates that Ti3C2T x The addition of did not change the crystal structure of FeSe2. x No obvious Ti3C2T x diffraction peak, which may be due to FeSe2 shielding the low content Ti3C2T x Caused by.

[0063] FT-IR and XPS were used to analyze the chemical bonds and element valence states of the prepared materials. Figure 2 As shown in (b), the transmission spectrum of the FT sample is very similar to that of FeSe2. Since there is no obvious FT-IR peak, no Ti3C2T x Typical signal. At 3200-3700cm -1 The broad absorption peaks observed in the range of 1634 cm-1 come from the stretching vibration modes of physically adsorbed amino and hydroxyl groups (e.g., -NH, -OH). -1 The peak at belongs to the stretching vibration mode of C=O.

[0064] In the XPS analysis of FT-3%, Figure 2 c is C1s, and its binding energies of 281.9 eV, 284.8 eV, 286.2 eV, and 288.4 eV are attributed to C-Ti, sp 2 However, the C-Ti peak (282.2 eV) of FT-3% shifts to higher binding energy, indicating that FeSe2 and Ti3C2T x Interfacial charge transfer occurs between Ti3C2T x Ti2p spectrum ( Figure 2 In (d), the four peaks at 455.2, 456.3, 458.6, and 461.7 eV correspond to Ti-C2p 3 / 2 、Ti-C(Ti 2+ )、Ti-O2p 3 / 2 and Ti-C(Ti 2+ ). For FT-3%, Ti-C2p 3 / 2 (455.3eV) and Ti-C (Ti 2+ The binding energy of )(456.7 eV) shows a positive shift compared with that of FeSe2, which indicates that in the FT heterojunction, FeSe2 and Ti3C2T x There is interfacial charge migration. The binding energy is 452.7 eV and belongs to the satellite peak. In the high-resolution Fe2p spectrum of FeSe2 Figure 2 In the middle e, the six fitting peaks are located at 706.9eV (2p 3 / 2 , Fe 2+ )、710.8eV(2p 3 / 2 , Fe 3+ )、712.7eV(Fe 3+ )、719.7eV(2p 1 / 2 , Fe 2+ )、724.2eV(2p 1 / 2 , Fe 3+) and 726.3 eV (Sat.), which is consistent with the peak of FT-3%. These results indicate that Fe 2+ and Fe 3+ The coexistence of is beneficial to the activation of PMS during the catalytic reaction. Figure 2 As shown in f, it is located at 53.0eV (3d 5 / 2 )、54.7eV(3d 5 / 2 ) and 55.5eV(3d 3 / 2 ) are attributed to the Fe-Se bond. It can also be found that due to the FeSe2-Ti3C2T x Due to the interfacial charge migration between heterojunctions, the binding energy of Se3d of FT-3% is negatively shifted compared with that of FeSe2 ( Figure 2 (f)

[0065] Figure 3 for FeSe2 and different FeSe2 / Ti3C2T x UV-visible spectra of composite catalysts; e.g. Figure 3 As shown, the visible light response range of FeSe2 and FT samples is very wide in the range of 200 to 800 nm.

[0066] Application Example 1

[0067] A tetracycline TC aqueous solution with a concentration of 20 mg / L was prepared. 50 mL of TC solution was taken, and 10 mg of the catalyst was added to the TC solution (50 mL, 20 mg / L). The mixture was then stirred in the dark at room temperature for 30 minutes to reach an adsorption-desorption equilibrium. The pH value of the system was not adjusted before the reaction began. Potassium persulfate was added to the mixture to a concentration of 1 mM. The visible light source was provided by a metal halide lamp with a 420 nm cutoff filter. 3.0 mL of the solution was taken out every 3 minutes and filtered through a 0.22 μm filter to separate the catalyst. The concentration of TC was measured at a wavelength of λ=357.5 nm using an ultraviolet-visible spectrophotometer (UV-2600).

[0068] The degradation efficiency of the catalyst was evaluated by the following formula:

[0069] Degradation efficiency: (η)% = (1-C / C0) × 100 (1)

[0070] Where C is the TC concentration at different sampling time intervals (t) during the degradation process, and C0 is the initial concentration of TC when the adsorption-desorption equilibrium is reached.

[0071] The following performance tests were all conducted according to the catalytic process of Application Example 1, and the conditions were changed accordingly to test the effects of different conditions on the degradation effect.

[0072] Figure 4FeSe2 / Ti3C2T prepared in Example 2 x XRD comparison chart before and after use; Figure 4 As shown, after the prepared FT-3% sample was recycled for 4 times in the manner of Application Example 1, the crystal structure did not change significantly, indicating that the catalyst had good stability.

[0073] Figure 5 (a) The degradation effect of TC under different conditions; (b) Ti3C2T with different doping amounts x TC degradation characteristics (test conditions are: photocatalyst: 0.2 g / L; TC solution: 20 mg / L, 50 mL, pH = 5.8, visible light irradiation at room temperature; sulfuric acid and sodium hydroxide were used to adjust the pH value, respectively); in the PMS / Vis system, the effects of (c) initial pH value (5.8), (d) PMS and (e) FT-3% catalyst dosage on TC degradation; (f) Cl - 、(g)HCO3 - 、(h)NO3 - and (i) H2PO4 - Effect of coexisting anions on TC degradation by FT-3% catalyst.

[0074] like Figure 5 As shown in Figure a, after adding PMS, the degradation efficiency of TC is only 33% due to the autonomous decomposition of PMS. However, with the introduction of catalyst, the degradation efficiency is significantly improved, FeSe2 / PMS, Ti3C2T x The degradation efficiencies of the FeSe2-Ti3C2T / PMS and FT-3% / PMS systems were 61%, 33%, and 82%, respectively. x The construction of FeSe2 greatly improves its catalytic performance. It is worth noting that with the introduction of visible light, the degradation efficiency is further improved, and the FT-3% / PMS / Vis system has the highest degradation efficiency (95%) within 24 minutes. Figure 6 As shown in Figure a, the apparent rate constant of TC degradation was calculated by fitting the pseudo-first-order equation (Eq. 2) to evaluate the degradation rate of the catalyst under different conditions:

[0075]

[0076] Where C0 and C represent the initial concentration of TC and the residual concentration at time t, respectively; k0 is the apparent kinetic constant.

[0077] In addition, the study of Ti3C2T x To determine the optimal dosage of Ti3C2T x Role in TC catalytic degradation. Figure 5The TC degradation rates of FT-0% (only FeSe2), FT-1%, FT-3%, and FT-5% are 85%, 88%, 95%, and 90%, respectively, indicating that Ti3C2T x The optimal dosage is 3%. Under this condition, the adsorption capacity and charge transfer capacity are significantly enhanced, thus achieving the best catalytic performance (such as Figure 5 However, excessive Ti3C2T x (FT-5%) would block incident photons and occupy active sites during the catalytic process, resulting in a decrease in catalytic performance.

[0078] When pH is in the range of 3 to 11, the effect of pH value on TC degradation in the FT / PMS / Vis system was studied. Figure 5 As shown in Figure c, the results show that under acidic conditions, due to excessive dissociation of H + Lead to HSO5 - The decomposition rate is low because the PMS is consumed, thereby inhibiting the activation of PMS. In contrast, alkaline solutions (such as pH = 11) can promote the conversion of PMS into active substances, thereby facilitating the degradation of pollutants. In addition, these results confirm that the FT-3% catalyst has high catalytic activity over a wide pH range. The FT-3% catalyst was used to explore the effects of PMS concentration, catalyst dosage, and TC concentration in the FT / PMS / Vis system. Figure 5 Figure d shows that as the PMS concentration increases from 0 mM to 1 mM, the TC degradation efficiency increases with the increase in PMS activity. However, when the PMS concentration reaches 2.0 mM, the TC removal rate decreases significantly, which may be due to the fact that the excess PMS hinders the effective adsorption of TC by the catalyst. In addition, Figure 5 Figure e shows that when the PMS concentration is 1 mM, the TC removal rate increases from 60% to 95% when the catalyst dosage increases from 0 g / L to 0.2 g / L, which indicates that the larger the catalyst dosage, the more reaction sites there are, thus improving the TC removal rate. However, when the catalyst dosage reaches 0.4 g / L, the catalytic performance begins to decline, which may be due to the fact that too much catalyst blocks the incident light, thereby inhibiting the activation of PMS. Figure 6 Figure b further shows that when the TC concentration is 10, 20 and 30 mg / L, the degradation efficiency is 93%, 95% and 91%, respectively. Even at a concentration of 40 mg / L, the FT-3% catalyst still has a high TC elimination efficiency of 87%, which confirms that the catalytic performance of the FT / PMS / Vis system is very significant. Finally, considering the catalytic performance and economic factors, the optimal catalytic conditions were determined to be 1 mM PMS, 0.2 g / L catalyst and 20 mg / L TC.

[0079] To explore the anti-interference and universality of the FT / PMS / Vis system in nature, three common anions (Cl - ,HCO3 - ,NO3 - , and H2PO4 - ), with concentrations of 0.01, 0.05 and 0.09 M respectively. Figure 5 The results shown in f and h show that with the increase of Cl - and NO3 - With the increase of concentration, the degradation efficiency of TC gradually increases, and the effect on TC degradation can be ignored. Figure 5 Medium g shows, 0.01MHCO3 - The degradation of TC was significantly inhibited, which may be due to the fact that HCO3 - Clear part h + , as shown in (Eq.3):

[0080]

[0081] like Figure 5 As shown in i, H2PO4 - The increase in concentration inhibits the degradation of TC, causing the degradation rate to drop from 95% to 65%. Possible factors causing this phenomenon: First, a small amount of H2PO4 - It will compete with PMS for active sites, resulting in a decrease in TC removal efficiency. Secondly, coexisting anions will scavenge active species, thereby limiting the degradation of TC. Finally, H2PO4 - May also help to form a buffer in FT / PMS / Vis systems.

[0082] Four water sources were collected from different water sources: water from Zhaoding River in Xinxiang City, water from the artificial lake of Xinxiang Medical College, tap water and deionized water. A tetracycline solution with a concentration of 20 mg / L was prepared using the four water sources, and 50 mL was added to add 10 mg of the catalyst prepared in Example 2. After dark reaction for 30 minutes, PMS was added to make its concentration 1 mM, and visible light was introduced to carry out catalytic experiments.

[0083] Figure 7 (a) different water sources; (b) degradation rates of different pollutants; (c) stability in the cycle experiment; (d) leaching rate of metal ions by FT-3%.

[0084] like Figure 7 As shown in Figure a, the FT / PMS / Vis system exhibited high TC degradation efficiency in different water media, indicating that the inhibitory effect of the water matrix was minimal. To evaluate the versatility of the system, organic dyes (methyl orange, MO), metronidazole (MNZ), and oxytetracycline (OTC) pollutants were selected for degradation. Figure 7As shown in (b), within 24 min, the degradation efficiencies of OTC, MO, and MNT reached 94.9%, 96.7%, and 61.3%, respectively, indicating that the system has strong catalytic activity for the degradation of common pollutants. Figure 7 Figure c shows that the TC removal efficiency is as high as 86.0% after four cycles. Figure 7 The results show that the catalyst of the present invention has excellent and stable effect on the degradation of tetracycline, and has certain universality in the removal of other pollutants, providing a feasible solution for the degradation of other antibiotics.

[0085] Inductively coupled plasma optical emission spectroscopy (ICP-OES, Varian) was used for metal ion leaching analysis. Figure 7 Figure d and Table 1 describe the changes in metal ion concentrations throughout the FT-3% catalytic tetracycline process. After four catalytic cycles, the leaching rates of iron (Fe) and titanium (Ti) differed by 0.62% and 0.33%, respectively. The results of inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis (Table 1) further demonstrated that the FT / PMS / Vis system had minimal metal leaching, even over a wide pH range.

[0086] Table 1 ICP-OES analysis of leached iron and titanium ion concentrations in the FT / PMS / Vis system

[0087]

[0088] The above results demonstrate the effectiveness of the FT / PMS / Vis system in addressing and mitigating metal leaching issues, thereby reducing the risk of secondary contamination, and the system's ability to maintain its integrity and prevent the release of metals into the surrounding environment. This not only demonstrates the system's reliability and ability to be applied in a variety of applications, but also highlights its potential in promoting environmental sustainability.

[0089] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing an iron diselenide-Mxene composite catalyst, It is characterized in that The following steps are involved: mixing the iron salt and the first solvent to obtain an iron-containing solution; Ti 3 C 2 T x , Se powder and a second solvent are mixed to obtain a selenium-containing dispersion; The iron-containing solution is mixed with the selenium-containing dispersion, and a solvent thermal reaction is carried out to obtain an iron diselenide-Mxene composite catalyst.

2. The preparation method according to claim 1, It is characterized in that The iron salt includes ferric chloride; and the first solvent includes ethanolamine.

3. The preparation method according to claim 1, It is characterized in that The molar ratio of the iron salt to the Se powder is 1:1-3.

4. The preparation method according to claim 1, It is characterized in that In the iron diselenide-Mxene composite catalyst, iron diselenide and Ti 3 C 2 T x The mass ratio is 1.07:0.01~0.

07.

5. The preparation method according to claim 1, It is characterized in that The second solvent includes ethanolamine.

6. The preparation method according to claim 1, It is characterized in that The temperature of the solvent thermal reaction is 120-180° C. and the time is 8-12 hours.

7. The iron diselenide-Mxene composite catalyst prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the iron diselenide-Mxene composite catalyst according to claim 7 in the degradation of tetracycline.

9. The use according to claim 8, It is characterized in that The application method comprises: mixing the iron diselenide-Mxene composite catalyst, a tetracycline-containing solution and peroxymonosulfate, and degrading the obtained mixed solution.

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