Defect engineering modified composite catalyst as well as preparation method and application thereof

Abstract

The invention discloses a defect engineering modified composite catalyst as well as a preparation method and application thereof, and belongs to the technical field of environmental material preparation. The preparation method comprises the following steps: (1) performing reduction heat treatment on a titanium silicalite molecular sieve in a hydrogen-containing inert atmosphere to obtain an oxygen vacancy-containing titanium silicalite molecular sieve; and (2) stirring and mixing the oxygen vacancy-containing titanium silicalite molecular sieve solution and the ferric salt solution, centrifuging the product, washing with water, washing with alcohol, and drying to obtain the defect engineering modified composite catalyst. The titanium silicalite molecular sieve is firstly subjected to reduction heat treatment to construct oxygen vacancies, then iron ions are specifically anchored on the oxygen vacancies, the composite catalyst with excellent photocatalytic activity and stability is prepared, the composite catalyst is used for treating macrolide antibiotics in water, and efficient degradation of antibiotic wastewater is achieved.

Description

Technical Field

[0001] This invention relates to the field of environmental materials preparation technology, and in particular to a defect-engineered composite catalyst, its preparation method, and its application. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] To address environmental organic pollution, various green methods have been developed for removing organic pollutants from water bodies. Photocatalysis, which utilizes solar energy to efficiently degrade pollutants, has attracted considerable attention as a low-cost water purification method without secondary pollution. Developing highly efficient photocatalysts is crucial, and researchers have explored numerous strategies to enhance their activity, such as morphology manipulation, heterostructure construction, ion doping, and defect engineering.

[0004] Defect engineering, by intentionally introducing defects to modulate the properties and catalytic performance of catalysts, has proven effective in regulating photocatalyst performance in solar-to-chemical energy conversion. Oxygen vacancies (Ov) have been widely incorporated into photocatalytic materials such as TiO2, ZnO, BiO2, Bi2WO6, and WO3 to enhance photocatalytic performance by improving light absorption, charge transfer and separation, and surface reactions. However, Ov can also reduce the stability of the crystal structure, thus limiting its application. Therefore, developing cost-effective, efficient, stable, and industrially viable oxygen-vacancy photocatalysts is of great significance. Among numerous photocatalysts, the titanium-silicon molecular sieve TS-1 exhibits excellent photocatalytic performance due to its regular pore structure, high pore volume, and high specific surface area, while also being reasonably priced and exhibiting outstanding stability, making it a potential candidate for industrial applications.

[0005] Defect engineering, particularly the introduction of oxygen vacancies (Ov), is a powerful tool for modulating the electronic structure and surface properties of semiconductor catalysts. Ov can act as electron-trapping centers, promoting charge separation, and can also serve as active sites to adsorb and activate reactant molecules. However, in photocatalytic reaction environments, especially under aqueous phase and light irradiation conditions, highly active oxygen vacancies are often unstable, prone to structural relaxation or re-oxidation, leading to catalyst deactivation. This "activity-stability" contradiction severely restricts the practical application of defect-based catalysts. Therefore, how to construct stable and efficient active defect sites in titanium silicate molecular sieves and develop materials that possess both excellent photocatalytic activity and long-term operational stability is a significant and challenging issue in this field. Summary of the Invention

[0006] In view of this, the present invention provides a composite catalyst modified by defect engineering, its preparation method, and its application. By first constructing oxygen vacancies through reducing heat treatment of a titanium-silicon molecular sieve, and then utilizing the specific anchoring of iron ions onto these oxygen vacancies, a composite catalyst with excellent photocatalytic activity and stability is prepared and used to treat macrocyclic lactone antibiotics in water, achieving efficient degradation of antibiotic wastewater. This composite catalyst is composed of a titanium-silicon molecular sieve with iron ions anchored to oxygen-vacancy sites. The oxygen vacancies act as electron-capturing centers to promote charge separation, while the iron ions act as electron donors to enhance electron supply. The synergistic effect of these two factors not only significantly improves the efficiency of photogenerated charge separation but also effectively solves the core problem of easy deactivation of purely defective materials. This method is simple and operates under mild conditions, providing a new strategy for developing novel photocatalytic materials that are efficient, stable, and easily applicable in industrial settings.

[0007] In a first aspect, the present invention provides a method for preparing a composite catalyst modified by defect engineering, comprising the following steps: (1) In an inert atmosphere containing hydrogen, titanium-silicon molecular sieves are subjected to reduction heat treatment to obtain titanium-silicon molecular sieves containing oxygen vacancies. (2) The titanium-silicon molecular sieve solution containing oxygen vacancies is stirred and mixed with the iron salt solution. The product is centrifuged, washed with water, washed with alcohol, and dried to obtain the composite catalyst modified by defect engineering.

[0008] By employing a two-step strategy of first constructing oxygen vacancies and then anchoring metal ions, highly active defect sites (oxygen vacancies) are created in the titanium-silicon molecular sieve framework using reduction heat treatment. Subsequently, iron ions are specifically anchored to these oxygen vacancies. This method not only constructs highly efficient photogenerated charge separation centers in situ but also significantly enhances the structural stability of the defect sites by forming a strongly interacting "Fe-Ov" structure, thereby synergistically improving the photocatalytic activity and cycle life of the catalyst.

[0009] In some embodiments, the titanium-silicon molecular sieve is a Ti-containing zeolite molecular sieve selected from TS. 1, TS 2, Ti MCM One or more of 41; The iron salt is selected from one or more of ferric nitrate, ferric sulfate, and ferric chloride; The solvent is selected from one or more of water, methanol, and ethanol.

[0010] In some embodiments, in step (1), the inert atmosphere is argon or nitrogen, and the volume fraction of hydrogen in the mixture is 2%-20%.

[0011] In some embodiments, in step (1), the heating rate of the heat treatment is 5-10 °C / min; The heat treatment temperature is 200-800℃, preferably 550℃; The heat treatment time is 2-8 hours.

[0012] In some embodiments, in step (2), the ratio of iron salt to oxygen-vacant titanium-silicon molecular sieve raw material m(Fe):m(oxygen-vacant titanium-silicon molecular sieve) is 0.001-0.2, where m(Fe) refers to the mass of Fe contained in the iron salt raw material, and m(oxygen-vacant titanium-silicon molecular sieve) refers to the mass of the oxygen-vacant titanium-silicon molecular sieve. When the Fe loading is too low, the number of Fe ions anchored on the oxygen vacancies is too small, and the electron donor effect and oxygen vacancy stabilizing effect cannot be fully utilized, resulting in limited improvement in the charge separation efficiency of the composite catalyst; when the Fe loading is too high, the excess Fe ions will agglomerate into Fe oxide particles on the surface of the molecular sieve, blocking the pores and covering the active sites, thus reducing the catalytic performance. The raw material ratio can also be expressed as a percentage, with the ratio of iron salt to oxygen-vacant titanium-silicon molecular sieve raw material being 0.1-20%.

[0013] In some embodiments, in step (2), the stirring and mixing time is 10-20 min.

[0014] Secondly, the present invention provides a composite catalyst with defect engineering modification, prepared by the aforementioned preparation method.

[0015] Thirdly, the present invention provides the application of the defect-engineered modified composite catalyst in the adsorption of antibiotic pollutants, wherein the composite catalyst is added to antibiotic wastewater and mixed, and adsorption is carried out by stirring under dark conditions.

[0016] In some embodiments, the antibiotic is a macrolide antibiotic; further, the macrolide antibiotic includes one or more of erythromycin, azithromycin, clarithromycin, and roxithromycin.

[0017] In some embodiments, the amount of the composite catalyst added is 0.01. 10g / L.

[0018] In some embodiments, the stirring time under dark conditions is at least 30 minutes.

[0019] Fourthly, the present invention provides the application of the defect-engineered modified composite catalyst in the photocatalytic degradation of antibiotic pollutants. The composite catalyst is added to antibiotic wastewater, stirred and mixed in the dark, and then irradiated with ultraviolet light. The power of the ultraviolet lamp is 300-500W.

[0020] In some embodiments, the antibiotic is a macrolide antibiotic; further, the macrolide antibiotic includes one or more of erythromycin, azithromycin, clarithromycin, and roxithromycin.

[0021] In some embodiments, the amount of the composite catalyst added is 0.01. 10g / L.

[0022] In some embodiments, the stirring time under dark conditions is at least 30 minutes, and the ultraviolet light irradiation time is at least 1 hour.

[0023] Compared with the prior art, the present invention has achieved the following beneficial effects: (1) This invention first constructs highly active oxygen vacancies (Ov) in titanium-silicon molecular sieves through controlled reduction heat treatment, and then uses oxygen vacancies as specific anchoring sites to fix Fe ions. This method not only realizes the construction of active sites (oxygen vacancies), but also fundamentally enhances the stability of the defect structure by forming strongly interacting "Fe-Ov" bonds, effectively solving the core problem of easy deactivation of traditional defective photocatalysts in aqueous photocatalytic environments.

[0024] (2) This invention significantly improves the photogenerated charge separation and transport efficiency of the composite catalyst by utilizing the ability of oxygen vacancies to capture photogenerated electrons and the electron regulation and supply effect of anchored Fe ions. Systematic characterization and theoretical calculations confirm that Fe ions preferentially anchor at oxygen vacancies and form strong interactions. This structure not only reduces charge transfer resistance but also optimizes the band structure and electronic density of states of the material, thereby enhancing catalytic performance. In the degradation of macrolide antibiotics such as erythromycin, its photocatalytic activity is far higher than that of the original titanium-silicon molecular sieve and unstable pure defect materials. Most importantly, the anchoring of Fe ions ensures that the catalyst's performance remains stable after multiple cycles of use, solving the core problem of easy deactivation in pure defect materials.

[0025] (3) This invention uses titanium silicon molecular sieve as the starting material and adopts conventional heat treatment and impregnation process. The steps are simple, the conditions are mild and controllable, and it has the potential for large-scale production and application. It has broad prospects in the field of deep treatment of industrial wastewater. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0027] Figure 1 This is a schematic diagram of the composite catalyst synthesis process; Figure 2 X-ray diffraction patterns of the catalysts in Examples 1-4 and Comparative Examples 1-2; Figure 3 The images shown are scanning electron microscope (SEM) and transmission electron microscope (TEM) images of the catalysts of Example 2, Comparative Example 1, and Comparative Example 2. In the images, A is the SEM image of TS-1, B is the SEM image of BTS, C is the SEM image of Fe1BTS, D is the SEM image of TS-1, E is the SEM image of BTS, H is the SEM image of Fe1BTS, G is the TEM image of TS-1, H is the TEM image of BTS, and I is the TEM image of Fe1BTS. Figure 4 XPS spectra of catalysts in Example 2, Comparative Example 1 and Comparative Example 2, where A represents O 1s and B represents Ti 2p; Figure 5 The transient photocurrent curves of the catalysts in Examples 1, 2, 1, and 2 are shown. Figure 6 Electrochemical impedance spectroscopy of the catalysts in Example 2, Comparative Example 1, and Comparative Example 2; Figure 7 The test results for treating erythromycin wastewater with different catalysts are shown. In this paper, A represents the adsorption effect and B represents the photocatalytic effect. Figure 8 The test results for treating erythromycin wastewater with catalysts of different concentrations in Example 2 are shown. In this paper, A represents the adsorption effect and B represents the photocatalytic effect. Figure 9 The results of the catalyst in Example 2 for treating erythromycin wastewater of different concentrations are shown. In this example, A represents the adsorption effect and B represents the photocatalytic effect. Figure 10 The results of repeated use stability tests of the catalysts in Example 2 and Comparative Example 2 are shown, where A represents Fe1BTS and B represents BTS. Figure 11 The DMPO-•OH adduct and DMPO-•O2 catalyst of Example 2 - EPR spectrum of the adduct; Figure 12 The effect of the capture agent on the degradation efficiency of erythromycin; Figure 13 This is a schematic diagram of the photocatalytic process using a composite catalyst. Detailed Implementation

[0028] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] Example 1 Titanium silicate molecular sieve TS-1 was calcined at 550°C for 6 hours under a 5% H2 / Ar atmosphere at a rate of 5°C / min to obtain a black product containing oxygen vacancies, denoted as BTS. 1 g of BTS was dispersed in 50 mL of 20% methanol aqueous solution and sonicated for 10 min in a sealed container to prepare a BTS dispersion. Separately, 0.036 g of Fe(NO3)3•9H2O was dissolved in deionized water to prepare 10 mL of Fe precursor solution. Both solutions were first purged with Ar for 10 min, and then 10 mL of Fe precursor solution was added to 50 mL of BTS dispersion and stirred vigorously for 10 min. The mixture was then centrifuged, washed with water and alcohol, and dried overnight at 50°C.

[0030] In this embodiment, the ratio of iron salt to oxygen-vacant titanium-silicon molecular sieve raw material is 0.5%, and the resulting composite catalyst is denoted as Fe. 0.5 BTS.

[0031] Example 2 Titanium silicate molecular sieve TS-1 was calcined at 550°C for 6 hours under a 5% H2 / Ar atmosphere at a rate of 5°C / min to obtain a black product containing oxygen vacancies, denoted as BTS. 1 g of BTS was dispersed in 50 mL of 20% methanol aqueous solution and sonicated for 10 min in a sealed container to prepare a BTS dispersion. Separately, 0.072 g of Fe(NO3)3•9H2O was dissolved in deionized water to prepare 10 mL of Fe precursor solution. Both solutions were first purged with Ar for 10 min, and then 10 mL of Fe precursor solution was added to 50 mL of BTS dispersion and stirred vigorously for 10 min. The mixture was then centrifuged, washed with water and alcohol, and dried overnight at 50°C.

[0032] In this embodiment, the ratio of iron salt to oxygen-vacant titanium-silicon molecular sieve raw material is 1%, and the resulting composite catalyst is denoted as Fe1BTS.

[0033] Example 3 Titanium silicate molecular sieve TS-1 was calcined at 550°C for 6 hours under a 5% H2 / Ar atmosphere at a rate of 5°C / min to obtain a black product containing oxygen vacancies, denoted as BTS. 1 g of BTS was dispersed in 50 mL of 20% methanol aqueous solution and sonicated for 10 min in a sealed container to prepare a BTS dispersion. Separately, 0.108 g of Fe(NO3)3•9H2O was dissolved in deionized water to prepare 10 mL of Fe precursor solution. Both solutions were first purged with Ar for 10 min, and then 10 mL of Fe precursor solution was added to 50 mL of BTS dispersion and stirred vigorously for 10 min. The mixture was then centrifuged, washed with water and alcohol, and dried overnight at 50°C.

[0034] In this embodiment, the ratio of iron salt to oxygen-vacant titanium-silicon molecular sieve raw material is 1.5%, and the resulting composite catalyst is denoted as Fe. 1.5 BTS.

[0035] Example 4 Titanium silicate molecular sieve TS-1 was calcined at 550°C for 6 hours under a 5% H2 / Ar atmosphere at a rate of 5°C / min to obtain a black product containing oxygen vacancies, denoted as BTS. 1 g of BTS was dispersed in 50 mL of 20% methanol aqueous solution and sonicated for 10 min in a sealed container to prepare a BTS dispersion. Separately, 0.144 g of Fe(NO3)3•9H2O was dissolved in deionized water to prepare 10 mL of Fe precursor solution. Both solutions were first purged with Ar for 10 min, and then 10 mL of Fe precursor solution was added to 50 mL of BTS dispersion and stirred vigorously for 10 min. The mixture was then centrifuged, washed with water and alcohol, and dried overnight at 50°C.

[0036] In this embodiment, the ratio of iron salt to oxygen-vacant titanium-silicon molecular sieve raw material is 2%, and the resulting composite catalyst is denoted as Fe2BTS.

[0037] Comparative Example 1 Original titanium-silicon molecular sieve catalyst TS-1.

[0038] Comparative Example 2 Titanium silicate molecular sieve TS-1 was calcined at 550°C for 6 hours under a 5% H2 / Ar atmosphere at a rate of 5°C / min to obtain a black product containing oxygen vacancies, denoted as BTS.

[0039] 1. Catalyst Characterization Figure 1 The diagram shows the synthesis process of the composite catalyst. It can be seen that the Ti-O-Si bond breaks to form oxygen vacancies, and the defective electronic structure attracts Fe ions during the loading process.

[0040] This invention successfully prepared a composite catalyst with defect engineering modification, such as... Figure 2 As shown, all samples exhibited MFI characteristic diffraction peaks. The crystallinity of BTS decreased slightly, while the crystallinity did not change significantly after Fe modification.

[0041] like Figure 3 As shown, SEM ( Figure 3 AF showed that TS-1 was an aggregate of ~200 nm (primary particle size ~10 nm), and the morphology of BTS and Fe1BTS showed no significant change. No Fe oxide nanoparticles were observed. TEM ( Figure 3 In GI), the BTS lattice fringes show breakage, and the Fe1BTS discontinuous fringes decrease.

[0042] like Figure 4 As shown in Figure A, the binding energy of the Si-O / Ti-O peak in Fe1BTS decreases to 533.1 eV; the intensity of the Ov-related OⅢ peak increases with increasing BTS content, and further increases after Fe modification. Figure 4 As shown in B, the Ti of BTS3+ The peak shifts to lower binding energies, and rebounds slightly after Fe modification, indicating that the electron-withdrawing effect of Fe regulates the electron density of Ti.

[0043] like Figure 5 As shown, the photogenerated carrier separation efficiency of BTS and TS-1 is similar. The photocurrent is significantly enhanced after Fe anchoring, which is attributed to Fe acting as an electron donor and filling electron traps. Figure 6 As shown, Fe1BTS has the smallest arc radius, indicating that oxygen vacancies and Fe together reduce charge transfer resistance.

[0044] 2. Catalysis test Application Example 1 6 mg of Example 2 (Fe1BTS) was dispersed in 10 mL of erythromycin aqueous solution and photodegraded at room temperature. The solution was stirred in the dark for 30 minutes before the light source was turned on to allow for erythromycin adsorption. Desorption equilibrium was established. Samples were taken periodically, filtered through a 0.22 μm filter, and the initial adsorption amount was determined using a UV-Vis spectrophotometer. Subsequently, a 300W xenon lamp was turned on to initiate the photoreaction. Samples were taken every 10-20 minutes, filtered, and the erythromycin concentration was determined.

[0045] The absorbance of erythromycin in the characteristic wavelength band of 242 nm was measured using a UV-Vis spectrophotometer. The concentration of erythromycin was obtained with reference to a standard curve, and the adsorption rate and degradation rate of erythromycin were calculated using the following formula: C=15.4898A(1) In the formula, C is the concentration of erythromycin and A is the absorbance of erythromycin.

[0046] Adsorption rate = (1-C) t / C0)×100%(2) Degradation rate = (1-C) t / C0′)×100%(3) In the formula, C0 is the initial concentration of the antibiotic, C t C0′ represents the concentration of the antibiotic at a certain moment, and C0′ represents the concentration of the antibiotic 30 minutes after adsorption.

[0047] Application Example 2 The content of this application example is the same as that of Application Example 1, except that the catalyst used is different. Comparative Example 1 (TS-1), Comparative Example 2 (BTS), and Example 1 (Fe) are used respectively. 0.5 BTS), Example 3 (Fe) 1.5 Experiments were conducted using catalysts from Example 4 (Fe2BTS) instead of Fe1BTS.

[0048] like Figure 7As shown in Figure A, all catalysts reached adsorption equilibrium within 10 minutes, with an adsorption rate of ~45%. Figure 7 As shown in B, the blank experiment showed slight self-degradation of erythromycin; the degradation rate of TS-1 was 63.2% at 60 min, BTS increased to 73.3%, and Fe1BTS achieved the best degradation rate of 83.69%.

[0049] Application Example 3 The content of this application example is the same as that of Application Example 1, except that the catalyst concentrations are different. The catalyst concentrations are 0.2 g / L, 0.4 g / L, and 0.8 g / L, respectively.

[0050] like Figure 8 As shown, the adsorption and degradation performance of the composite catalyst gradually improved within the range of 0.2–0.8 g / L.

[0051] Application Example 4: The content of this application example is the same as that of Application Example 1, except that the concentration of erythromycin is different. The concentrations of the degraded erythromycin aqueous solutions are 2 mg / L, 4 mg / L, 6 mg / L, 8 mg / L, and 10 mg / L, respectively.

[0052] like Figure 9 As shown in Figure A, the adsorption rate decreases with increasing initial erythromycin concentration. Figure 9 As shown in Figure B, the degradation rate of 2 mg / L erythromycin aqueous solution was the highest at 60 min, reaching ~91%, while the degradation rate of 10 mg / L erythromycin aqueous solution was the lowest.

[0053] Application Example 5 The reusability and stability of the material were evaluated through cyclic degradation experiments. The catalyst after antibiotic degradation was recovered by high-speed centrifugation. The resulting solid was washed three times with anhydrous ethanol and centrifuged to remove impurities remaining on the catalyst surface. It was then dried in a drying oven at 120°C for 12 hours. The dried photocatalytic material was recycled four times, and the corresponding degradation rate was calculated.

[0054] The content of this application example is the same as that of Application Example 1, except that the Fe1BTS catalyst was recycled four times. Furthermore, the BTS catalyst was recycled four times.

[0055] like Figure 10 As shown, stability tests revealed that Fe1BTS showed almost no performance degradation over four consecutive rounds, while BTS experienced a significant decrease starting from the second round, attributed to the instability of the oxygen vacancy structure.

[0056] Application Example 6 The photocatalytic mechanism of Fe1BTS was investigated using free radical capture experiments and electron paramagnetic resonance (EPR) technology.

[0057] (1) EPR detection: such as Figure 11 As shown, using DMPO as a spin trapping agent, no obvious signal was detected under dark conditions. However, after 2 minutes of UV irradiation, a strong characteristic DMPO-•OH quartet signal was detected in the Fe1BTS aqueous dispersion system, and DMPO-•O2 was detected in the methanol dispersion system. - The characteristic six-peak signal directly confirms the presence of •OH and •O2 under illumination. - The generation of .

[0058] (2) Capture experiment: Isopropanol (IPA, hydroxyl radical •OH scavenger) and benzoquinone (BQ, superoxide radical •O2) were added to the standard photocatalytic system respectively. - Hole scavenger), disodium ethylenediaminetetraacetate (EDTA-2Na, hole h+ scavenger), and silver nitrate (AgNO3, electron e+ scavenger). - (Cleanser). For example... Figure 12 As shown, the addition of IPA had the most significant inhibitory effect on the reaction, followed by BQ, while EDTA-2Na and AgNO3 had relatively small effects, indicating that •OH is the main reactive species, and •O2 - Next.

[0059] Based on the above results, the following is proposed: Figure 13 The reaction mechanism shown is as follows: Under illumination, oxygen vacancies in the BTS framework and anchored Fe ions synergistically promote photogenerated electrons (e-). - ) and holes (h + The separation of ) e. - •O2 is generated by the capture of O2 adsorbed on the surface. - h + Or with H2O / OH - The reaction generates •OH radicals. These strong oxidizing free radicals attack and mineralize erythromycin molecules. Fe ions, acting as electron donors, continuously supply electrons to the system, enhancing the reaction with •O2. - The generation pathway was determined, and the catalytic cycle was stabilized.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a composite catalyst modified by defect engineering, characterized in that, Includes the following steps: (1) In an inert atmosphere containing hydrogen, titanium-silicon molecular sieves are subjected to reduction heat treatment to obtain titanium-silicon molecular sieves containing oxygen vacancies. (2) The titanium-silicon molecular sieve solution containing oxygen vacancies is stirred and mixed with the iron salt solution. The product is centrifuged, washed with water, washed with alcohol, and dried to obtain the composite catalyst modified by defect engineering.

2. The preparation method according to claim 1, characterized in that, The titanium-silicon molecular sieve is a Ti-containing zeolite molecular sieve selected from TS. 1, TS 2, Ti MCM One or more of 41; The iron salt is selected from one or more of ferric nitrate, ferric sulfate, and ferric chloride; The solvent is selected from one or more of water, methanol, and ethanol.

3. The preparation method according to claim 1, characterized in that, In step (1), the inert atmosphere is argon or nitrogen, and the volume fraction of hydrogen in the mixture is 2%-20%.

4. The preparation method according to claim 1, characterized in that, In step (1), the heating rate of the heat treatment is 5-10℃ / min; The heat treatment temperature is 200-800℃, preferably 550℃; The heat treatment time is 2-8 hours.

5. The preparation method according to claim 1, characterized in that, In step (2), the ratio of iron salt to oxygen-vacant titanium-silicon molecular sieve raw material m(Fe):m(oxygen-vacant titanium-silicon molecular sieve) is 0.001-0.2, where m(Fe) refers to the mass of Fe contained in the iron salt raw material, and m(oxygen-vacant titanium-silicon molecular sieve) refers to the mass of oxygen-vacant titanium-silicon molecular sieve.

6. The preparation method according to claim 1, characterized in that, In step (2), the stirring and mixing time is 10-20 min.

7. The defect-engineered composite catalyst prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the defect-engineered composite catalyst as described in claim 7 in the adsorption of antibiotic pollutants, characterized in that, A composite catalyst was added to antibiotic wastewater and mixed, then stirred and adsorbed under dark conditions. The antibiotic is a macrolide antibiotic; further, the macrolide antibiotic includes one or more of erythromycin, azithromycin, clarithromycin, and roxithromycin; The amount of the composite catalyst added is 0.

01. 10g / L; Stirring time should be at least 30 minutes in the dark.

9. The application of the defect-engineered composite catalyst as described in claim 7 in the photocatalytic degradation of antibiotic pollutants, characterized in that, Add a composite catalyst to the antibiotic wastewater, stir and mix it in the dark, and then irradiate it with ultraviolet light. The power of the ultraviolet lamp is 300-500W.

10. The application as described in claim 9, characterized in that, The antibiotic is a macrolide antibiotic; further, the macrolide antibiotic includes one or more of erythromycin, azithromycin, clarithromycin, and roxithromycin; The amount of the composite catalyst added is 0.

01. 10g / L; Stirring time in the dark should be at least 30 minutes, and ultraviolet light irradiation time should be at least 1 hour.

Images