A multilayer manganese-titanium dioxide@carbon catalyst, its preparation method and application

Abstract

This invention proposes a multilayer manganese-titanium dioxide@carbon catalyst, its preparation method, and its application, belonging to the field of environmental catalysis technology. The invention uses transition metal manganese salts to modify multilayer titanium-based MXene materials via impregnation to obtain Mn-MXene composite materials. The Mn-MXene composite materials are then calcined under a CO2 atmosphere to obtain the multilayer manganese-titanium dioxide@carbon catalyst. The preparation method is simple, and the resulting catalyst exhibits high antioxidant performance and stability. The incorporation of transition metal manganese further enhances the active sites of the TiO2@C catalyst, enabling the multilayer manganese-titanium dioxide@carbon catalyst to achieve efficient removal of organic wastewater under ozone conditions.

Description

Technical Field

[0001] This invention belongs to the field of environmental catalysis technology, and particularly relates to a multilayer manganese-titanium dioxide@carbon catalyst, its preparation method and application. Background Technology

[0002] With the continuous advancement of social development, global demands and consumption of water resources are constantly increasing. The discharge of untreated wastewater from human activities and industrial processes causes serious water pollution, posing significant harm to humans, aquatic life, and ecosystems. Some pollutants in water bodies are toxic, carcinogenic, mutagenic, or have poor biodegradability, seriously endangering human health and the ecological environment. Traditional water treatment methods mainly include advanced oxidation processes, membrane separation, chemical precipitation, flocculation, biological treatment, and adsorption. However, most of these technologies have certain drawbacks, such as complex removal mechanisms, high energy consumption, excessive use of chemicals, low regeneration and reuse rates, sludge and byproduct generation, and low removal rates for low-concentration pollutants. Therefore, finding a safe, effective, and environmentally friendly method to remove pollutants from water is an urgent research need in the field of environmental engineering.

[0003] MXene's unique two-dimensional structure not only endows it with an extremely high specific surface area but also possesses abundant surface functional groups (-OH, -O, -F, etc.), giving it excellent biocompatibility, hydrophilicity, high conductivity, and catalytic activity. This makes it an ideal candidate material in numerous fields such as environmental remediation, sensors, energy, and biology. However, because the metal atoms of MXene are exposed on the layered surface, they are easily oxidized in oxygen-rich, humid, and high-temperature environments, leading to the collapse of its two-dimensional structure and loss of its intrinsic properties. This makes it difficult to achieve efficient and stable removal of organic wastewater, and also results in high costs. Summary of the Invention

[0004] To address the issues of low antioxidant capacity, stability, and catalytic performance of MXene, this invention proposes a multilayer manganese-titanium dioxide@carbon catalyst, its preparation method, and its application. The multilayer titanium-based MXene material is modified by impregnation with transition metal manganese salt, and then calcined in a microwave tube furnace under a CO2 atmosphere to obtain the multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst). This catalyst retains the multilayer two-dimensional structure of MXene while exhibiting high antioxidant performance and stability, achieving efficient ozone catalytic degradation of organic wastewater.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] One of the technical solutions of the present invention:

[0007] A method for preparing a multilayer manganese-titanium dioxide@carbon catalyst involves modifying a multilayer titanium-based MXene material with a transition metal manganese salt via an impregnation method to obtain a Mn-MXene composite material, followed by calcining the Mn-MXene composite material under a CO2 atmosphere to obtain the multilayer manganese-titanium dioxide@carbon catalyst.

[0008] Furthermore, the transition metal manganese salt is one or more of manganese nitrate, manganese sulfate, or manganese chloride.

[0009] Furthermore, the modification of multilayer titanium-based MXene materials by impregnation using transition metal manganese salt includes the following steps: dissolving transition metal manganese salt in water, then adding multilayer titanium-based MXene materials and stirring evenly to obtain a suspension solution, and then allowing the suspension solution to stand, centrifuge, wash, and dry to obtain the Mn-MXene composite material.

[0010] Furthermore, the concentration of manganese ions in the suspension is 0.02–0.06 mol / L, and the mass concentration of the multilayer titanium-based MXene material in the suspension is 0.5–1.0%.

[0011] Furthermore, the drying temperature is 50–70°C, and the drying time is 24 hours.

[0012] The transition metal manganese salt is first prepared into a solution, with the manganese ion concentration in the solution being 0.02–0.06 mol / L, and the amount of the multilayer titanium-based MXene material added is 0.5–1.0 wt%.

[0013] Furthermore, the calcination temperature is 400–700°C, and the holding time is 2–5 hours.

[0014] Furthermore, the heating rate of the calcination is 10–30 °C / min.

[0015] Furthermore, the gas volumetric flow rate of the CO2 is 75–150 sccm.

[0016] Furthermore, the modification of multilayer titanium-based MXene materials by impregnation with transition metal manganese salts also includes centrifugation, washing, and drying steps.

[0017] More specifically, the preparation method of the multilayer manganese-titanium dioxide@carbon catalyst of the present invention includes the following steps:

[0018] (1) Dissolve a transition metal manganese salt (manganese nitrate, manganese sulfate or manganese chloride) in deionized water, add multilayer titanium-based MXene material under stirring, stir continuously for 2 hours and let stand for 24 hours to obtain a suspension solution. The concentration of manganese ions in the suspension solution is 0.02 to 0.06 mol / L, and the mass concentration of multilayer titanium-based MXene material in the suspension solution is 0.5 to 1.0%.

[0019] (2) The above suspension was centrifuged and washed until neutral, and then dried at 50℃~70℃ for 24h to obtain Mn modified Mn-MXene composite material.

[0020] (3) Grind the Mn-MXene composite material into powder and place it in a microwave tube furnace. Under an Ar atmosphere, rapidly heat the material to 400-700°C at a heating rate of 10-30°C / min. Then, introduce CO2 (volume flow rate of 75-150 sccm) and keep it at that temperature for 2-5 hours. After natural cooling to room temperature under an inert atmosphere or CO2 atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) is obtained.

[0021] The second technical solution of the present invention:

[0022] A multilayer manganese-titanium dioxide@carbon catalyst prepared by the aforementioned method.

[0023] The third technical solution of the present invention:

[0024] The application of the multilayer manganese-titanium dioxide@carbon catalyst in the ozone catalytic degradation of organic wastewater.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] (1) The multilayer Mn-TiO2@C catalyst for ozone catalytic degradation of organic wastewater of the present invention has a simple preparation process, high antioxidant performance and stability. At the same time, the incorporation of the transition metal manganese further enhances the active sites of the TiO2@C catalyst, enabling the Mn-TiO2@C catalyst to achieve efficient removal of organic wastewater under ozone conditions. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0028] Figure 1 SEM image of the Mn-TiO2@C catalyst prepared in Example 1;

[0029] Figure 2 EDS image of the Mn-TiO2@C catalyst prepared in Example 1;

[0030] Figure 3 XRD patterns of the Mn-TiO2@C catalyst prepared in Example 1 and the catalyst prepared in Comparative Example 1. Detailed Implementation

[0031] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0032] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0033] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0034] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0035] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0036] This invention proposes a method for preparing a multilayer manganese-titanium dioxide@carbon catalyst. The method involves modifying a multilayer titanium-based MXene material with a transition metal manganese salt via an impregnation method to obtain a Mn-MXene composite material. The Mn-MXene composite material is then calcined under a CO2 atmosphere to obtain the multilayer manganese-titanium dioxide@carbon catalyst.

[0037] In a preferred embodiment of the present invention, the transition metal manganese salt is one or more of manganese nitrate, manganese sulfate, or manganese chloride.

[0038] Manganese has a 3d electronic configuration. 5 4s 2Manganese oxide is a variable-valence element, unstable in nature, and can form compounds with oxidation states ranging from -3 to +7, making it the transition metal element with the most oxidation states. Furthermore, manganese oxide has a large number of hydroxyl components on its surface, which can react with ozone to generate hydroxyl radicals, enabling non-selective oxidation and removal of organic pollutants.

[0039] In a preferred embodiment of the present invention, the modification of multilayer titanium-based MXene material by impregnation with transition metal manganese salt includes the following steps: dissolving transition metal manganese salt in water, then adding multilayer titanium-based MXene material and stirring evenly to obtain a suspension solution, and then allowing the suspension solution to stand, centrifuge, wash, and dry to obtain the Mn-MXene composite material.

[0040] More specifically, the concentration of manganese ions in the suspension is 0.02–0.06 mol / L, the mass concentration of the multilayer titanium-based MXene material in the suspension is 0.5–1.0%, and the multilayer titanium-based MXene material is Ti3C2 material.

[0041] More specifically, the drying temperature is 50–70°C, and the drying time is 24 hours.

[0042] In a preferred embodiment of the present invention, the calcination temperature is 400-700°C and the holding time is 2-5 hours.

[0043] In a preferred embodiment of the present invention, the heating rate of the roasting is 10-30°C / min.

[0044] Calcining Mn-MXene composite materials in a CO2 atmosphere at 400–700℃ allows the multilayer titanium-based MXene material to chemically react with CO2 to generate TiO2 and C, while retaining its two-dimensional structure. Simultaneously, the easily oxidized multilayer titanium-based Ti3C2 in aqueous solution is transformed into the recalcitrant TiO2@C composite material, significantly enhancing its antioxidant capacity. If the calcination temperature is too high, the TiO2 is predominantly rutile, with larger particles and insufficient ozone catalytic performance. If the calcination temperature is too low, the generated TiO2 is predominantly anatase, exhibiting strong catalytic performance, but the reaction process is slow, making it difficult to achieve complete conversion of the multilayer titanium-based MXene, thus compromising antioxidant performance.

[0045] In a preferred embodiment of the present invention, the gas volumetric flow rate of CO2 is 75-150 sccm.

[0046] In this embodiment of the invention, room temperature refers to 25±2℃.

[0047] All raw materials used in the embodiments of this invention were obtained through commercial purchase.

[0048] The technical solution of the present invention will be further illustrated by the following embodiments.

[0049] The multilayer titanium-based MXene material used in the following examples is specifically Ti3C2 material, purchased from Jilin Yiyi Technology Co., Ltd.

[0050] Example 1

[0051] (1) Manganese nitrate was dissolved in deionized water, and multilayer titanium-based MXene material (Ti3C2 material) was added under stirring. The mixture was stirred for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension was 0.04 mol / L, and the mass concentration of multilayer titanium-based MXene material was 0.7%.

[0052] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 60°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0053] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 550°C at a heating rate of 20°C / min. Then CO2 (volume flow rate of 100 sccm) was introduced and kept at the temperature for 3 hours. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0054] The Mn-TiO2@C catalyst prepared in Example 1 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 98.5%.

[0055] Example 2

[0056] (1) Dissolve manganese nitrate in deionized water, add multilayer titanium-based MXene material (Ti3C2 material) under stirring, and continue stirring for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension is 0.06 mol / L, and the mass concentration of multilayer titanium-based MXene material is 1%.

[0057] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 70°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0058] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 550°C at a heating rate of 30°C / min. Then CO2 (volume flow rate of 150 sccm) was introduced and kept at the temperature for 5 h. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0059] The Mn-TiO2@C catalyst prepared in Example 2 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 85%.

[0060] Example 3

[0061] (1) Dissolve manganese nitrate in deionized water, add multilayer titanium-based MXene material (Ti3C2 material) under stirring, and continue stirring for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension is 0.02 mol / L, and the mass concentration of multilayer titanium-based MXene material is 0.5%.

[0062] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 50°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0063] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 550°C at a heating rate of 30°C / min. Then CO2 (volume flow rate of 75 sccm) was introduced and the temperature was maintained for 2 hours. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0064] The Mn-TiO2@C catalyst prepared in Example 3 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 80%.

[0065] Example 4

[0066] (1) Dissolve manganese nitrate in deionized water, add multilayer titanium-based MXene material (Ti3C2 material) under stirring, and continue stirring for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension is 0.02 mol / L, and the mass concentration of multilayer titanium-based MXene material is 1%.

[0067] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 60°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0068] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 550°C at a heating rate of 20°C / min. Then CO2 (volume flow rate of 100 sccm) was introduced and kept at the temperature for 3 hours. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0069] The Mn-TiO2@C catalyst prepared in Example 4 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 82%.

[0070] Example 5

[0071] (1) Manganese nitrate was dissolved in deionized water, and multilayer titanium-based MXene material (Ti3C2 material) was added under stirring. The mixture was stirred for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension was 0.04 mol / L, and the mass concentration of multilayer titanium-based MXene material was 0.7%.

[0072] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 60°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0073] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 550°C at a heating rate of 30°C / min. Then CO2 (volume flow rate of 75 sccm) was introduced and the temperature was maintained for 5 h. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0074] The Mn-TiO2@C catalyst prepared in Example 5 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 86%.

[0075] Example 6

[0076] (1) Manganese nitrate was dissolved in deionized water, and multilayer titanium-based MXene material (Ti3C2 material) was added under stirring. The mixture was stirred for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension was 0.04 mol / L, and the mass concentration of multilayer titanium-based MXene material was 0.7%.

[0077] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 60°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0078] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 550°C at a heating rate of 30°C / min. Then CO2 (volume flow rate of 150 sccm) was introduced and kept at the temperature for 2 hours. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0079] The Mn-TiO2@C catalyst prepared in Example 6 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 91%.

[0080] Example 7

[0081] (1) Manganese nitrate was dissolved in deionized water, and multilayer titanium-based MXene material (Ti3C2 material) was added under stirring. The mixture was stirred for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension was 0.04 mol / L, and the mass concentration of multilayer titanium-based MXene material was 0.7%.

[0082] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 60°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0083] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 450°C at a heating rate of 30°C / min. Then CO2 (volume flow rate of 100 sccm) was introduced and kept at the temperature for 3 hours. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0084] The Mn-TiO2@C catalyst prepared in Example 7 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 80%.

[0085] Example 8

[0086] (1) Manganese nitrate was dissolved in deionized water, and multilayer titanium-based MXene material (Ti3C2 material) was added under stirring. The mixture was stirred for 2 hours to obtain a suspension. The concentration of manganese ions in the suspension was 0.04 mol / L, and the mass concentration of multilayer titanium-based MXene material was 0.7%.

[0087] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was placed in an oven at 60°C and dried for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0088] (3) The Mn-MXene composite material prepared above was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 700°C at a heating rate of 30°C / min. Then CO2 (volume flow rate of 100 sccm) was introduced and the temperature was maintained for 3 hours. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0089] The Mn-TiO2@C catalyst prepared in Example 8 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 87%.

[0090] Example 9

[0091] (1) Dissolve transition metal manganese salt (manganese sulfate) in deionized water, add multilayer titanium-based MXene material (Ti3C2 material) under stirring, and continue stirring for 2 hours to obtain a suspension solution. The concentration of manganese ions in the suspension solution is 0.06 mol / L, and the mass concentration of multilayer titanium-based MXene material is 0.5%.

[0092] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was dried at 70°C for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0093] (3) The Mn-MXene composite material was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 400℃ at a heating rate of 30℃ / min. Then CO2 (volume flow rate of 150 sccm) was introduced and kept at the temperature for 5 hours. After natural cooling to room temperature under Ar atmosphere, a multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0094] The Mn-TiO2@C catalyst prepared in Example 9 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 61%.

[0095] Example 10

[0096] (1) Dissolve transition metal manganese salt (manganese chloride) in deionized water, add multilayer titanium-based MXene material (Ti3C2 material) under stirring, and continue stirring for 2 hours to obtain a suspension solution. The concentration of manganese ions in the suspension solution is 0.02 mol / L, and the mass concentration of multilayer titanium-based MXene material is 1.0%.

[0097] (2) The suspension prepared above was allowed to stand for 24 hours, centrifuged to separate the precipitate and washed until neutral. Then it was dried at 50°C for 24 hours to obtain the Mn-modified Mn-MXene composite material.

[0098] (3) The Mn-MXene composite material was ground into powder and placed in a microwave tube furnace. Under Ar atmosphere, the temperature was rapidly increased to 700℃ at a heating rate of 10℃ / min. Then CO2 (volume flow rate of 75 sccm) was introduced and the temperature was maintained for 2 hours. After natural cooling to room temperature under Ar atmosphere, the multilayer manganese-titanium dioxide@carbon catalyst (Mn-TiO2@C catalyst) was obtained.

[0099] The Mn-TiO2@C catalyst prepared in Example 10 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 87%.

[0100] Comparative Example 1

[0101] Same as Example 1, except that steps (1) and (2) are omitted, specifically:

[0102] Multilayer titanium-based MXene material (Ti3C2 material) was ground into powder and placed in a microwave tube furnace. Under an Ar atmosphere, the temperature was rapidly increased to 550°C at a heating rate of 20°C / min. Then, CO2 (volume flow rate of 100 sccm) was introduced and the temperature was maintained for 3 hours. After natural cooling to room temperature under an Ar atmosphere, the catalyst was obtained.

[0103] The Mn-TiO2@C catalyst prepared in Example 1 and the catalyst prepared in Comparative Example 1 were characterized by scanning electron microscopy, X-ray diffraction, and EDS. Figure 1 This is a SEM image of the Mn-TiO2@C catalyst prepared in Example 1. Figure 2 The image shows the EDS spectrum of the Mn-TiO2@C catalyst prepared in Example 1. Figure 3 XRD patterns of the Mn-TiO2@C catalyst prepared in Example 1 and the catalyst prepared in Comparative Example 1. Figures 1-3It can be seen that the Mn-TiO2@C catalyst prepared in Example 1 of the present invention is mainly a multilayer structure containing four elements: Mn, Ti, C and O, of which TiO2 is mainly anatase.

[0104] Comparative Example 2

[0105] Same as Example 1, except that manganese nitrate is replaced with ferric nitrate.

[0106] The catalyst prepared in Comparative Example 2 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 85%.

[0107] Comparative Example 3

[0108] Same as Example 1, except that the temperature is rapidly increased to 300°C at a heating rate of 30°C / min in an Ar atmosphere.

[0109] The catalyst prepared in Comparative Example 3 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 65%.

[0110] Comparative Example 4

[0111] Same as Example 1, except that the temperature is rapidly increased to 1000°C at a heating rate of 30°C / min in an Ar atmosphere.

[0112] The catalyst prepared in Comparative Example 4 was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. The COD removal rate of humic acid was 78%.

[0113] Antioxidant properties and stability determination

[0114] The Mn-TiO2@C catalyst prepared in Example 1 was subjected to multiple cycles of catalytic degradation of humic acid solution according to the above method. The catalyst was added to a 500 mg / L humic acid solution at a dosage of 0.2 g / L, and ozone was introduced for a reaction of 45 min. After the reaction was completed, the catalyst was centrifuged, washed, and dried at 60 °C for 12 h. The resulting product was then used again for the catalytic degradation of humic acid solution. After 5 cycles, the humic acid degradation rate of the Mn-TiO2@C catalyst decreased from 98.5% to 93.4%.

[0115] Using the multilayer titanium-based MXene material (Ti3C2 material) used in Example 1 as a catalyst, the humic acid solution was catalyzed through multiple cycles according to the above method, and the humic acid degradation rate was reduced from 81% to 50%.

[0116] This shows that the multilayer Mn-TiO2@C catalyst prepared in this invention can maintain high catalytic activity after multiple cycles under a strong oxidizing atmosphere when ozone is introduced, indicating that the multilayer Mn-TiO2@C catalyst has high antioxidant performance and stability.

[0117] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. The application of a multilayer manganese-titanium dioxide@carbon catalyst in the ozone catalytic degradation of organic wastewater, characterized in that, The organic wastewater is organic wastewater containing humic acid. The amount of the multilayer manganese-titanium dioxide@carbon catalyst added to the organic wastewater is 0.2 g / L, and the ozone catalytic reaction time is 45 min. The preparation method of the multilayer manganese-titanium dioxide@carbon catalyst involves dissolving a transition metal manganese salt in water, then adding a multilayer titanium-based MXene material and stirring until a suspension is obtained. The suspension is then allowed to stand, centrifuged, washed, and dried to obtain the Mn-MXene composite material. Finally, the Mn-MXene composite material is calcined under a CO2 atmosphere to obtain the multilayer manganese-titanium dioxide@carbon catalyst; the calcination temperature is 400–700°C. The transition metal manganese salt is one or more of manganese nitrate, manganese sulfate, or manganese chloride; The concentration of manganese ions in the suspension is 0.02–0.06 mol / L, and the mass concentration of the multilayer titanium-based MXene material in the suspension is 0.5–1.0%.

2. The application of the multilayer manganese-titanium dioxide@carbon catalyst according to claim 1 in the ozone catalytic degradation of organic wastewater, characterized in that, The roasting time is 2 to 5 hours.

3. The application of the multilayer manganese-titanium dioxide@carbon catalyst according to claim 1 in the ozone catalytic degradation of organic wastewater, characterized in that, The heating rate for roasting is 10–30 °C / min.

4. The application of the multilayer manganese-titanium dioxide@carbon catalyst according to claim 1 in the ozone catalytic degradation of organic wastewater, characterized in that, The gas volumetric flow rate of CO2 is 75–150 sccm.

5. The application of the multilayer manganese-titanium dioxide@carbon catalyst according to claim 1 in the ozone catalytic degradation of organic wastewater, characterized in that, The drying temperature is 50-70℃, and the drying time is 24 hours.

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