Iron-based nanoclay materials of functional motif architecture, methods of making and applications thereof

Abstract

The application discloses an iron-based nanoclay material with a functional base sequence structure and a preparation method and application thereof, and the preparation method comprises the following steps: acidizing nanoclay, mixing the nanoclay with ferrocene and an organic solvent to prepare a precursor, and pyrolyzing the precursor to obtain the iron-based nanoclay material with the functional base sequence structure.In the application, the nanoclay is acidized, ferrocene is used as a doped iron source, and the iron-based nanoclay material with the functional base sequence structure, which has a large specific surface area, a large number of active sites, excellent catalytic performance and good structural stability, can be prepared through pyrolysis.The iron-based nanoclay material can be used as a persulfate catalyst to treat emerging pollutant wastewater, effectively degrades the emerging pollutants, has little interference from pH, can exert catalytic performance under very wide pH conditions, has the advantages of simple process, convenient operation, low cost, high treatment efficiency, good degradation effect and the like, and has important significance for effectively removing the emerging pollutants in the environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of environmental new materials, and relates to a functional building block sequence iron-based nanoclay material and a preparation method and application thereof. BACKGROUND

[0002] With the continuous advancement of industrialization and urbanization, various emerging pollutants such as drug residues, microplastics, endocrine disruptors and the like pose a serious threat to the ecological system (such as wetland ecological system). These pollutants are not only difficult to remove through natural degradation processes, but also can be amplified through the food chain, ultimately affecting human health. Therefore, effectively removing emerging pollutants in the environment is a technical problem that needs to be solved at the present stage.

[0003] The activated persulfate-based advanced oxidation process is an efficient and environmentally friendly water treatment technology. This system mainly uses persulfate (such as sodium persulfate or potassium persulfate) as an oxidant, which is activated under certain conditions to produce highly active sulfate radicals (SO4 ·- ) and hydroxyl radicals (·OH). Due to the strong oxidizing ability of these radicals, they can efficiently decompose organic pollutants in water. However, persulfate is often difficult to exhibit its superior oxidation performance without a catalyst. Therefore, there is an urgent need to obtain a catalyst that can efficiently activate persulfate.

[0004] Iron is a recognized catalyst that can efficiently activate the persulfate system to generate free radicals, but it is prone to aggregation and detachment from the carrier in water, causing secondary pollution. Fixing iron on the carrier is an effective improvement strategy to prevent aggregation and detachment, but existing supported iron-based catalysts mainly load iron and its oxides on the surface of the carrier or fill them inside the carrier, which has the following defects: (1) it is difficult to effectively prevent iron metal ions from entering the treatment system due to dissolution, and secondary pollution is still very easy to occur, especially when iron and its oxides are loaded on the surface of the carrier, the possibility of iron active substances detaching from the carrier is still very high; (2) it is difficult to effectively increase the specific surface area of the catalyst, resulting in a small number of active sites, which makes it difficult to quickly activate persulfate, especially when iron and its oxides are filled inside the carrier, the specific surface area of the catalyst is smaller, the number of active sites is less, and the catalytic performance is poorer. Therefore, obtaining a supported iron-based catalyst with large specific surface area, large number of active sites, excellent catalytic performance and good structural stability is of great significance for efficiently activating persulfate and achieving rapid and complete removal of emerging pollutants. SUMMARY

[0005] The technical problems to be solved by the present application are to overcome the deficiencies of the prior art, and to provide a functional motif sequence iron-based nanoclay material with large specific surface area, large number of active sites, excellent catalytic performance and good structural stability, and a preparation method and application thereof.

[0006] To solve the above technical problems, the present application adopts the following technical solutions:

[0007] A preparation method of a functional motif sequence iron-based nanoclay material, comprising the following steps:

[0008] S1, acidifying the nanoclay;

[0009] S2, mixing, stirring, and drying the acidified nanoclay, ferrocene, and organic solvent in step S1 to obtain a precursor;

[0010] S3, pyrolyzing the precursor obtained in step S2 to obtain the functional motif sequence iron-based nanoclay material.

[0011] The preparation method is further improved, in step S1, the nanoclay is acidified by an acidic solution; the acidic solution is at least one of acetic acid solution, sulfuric acid solution, and nitric acid solution; the volume ratio of acid to water in the acidic solution is 1:2-5.

[0012] The preparation method is further improved, in step S1, the nanoclay is at least one of halloysite, sepiolite, and montmorillonite.

[0013] The preparation method is further improved, in step S1, the acidification time is 12-24 hours.

[0014] The preparation method is further improved, in step S2, the mass ratio of the acidified nanoclay to the ferrocene is 1-5:1; the organic solvent is at least one of ethanol, methanol, and acetone; and the stirring time is 4-24 hours.

[0015] The preparation method is further improved, in step S3, the pyrolysis is carried out in a protective atmosphere; the gas in the protective atmosphere is any one of nitrogen, helium, neon, and argon; the heating rate during the pyrolysis process is 5-15℃ / min; the pyrolysis temperature is 400-600℃; and the pyrolysis time is 2-4 hours.

[0016] As a general technical concept, the present application also provides a functional motif sequence iron-based nanoclay material prepared by the above preparation method.

[0017] The functional motif-sequenced iron-based nanoclay material is further improved, and the functional motif-sequenced iron-based nanoclay material comprises a nanoclay material doped with iron atoms, and the nanoclay material has a nanotube structure.

[0018] As a general technical concept, the application also provides an application of the functional motif-sequenced iron-based nanoclay material as a catalyst for degrading emerging pollutants.

[0019] The application is further improved, and the functional motif-sequenced iron-based nanoclay material is used as a catalyst for degrading emerging pollutants in water, and the application comprises the following steps: mixing the functional motif-sequenced iron-based nanoclay material, water containing emerging pollutants, and persulfate to perform a catalytic reaction, so as to complete the degradation of the emerging pollutants in the water.

[0020] The application is further improved, and the amount of the functional motif-sequenced iron-based nanoclay material added is 0.01 g to 0.2 g per liter of the water containing emerging pollutants; and the initial concentration of the persulfate in the catalytic reaction system is controlled to be 2 mM.

[0021] The application is further improved, and the initial concentration of the emerging pollutants in the water containing emerging pollutants is ≤10 mg / L; the emerging pollutants in the water containing emerging pollutants are at least one of perfluorinated compounds, antibiotics, microplastics, and endocrine disruptors; the antibiotics are norfloxacin; the persulfate is peroxymonosulfate and / or peroxodisulfate; and the time of the catalytic reaction is ≥2 min.

[0022] Compared with the prior art, the application has the following advantages:

[0023] (1)In view of the small specific surface area, small number of active sites, poor catalytic performance, poor structural stability and other deficiencies existing in the existing supported iron-based catalyst, and the defects such as difficult to efficiently activate persulfate and high risk of secondary pollution caused thereby, the application creatively provides a preparation method of functional motif sequence iron-based nanoclay material, which acidizes the nanoclay first, corrodes the surface of the nanoclay, which not only widens the inner diameter of the nanoclay tube, but also corrodes part of the aluminum sites in the inner diameter, thereby facilitating the subsequent adsorption and doping of iron, and on this basis, mixes the acidized nanoclay and ferrocene in an organic solvent, dissolves the ferrocene in the organic solvent, fully mixes the ferrocene and the nanoclay, which is conducive to promoting the adsorption and loading of the nanoclay on the ferrocene, and finally pyrolyzes the nanoclay loaded with ferrocene, and under the action of high temperature, the iron atoms are doped into the nanoclay with ferrocene as the iron source. In particular, during the acidizing and pyrolyzing processes, the basic structure of the nanoclay is not destroyed, and the nanoclay doped with iron elements still exhibits the same nanotube structure as the original nanoclay, which not only increases the specific surface area of the material, but also forms uniform and firm iron active sites on the surface and inside of the nanoclay, thereby increasing the iron active sites while effectively reducing the dissolution of iron, thereby obtaining a functional motif sequence iron-based nanoclay material with large specific surface area, large number of active sites, excellent catalytic performance and good structural stability. At the same time, the preparation method of the application also has the advantages of simple process, easy operation, low cost and the like, and is suitable for large-scale preparation and industrial application.

[0024] (2)In the preparation method of the application, the nanoclay used has the advantages of wide source, low price and low toxicity, which can effectively reduce the material preparation cost and realize harmlessness to the environment.

[0025] (3)The application also provides an application of the functional motif sequence iron-based nanoclay material as a persulfate catalyst in degrading emerging pollutants, for example, the functional motif sequence iron-based nanoclay material is used as a persulfate catalyst to degrade emerging pollutants in water, specifically, the functional motif sequence iron-based nanoclay material, water containing emerging pollutants and persulfate are mixed for catalytic reaction, which can complete the degradation of emerging pollutants in water, and has the advantages of simple process, easy operation, low cost, high treatment efficiency and good degradation effect, and can effectively degrade emerging pollutants. In particular, the functional motif sequence iron-based nanoclay material used is less affected by pH, can play a catalytic role under very wide pH conditions, and can exhibit very high treatment efficiency and very good removal effect, which has important significance for effectively removing emerging pollutants in the environment. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0027] Figure 1 SEM image of the original halloysite material used in Example 1 of the present application.

[0028] Figure 2 SEM image of the functional motif-structured iron-based halloysite material (Fr-HNT) prepared in Example 1 of the present application.

[0029] Figure 3 TEM image of the functional motif-structured iron-based halloysite material (Fr-HNT) prepared in Example 1 of the present application.

[0030] Figure 4 Iron fitting figure of the X-ray photoelectron spectroscopy of the halloysite material (HNT) after acidification in Example 1 of the present application.

[0031] Figure 5 Iron fitting figure of the SX-ray photoelectron spectroscopy of the functional motif-structured iron-based halloysite material (Fr-HNT) prepared in Example 1 of the present application.

[0032] Figure 6 Norfloxacin removal comparison figure of the functional motif-structured iron-based halloysite material (Fr-HNT), the halloysite material (HNT) after acidification and the supported iron-based catalyst (Fe2O3-HNT) in Example 4 of the present application.

[0033] Figure 7 Norfloxacin removal effect figure of the functional motif-structured iron-based halloysite material (Fr-HNT) in Example 5 of the present application under different pH conditions.

[0034] Figure 8 Norfloxacin removal effect figure of the functional motif-structured iron-based halloysite material (Fr-HNT) in Example 6 of the present application on different concentrations of norfloxacin. DETAILED DESCRIPTION

[0035] The present application provides a preparation method of a functional motif-structured iron-based nanoclay material, comprising the following steps:

[0036] S1, acidifying the nanoclay.

[0037] S2, mixing the nanoclay after acidification in step S1, ferrocene and an organic solvent, stirring, drying to obtain a precursor.

[0038] S3, pyrolyzing the precursor obtained in step S2 to obtain the iron-based nanoclay material with functional motif.

[0039] In the present application, the nanoclay is acidized by acetic acid solution, and the acidizing time is 12h-24h, preferably, the acidizing time is 14h-22h, further preferably, the acidizing time is 15h-20h.

[0040] In the present application, the acetic acid solution is obtained by mixing acetic acid and water, and the volume ratio of acetic acid to water is 1:2-5, preferably, the volume ratio of acetic acid to water is 1:3-4, further preferably, the volume ratio of acetic acid to water is 1:3.5.

[0041] In the present application, the nanoclay is at least one of halloysite, sepiolite and montmorillonite, preferably, the nanoclay is halloysite and montmorillonite, further preferably, the nanoclay is halloysite.

[0042] In the present application, the mass ratio of the acidized nanoclay to ferrocene is 1-5:1, preferably, the mass ratio of the acidized nanoclay to ferrocene is 1-4:1, further preferably, the mass ratio of the acidized nanoclay to ferrocene is 1.5-4:1.

[0043] In the present application, the organic solvent is at least one of ethanol, methanol and acetone, preferably, the organic solvent is ethanol and methanol, further preferably, the organic solvent is ethanol.

[0044] In the present application, the stirring time of the acidized nanoclay and ferrocene in the organic solvent is 4h-24h, preferably, the stirring time is 8h-20h, further preferably, the stirring time is 12h-16h.

[0045] In the present application, the pyrolysis is carried out in a protective atmosphere, and the gas in the protective atmosphere is any one of nitrogen, helium, neon and argon, preferably, the gas is argon or nitrogen, further preferably, the gas is nitrogen.

[0046] In the present application, the heating rate during pyrolysis is 5℃ / min-15℃ / min, preferably, the heating rate is 8℃ / min-12℃ / min, further preferably, the heating rate is 9℃ / min-10℃ / min.

[0047] In the present application, the pyrolysis temperature is 400℃-600℃, preferably, the pyrolysis temperature is 450℃-550℃, further preferably, the pyrolysis temperature is 500℃-550℃.

[0048] In the present application, the pyrolysis time is 2h-4h, preferably, the pyrolysis time is 2.2h-3.8h, further preferably, the pyrolysis time is 2.1h-2.6h.

[0049] In the present application, the prepared functional motif structured iron-based nanoclay material comprises a nanoclay material doped with iron atoms, wherein the nanoclay material is in a nanotube structure.

[0050] The present application also provides an application of the functional motif structured iron-based nanoclay material as a catalyst for persulfate in degrading emerging pollutants, for example, using the functional motif structured iron-based nanoclay material as a catalyst for persulfate to degrade emerging pollutants in water, comprising the following steps: mixing the functional motif structured iron-based nanoclay material, water containing emerging pollutants, and persulfate to perform a catalytic reaction, and completing the degradation of emerging pollutants in the water.

[0051] In the present application, the addition amount of the functional motif structured iron-based nanoclay material is 0.1 g to 0.2 g per liter of the water containing emerging pollutants.

[0052] In the present application, the initial concentration of persulfate in the catalytic reaction system is controlled to be 2 mM.

[0053] In the present application, the initial concentration of emerging pollutants in the water containing emerging pollutants is ≤10 mg / L, and the emerging pollutants in the water containing emerging pollutants are at least one of perfluorinated compounds, antibiotics, microplastics, and endocrine disruptors, wherein the antibiotic is norfloxacin.

[0054] In the present application, the persulfate used is peroxymonosulfate and / or peroxodisulfate.

[0055] In the present application, the time of the catalytic reaction is ≥2 min.

[0056] The present application is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present application is not limited thereby. In the following embodiments of the present application, if not specifically stated, the materials and instruments used are commercially available, the equipment used is conventional equipment, and the data obtained are the average values of more than three repeated experiments.

[0057] Example 1

[0058] A preparation method of a functional motif structured iron-based nanoclay material, specifically a preparation method of a functional motif structured iron-based halloysite material, comprising the following steps:

[0059] S1, acidifying the nanoclay, specifically:

[0060] The halloysite is naturally air-dried, and the halloysite is acidified in an acetic acid and water mixed solution (the volume ratio of acetic acid to water in the mixed solution is 1:3), stirred under magnetic stirring for 12 h, the liquid is separated out using a centrifuge, and the acidified halloysite is dried.

[0061] S2. According to the mass ratio of acidified nano-clay to ferrocene of 2:1, halloysite (HNT), ferrocene (commercially available) and ethanol dried in step S1 are mixed, stirred under magnetic conditions for 12 hours, and dried to obtain the precursor.

[0062] S3. The precursor obtained in step S2 is pyrolyzed. Specifically, the precursor is placed in a tube furnace and heated to 550°C at a heating rate of 10°C / min under a nitrogen atmosphere. The temperature is held for 2 hours and then naturally cooled to room temperature to obtain an iron-based halloysite material with a functional unit sequence structure, named Fr-HNT.

[0063] In this embodiment, the prepared functional modular structure of iron-based halloysite material includes nano-clay material, which is doped with iron and has a nanotube structure, wherein the nano-clay material is halloysite.

[0064] Figure 1 This is a SEM image of the original halloysite material used in Embodiment 1 of the present invention.

[0065] Figure 2 SEM image of the iron-based halloysite material (Fr-HNT) with functional modular structure prepared in Example 1 of this invention.

[0066] Figure 3 TEM image of the iron-based halloysite material (Fr-HNT) with functional modular structure prepared in Example 1 of this invention.

[0067] Depend on Figures 1 to 3 It can be seen that in the preparation method of the present invention, the basic structure of the iron-based halloysite material obtained by acidification and pyrolysis is not destroyed, and it still exhibits the same nanotube structure as the original halloysite material.

[0068] Figure 4 This is an iron fitting diagram of the X-ray photoelectron spectrum of the acidified halloysite material (HNT) in Example 1 of the present invention.

[0069] Figure 5 Iron fitting diagram of SX-ray photoelectron energy spectrum of iron-based halloysite material (Fr-HNT) with functional modular order prepared in Example 1 of this invention.

[0070] Depend on Figure 4 and Figure 5 It is understood that in this invention, after acidification, mixing with ferrocene, and pyrolysis, iron atoms are successfully doped into halloysite, which is beneficial to improving the number of active sites and structural stability.

[0071] Example 2

[0072] A preparation method of a functional motif sequence iron-based nanoclay material, in particular, a functional motif sequence iron-based montmorillonite material, comprising the following steps:

[0073] S1, acidifying the nanoclay, specifically:

[0074] The montmorillonite is naturally air-dried, and the montmorillonite is acidified in an acetic acid and water mixed solution (the volume ratio of acetic acid to water in the mixed solution is 1:5), stirred under magnetic stirring for 16 h, the liquid is separated out using a centrifuge, and the acidified montmorillonite is dried.

[0075] S2, according to the mass ratio of the acidified nanoclay to ferrocene of 2:1, the dried montmorillonite in step S1, ferrocene (purchased) and ethanol are mixed, stirred under magnetic conditions for 16 h, dried, and a precursor is obtained.

[0076] S3, pyrolyzing the precursor obtained in step S2, specifically: the precursor is placed in a tube furnace, heated to 500℃ at a heating rate of 9℃ / min under a nitrogen atmosphere, kept for 2.5 h, naturally cooled to room temperature, and a functional motif sequence iron-based montmorillonite material is obtained.

[0077] Example 3

[0078] A preparation method of a functional motif sequence iron-based nanoclay material, in particular, a functional motif sequence iron-based sepiolite material, comprising the following steps:

[0079] S1, acidifying the nanoclay, specifically:

[0080] The sepiolite is naturally air-dried, and the sepiolite is acidified in an acetic acid and water mixed solution (the volume ratio of acetic acid to water in the mixed solution is 1:4), stirred under magnetic stirring for 15 h, the liquid is separated out using a centrifuge, and the acidified sepiolite is dried.

[0081] S2, according to the mass ratio of the acidified nanoclay to ferrocene of 2:1, the dried sepiolite in step S1, ferrocene (purchased) and ethanol are mixed, stirred under magnetic conditions for 15 h, dried, and a precursor is obtained.

[0082] S3, pyrolyzing the precursor obtained in step S2, specifically: the precursor is placed in a tube furnace, heated to 600℃ at a heating rate of 10℃ / min under a nitrogen atmosphere, kept for 2 h, naturally cooled to room temperature, and a functional motif sequence iron-based sepiolite material is obtained.

[0083] Comparative Example 1

[0084] A preparation method of a supported iron-based catalyst, comprising the following steps:

[0085] The halloysite was naturally air-dried, the mass ratio of Fe2O3 to HNT was 1:2, the halloysite and ferric oxide (Fe2O3) were acidized in a mixed solution of acetic acid and water (the volume ratio of acetic acid to water in the mixed solution was 1:3), stirred under magnetic conditions for 12 h, dried, and the material obtained after drying was placed in a tube furnace for pyrolysis under a nitrogen atmosphere, the heating rate during pyrolysis was 5℃ / min, the temperature reached 550℃ and was kept for 2 h, and then naturally cooled to room temperature to obtain a supported iron-based catalyst, which was named Fe2O3-HNT.

[0086] Example 4

[0087] The application of an iron-based nanoclay material with a functional motif as a catalyst for persulfate in degrading emerging pollutants, in particular, the application of an iron-based nanoclay material with a functional motif as a catalyst for persulfate to activate peroxodisulfate to degrade norfloxacin (NOR) in water, includes the following steps:

[0088] 10 mg of the iron-based halloysite material with a functional motif (Fr-HNT) prepared in Example 1 was added to 100 mL of a 5 mg / L norfloxacin (NOR) solution (the pH value of the solution was 6.5), 1 mL of a 0.2 mol / L peroxodisulfate solution was added for catalytic reaction for 1 h, and the degradation of norfloxacin in water was completed.

[0089] Control group 1: the acidified halloysite material (HNT) was used instead of the iron-based halloysite material with a functional motif (Fr-HNT), and other conditions were the same.

[0090] Control group 2: the supported iron-based catalyst (Fe2O3-HNT) was used instead of the iron-based halloysite material with a functional motif (Fr-HNT), and other conditions were the same.

[0091] During the catalytic reaction, the residual concentration of norfloxacin in the solution was determined by sampling, and the removal rate of norfloxacin in different systems was calculated, as shown in Table 1 and Figure 6 .

[0092] Table 1 Removal rate of norfloxacin in different systems

[0093] Example 4 Control 1 Control 2 Norfloxacin removal 98.7％ 2.3％ 40％

[0094] As can be seen from Table 1, the iron-based halloysite material with the functional motif prepared in the application has a removal rate of norfloxacin in water of more than 98% within 1h of reaction time, has a far higher ability to activate persulfate than the acid-activated halloysite material (HNT) and is also far higher than the supported iron-based catalyst prepared in Comparative Example 1, which shows that the iron-based halloysite material with the functional motif prepared in the application has the advantages of large specific surface area, large number of active sites, excellent catalytic performance, good structural stability and the like, is a material that can effectively remove emerging pollutants in water and has low cost, and can be widely used to activate persulfate and effectively remove emerging pollutants in water.

[0095] Figure 6 The removal of norfloxacin by the functional motif iron-based halloysite material (Fr-HNT) in Example 4 of the application, the acid-activated halloysite material (HNT) and the supported iron-based catalyst (Fe2O3-HNT) is shown in the following figure. Figure 6 It can be seen that the processing efficiency of Fr-HNT on NOR is higher than that of Fe2O3-HNT and HNT, which shows that the Fr-HNT of the application has a better ability to activate persulfate to degrade pollutants than the halloysite material prepared from ordinary inorganic iron source and the original halloysite material.

[0096] Example 5

[0097] The application of a functional motif iron-based nanoclay material as a persulfate catalyst in degrading emerging pollutants, specifically, the application of the functional motif iron-based nanoclay material as a persulfate catalyst to activate persulfate to degrade norfloxacin (NOR) in water, comprises the following steps:

[0098] Take 5 portions of the functional motif iron-based halloysite material (Fr-HNT) prepared in Example 1, each 10mg, and add them to norfloxacin (NOR) solutions with pH values of 3, 5, 7, 9 and 11 (the volumes of these solutions are all 100mL and the concentrations are all 5mg / L), and add 1mL of persulfate solution with a concentration of 0.2mol / L to each solution to perform catalytic reaction for 1h to complete the degradation of norfloxacin in water.

[0099] During the catalytic reaction, the residual concentration of norfloxacin in the solution is determined by sampling, and the removal rate of norfloxacin under different pH conditions is calculated, as shown in Table 2. Figure 7

[0100] Figure 7 The removal effect of the functional motif iron-based halloysite material (Fr-HNT) in Example 5 of the application on norfloxacin under different pH conditions is shown in the following figure. Figure 7 ​It can be known that the iron-based halloysite material with functional motif sequence prepared in the application has good activation capacity for peroxymonosulfate under different pH conditions, and achieves high-efficiency removal of norfloxacin. It can be seen that the norfloxacin material prepared in the application can stably produce catalytic effect in a wide pH value range, and has great potential in practical water body application.

[0101] Example 6

[0102] The application of a functional motif sequence iron-based nanoclay material as a catalyst for persulfate in degrading emerging pollutants, in particular, the application of a functional motif sequence iron-based nanoclay material as a catalyst for persulfate in activating peroxymonosulfate to degrade norfloxacin (NOR) in water, comprises the following steps:

[0103] Take 5 portions of the functional motif sequence iron-based halloysite material (Fr-HNT) prepared in Example 1, each 10 mg, and add them into norfloxacin (NOR) solutions with concentrations of 1 mg / L, 5 mg / L, 10 mg / L, 20 mg / L and 50 mg / L (the volumes of these solutions are all 100 mL, and the pH is all 6.5), and add 1 mL of peroxymonosulfate solution with a concentration of 0.2 mol / L to carry out catalytic reaction for 1 h to complete the degradation of norfloxacin in water.

[0104] During the catalytic reaction, the residual concentration of norfloxacin in the solution is determined by sampling, and the removal rate of the functional motif sequence iron-based halloysite material (Fr-HNT) for norfloxacin with different concentrations is calculated, as shown in Figure 8 .

[0105] Figure 8 The figure of the removal effect of the functional motif sequence iron-based halloysite material (Fr-HNT) in Example 6 of the application for norfloxacin with different concentrations is shown in Figure 8 It can be known that the functional motif sequence iron-based halloysite material prepared in the application has very obvious treatment effect on norfloxacin within 10 mg / L under the preferred preparation conditions, only by using a small amount of material and oxidant, although the removal effect on norfloxacin with concentrations of 20 mg / L and 50 mg / L is not good, but the concentration of norfloxacin in actual wastewater is difficult to reach this concentration level, and if there is wastewater with high-concentration norfloxacin, the amount of the material and the oxidant of the application can be appropriately increased. In summary, the functional motif sequence iron-based halloysite material prepared in the application has great application potential in dealing with norfloxacin in actual water.

[0106] From the above results, compared with conventional supported iron-based catalysts, in the present application, by acidizing the nanoclay and using ferrocene as a doped iron source, an iron-based nanoclay material with a functional motif sequence structure of large specific surface area, a large number of active sites, excellent catalytic performance, and good structural stability can be prepared by pyrolysis. As a catalyst for persulfate, it can effectively degrade emerging pollutants, especially the functional motif sequence structure of the iron-based nanoclay material used is less affected by pH, can exert catalytic efficiency under very wide pH conditions, and can exhibit very high treatment efficiency and very good removal effect. It has the advantages of simple process, easy operation, low cost, high treatment efficiency, good degradation effect, etc. It has important significance for effectively removing emerging pollutants in the environment.

[0107] The above examples are only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above examples. Any technical solutions that fall within the scope of the present application are within the protection scope of the present application. It should be noted that improvements and refinements made by ordinary skilled persons in the art without departing from the principles of the present application should also be considered within the protection scope of the present application.

Claims

1. A method for preparing a functional building block sequence of an iron-based nanoclay material, characterized by, The method comprises the following steps: S1, acidizing the nanoclay; S2, mixing the acidized nanoclay in step S1, ferrocene and an organic solvent, stirring, drying to obtain a precursor; S3, pyrolyzing the precursor obtained in step S2 to obtain the functional motif sequence iron-based nanoclay material; The pyrolysis is carried out in a protective atmosphere; the gas in the protective atmosphere is any one of nitrogen, helium, neon and argon; the temperature of the pyrolysis is 400-600 DEG C.

2. The production method according to claim 1, characterized by, In step S1, the nanoclay is acidized by an acidic solution; the acidic solution is at least one of acetic acid solution, sulfuric acid solution and nitric acid solution; the volume ratio of acid to water in the acidic solution is 1:2-5.

3. The preparation method according to claim 2, characterized in that, In step S1, the nanoclay is at least one of halloysite, sepiolite and montmorillonite.

4. The preparation method according to claim 2, characterized in that, In step S1, the acidizing time is 12-24 hours.

5. The production method according to any one of claims 1 to 4, characterized by, In step S2, the mass ratio of the acidized nanoclay to the ferrocene is 1-5:1; the organic solvent is at least one of ethanol, methanol and acetone; the stirring time is 4-24 hours. In step S3, the heating rate in the pyrolysis process is 5-15 DEG C / min; the pyrolysis time is 2-4 hours.

6. An iron-based nanoclay material of a functional motif sequence, characterized in that, The functional motif sequence iron-based nanoclay material is prepared by the method of any one of claims 1-5.

7. The functional building block based iron-based nanoclay material according to claim 6, wherein, The functional motif sequence iron-based nanoclay material comprises a nanoclay material doped with iron atoms; the nanoclay material has a nanotube structure.

8. Use of the functional motif sequence iron-based nanoclay material of claim 6 or 7 as a catalyst for persulfate in degrading emerging pollutants.

9. Use according to claim 8, characterized in that, The functional motif sequence iron-based nanoclay material is used as a catalyst for persulfate in degrading emerging pollutants in water, which comprises the following steps: mixing the functional motif sequence iron-based nanoclay material, water containing emerging pollutants and persulfate to perform a catalytic reaction, thereby completing the degradation of emerging pollutants in the water; the addition amount of the functional motif sequence iron-based nanoclay material is 0.1-0.2 g per liter of the water containing emerging pollutants; the initial concentration of persulfate in the catalytic reaction system is controlled to be 2 mM.

10. Use according to claim 9, characterized in that, The initial concentration of emerging pollutants in the water containing emerging pollutants is ≤10 mg / L; the emerging pollutants in the water containing emerging pollutants are at least one of perfluorinated compounds, antibiotics, microplastics and endocrine disruptors; the antibiotic is norfloxacin; the persulfate is peroxymonosulfate and / or peroxodisulfate; the catalytic reaction time is ≥2 min.

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