Supported modified nanoscale zero-valent iron catalyst as well as preparation method and application thereof
By preparing a supported modified nano zero-valent iron catalyst under mild conditions, the problem of difficulty in activation of PDS in the prior art is solved, and efficient degradation of pesticide pollutants is achieved, and good application prospects are provided.
Patent Information
- Application Number
- CN202510276391.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2025-06-13
AI Technical Summary
The prior art is difficult to efficiently and rapidly activate persulfate (PDS) under mild conditions, thereby degrading organic pollutants present in the environment.
A supported modified nano zero-valent iron catalyst was used to reduce and vulcanize iron salts with carbon-based support, borohydride and sulfur compounds under an inert atmosphere to prepare a catalyst that can efficiently activate PDS under mild conditions.
This catalyst can efficiently activate PDS under mild conditions, produce more active substances, significantly improve the degradation efficiency of pesticide pollutants, and is simple in preparation and low in cost.
Smart Images
Figure CN120132874A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of catalyst preparation, and particularly relates to a supported modified nano zero-valent iron catalyst, a preparation method thereof and an application thereof. Background Art
[0002] With the continuous development of industries such as industry and agriculture, it is found that various organic chemicals (such as pesticides, various antibiotic drugs, personal care products, etc.) are detected in industrial wastewater, domestic sewage and agricultural sewage discharged without treatment. They have the characteristics of low concentration, long-term existence in the environment and difficult biodegradation, and the potential organic pollution problems brought about are becoming more and more serious.
[0003] Advanced oxidation processes (AOPs), such as traditional processes like Fenton / Fenton-like oxidation, ozone oxidation / catalytic ozone oxidation, photocatalytic oxidation and electrochemical oxidation, all use hydroxyl radicals (·OH) as reactive oxygen species (ROS) to degrade pesticides, and have good effects. Among them, sulfate radicals generated by persulfate (PDS)-based Fenton-like oxidation have a higher redox potential (2.5 - 3.1 V) and a longer half-life (30 - 40 μs). How to effectively activate persulfate to degrade pollutants under mild conditions is a great challenge.
[0004] Therefore, there is an urgent need for a preparation method of a supported modified nano zero-valent iron catalyst that can effectively activate PDS under mild conditions, and then generate corresponding reactive species for degrading pollutants. Summary of the Invention
[0005] To overcome the problem that the catalysts in the prior art cannot activate PDS more efficiently and rapidly under mild conditions, the purpose of the present invention is to provide a supported modified nano zero-valent iron catalyst, a preparation method thereof and an application thereof. This catalyst can activate PDS under mild conditions and degrade pollutants.
[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:
[0007] A preparation method of a supported modified nano zero-valent iron catalyst, comprising the following steps:
[0008] Under an inert atmosphere, a borohydride solution and a sulfur compound solution are added to a mixture of an iron salt solution and a carbon-based carrier, and a reduction and sulfidation reaction is carried out to obtain a supported modified nano zero-valent iron catalyst.
[0009] Further, the carbon-based carrier is C 3 N 4 .
[0010] Further, the iron salt is any one of ferric chloride, ferrous sulfate and ferric sulfate.
[0011] Further, the inert atmosphere is one of nitrogen and argon.
[0012] Further, adding a borohydride solution and a sulfur compound solution to the mixture of the iron salt solution and the carbon-based support for reduction and sulfidation reactions, including:
[0013] Adding the borohydride solution to the mixture of the iron salt solution and the carbon-based support, carrying out the reduction reaction, and then adding the sulfur compound solution for the sulfidation reaction; or
[0014] Adding the borohydride solution and the sulfur compound solution to the mixture of the iron salt solution and the carbon-based support simultaneously for reduction and sulfidation reactions.
[0015] Further, the borohydride is one of KBH 4 and NaBH 4 one of them.
[0016] Further, the sulfur-containing compound is Na 2 S 2 O 4 、Na 2 S 2 O 3 、Na 2 S or any one of them.
[0017] Further, the molar ratio of the iron salt, the borohydride and the sulfur-containing compound is 0.2 - 0.6:1 - 3:0.1 - 0.3; the time for the reduction and sulfidation reactions is 60 - 120 min.
[0018] A supported modified nano-zero-valent iron catalyst, in which the modified zero-valent iron is uniformly dispersed on the support at the nanoscale.
[0019] Application of a supported modified nano-zero-valent iron catalyst in degrading pollutants.
[0020] Compared with the prior art, the beneficial effects of the present invention are:
[0021] In the present invention, an iron salt solution, borohydride, and a sulfur compound are used as raw materials under an inert atmosphere for liquid-phase reduction and sulfidation to prepare a supported modified nano-zero-valent iron catalyst. If the inert atmosphere is insufficient and air enters, the reduction of the iron salt will be incomplete, and it will be impossible to form a zero-valent iron material relatively completely. The modified iron sites in the prepared catalyst are nanoscale, and the carrier can effectively disperse the active sites uniformly. Through the modification of nano-zero-valent iron and the interaction between the surface-loaded modified nano-zero-valent iron and the carrier, the active sites are dispersed and stabilized, thereby increasing the reaction activity and stability of the catalyst. The active sites of this catalyst can be used to effectively break the O-O bond and play the role of efficiently activating PDS without the need to introduce external energy additionally. The preparation method of the present invention is simple and low in cost.
[0022] Further, the carrier using C 3 N 4 has no adsorption effect on the pollutant ATZ (atrazine) and the generated active free radicals, and will not interfere with the evaluation of the degradation performance due to adsorption. By comparing with the comparative materials, it can be seen that the adsorption of ATZ by the activated carbon material in the comparative materials does not belong to true degradation in the real sense, which will cover the active sites, consume the generated active free radicals, and reduce the utilization rate of PDS persulfate). Therefore, the comparative materials cannot efficiently activate PDS to degrade pollutants.
[0023] The supported modified nano-zero-valent iron catalyst prepared by the present invention can more efficiently and rapidly activate PDS under mild conditions, thereby generating more active substances to achieve the efficient degradation of pesticide pollutants, and has good application prospects. Description of the Drawings
[0024] Figure 1 Scanning electron microscope images of the supported modified nano-zero-valent iron catalyst prepared in Example 1; among them, (a) is at a low magnification, and (b) is at a high magnification;
[0025] Figure 2 Scanning electron microscope images of nZVI without sulfidation and loaded on the carrier in Comparative Example 1; among them, (a) is at a low magnification, and (b) is at a high magnification;
[0026] Figure 3 X-ray diffraction spectra of the supported modified nano-zero-valent iron catalyst prepared in Example 1 and the comparative materials of Comparative Examples 1-3;
[0027] Figure 4 X-ray photoelectron spectroscopy of the supported modified nano-zero-valent iron catalyst prepared in Example 1; among them, (a) is the C element, (b) is the N element, (c) is the Fe element, and (d) is the S element;
[0028] Figure 5 Performance diagram of the supported modified nano-zero-valent iron catalyst prepared in Example 1 and the comparative material for activating PDS to degrade atrazine (ATZ, pesticide); wherein, (a) is the degradation effect diagram of the catalyst and the comparative material, and (b) is the degradation rate fitting curve of different catalysts;
[0029] Figure 6 Schematic diagram for the preparation of the supported modified nano-zero-valent iron catalyst of the present invention. Detailed implementation manners
[0030] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.
[0031] Heterogeneous catalysts have the advantages of stable properties, a relatively wide pH tolerance range, and easy control compared with the homogeneous catalysts commonly used before. Among them, nano-zero-valent iron in common metal-based heterogeneous catalysts has good application and degradation performance, but it has strong magnetism and high surface energy, and it is extremely easy to aggregate itself, reducing the surface area, thereby reducing its reaction activity.
[0032] Therefore, the present invention considers that using a carrier material with better dispersibility and stability to effectively load the active nano-zero-valent iron and effectively modify it can improve the stability of the active sites and the intrinsic reaction activity at the same time.
[0033] See Figure 6 , a preparation method of a supported modified nano-zero-valent iron catalyst of the present invention, comprising the following steps:
[0034] Under a high-purity inert atmosphere, add 100 mg to 300 mg of a carbon-based carrier material into 100 mL of an iron salt aqueous solution with a concentration of 0.05 to 0.15 mol / L and continuously stir to obtain a mixture containing an iron salt and C 3 N 4 mixture;
[0035] Dissolve 1 to 3 mol / L of borohydride in 25 mL of deionized water to obtain a solution containing borohydride;
[0036] Dissolve 0.1 to 0.3 mol / L of a sulfur-containing compound in 25 mL of deionized water to obtain a sulfur-containing compound solution.
[0037] Drop the above-mentioned borohydride solution and sulfur-containing compound solution into the mixture containing an iron salt and C 3 N4 In the mixture; after the dropping is completed, keep stirring for a total time of 60 - 120 min, let it stand, precipitate the lower layer by centrifugation, and dry it in a vacuum drying oven at 60 - 80 °C to obtain the supported modified nano-zero-valent iron catalyst.
[0038] The carbon-based carrier material described is C 3 N 4 .
[0039] The inert atmosphere is one of nitrogen and argon.
[0040] The iron salt described is any one of ferric chloride, ferrous sulfate, and ferric sulfate.
[0041] Furthermore, the solution containing borohydride and the solution containing sulfur-containing compound are dropped into the mixture containing iron salt and C 3 N 4 It can be divided into one-pot method mixed dropping and two-step method sequential dropping.
[0042] Furthermore, the borohydride described is one of KBH 4 and NaBH 4 .
[0043] Furthermore, the sulfur-containing compound described is any one of Na 2 S 2 O 4 , Na 2 S 2 O 3 and Na 2 S.
[0044] Furthermore, the drying method described is vacuum drying, and the drying temperature is 60 - 80 °C.
[0045] The supported modified nano-zero-valent iron catalyst prepared by the method described above has the modified zero-valent iron uniformly dispersed in nanoscale on the carrier without large particle aggregation.
[0046] The supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 prepared by the present invention can achieve the activation of PDS and the efficient degradation of pesticide pollutants under normal temperature and pressure conditions, and play a role in the field of controlling water pollution.
[0047] Example 1
[0048] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0049] In high-purity N 2Under an atmosphere, the carbon-based carrier material was added to the iron salt solution and continuously stirred. The specific process was as follows: Ferric chloride was dissolved in 100 mL of deionized water to obtain a 0.1 mol / L ferric chloride solution, and 200 mg of C 3 N 4 was added to the above ferric chloride solution and continuously stirred to obtain a mixture containing iron salt and C 3 N 4 ;
[0050] NaBH 4 was dissolved in 25 mL of deionized water to obtain a 2 mol / L NaBH 4 solution, and it was slowly added dropwise to the above mixture containing iron salt and C 3 N 4 for liquid-phase reduction of ferric chloride, and the reaction continued for 45 min;
[0051] After that, Na 2 S was dissolved in 25 mL of deionized water to obtain a 0.2 mol / L Na 2 S solution, and it was again slowly added dropwise to the above reduced system for sulfidation modification, and the reaction continued for 45 min.
[0052] It was left standing and the lower layer was centrifuged and precipitated, then taken out and placed in a vacuum drying oven at 70 °C for drying to obtain a supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 material with nano-scale dispersion on the surface of the carrier.
[0053] Referring to Figure 1 (a) and (b) in, it can be seen that on the supported sulfided nano-zero-valent iron catalyst, SnZVI is distributed relatively evenly in the form of particles on the curled lamellar C 3 N 4 carrier.
[0054] Referring to Figure 4 (a), (b), (c) and (d) in, it can be seen that there are four elements present on the supported sulfided nano-zero-valent iron catalyst, and the presence of the XPS peak of the S element indicates its successful doping in the material.
[0055] Comparative Example 1
[0056] Same as Example 1, except that no C 3 N 4 was added and no sulfur-containing compound was added to obtain nano-zero-valent iron, denoted as nZVI, Figure 2 (a) and (b) in show the aggregated long strip-like chain structure of zero-valent iron. The particles are large due to aggregation, reducing the specific surface area and making it unable to be fully utilized.
[0057] Comparative Example 2
[0058] Same as Example 1, except that C is not added 3 N 4 , to obtain a sulfided nano zero-valent iron catalyst, denoted as SnZVI.
[0059] Comparative Example 3
[0060] Same as Example 1, except that sulfidation is not carried out without adding sulfur-containing compounds, to obtain an unsulfided supported nano zero-valent iron catalyst, denoted as nZVI@C 3 N 4 .
[0061] Referring to Figure 3 , it can be seen that the supported sulfided nano zero-valent iron catalyst has relatively obvious peaks at (110) and (211) in the XRD pattern, which are the peaks belonging to nano zero-valent iron, and an obvious peak belonging to C 3 N 4 at (002). However, the peaks of the doped S element cannot be observed for all five materials.
[0062] Under normal temperature and pressure conditions, the supported sulfided nano zero-valent iron catalyst is added to a 10 ppm atrazine solution and reacted for a certain time (30 min). The reaction results are shown in Figure 5 in (a) and (b). It can be seen that the supported sulfided nano zero-valent iron catalyst can effectively activate PDS to degrade the pollutant atrazine in an open system, and its degradation performance is greater than that of the unsulfided supported nano zero-valent iron catalyst, sulfided nano zero-valent iron catalyst and nano zero-valent iron. The pseudo-first-order kinetic constant is the highest and the degradation reaction rate is the fastest. Therefore, modifying the active sites and loading them on a stable support can improve the reaction activity of the catalyst.
[0063] Example 2
[0064] A preparation method of a supported modified nano zero-valent iron catalyst of the present invention comprises the following steps:
[0065] Under a high-purity Ar atmosphere, a carbon-based carrier material is added to an iron salt solution and continuously stirred. The specific process is as follows: dissolve ferrous sulfate in 100 mL of deionized water to obtain a 0.15 mol / L ferrous sulfate solution, and add 300 mg of C 3 N 4 to the above ferrous sulfate solution and continuously stir to obtain a mixture containing iron salt and C 3 N 4 ;
[0066] Add NaBH4 Dissolve it in 25 mL of deionized water to obtain a 3 mol / L NaBH 4 solution, and slowly add it dropwise to the above mixture of iron salt and C 3 N 4 for the liquid-phase reduction of ferrous sulfate, and continuously react for 60 min;
[0067] After that, dissolve Na 2 S in 25 mL of deionized water to obtain a 0.3 mol / L Na 2 S solution, and slowly add it dropwise to the above-reduced system again for sulfidation modification, and continuously react for 60 min.
[0068] Let it stand and centrifuge the lower layer to precipitate, take it out and place it in a vacuum drying oven at 60 °C for drying to obtain a supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 material with nano-scale dispersion on the carrier surface.
[0069] Example 3
[0070] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0071] Under a high-purity N 2 atmosphere, add the carbon-based carrier material to the iron salt solution and continuously stir. The specific process is as follows: dissolve ferric sulfate in 100 mL of deionized water to obtain a 0.05 mol / L ferric sulfate solution, add 100 mg of C 3 N 4 to the above ferric sulfate solution, and continuously stir to obtain a mixture of iron salt and C 3 N 4 ;
[0072] Dissolve NaBH 4 in 25 mL of deionized water to obtain a 1 mol / L NaBH 4 solution, and slowly add it dropwise to the above mixture of iron salt and C 3 N 4 for the liquid-phase reduction of ferric sulfate, and continuously react for 30 min;
[0073] After that, dissolve Na 2 S in 25 mL of deionized water to obtain a 0.1 mol / L Na 2 S solution, and slowly add it dropwise to the above-reduced system again for sulfidation modification, and continuously react for 30 min.
[0074] Let it stand and centrifuge the lower layer to precipitate, take it out and place it in a vacuum drying oven at 80 °C for drying to obtain a supported modified nano-zero-valent iron catalyst SnZVI@C with nano-scale dispersion on the carrier surface 3 N 4 material.
[0075] Example 4
[0076] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0077] Under a high-purity N 2 atmosphere, add the carbon-based carrier material to the iron salt solution and continuously stir. The specific process is as follows: Dissolve ferric chloride in 100 mL of deionized water to obtain a 0.1 mol / L ferric chloride solution. Add 200 mg of C 3 N 4 to the above-mentioned ferric chloride solution and continuously stir to obtain a mixture containing iron salt and C 3 N 4 ;
[0078] Dissolve NaBH 4 and Na 2 S 2 O 4 in 50 mL of deionized water to obtain a solution. Among them, the concentration of NaBH 4 is 2 mol / L, and the concentration of Na 2 S 2 O 4 is 0.2 mol / L, and slowly drop it into the above-mentioned mixture containing iron salt and C 3 N 4 while performing liquid-phase reduction and sulfidation modification of ferric chloride, and continuously react for 90 min.
[0079] Let it stand and centrifuge the lower layer to precipitate, take it out and place it in a vacuum drying oven at 70 °C for drying to obtain a supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 material.
[0080] Example 5
[0081] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0082] Under a high-purity Ar atmosphere, add the carbon-based carrier material to the iron salt solution and continuously stir. The specific process is as follows: Dissolve ferrous sulfate in 100 mL of deionized water to obtain a 0.15 mol / L ferrous sulfate solution. Add 300 mg of C 3 N4 Add it to the above-mentioned ferrous sulfate solution and continuously stir to obtain a mixture of iron salt and C 3 N 4 ;
[0083] Dissolve NaBH 4 and Na 2 S 2 O 3 in 50 mL of deionized water to obtain a solution. Among them, the concentration of NaBH 4 is 3 mol / L, and the concentration of Na 2 S 2 O 3 is 0.3 mol / L. Then slowly drip it into the above-mentioned mixture of iron salt and C 3 N 4 while carrying out the liquid-phase reduction and sulfidation modification of ferrous sulfate, and continuously react for 120 min.
[0084] Let it stand and centrifuge the lower layer to precipitate, take it out and place it in a vacuum drying oven at 60 °C for drying to obtain a supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 material with nano-scale dispersion on the carrier surface.
[0085] Example 6
[0086] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0087] Under a high-purity N 2 atmosphere, add the carbon-based carrier material to the iron salt solution and continuously stir. The specific process is as follows: Dissolve ferric sulfate in 100 mL of deionized water to obtain a 0.05 mol / L ferric sulfate solution, and add 100 mg of C 3 N 4 to the above-mentioned ferric sulfate solution and continuously stir to obtain a mixture of iron salt and C 3 N 4 ;
[0088] Dissolve NaBH 4 and Na 2 S 2 O 4 in 50 mL of deionized water to obtain a solution. Among them, the concentration of NaBH 4 is 1 mol / L, and the concentration of Na 2 S 2 O 4 is 0.1 mol / L. Then slowly drip it into the above-mentioned mixture of iron salt and C 3 N4 The liquid-phase reduction and sulfidation modification of ferric sulfate were carried out simultaneously in the mixture, and the reaction was continued for 60 min.
[0089] Let it stand and centrifuge the lower layer to precipitate, take it out and place it in a vacuum drying oven at 80 °C for drying to obtain the supported modified nano-zero-valent iron catalyst SnZVI@C with nanoscale dispersion on the carrier surface 3 N 4 material.
[0090] Example 7
[0091] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0092] Under a high-purity Ar atmosphere, add the carbon-based carrier material to the iron salt solution and continuously stir. The specific process is as follows: dissolve ferrous sulfate in 100 mL of deionized water to obtain a 0.1 mol / L ferrous sulfate solution, and add 300 mg of C 3 N 4 to the above-mentioned ferrous sulfate solution and continuously stir to obtain a mixture containing iron salt and C 3 N 4 mixture;
[0093] Dissolve NaBH 4 in 25 mL of deionized water to obtain a 3 mol / L KBH 4 solution, and slowly drip it into the above-mentioned mixture containing iron salt and C 3 N 4 for the liquid-phase reduction of ferrous sulfate, and continue the reaction for 60 min;
[0094] Then dissolve Na 2 S in 25 mL of deionized water to obtain a 0.15 mol / L Na 2 S solution, and slowly drip it into the above-reduced system again for sulfidation modification, and continue the reaction for 60 min.
[0095] Let it stand and centrifuge the lower layer to precipitate, take it out and place it in a vacuum drying oven at 60 °C for drying to obtain the supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 material.
[0096] Example 8
[0097] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0098] Under a high-purity Ar atmosphere, add the carbon-based carrier material to the iron salt solution and continuously stir. The specific process is as follows: Dissolve ferrous sulfate in 100 mL of deionized water to obtain a 0.05 mol / L ferrous sulfate solution, and add 300 mg of C 3 N 4 to the above ferrous sulfate solution and continuously stir to obtain a mixture containing iron salt and C 3 N 4 ;
[0099] Dissolve NaBH 4 in 25 mL of deionized water to obtain a 1 mol / L NaBH 4 solution, and slowly add it dropwise to the above mixture containing iron salt and C 3 N 4 for liquid-phase reduction of ferrous sulfate, and continuously react for 60 min;
[0100] After that, dissolve Na 2 S in 25 mL of deionized water to obtain a 0.2 mol / L Na 2 S solution, and again slowly add it dropwise to the above reduced system for sulfidation modification, and continuously react for 60 min.
[0101] Let it stand and centrifuge the lower layer to precipitate, take it out and place it in a vacuum drying oven at 60 °C for drying to obtain a supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 material with nano-scale dispersion on the surface of the carrier.
[0102] Example 9
[0103] A preparation method of a supported modified nano-zero-valent iron catalyst of the present invention includes the following steps:
[0104] Under a high-purity Ar atmosphere, add the carbon-based carrier material to the iron salt solution and continuously stir. The specific process is as follows: Dissolve ferrous sulfate in 100 mL of deionized water to obtain a 0.15 mol / L ferrous sulfate solution, and add 300 mg of C 3 N 4 to the above ferrous sulfate solution and continuously stir to obtain a mixture containing iron salt and C 3 N 4 ;
[0105] Dissolve NaBH 4 in 25 mL of deionized water to obtain a 3 mol / L NaBH 4 solution, and slowly add it dropwise to the above mixture containing iron salt and C 3 N 4Perform liquid-phase reduction of ferrous sulfate in the mixture and continuously react for 60 min;
[0106] After that, dissolve Na 2 S in 25 mL of deionized water to obtain a 0.3 mol / L Na 2 S solution, and slowly add it dropwise to the above-reduced system again with a disposable syringe for sulfidation modification, and continuously react for 60 min.
[0107] Let it stand and centrifuge and precipitate the lower layer, take it out and place it in a vacuum drying oven at 60 °C for drying to obtain a supported modified nano-zero-valent iron catalyst SnZVI@C 3 N 4 material with nano-scale dispersion on the surface of the carrier.
[0108] The above is only an illustration of the best embodiment of the present invention, but it should not be construed as a limitation of the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to change. Any changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.
[0109] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
Claims
1. A method for preparing a supported modified nanometer zero-valent iron catalyst, characterized in that: The following steps are involved: Under an inert atmosphere, a borohydride solution and a sulfur compound solution are added to a mixture of an iron salt solution and a carbon-based carrier to carry out reduction and sulfurization reactions to obtain a supported modified nano zero-valent iron catalyst.
2. The method for preparing the supported modified nanometer zero-valent iron catalyst according to claim 1, characterized in that: The carbon-based support is C3N4.
3. The method for preparing the supported modified nano zero-valent iron catalyst according to claim 1, characterized in that: The iron salt is any one of ferric chloride, ferrous sulfate and ferric sulfate.
4. The method for preparing a supported modified nanometer zero-valent iron catalyst according to claim 1, characterized in that: The inert atmosphere is one of nitrogen and argon.
5. The method for preparing a supported modified nanometer zero-valent iron catalyst according to claim 1, characterized in that: Adding a borohydride solution and a sulfur compound solution to a mixture of an iron salt solution and a carbon-based carrier to carry out a reduction and sulfurization reaction, comprising: Adding a borohydride solution to a mixture of an iron salt solution and a carbon-based carrier to carry out a reduction reaction, and then adding a sulfur compound solution to carry out a sulfurization reaction; or The borohydride solution and the sulfur compound solution are simultaneously added to a mixture of the iron salt solution and the carbon-based carrier to carry out reduction and sulfurization reactions.
6. The method for preparing a supported modified nanometer zero-valent iron catalyst according to claim 5, characterized in that: The borohydride is one of KBH4 and NaBH4.
7. The method for preparing a supported modified nanometer zero-valent iron catalyst according to claim 5, characterized in that: The sulfur-containing compound is any one of Na2S2O4, Na2S2O3 and Na2S.
8. The method for preparing a supported modified nanometer zero-valent iron catalyst according to claim 1, characterized in that: The molar ratio of the iron salt, the borohydride and the sulfur-containing compound is 0.2-0.6:1-3:0.1-0.3; the time for the reduction and sulfurization reaction is 60-120 minutes.
9. A supported modified nano zero-valent iron catalyst prepared by the method according to any one of claims 1 to 8, characterized in that: The modified zero-valent iron in the catalyst is uniformly dispersed on the carrier at nanometer level.
10. Use of a supported modified nano zero-valent iron catalyst prepared by the method according to any one of claims 1 to 8 in the degradation of pollutants.