Preparation method and application of nanotube-encapsulated iron particle catalyst
The nano-iron particles are coated through the nanotube encapsulation structure to prepare Fe/Fe3C@NCNT catalyst, which solves the problems of high metal leaching and high cost of nano-iron particle catalysts in acidic environments, and achieves efficient degradation of tetracyclines in organic wastewater , phenols and dye-based contaminants, and the catalyst can be reused.
Patent Information
- Application Number
- CN202410886969.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-03
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2044-07-03
AI Technical Summary
The existing nano-iron particle catalysts have problems such as high metal leaching, high cost, large catalyst addition and inability to recover in an acidic environment, making it difficult to efficiently degrade tetracycline, phenol and dye pollutants in organic wastewater.
By designing the nanotube encapsulation structure, nitrogen-doped nanotubes are coated with nanoferrous particles, and the Fe/Fe3C@NCNT catalyst is prepared, and the catalyst is used to activate persulfate to degrade pollutants in organic wastewater to achieve efficient degradation.
It achieves high stability and low cost preparation of catalysts, has high degradation efficiency, and can be reused, solving the problems of metal loss and large amount of dosage, and is suitable for efficient degradation of tetracyclines, phenols and dyes.
Smart Images
Figure CN118681585B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic wastewater treatment, and in particular to a preparation method and application of a nanotube-encapsulated iron particle catalyst. Background Art
[0002] Organic synthetic drugs such as antibiotics have made significant contributions to human health. However, incomplete use of antibiotics has led to their residues entering natural water bodies through various channels. This type of organic pollutants is difficult to be naturally degraded and is highly toxic and diffusible. The treatment of this type of organic wastewater is a difficult problem in current research.
[0003] At present, advanced oxidation treatment (AOP) is an emerging technology for degrading organic pollutants in water. Compared with physical and chemical precipitation, microbial therapy and membrane separation technology, AOP through the activation of persulfate (PDS, PMS) has the advantages of high efficiency, high environmental resistance and high selectivity. Sulfate activated by the catalyst produces reactive oxygen species (ROS) with high oxidizing ability, which can degrade organic pollutants into low-toxic substances or even completely mineralize them.
[0004] Transition metal-doped carbon-based catalysts have shown excellent prospects in wastewater treatment due to their high catalytic activity. Iron-based catalysts based on nanoparticles (such as nano-iron, iron carbide, and iron oxide) have been shown to have excellent catalytic activity, and they activate PMS through changes in metal valence states. However, the presence of nano-iron particles will greatly increase the amount of iron ion leaching, especially in acidic environments, which has problems such as high metal leaching and high cost.
[0005] In view of the above problems, a preparation method and application of a nanotube-encapsulated iron particle catalyst are proposed. Summary of the invention
[0006] The purpose of the present invention is to provide a preparation method and application of a nanotube-encapsulated iron particle catalyst. By designing a nanoparticle carrier structure, the coating of nano iron particles by nitrogen-doped nanotubes is achieved, and the catalyst has the advantage of high stability. The preparation method of the present invention is simple, low-cost, and easy to produce on a large scale. The catalyst is used to activate permonosulfate to degrade pollutants in organic wastewater, thereby solving the disadvantages of large catalyst dosage, catalyst non-recyclability, catalyst metal loss, etc., and is used for the efficient degradation of tetracyclines, phenols and dyes.
[0007] To achieve the above object, the present invention provides a method for preparing a nanotube-encapsulated iron particle catalyst, comprising the following steps:
[0008] S1, placing a certain amount of melamine, cyanuric acid, and 2,4-diamino-6-hydroxypyrimidine in deionized water, respectively, and dissolving them fully to obtain a melamine solution, a cyanuric acid solution, and a 2,4-diamino-6-hydroxypyrimidine solution;
[0009] S2, adding a certain amount of ferric chloride solution to the melamine solution, and then mixing it with the cyanuric acid solution and 2,4-diamino-6-hydroxypyrimidine solution obtained in S1;
[0010] S3, after the reaction is completed, centrifuge, wash and dry with deionized water to obtain a solid substance;
[0011] S4, grinding the solid material obtained in S3 evenly, placing it in a tube furnace for high-temperature calcination to obtain the final product Fe / Fe3C@NCNT.
[0012] Preferably, in S1, the masses of melamine, cyanuric acid and 2,4-diamino-6-hydroxypyrimidine are 1g to 3g, 1g to 3.5g and 1g to 3g respectively; the dissolution temperature is 80 to 100°C, and the amount of deionized water used is 50 to 150ml.
[0013] Preferably, in S2, the concentration of the ferric chloride solution is 5 g / L, and the dosage is 10 to 30 ml.
[0014] Preferably, in S3, centrifugal treatment is performed in a centrifuge with a rotation speed of 6000-7000 r / min, washing is performed 3-5 times, and drying is performed in a blast drying oven at a drying temperature of 60-80°C.
[0015] Preferably, in S4, the calcination conditions of the tubular furnace are: under a nitrogen atmosphere, keep the temperature at 30°C for 1 hour; then increase the temperature to 550°C and keep the temperature for 2 hours, with a heating rate of 5-10°C / min; then increase the temperature to 700-900°C and keep the temperature for 2 hours, with a heating rate of 5-10°C / min; finally cool down to 500°C and end, with a cooling rate of 10-20°C / min.
[0016] The present invention also provides a nanotube-encapsulated iron particle catalyst, and Fe / Fe3C@NCNT is prepared by the above preparation method.
[0017] Preferably, the Fe / Fe3C@NCNT is used to activate peroxymonosulfate to degrade pollutants in organic wastewater;
[0018] The specific steps of the pollutant degradation experiment are as follows: ultrasonically place the Fe / Fe3C@NCNT catalyst in deionized water for a period of time to disperse and inky the catalyst; then place the resulting catalyst solution in a water bath, maintain a constant temperature of 25°C, add the pollutant and stir for 10 minutes, then add peroxymonosulfate and start timing; after reacting for 30 minutes, test the residual concentration of the pollutant.
[0019] Therefore, the preparation method and application of a nanotube-encapsulated iron particle catalyst of the present invention realize the coating of nano iron particles by nitrogen-doped nanotubes by designing a nano particle carrier structure, and has the advantage of high stability. The preparation method of the process is simple, low-cost, and easy to produce on a large scale. The catalyst is used to activate permonosulfate to degrade pollutants in organic wastewater, solving the shortcomings of large catalyst dosage, catalyst non-recyclability, catalyst metal loss, etc., and is used for the efficient degradation of tetracyclines, phenols and dyes.
[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a scanning electron microscope image of the catalyst prepared in Example 1 of the present invention;
[0022] Figure 2 This is a projection electron microscope image of the catalyst prepared in Example 1 of the present invention;
[0023] Figure 3 The catalyst prepared in Application Examples 1-3 of the present invention is used for the adsorption and degradation curves of activated peroxymonosulfate to degrade tetracycline hydrochloride, wherein (a) is the adsorption curve and (b) is the degradation curve;
[0024] Figure 4 This is a comparison chart of the degradation performance of the catalyst in Application Example 1 of the present invention and the regenerated catalyst in Application Example 4;
[0025] Figure 5 This is a performance comparison chart of the catalyst in Application Example 5 of the present invention for degrading different pollutants. DETAILED DESCRIPTION
[0026] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.
[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.
[0028] Example 1
[0029] S1. Dissolve 1g melamine, 1g cyanuric acid and 1g 2,4-diamino-6-hydroxypyrimidine in 50ml deionized water respectively, keep the temperature at 80℃, and fully dissolve until the solution is transparent;
[0030] S2, slowly drop 10 ml of 5 g / L ferric chloride solution into the melamine solution obtained in S1, mix evenly, and then mix it with the cyanuric acid solution and 2,4-diamino-6-hydroxypyrimidine solution obtained in S1;
[0031] S3, after the reaction is completed, centrifuge and wash with deionized water for 3 times; dry the obtained solid matter in a blast drying oven at 80°C for 12 hours;
[0032] S4. Grind the solid material obtained in S3 evenly and place it in a tubular furnace for calcination; the calcination procedure is: in a nitrogen atmosphere, keep the temperature at 30°C for 1 hour; then increase the temperature to 550°C and keep the temperature for 2 hours, with a heating rate of 5°C / min; then increase the temperature to 800°C and keep the temperature for 2 hours, with a heating rate of 5°C / min; finally cool down to 500°C and end at a cooling rate of 10°C / min; the product obtained is Fe / Fe3C@NCNT-800.
[0033] The obtained product is tested, such as Figure 1 , 2 As shown, Fe / Fe3C@NCNT-800 presents a nanotube structure, with the outer shell being carbon nanotubes with uniformly distributed nitrogen and oxygen elements, and the interior of the nanotubes being aggregated iron nanoparticles.
[0034] Example 2
[0035] S1. Dissolve 1g melamine, 1g cyanuric acid and 1g 2,4-diamino-6-hydroxypyrimidine in 50ml deionized water respectively, keep the temperature at 80℃, and fully dissolve until the solution is transparent;
[0036] S2, slowly drop 10 ml of 5 g / L ferric chloride solution into the melamine solution obtained in S1, mix evenly, and then mix it with the cyanuric acid solution and 2,4-diamino-6-hydroxypyrimidine solution obtained in S1;
[0037] S3, after the reaction is completed, centrifuge and wash with deionized water for 3 times; dry the obtained solid matter in a blast drying oven at 80°C for 12 hours;
[0038] S4. Grind the solid material obtained in S3 evenly and place it in a tubular furnace for calcination; the calcination procedure is: in a nitrogen atmosphere, keep the temperature at 30°C for 1 hour; then increase the temperature to 550°C and keep the temperature for 2 hours, with a heating rate of 5°C / min; then increase the temperature to 700°C and keep the temperature for 2 hours, with a heating rate of 5°C / min; finally cool down to 500°C and end at a cooling rate of 10°C / min; the obtained product is Fe / Fe3C@NCNT-700.
[0039] Example 3
[0040] S1. Dissolve 1g melamine, 1g cyanuric acid and 1g 2,4-diamino-6-hydroxypyrimidine in 50ml deionized water respectively, keep the temperature at 80℃, and fully dissolve until the solution is transparent;
[0041] S2, slowly drop 10 ml of 5 g / L ferric chloride solution into the melamine solution obtained in S1, mix evenly, and then mix it with the cyanuric acid solution and 2,4-diamino-6-hydroxypyrimidine solution obtained in S1;
[0042] S3, after the reaction is completed, centrifuge and wash with deionized water for 3 times; dry the obtained solid matter in a blast drying oven at 80°C for 12 hours;
[0043] S4. Grind the solid material obtained in S3 evenly and place it in a tubular furnace for calcination; the calcination procedure is: in a nitrogen atmosphere, keep the temperature at 30°C for 1 hour; then increase the temperature to 550°C and keep the temperature for 2 hours, with a heating rate of 5°C / min; then increase the temperature to 900°C and keep the temperature for 2 hours, with a heating rate of 5°C / min; finally cool down to 500°C and end at a cooling rate of 10°C / min; the obtained product is Fe / Fe3C@NCNT-900.
[0044] The above Fe / Fe3C@NCNT catalyst was used to activate persulfate to degrade pollutants in organic wastewater. Taking tetracycline hydrochloride as an example, a degradation experiment was carried out in a 100 ml deionized water system with an initial pH of 7. The following is a detailed description in conjunction with the application examples.
[0045] Application Example 1
[0046] 1) 0.005 g of the Fe / Fe3C@NCNT-800 catalyst prepared in Example 1 was placed in 89 ml of deionized water and ultrasonicated for 10 min to disperse and ink the catalyst;
[0047] 2) The obtained Fe / Fe3C@NCNT-800 catalyst solution was placed in a water bath, maintained at a constant temperature of 25°C, 6 mL of tetracycline hydrochloride was added and stirred for 10 min to ensure the uniformity of tetracycline hydrochloride; then 5 ml of permonosulfate was added and the timing was started; after reacting for 30 min, the residual concentration of the pollutant was tested.
[0048] Application Example 2
[0049] The steps and conditions of this embodiment are the same as those of Application Example 1, except that the Fe / Fe3C@NCNT-800 catalyst is replaced with Fe / Fe3C@NCNT-700 prepared in Example 2.
[0050] Application Example 3
[0051] The steps and conditions of this embodiment are the same as those of Application Example 1, except that the Fe / Fe3C@NCNT-800 catalyst is replaced with Fe / Fe3C@NCNT-900 prepared in Example 2.
[0052] The content of tetracycline hydrochloride in application examples 1-3 was detected. Figure 3 As shown, after 30 minutes, the concentration of tetracycline hydrochloride in all systems decreased by more than 90%, indicating that the Fe / Fe3C@NCNT / PMS system prepared in the present invention can efficiently degrade tetracycline hydrochloride.
[0053] Application Example 4
[0054] The Fe / Fe3C@NCNT-800 used in Application Example 1 was magnetically recovered and used as a regenerated catalyst after washing, drying and annealing. The regenerated catalyst was used in the degradation experiment, and the steps in Application Example 1 were repeated for a total of 5 cycles.
[0055] like Figure 4 As shown, after 4 cycles, the degradation efficiency of tetracycline hydrochloride only decreased by 10%, while after annealing, the catalyst degradation performance was completely restored.
[0056] Application Example 5
[0057] The method in Application Example 1 was adopted, tetracycline hydrochloride was replaced by methylene blue and p-nitrophenol, and degradation experiments were carried out respectively, and their contents were detected respectively.
[0058] like Figure 5 As shown, after 30 min, the removal rates of methylene blue and p-nitrophenol by the Fe / Fe3C@NCNT-800 / PMS system were 98% and 85%, respectively, indicating that the catalyst prepared in the present invention has high efficiency for common organic pollutants.
[0059] Therefore, the preparation method and application of a nanotube-encapsulated iron particle catalyst of the present invention realize the coating of nano iron particles by nitrogen-doped nanotubes by designing a nano particle carrier structure, and has the advantage of high stability. The preparation method of the process is simple, low-cost, and easy to produce on a large scale. The catalyst is used to activate permonosulfate to degrade pollutants in organic wastewater, solving the shortcomings of large catalyst dosage, catalyst non-recyclability, catalyst metal loss, etc., and is used for the efficient degradation of tetracyclines, phenols and dyes.
[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.
Claims
1. A method for preparing a nanotube-encapsulated iron particle catalyst for activating peroxymonosulfate to degrade pollutants in organic wastewater, characterized in that: The following steps are involved: S1. Place a certain amount of melamine, cyanuric acid and 2,4-diamino-6-hydroxypyrimidine in deionized water respectively, and after fully dissolving, obtain a melamine solution, a cyanuric acid solution and a 2,4-diamino-6-hydroxypyrimidine solution; the masses of melamine, cyanuric acid and 2,4-diamino-6-hydroxypyrimidine are 1 g to 3 g, 1 g to 3.5 g and 1 g to 3 g respectively; the dissolution temperature is 80 to 100°C, and the amount of deionized water used is 50 to 150 ml; S2, adding a certain amount of ferric chloride solution to the melamine solution, and then mixing it with the cyanuric acid solution and 2,4-diamino-6-hydroxypyrimidine solution obtained in S1; S3, after the reaction is completed, centrifuge, wash and dry with deionized water to obtain a solid substance; S4. Grind the solid material obtained in S3 evenly and place it in a tubular furnace for high-temperature calcination. The calcination conditions are as follows: in a nitrogen atmosphere, keep the temperature at 30°C for 1 h; then increase the temperature to 550°C and keep the temperature at 2 h, with a heating rate of 5-10°C / min; then increase the temperature to 700-900°C and keep the temperature at 2 h, with a heating rate of 5-10°C / min; finally cool down to 500°C, with a cooling rate of 10-20°C / min, to obtain the final product, nanotube-encapsulated iron particle catalyst Fe / Fe3C@NCNT.
2. The preparation method according to claim 1, characterized in that: In the S2, the concentration of the ferric chloride solution is 5 g / L, and the dosage is 10-30 ml.
3. The preparation method according to claim 2, characterized in that: In S3, a centrifuge with a rotation speed of 6000-7000 r / min is used for centrifugal treatment, washing is performed 3-5 times, and drying is performed in a blast drying oven at a drying temperature of 60-80°C.
4. Application of a nanotube-encapsulated iron particle catalyst in activating peroxymonosulfate to degrade pollutants in organic wastewater, characterized in that: The nanotube-encapsulated iron particle catalyst Fe / Fe3C@NCNT is prepared by the preparation method described in any one of claims 1 to 3.