Preparation method of aminated MXene / MnO2 composite material and application of aminated MXene / MnO2 composite material in adsorbing pollutants
Aminated MXene/MnO2 composite materials were prepared by LiF/HCl etching and hydrothermal reaction, which solved the problems of poor stability and self-polymerization of MXene materials. This method achieved efficient removal of tetracycline and chromium ions from aqueous solutions and exhibited excellent adsorption performance and reusability.
Patent Information
- Application Number
- CN202511189412.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-25
- Publication Date
- 2025-10-31
AI Technical Summary
Existing MXene materials suffer from poor stability and easy self-polymerization of layered structures in the field of pollutant adsorption, making it difficult to efficiently remove tetracycline and chromium ions from aqueous solutions.
MXene powder was prepared by LiF/HCl etching and then functionalized with 3-aminopropyltriethoxysilane. MnO2 particles were then grown in situ between and on the surface of the MXene layers by hydrothermal reaction to form a stable intercalation structure and enhance adsorption capacity.
The prepared aminated MXene/MnO2 composite material achieved removal rates of 98.9% and 98.8% for tetracycline and chromium ions, respectively, and maintained a removal rate of over 80% after 10 adsorption-desorption cycles, significantly improving the adsorption efficiency.
Smart Images
Figure CN120860976A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional material preparation, specifically relating to a method for preparing an aminoated MXene / MnO2 composite material and its application in adsorbing pollutants. Background Technology
[0002] With rapid industrialization and urbanization, large amounts of toxic wastewater are discharged into the natural environment, leading to increasingly serious water pollution problems. Currently, antibiotics and heavy metal ions are considered two major pollutants in natural water bodies. Antibiotics are widely used in animal husbandry and pharmaceutical manufacturing. Most antibiotics cannot be completely metabolized or absorbed by organisms, and antibiotics flowing into natural water environments can promote drug resistance in microorganisms, posing a significant threat to public health. Among the many types of antibiotics, tetracycline (TC) accounts for about one-third of the total antibiotic production and ranks second in usage. On the other hand, chromium ions (Cr(VI)) are an important colorant widely used in industrial production such as electroplating and organic synthesis. Untreated Cr(VI) possesses extremely strong oxidizing, mutagenic, and teratogenic properties, which can severely harm animal and human health once released into the natural environment. Therefore, using efficient and environmentally friendly methods to remove these pollutants from aqueous solutions is becoming increasingly important. Currently, common methods for treating antibiotic and heavy metal ion wastewater include catalysis, adsorption, ion exchange, membrane separation, and biodegradation. Among these methods, adsorption is considered one of the most promising in wastewater treatment due to its ease of operation, high removal efficiency, and sustainability. Therefore, designing a high-performance adsorbent capable of simultaneously treating TC and Cr(VI) is of paramount importance for the protection of human health and the natural environment.
[0003] In recent years, MXene, as a novel two-dimensional transition metal carbide / nitride, has attracted considerable attention from researchers. Due to its regular layered structure and abundant surface functional groups, MXene's application in pollutant adsorption has been extensively studied. While traditional surface-modified MXene or MXene-based composites can effectively remove various pollutants from aqueous solutions, MXene materials suffer from poor stability and a tendency for self-polymerization due to their layered structure, limiting their application in pollutant adsorption. Summary of the Invention
[0004] This invention provides a method for preparing an aminated MXene / MnO2 composite material and its application in adsorbing pollutants. The method for preparing the aminated MXene / MnO2 composite material is as follows: (1) The Al layer of Ti3AlC2 was acidically etched by LiF / HCl etching, then washed with deionized water, and freeze-dried to obtain MXene powder; ethanol, deionized water and ammonia were mixed to obtain an alkaline solution, then MXene powder and 3-aminopropyltriethoxysilane were added, and the mixture was stirred at 30-60℃ for 2-10 h. After washing with deionized water and ethanol, the mixture was freeze-dried to obtain aminated MXene. (2) Mix aminated MXene and MnSO4 in deionized water and stir magnetically at 30-60℃ for 1-3 h; then add (NH4)2S2O8, stir and mix evenly, transfer to a high-pressure reactor, and hydrothermally react at 100-150℃ for 1-3 h. Wash the product with deionized water and freeze dry to obtain aminated MXene / MnO2 composite material.
[0005] The volume ratio of ethanol, deionized water, and ammonia in the alkaline solution is 30-40:1-3:2-5.
[0006] The addition ratio of MXene powder to 3-aminopropyltriethoxysilane is 0.01-0.8 g / mL.
[0007] The mass ratio of the aminated MXene, MnSO4 and (NH4)2S2O8 is 1-3:1-3:2-4.
[0008] The amination-modified MXene / MnO2 composite material prepared above was used to adsorb and remove TC and / or Cr(VI) from wastewater. After adsorption, the amination-modified MXene / MnO2 composite material was soaked in anhydrous ethanol for desorption, and then freeze-dried for regeneration and reuse.
[0009] This invention combines surface end-group regulation of MXene with in-situ growth technology. First, APTES is used to functionalize MXene with amino groups, grafting abundant amino functional groups into the interlayer and surface of MXene. Then, Mn... 2+MnO2 particles are anchored between the layers and surface of aminated MXene through electrostatic attraction and chemisorption. Subsequently, (NH4)2S2O8 is added to grow MnO2 particles in situ between the layers and surface of the aminated MXene via a hydrothermal reaction, forming a stable intercalated structure. This structure effectively suppresses the self-polymerization effect between the MXene nanosheets and allows the adsorption active sites between the layers of the aminated MXene material to fully contact pollutant molecules, enhancing the adsorption capacity of the composite material. The prepared aminated MXene / MnO2 composite material exhibits excellent adsorption capacity for tetracycline (TC) and chromium ions (Cr(VI)) in aqueous solution, with removal rates of 98.9% and 98.8%, respectively. Even after 10 consecutive adsorption-desorption cycles, the removal rate of both pollutants remains above 80%. This invention provides a new approach for the preparation of MXene-based composite adsorbent materials and a new method for the removal of antibiotics and heavy metal ions from aqueous solutions, showing broad application prospects. Attached Figure Description
[0010] Figure 1 The image shows the microstructure of the aminoated MXene prepared in Example 1.
[0011] Figure 2 Microscopic morphology of MnO2 prepared for the example.
[0012] Figure 3 The image shows the microstructure of the aminated MXene / MnO2 composite material prepared in Example 1.
[0013] Figure 4 X-ray diffraction patterns of the aminated MXene / MnO2 composite material and related materials prepared in Example 1.
[0014] Figure 5 The graph shows a comparison of the adsorption performance of the aminated MXene / MnO2 composite material prepared in Example 1 and related materials for TC and Cr(VI) in aqueous solution.
[0015] Figure 6 The graph shows the cyclic adsorption performance of the aminated MXene / MnO2 composite material prepared in Example 1 for TC and Cr(VI) in aqueous solution. Detailed Implementation
[0016] To make the objectives, technical solutions, and technical effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Example 1
[0017] (1) Preparation of amination-modified MXene: Acidic solution was prepared by mixing 1.6 g LiF with 20 mL HCl and stirring for 10 min. Then, 1 g Ti3AlC2 was slowly added to the acidic solution, and the mixture was magnetically stirred at 45 °C for 48 h to fully etch the Al layer. Finally, the etched product was washed several times with deionized water at 3500 rpm until the pH of the supernatant was >6.0. The resulting precipitate was freeze-dried for 48 h to obtain MXene powder.
[0018] 1 g of MXene powder was added to an alkaline solution prepared by mixing 160 mL of ethanol, 10 mL of deionized water and 15 mL of ammonia. Then, 8 mL of 3-aminopropyltriethoxysilane (APTES) was added, and the mixture was magnetically stirred at 45 °C for 6 h. The product was then washed with deionized water and ethanol at 6000 rpm by centrifugation. The resulting product was freeze-dried for 48 h to obtain aminated MXene.
[0019] like Figure 1 As shown, the acidic etching solution successfully etched the Al layer of Ti3AlC2, and the amino functionalization process further expanded the interlayer spacing of MXene, resulting in a clear layered structure for the aminated MXene. This structure is beneficial for the subsequent heating and stirring process with MnSO4, allowing Mn to... 2+ Fully anchored between the layers and the surface of amino-modified MXene. These anchored Mn 2+ MnO2 particles will grow in situ during the hydrothermal reaction.
[0020] (2) Preparation of aminated MXene / MnO2 composite material: 0.125 g of aminated MXene and 0.125 g of MnSO4·H2O were added to 100 mL of deionized water, and the mixture was magnetically stirred at 45 °C for 2 h. During this process, Mn 2+ Ions were sufficiently anchored between the layers and on the surface of the aminated MXene. Subsequently, 0.175 g of (NH4)2S2O8 was added to the mixture, and the mixture was magnetically stirred for 10 min to ensure complete mixing. Finally, the mixture was transferred to a Teflon-lined stainless steel autoclave and hydrothermally reacted at 120 °C for 2 h. The product was washed several times with deionized water at 6000 rpm and freeze-dried for 48 h to obtain the aminated MXene / MnO2 composite material.
[0021] like Figure 3 As shown, the aminated MXene / MnO2 composite material exhibits a clear intercalation structure, with MnO2 particles distributed between the layers and on the surface of the aminated MXene.
[0022] like Figure 4As shown, characteristic peaks belonging to both amino-modified MXene and MnO2 can be observed simultaneously in the X-ray diffraction spectrum of the amino-modified MXene / MnO2 composite material, further verifying the successful composite of amino-modified MXene and MnO2.
[0023] Preparation of the comparative material MnO2: 0.125 g of MnSO4·H2O and 0.175 g of (NH4)2S2O8 were added to 100 mL of deionized water, and the mixture was magnetically stirred at 45 °C for 10 min to ensure complete mixing. Subsequently, the mixture was transferred to a Teflon-lined stainless steel autoclave and hydrothermally reacted at 120 °C for 2 h. The hydrothermal product was washed several times with deionized water at 6000 rpm, and then dried in an oven for 12 h to obtain MnO2. Figure 2 As shown, the MnO2 particles exhibit a sea urchin-like structure.
[0024] Adsorption performance tests of aminated MXene / MnO2 composites for TC and Cr(VI): Test Procedure: Add 25 mL of a 100 mg / L adsorbate solution to the test bottle, followed by 10 mg of adsorbent material. Place the test bottle on a shaker and shake for 5 h, then remove the bottle and allow it to stand for approximately 1 h. After complete separation of the solid-liquid mixture, take 5 mL of the supernatant and determine the residual concentration of the adsorbate using a UV-Vis spectrometer (PERSEE, TU-1901). Alternatively, TC solution can be measured directly at 357 nm, while Cr(VI) solution requires treatment using the 1,5-diphenylurea method and measurement at 464 nm. The adsorption conditions are: C0 = 100 mg / L, V = 25 mL, m = 10 mg, t = 5 h, T = 25℃.
[0025] like Figure 5 As shown, aminated MXene achieved removal rates of 75.8% and 51.8% for TC and Cr(VI), respectively, while MnO2 achieved removal rates of 19.7% and 52.5% for the two pollutants, respectively. Neither material effectively removed TC and Cr(VI) from the aqueous solution. However, the aminated MXene / MnO2 composite material achieved removal rates of 98.9% and 98.8% for TC and Cr(VI), respectively, effectively removing the pollutants from the aqueous solution.
[0026] Cyclic adsorption performance of aminated MXene / MnO2 composite material for TC and Cr(VI): After the adsorption process was completed, the aminated MXene / MnO2 composite material loaded with adsorbate was collected and immersed in 50 mL of anhydrous ethanol for 2 h to allow for complete desorption of the adsorbate. The regenerated aminated MXene / MnO2 composite material was freeze-dried for 48 h and used for the next adsorption-desorption cycle test.
[0027] like Figure 6 As shown, after 10 adsorption-desorption cycles, the aminated MXene / MnO2 composite material maintained a removal rate of over 80% for both pollutants. This verifies the excellent reusability of the material.
Claims
1. A method for preparing an aminated MXene / MnO2 composite material, characterized in that, The specific steps of the preparation method are as follows: (1) The Al layer of Ti3AlC2 was acidically etched by LiF / HCl etching, then washed with deionized water, and freeze-dried to obtain MXene powder; ethanol, deionized water and ammonia were mixed to obtain an alkaline solution, then MXene powder and 3-aminopropyltriethoxysilane were added, and the mixture was stirred at 30-60℃ for 2-10 h. After washing with deionized water and ethanol, the mixture was freeze-dried to obtain aminated MXene. (2) Mix aminated MXene and MnSO4 in deionized water and stir magnetically at 30-60℃ for 1-3 h; then add (NH4)2S2O8, stir and mix evenly, transfer to a high-pressure reactor, and hydrothermally react at 100-150℃ for 1-3 h. Wash the product with deionized water and freeze dry to obtain aminated MXene / MnO2 composite material.
2. The preparation method according to claim 1, characterized in that, The volume ratio of ethanol, deionized water, and ammonia in the alkaline solution is 30-40:1-3:2-5.
3. The preparation method according to claim 1, characterized in that, The addition ratio of MXene powder to 3-aminopropyltriethoxysilane is 0.01-0.8 g / mL.
4. The preparation method according to claim 1, characterized in that, The mass ratio of the aminated MXene, MnSO4 and (NH4)2S2O8 is 1-3:1-3:2-4.
5. The application of the aminated MXene / MnO2 composite material prepared by the method according to any one of claims 1-4 for the adsorption and removal of tetracycline TC and / or Cr(VI) from wastewater.
6. The application according to claim 5, characterized in that, The adsorbed aminated MXene / MnO2 composite material can be desorbed by soaking in anhydrous ethanol, and then regenerated and reused after freeze-drying.