Preparation method of MIL-88B (Fe) encapsulated NiO nanoparticle composite material and application of MIL-88B (Fe) encapsulated NiO nanoparticle composite material in catalytic ozonolysis
The MIL-88B(Fe)-encapsulated NiO nanoparticle composite material was prepared by a solvothermal method, which solved the problem of low efficiency of NiO catalyst in ozone decomposition under high humidity and achieved efficient and stable ozone degradation effect.
Patent Information
- Application Number
- CN202510872925.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-10-21
AI Technical Summary
Existing NiO catalysts have low catalytic ozone decomposition efficiency and short service life in high humidity environments, making it difficult to achieve efficient ozone degradation under mild conditions.
A solvothermal method was used to prepare a NiO nanoparticle composite material encapsulated in MIL-88B(Fe). By uniformly embedding NiO nanoparticles into the pores of MIL-88B(Fe), a NiO@MIL-88B(Fe) composite material was formed, which maintained its unique structure and high specific surface area, and provided sufficient active sites and mass transfer channels.
Achieving nearly 100% ozone degradation efficiency in high humidity environments solves the problem of poor activity of NiO catalysts under high humidity, extends service life, and is suitable for practical environmental ozone pollution control.
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Figure CN120815577A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of new materials, and particularly relates to a preparation method of a MIL-88B (Fe)-encapsulated NiO nanoparticle composite material and an application of the composite material in catalytic ozone decomposition. Background Art
[0002] The rapid global economic development and accelerated industrialization have led to a continuous increase in ground-level ozone (O3) concentrations. Surface ozone poses a serious threat to human health, hinders plant growth, affects crop yields, and disrupts the balance of ecosystems, leading to severe O3 pollution. Ozone pollution control has become an unavoidable reality. Therefore, efficient ozone degradation is of great significance for improving air quality and creating a healthier living environment. Among the current O3 pollution control methods, catalytic decomposition has attracted considerable attention due to its mild reaction conditions, high efficiency, cost-effectiveness, and environmental friendliness.
[0003] The valence electron configuration of nickel (Ni) is 3d 8 4s 2 , which can form a variety of oxidized compounds. Among them, nickel oxide (NiO) has become the most practical nickel oxide due to its excellent chemical stability and has been proven to have excellent catalytic ozone decomposition performance. Metal-organic frameworks (MOFs), as new crystalline porous materials, have a highly ordered pore system and excellent specific surface area performance, with uniform and controllable pore size distribution. The unique pore structure of the metal-organic framework is suitable as an active carrier to encapsulate various guest molecules and achieve a synergistic effect between the host and the guest. This characteristic can not only significantly enhance the catalytic activity, but also exhibit good moisture resistance, providing a solid foundation for efficient catalytic ozone decomposition.
[0004] At present, catalytic decomposition technology in ozone pollution control research is widely recognized as an ideal ozone decomposition technology because it can achieve efficient conversion under relatively mild conditions, has low energy consumption, and has the advantages of safety, economy, and environmental protection. The commonly used NiO catalyst has attracted much attention due to its abundant reserves and low cost. NiO exhibits certain ozone decomposition activity under room temperature and dry conditions, and its surface lattice oxygen can promote the decomposition of ozone molecules. However, when the ambient humidity increases, water molecules are adsorbed on the NiO surface in large quantities, which not only hinders the contact between ozone molecules and active sites, but may also cause hydration reactions of active components, resulting in a significant decrease in catalytic efficiency. Therefore, the development of NiO-based composite materials with both high catalytic activity and excellent moisture resistance is the key to catalytic degradation of ozone pollution. Summary of the Invention
[0005] To solve the above problems, the present invention provides a preparation method of a MIL-88B(Fe)-encapsulated NiO nanoparticle composite material and its application in ozone degradation performance research.
[0006] The technical solution adopted by the present invention is: a method for preparing a MIL-88B (Fe) encapsulated NiO nanoparticle composite material, comprising the following steps:
[0007] 1) Dissolving a nickel-based compound and urea CO(NH2)2 in deionized water and ultrasonicating the solution to obtain a homogeneous green solution as a NiO metal oxide precursor;
[0008] 2) mixing terephthalic acid H2BDC and sodium hydroxide solution in DMF solvent, adding FeCl3·6H2O after thorough stirring, sonicating, reacting, and centrifuging and washing after the reaction to obtain MIL-88B(Fe);
[0009] 3) The MIL-88B(Fe) material is added to a hydrophobic solvent and ultrasonically dispersed, and then the NiO metal oxide precursor solution is slowly injected into the continuously stirred MIL-88B(Fe) suspension system, and vigorous stirring is performed to promote uniform bonding;
[0010] 4) filtering to remove the organic solvent, collecting the solid product and performing heat treatment to obtain a NiO@MIL-88B(Fe) composite material.
[0011] In the above preparation method, in step 1), the nickel-based compound is Ni(NO3)2·6H2O, and the mass ratio of Ni(NO3)2·6H2O to urea is 1:1.
[0012] In the above preparation method, in step 2), the molar ratio of terephthalic acid H2BDC to FeCl3·6H2O is 1:1.
[0013] In the above preparation method, in step 2), the reaction is carried out in an autoclave at 100° C. for 12 hours.
[0014] In the above preparation method, in step 2), the hydrophobic solvent is n-hexane.
[0015] In the above preparation method, in step 3), the slow injection speed is 10 μL / min.
[0016] In the above preparation method, in step 4), the heat treatment is performed at 200° C. for 30 minutes.
[0017] The application of the MIL-88B (Fe) encapsulated NiO nanoparticle composite material prepared by the above preparation method in catalytic ozone decomposition.
[0018] The above application method is as follows: the NiO@MIL-88B(Fe) composite material is mixed with quartz sand and then ground, and ozone is introduced to decompose the ozone.
[0019] In the above application, the relative humidity during ozone decomposition is 30-70% and the temperature is 40°C.
[0020] The beneficial effects of the present invention are:
[0021] 1. The NiO@MIL-88B(Fe) composite catalytic material prepared by the present invention has the following characteristics: a) MIL-88B(Fe), a metal-organic framework (MOF) material with excellent thermal and chemical stability, serves as a carrier for encapsulating NiO nanoparticles, and its unique octahedral and tetrahedral structures are completely preserved throughout the preparation process; b) NiO nanoparticles are uniformly embedded in the pore network of MIL-88B(Fe) through the synergistic effect of polar and non-polar solvents in the solvothermal method, avoiding disordered accumulation on the surface of the material; c) MIL-88B(Fe) encapsulation of NiO nanoparticles enables the composite material to maintain a high specific surface area and rich pore structure, thereby providing sufficient active sites and mass transfer channels for the catalytic reaction.
[0022] 2. Preparation method of the present invention The preparation method of the present invention is simple to operate, recyclable and operates under mild conditions.
[0023] 3. The NiO@MIL-88B(Fe) composite catalytic material prepared by the present invention can effectively solve the problems of poor activity, weak moisture resistance and short service life of nickel oxide in ozone decomposition catalysis. At the same time, the NiO@MIL-88B(Fe) of the present invention achieves almost 100% ozone degradation efficiency in a high humidity environment, realizing the control of ozone pollution under actual environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 3. It is the infrared spectra of NiO, MIL-88B(Fe) and NiO@MIL-88B(Fe) composite materials prepared in Example 1.
[0025] Figure 2 Graph showing the ozone decomposition rates of NiO, MIL-88B(Fe) and NiO@MIL-88B(Fe) composite materials prepared in Example 1 at 40° C. and 50% RH.
[0026] Figure 3 This is a graph showing the ozone decomposition rate of the NiO@MIL-88B(Fe) composite material prepared in Example 1 under switching conditions of 30% RH and 70% RH.
[0027] Figure 4 is the PXRD pattern of 10% NiO@MIL-88B(Fe) prepared in Example 1 after exposure to ozone. DETAILED DESCRIPTION
[0028] To clarify the purpose, technical solutions and advantages of the present invention, the following will describe the technical solutions in the embodiments of the present invention in more detail in conjunction with the preferred embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of them.
[0029] Example 1
[0030] A method for preparing a MIL-88B (Fe)-encapsulated NiO nanoparticle composite material comprises the following steps:
[0031] 1) Dissolve 600 mg of Ni(NO3)2·6H2O and 600 mg of urea (CO(NH2)2) in 1 mL of deionized water and ultrasonicate for 5 minutes to obtain a homogeneous green solution as a NiO metal precursor.
[0032] 2) 166 mg of phthalic acid (H2BDC) and 32 mg of sodium hydroxide solution were mixed in 5 mL of DMF solvent, stirred thoroughly, and then 270 mg of FeCl3·6H2O was added. The mixture was ultrasonically treated for 10 minutes and then reacted in an autoclave at 100°C for 12 hours. After the reaction, the mixture was centrifuged and washed several times with DMF and ethanol to obtain MIL-88B(Fe).
[0033] 3) 100 mg of pre-synthesized MIL-88B(Fe) material was added to 20 mL of n-hexane and ultrasonically dispersed for 10 minutes. Then, 100 μL of NiO metal precursor solution was slowly injected into the continuously stirred MIL-88B(Fe) suspension system at a rate of 10 μL / min, and vigorous stirring was maintained for 3 hours to promote uniform combination of components.
[0034] 4) After removing the organic solvent by filtration, the collected solid product was heat treated at 200°C for 30 minutes to successfully prepare the NiO@MIL-88B(Fe) composite catalytic material.
[0035] Figure 1 The infrared spectra of NiO, MIL-88B(Fe) and NiO@MIL-88B(Fe) composite materials prepared in Example 1 were obtained using a Fourier transform infrared spectrometer manufactured by Thermo Fisher Scientific. The instrument has high resolution and sensitivity and can quickly and accurately obtain infrared spectral information of the samples.
[0036] Depend on Figure 1 It can be seen that MIL-88B(Fe) at 1633cm -1 There is an obvious peak at the wave number of 750cm, which is caused by the stretching vibration of C=O in -COOH, indicating that the -COOH in the ligand H2BDC has completely removed the proton to -COO-; -1 Out-of-plane bending vibration of the CH ring in the terephthalic acid ligand; 582 cm-1 The absorption peak at the center is characteristic of NiO. Comparison of the infrared spectra of MIL-88B(Fe) and its composite material reveals essentially identical spectral characteristics, indicating that the introduction of NiO and subsequent heat treatment did not alter the functional group composition of the support material. Due to the low NiO loading, no significant NiO signature was detected in the infrared spectrum of the composite sample. This confirms that the target materials were successfully prepared.
[0037] Example 2 Evaluation of the catalytic ozone decomposition performance of NiO@MIL-88B(Fe) composite materials
[0038] The experiment used an ozone catalytic performance test system to evaluate the ozone degradation efficiency of NiO, MIL-88B(Fe), and NiO@MIL-88B(Fe) composite materials. The performance of the catalyst in degrading ozone was evaluated by the ozone decomposition rate. The specific operation was as follows: 50mg of NiO@MIL-88B(Fe) catalyst and 450mg of quartz sand were accurately weighed to obtain 10% NiO@MIL-88B(Fe), and then uniformly ground in an agate mortar. It was added to a U-shaped reaction tube with an inner diameter of 6mm. The ozone detection device model was Model 202 (2B Technology), and the specific test conditions were: an ozone inlet airflow rate of 1L / min, a relative humidity of 30-70%, a test temperature of 40°C, and an ozone concentration of 20ppm.
[0039] Figure 2 Graph showing the ozone decomposition rates of NiO, MIL-88B(Fe) and 10% NiO@MIL-88B(Fe) composite materials prepared in Example 1 at 40°C and 50% RH.
[0040] Depend on Figure 2 It can be seen that NiO has a high ozone decomposition rate at the beginning, and its decomposition rate drops significantly after about 4 hours, eventually dropping to about 40%. The ability to decompose ozone gradually weakens, which may be due to the insufficient desorption capacity of intermediate oxygen species at the active sites, causing the active sites to be gradually occupied. The decomposition rate of MIL-88B (Fe) is close to 100% at the beginning, and the decomposition rate reaches about 89% after 3 hours. The decomposition rate of 10% NiO@MIL-88B (Fe) remains at a high level of 100% throughout the 0-10 hour period, showing good activity and stability. The NiO@MIL-88B (Fe) composite material composite catalytic material of the present invention can decompose ozone efficiently and stably over a long period of time, and encapsulating NiO in MOF can significantly improve the catalytic performance of both.
[0041] Figure 3 Figure 1 is the ozone decomposition rate diagram of the NiO@MIL-88B(Fe) composite material prepared in Example 1 under 30% RH and 70% RH switching. Figure 3 It can be seen that from 0 to 20 hours, the NiO@MIL-88B(Fe) switched between 30% RH and 70% RH every 5 hours, and the ozone decomposition rate remained stable at 100%. There was no decrease in the decomposition rate over a long period of time. This shows that the 10% NiO@MIL-88B(Fe) composite material has good stability and adaptability in terms of ozone decomposition performance.
[0042] Example 3 Stability Analysis of NiO@MIL-88B(Fe)
[0043] Figure 4 This is the PXRD pattern of 10% NiO@MIL-88B(Fe) after ozone exposure prepared in Example 1. The test instrument is Advance D8 from Bruker, Germany, using a Cu target and scanning in the 2theta range of 5-40°. Figure 4 It can be seen that after exposure to 20ppm ozone, the NiO@MIL-88B(Fe) maintained a PXRD pattern that was almost identical to the initial sample. The absence of diffraction peaks from the NiO crystal planes in the PXRD pattern indicates that the NiO is encapsulated within the pores of the MIL-88B(Fe), forming nanoscale particles that do not generate diffraction patterns that can be captured by PXRD. These results demonstrate that NiO@MIL-88B(Fe) possesses excellent structural stability under the test conditions.
[0044] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. A method for preparing a MIL-88B (Fe) encapsulated NiO nanoparticle composite material, characterized in that: The steps include: 1) Dissolving a nickel-based compound and urea CO(NH2)2 in deionized water and ultrasonicating the solution to obtain a homogeneous green solution as a NiO metal oxide precursor; 2) mixing terephthalic acid H2BDC and sodium hydroxide solution in DMF solvent, adding FeCl3·6H2O after thorough stirring, sonicating, reacting, and centrifuging and washing after the reaction to obtain MIL-88B(Fe); 3) The MIL-88B(Fe) material is added to a hydrophobic solvent and ultrasonically dispersed, and then the NiO metal oxide precursor solution is slowly injected into the continuously stirred MIL-88B(Fe) suspension system, and vigorous stirring is performed to promote uniform bonding; 4) filtering to remove the organic solvent, collecting the solid product and performing heat treatment to obtain a NiO@MIL-88B(Fe) composite material.
2. The preparation method according to claim 1, wherein in step 1), the nickel-based compound is Ni(NO3)2·6H2O, and the mass ratio of Ni(NO3)2·6H2O to urea is 1:
1.
3. The preparation method according to claim 1, wherein in step 2), the molar ratio of terephthalic acid H2BDC to FeCl3·6H2O is 1:
1.
4. The preparation method according to claim 1, wherein in step 2), the reaction is carried out in an autoclave at 100°C for 12 hours. The preparation method according to claim 1 , wherein in step 2), the hydrophobic solvent is n-hexane. 6 . The preparation method according to claim 1 , wherein in step 3), the speed of the slow injection is 10 μL / min.
7. The preparation method according to claim 1, wherein in step 4), the heat treatment is performed at 200°C for 30 minutes.
8. Use of the MIL-88B(Fe)-encapsulated NiO nanoparticle composite material prepared by the preparation method according to any one of claims 1 to 7 in catalytic ozone decomposition.
9. The use according to claim 8, characterized in that The method is as follows: the NiO@MIL-88B(Fe) composite material is mixed with quartz sand and then ground, and ozone is introduced to decompose the ozone.
10. The use according to claim 9, characterized in that The relative humidity during ozone decomposition is 30-70% and the temperature is 40°C.