阅读说明：本技术 一种uio-66@ma金属有机框架材料及其制备方法和应用 (UIO-66@ MA metal organic framework material and preparation method and application thereof ) 是由 张志娟 李雪 黄正旭 夏源韩 周振 于 2020-12-21 设计创作，主要内容包括：本发明提供了一种UIO-66@MA金属有机框架材料及其制备方法和应用,属于金属有机框架材料技术领域。本发明通过甲胺(MA)对UIO-66金属有机框架材料进行改性,使得甲胺中的氨基与UIO-66中的Zr～(4+)发生配位,得到负载甲胺的金属有机框架材料。本发明通过甲胺对UIO-66金属有机框架材料进行改性,所得得UIO-66@MA金属有机框架材料对己醛具有良好的选择性荧光检测能力和低检测限,且抗干扰能力强。实施例结果表明,本发明提供的UIO-66@MA金属有机框架材料对己醛的检测限可以低至0.815×10～2ppm。(The invention provides a UIO-66@ MA metal organic framework material and a preparation method and application thereof, belonging to the technical field of metal organic framework materials. The invention modifies UIO-66 metal organic framework material by Methylamine (MA), so that amino in methylamine and Zr in UIO-66 4+ And carrying out coordination to obtain the methylamine loaded metal organic framework material. The UIO-66 metal organic framework material is modified by methylamine, so that the obtained UIO-66@ MA metal organic framework material has good selective fluorescence detection capability and low detection limit on hexanal, and has strong anti-interference capability. The results of the examples show that the detection limit of the UIO-66@ MA metal organic framework material provided by the invention to hexanal can be as low as 0.815 multiplied by 10 2 ppm。)

1. A preparation method of [email protected] MA metal organic framework material comprises the following steps:

mixing the UIO-66 metal organic framework material with methylamine and an organic solvent, and carrying out a coordination reaction to obtain the [email protected] MA metal organic framework material.

2. The method of claim 1, wherein the UIO-66 metal-organic framework material has a mass to methylamine molar weight ratio of 1g (1.44 x 10)^-3～7.08×10^-3)mol。

3. The method according to claim 1, wherein the organic solvent is n-hexane and/or toluene.

4. The preparation method of claim 1 or 2, wherein the UIO-66 metal organic framework material has a mass to organic solvent volume ratio of 1g (100-120) mL.

5. The preparation method according to claim 1, wherein the temperature of the coordination reaction is 85 ℃ and the time is 12-24 h.

6. The [email protected] MA metal organic framework material prepared by the preparation method of any one of claims 1 to 5.

7. The [email protected] MA metal organic framework material as claimed in claim 6, wherein the BET specific surface area of the [email protected] MA metal organic framework material is 570-939 m²Per g, pore volume of

8. Use of the [email protected] MA metal organic framework material of claim 6 or 7 for the selective detection of hexanal.

Technical Field

The invention relates to the technical field of metal organic framework materials, in particular to a [email protected] MA metal organic framework material and a preparation method and application thereof.

Background

At present, among various factors causing environmental pollution and destruction, Volatile Organic Compounds (VOCs) have become an important source of air pollution, which is called one of three killers of air pollution today. Among the numerous VOCs pollutants, the aldehyde VOCs are pollutants with high harmfulness to human bodies, and the aldehyde VOCs have been listed as important environmental pollutants and hazards with potential carcinogenicity to human bodies by the world health organization. Hexanal, a characteristic aldehyde VOCs, causes respiratory tract injury after long-term inhalation into the human body, damages the immune system of the human body, and increases the incidence of pneumonia. However, the content of hexanal pollutants in the atmosphere is often extremely low, and is only 1-80 ppm, the detection limit of a common detection material on hexanal is high, and the common detection material cannot play an effective role in detecting low-concentration hexanal.

Disclosure of Invention

In view of the above, the invention aims to provide a [email protected] MA metal organic framework material, a preparation method and an application thereof, wherein the [email protected] MA metal organic framework material has selective fluorescence detection capability on hexanal and is low in detection limit.

In order to achieve the purpose of the invention, the invention provides the following technical scheme:

the invention provides a preparation method of a [email protected] MA metal organic framework material, which comprises the following steps:

mixing the UIO-66 metal organic framework material with methylamine and an organic solvent, and carrying out a coordination reaction to obtain the [email protected] MA metal organic framework material.

Preferably, the ratio of the mass of the UIO-66 metal-organic framework material to the molar weight of methylamine is 1g (1.44X 10)^-3～7.08×10^-3)mol。

Preferably, the organic solvent is n-hexane and/or toluene.

Preferably, the volume ratio of the mass of the UIO-66 metal organic framework material to the volume of the organic solvent is 1g (100-120) mL.

Preferably, the temperature of the coordination reaction is 85 ℃, and the time is 12-24 h.

The invention provides a [email protected] MA metal organic framework material prepared by the preparation method.

Preferably, the BET specific surface area of the [email protected] MA metal organic framework material is 570-939 m²Per g, pore volume of

The invention provides an application of the [email protected] MA metal organic framework material in selective hexanal detection.

The invention provides a [email protected] MA metal organic framework material and a preparation method and application thereof. The invention modifies UIO-66 metal organic framework material by Methylamine (MA), so that amino in methylamine and Zr in UIO-66⁴⁺And carrying out coordination to obtain the methylamine loaded metal organic framework material. The UIO-66 metal organic framework material is modified by methylamine, so that the [email protected] MA metal organic framework material has good selective fluorescence detection capability and low detection limit on hexanal, and has strong anti-interference capability. The results of the examples show that the detection limit of the [email protected] MA metal organic framework material provided by the invention to hexanal can be as low as 0.815 multiplied by 10²ppm。

Meanwhile, the [email protected] MA metal organic framework material provided by the invention also has the advantages of good thermal stability, good chemical stability and capability of being recycled for multiple times.

The invention provides a preparation method of a [email protected] MA metal organic framework material, which is a one-step reaction, is simple to operate and is suitable for industrial batch production.

Drawings

FIG. 1 shows N of UIO-66, UIO-66-MA1, UIO-66-MA2, UIO-66-MA3 and UIO-66-MA4₂Adsorption-desorption isotherms;

FIG. 2 is an X-ray diffraction diagram of UIO-66, UIO-66-MA1, UIO-66-MA2, UIO-66-MA3 and UIO-66-MA 4;

FIG. 3 is a thermogravimetric analysis diagram of UIO-66, UIO-66-MA1, UIO-66-MA2, UIO-66-MA3 and UIO-66-MA 4;

FIG. 4 is an infrared spectrum of UIO-66, UIO-66-MA1, UIO-66-MA2, UIO-66-MA3 and UIO-66-MA 4;

FIG. 5 is a fluorescence emission spectrum of UIO-66-MA1 after fluorescence sensing of hexanal at various concentrations;

FIG. 6 is a graph of fluorescence intensity of UIO-66-MA1 after fluorescence sensing of different VOCs.

Detailed Description

The invention provides a preparation method of the [email protected] MA metal organic framework material, which comprises the following steps:

and mixing the UIO-66 metal organic framework material with an organic solvent, and carrying out a coordination reaction to obtain the [email protected] MA metal organic framework material.

The preparation method of the UIO-66 metal organic framework material is not particularly limited, and the UIO-66 metal organic framework material can be prepared by adopting a scheme well known to a person skilled in the art. In an embodiment of the present invention, the method for preparing the UIO-66 metal-organic framework material preferably comprises:

mixing terephthalic acid, zirconium chloride and an organic solvent, and carrying out a solvothermal reaction to obtain the UIO-66 metal organic framework material.

Terephthalic acid, zirconium chloride and a polar organic solvent are mixed for solvothermal reaction to obtain the UIO-66 metal organic framework material. In the present invention, the molar ratio of terephthalic acid to zirconium chloride is preferably 0.5 to 3, and more preferably 1 to 2. In the present invention, the polar organic solvent is preferably N, N-dimethylformamide and/or N, N-diethylformamide; the ratio of the molar amount of terephthalic acid to the volume of the polar organic solvent is preferably 1 mmol: (40-50) mL. The invention does not require any particular mixing means, such as stirring, known to the person skilled in the art.

The solvent thermal reaction is preferably carried out in a polytetrafluoroethylene reaction kettle. In the invention, the temperature of the solvothermal reaction is preferably 120 ℃, and the time is preferably 18-30 h, and more preferably 20-24 h. In the invention, the reaction formula of the solvothermal reaction is shown as formula a:

6ZrCl₄+6C₈H₆O₄+HCON(CH₃)₂→C₄₈H₂₈O₃₂Zr₆+HCON(CH₃)₂formula (a).

After the solvothermal reaction, the method preferably carries out post-treatment on the obtained solvothermal reaction liquid to obtain the UIO-66 metal organic framework material. The post-treatment preferably comprises the steps of:

and sequentially filtering, washing with an organic solvent and drying the solvothermal reaction solution to obtain a solid of the UIO-66 metal organic framework material.

The present invention has no special requirement on the filtration mode, and the filtration mode known to those skilled in the art can be used, such as suction filtration. After the suction filtration, the filter residue is washed, and in the invention, the washing preferably comprises N' N-dimethylformamide washing and trichloromethane washing which are sequentially carried out. In the invention, the N' N-dimethylformamide washing mode is preferably soaking washing, and the soaking time of a single washing is preferably 20 h; the number of washing with N' N-dimethylformamide is preferably 3. In the invention, the chloroform washing mode is preferably soaking washing, and the time of soaking in single washing is preferably 20 h; the number of the chloroform washings is preferably 3. The invention removes the residual terephthalic acid in the pore structure of the UIO-66 metal organic framework material by the washing. In the invention, the drying temperature is preferably 150-200 ℃, and the drying time is preferably 8-12 h. In the present invention, the solid UIO-66 metal organic framework material is white crystal.

After the UIO-66 metal organic framework material is obtained, the UIO-66 metal organic framework material is mixed with methylamine and an organic solvent for carrying out coordination reaction to obtain the [email protected] MA metal organic framework material. In the present invention, the organic solvent is preferably n-hexane and/or toluene. In the present invention, the ratio of the mass of the UIO-66 metal-organic framework material to the molar weight of methylamine is preferably 1g (1.44X 10)^-3～7.08×10^-3) mol, more preferably 1g of (3X 10)^-3～5×10^-3) And (mol). In the present invention, the UIO-66 metal organicThe volume ratio of the mass of the frame material to the organic solvent is preferably 1g (100-120) mL, more preferably 1g: 120 mL. The present invention does not require any particular mixing means, and mixing means known to those skilled in the art may be used.

In the invention, the temperature of the coordination reaction is 85 ℃, and the time is 12-24 h, and more preferably 16-20 h. According to the invention, the coordination reaction is preferably carried out under the condition of stirring, and the stirring speed is preferably 200-350 rpm.

After the coordination reaction, the invention preferably carries out post-treatment on the obtained coordination reaction liquid to obtain the [email protected] MA metal organic framework material. The post-treatment preferably comprises the steps of:

and sequentially filtering, washing and drying the coordination reaction liquid to obtain a solid of the [email protected] MA metal organic framework material. The present invention has no special requirement on the filtration mode, and the filtration mode known to those skilled in the art can be used, such as suction filtration. After the suction filtration, washing filter residues after the suction filtration, wherein the washing detergent is preferably n-hexane; the invention does not require any particular type of washing, as is known to the person skilled in the art, such as rinsing. In the invention, the drying temperature is preferably 100-120 ℃, more preferably 110 ℃, and the time is preferably 8-12 h, more preferably 9-10 h.

The invention provides a [email protected] MA metal organic framework material prepared by the preparation method. In the invention, the BET specific surface area of the [email protected] MA metal organic framework material is preferably 570-939 m²In terms of volume of pores,/g, preferablyIn the present invention, UIO-66 is a Zr-based metal-organic framework material having the chemical formula C₄₈H₂₈O₃₂Zr₆The UIO-66 metal organic framework material is modified by methylamine, so that the obtained [email protected] MA metal organic framework material has good selective fluorescence detection capability and low detection limit on hexanal, and is anti-interferenceThe capability is strong. Meanwhile, the [email protected] MA metal organic framework material has a microporous structure, is good in thermal stability and chemical stability, and can realize more than 5 times of cyclic regeneration.

The invention provides an application of the [email protected] MA metal organic framework material in the detection of hexanal. When the [email protected] MA metal organic framework material is used for detecting hexanal, the [email protected] MA metal organic framework material has good selective fluorescence detection capability and low detection limit, and the detection limit can be as low as 0.815 multiplied by 10²ppm, and has good anti-interference capability, when other volatile organic compounds except hexanal exist in the gas, the fluorescence intensity of the [email protected] MA is not interfered by other volatile organic compounds.

The following examples are provided to illustrate the [email protected] MA metal organic framework materials of the present invention and the methods of preparation and use thereof, but should not be construed as limiting the scope of the invention.

Example 1

0.285g of zirconium chloride (ZrCl)₄1.223mmol), 0.2030g of terephthalic acid (C)₈H₆O₄1.222mmoL) and 50mL of DMF are put into a 100mL polytetrafluoroethylene reaction kettle, uniformly shaken and mixed, subjected to solvothermal reaction at 120 ℃ for 24 hours, naturally cooled to room temperature, taken out and subjected to suction filtration, the obtained solid is immersed in 50mL of DMF, subjected to suction filtration after 20 hours, repeated for three times, immersed in 50mL of trichloromethane again and repeated for three times. Then, the obtained product is filtered by suction and dried in a vacuum drying oven for 10 hours at the temperature of 200 ℃ to obtain white UIO-66.

Accurately weighing 0.5g of UIO-66 into a 100mL single-hole flask, adding 60mL of n-hexane, dropwise adding 0.72mol of Methylamine (MA), reacting at 85 ℃ under the stirring of 320rpm for 12h, cooling, carrying out suction filtration, washing with n-hexane, and finally drying at 110 ℃ for 12h to obtain the [email protected] MA metal organic framework material which is marked as UIO-66-MA 1.

Example 2

Example 2 differs from example 1 in that methylamine is added in an amount of 0.96mol and the resulting [email protected] MA metal organic framework material, designated UIO-66-MA 2.

Example 3

Example 3 differs from example 1 in that methylamine is added in an amount of 1.44mol and the resulting [email protected] MA metal organic framework material, designated UIO-66-MA 3.

Example 4

Example 4 differs from example 1 in that methylamine is added in an amount of 3.54mol and the resulting [email protected] MA metal organic framework material, designated UIO-66-MA 4.

Performance testing

(one) N-addition of UIO-66, UIO-66-MA1, UIO-66-MA2, UIO-66-MA3 and UIO-66-MA4 at 77K₂Adsorption-desorption test, resulting in N₂The adsorption-desorption isotherms are shown in figure 1. As can be seen in FIG. 1, both the UIO-66 and [email protected] MA metal organic framework materials are type I isotherms, indicating that these samples are predominantly microporous in structure with the pore structure parameters shown in Table 1.

Table 1 UIO-66 and the pore structure parameters of [email protected] MA obtained in examples 1 to 4

As can be seen from Table 1, the BET specific surface area, Langmuir specific surface area, micropore volume and total pore volume of the modified [email protected] MA material all gradually decreased with increasing methylamine addition concentration, and they were all smaller than the UIO-66 matrix framework, and their size order was: UIO-66> UIO-66-MA1> UIO-66-MA2> UIO-66-MA3> UIO-66-MA 4. Furthermore, as the concentration of the modifying agent increases, the average pore size increases, in order of their size: UIO-66-MA4> UIO-66-MA3> UIO-66-MA2> UIO-66-MA1> UIO-66. The reason for the increase in the average pore size may be due to a slight decrease in crystallinity of the material after modification, and as the concentration of methylamine increases, some pore-enlarging effect of methylamine on the material exists.

(II) subjecting UIO-66, UIO-66-MA1, UIO-66-MA2, UIO-66-MA3 and UIO-66-MA4 to polycrystalline X-ray diffraction (PXRD) analysis, wherein the X-ray diffraction pattern is shown in FIG. 2. Simlated in FIG. 2 is an analogous UIO-66 structure. As can be seen from FIG. 2, the present invention successfully synthesized UIO-66 metal organic framework materials; the position of a PXRD spectrogram of the [email protected] MA material modified by methylamine is basically consistent with that of the UIO-66 without obvious displacement, which shows that the crystal form of the modified [email protected] MA material is not changed and the topological structure is basically maintained.

(III) carrying out thermogravimetric analysis on the UIO-66, the UIO-66-MA1, the UIO-66-MA2, the UIO-66-MA3 and the UIO-66-MA4, wherein the thermogravimetric analysis chart is shown in FIG. 3. As can be seen from FIG. 3, the mass loss of UIO-66 and [email protected] MA is mainly divided into three stages, the first stage is about 120 ℃ from room temperature, the second stage is about 120-500 ℃, and the third stage is more than 500 ℃. As can be seen from the figure, the first stage is mainly the removal of free water molecules, and after modification, the percentage of the sample remaining after the water molecules are lost in the first stage is all larger than that of the original UIO-66, which shows that the guest water molecules are reduced after modification. ② for the original UIO-66 and [email protected] MA material, the second stage is mainly the removal of guest molecule. Third stage of collapse of crystal frame and decomposition into ZrO₂. In general, the thermal stability of the material remained essentially unchanged after introduction of methylamine within the UIO-66 material.

(IV) carrying out infrared spectrum analysis on the UIO-66, the UIO-66-MA1, the UIO-66-MA2, the UIO-66-MA3 and the UIO-66-MA4 to obtain an infrared spectrum diagram as shown in figure 4, wherein (a) and (b) in figure 4 respectively represent stretching vibration peaks in different wavelength ranges. As can be seen from (a) in FIG. 4, the original UIO-66 sample ranges from 3200 to 3400cm^-1Within this range is the associated-OH stretching vibration peak, the peak position shifts after methylamine modification, but still within this range, which is associated with the formation of a new-NH stretching vibration peak. As can be seen from (b) in FIG. 4, the thickness of the modified methylamine is 2800-3000 cm^-1A new C-H stretching vibration peak appears in the range. The original UIO-66 was 1259cm^-1No peak exists at the wavelength, and a new-CN stretching vibration peak appears after methylamine modification. The invention has been successfully achieved with [email protected] MA metal organic framework materials.

(V) use 0.815 × 10 respectively²ppm、1.223×10²ppm、1.630×10²ppm、2.038×10²ppm、2.445×10²ppm、3.260×10²ppm、4.075×10²ppm、6.520×10²ppm、0.815×10³ppm、1.002×10³ppm、5.008×10³ppm、1×10⁴ppm、5×10⁴ppm and 1X 10⁵ppm hexanal was used to test the fluorescence of UIO-66-MA1 from example 1 using a fluorescence spectrometer, and the resulting fluorescence emission spectrum is shown in FIG. 5. As can be seen from FIG. 5, as the hexanal concentration increases, the emission intensity at the optimal emission position decreases sequentially, the optimal emission peak position remains substantially unchanged at 405nm, wherein the hexanal concentration corresponding to the fluorescence curve at 405nm is 1.630X 10 from top to bottom sequentially²ppm、0.815×10²ppm、1.223×10²ppm、2.038×10²ppm、2.445×10²ppm、3.260×10²ppm、4.075×10²ppm、6.520×10²ppm、0.815×10³ppm、1.002×10³ppm、5.008×10³ppm、1×10⁴ppm、5×10⁴ppm and 1X 10⁵ppm (wt.%). The [email protected] MA metal organic framework material obtained by the invention is shown to have a hexanal concentration of 0.815 x 10²The fluorescence response is better at ppm.

(VI) the fluorescence of UIO-66-MA1 of example 1 was tested using ethylbenzene, 1-propanol, isoprene and hexanal alone and hexanal + ethylbenzene, hexanal + 1-propanol, hexanal + styrene, hexanal + isoprene, ethylbenzene + isoprene and ethylbenzene + 1-propanol in combination, and the results are shown in FIG. 6. As can be seen from FIG. 6, the [email protected] MA metal organic framework material has good selectivity for hexanal, and the fluorescence intensity is not substantially interfered by other components.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.