A MOFs material for adsorption of phenylurea herbicides and its preparation and application

Abstract

The present invention belongs to the technical field of metal-organic framework materials, and discloses an MOF material for adsorbing phenylurea herbicides, its preparation and application. The chemical formula of the MOF material is [CuL2(TiF6)]·8H2O, where L is the ligand bipyridylthiol; among them, each Cu 2+ is coordinated with the nitrogen atoms on four different bipyridylthiols in the circumferential direction, and its two axial ends are respectively coordinated with two different TiF6 2‑ to form a two-dimensional MOF layer containing one-dimensional wavy interlayer channels; adjacent two-dimensional MOF layers are stacked with each other through multiple hydrogen bonds between guest water molecules and F atoms on TiF6 2‑ to form a flexible three-dimensional structure. Moreover, the MOF material of the present invention can adjust its pore size by regulating the length of the ligand and the size of the anion column, and combines the F on TiF6 2‑ to form hydrogen bonds with phenylurea herbicides to achieve high-selectivity enrichment of phenylurea herbicides in traditional Chinese medicine.

Description

Technical Field

[0001] The present invention relates to the technical field of metal organic framework materials, and in particular to a MOFs material for adsorbing phenylurea herbicides and a preparation method and application thereof. Background Art

[0002] Phenylurea pesticides are a common herbicide and are widely used in agricultural fields around the world, such as weed control in fruits, crops, and Chinese herbal medicines. Due to their ecotoxicity, the widespread use of phenylurea herbicides also has an adverse effect on soil pollution, thus causing direct or indirect pollution of fruits, vegetables, and Chinese herbal medicines. In order to most effectively determine and evaluate the negative impact of phenylurea drugs on human health and ecological environmental systems, it is necessary to adsorb and extract herbicide residue pollution from the sample matrix. It is reported that there are currently several methods for the extraction and detection of phenylurea herbicide residues, such as extraction (QuEChERS), SPE, liquid-liquid microextraction (LLME), and dispersed liquid-liquid microextraction (DLLME). However, these methods have some disadvantages, such as consuming a large amount of sample, adsorbent, and organic solvent, long extraction time, and the use of toxic reagents. In addition, these methods have serious matrix effects, low extraction efficiency, high detection limit, and poor recovery and selectivity. Due to these limitations, it is necessary to develop a new material for the enrichment of phenylurea herbicides that is convenient, fast, effective, and sensitive.

[0003] The inventors considered that metal organic frameworks (MOFs) are a class of highly promising ordered porous materials assembled from metal ions and organic ligands. They are widely used in catalysis, gas storage / capture, drug delivery and sensors. Due to their inorganic-organic composition and high porosity, MOFs show good adsorption affinity and adsorption capacity for many compounds through various interactions (such as π-π stacking, hydrogen bonding, coordination bonding, van der Waals bonding and electrostatic interactions).

[0004] To this end, the present invention uses titanium hexafluoride as anion and bipyridyl sulfide as ligand to prepare a metal organic framework material constructed by titanium hexafluoride, which is used for highly selective enrichment of phenylurea herbicides in traditional Chinese medicine. Summary of the invention

[0005] The present invention provides a MOFs material for adsorption of phenylurea herbicides and its preparation and application. The present invention can precisely regulate the specific recognition performance of the MOFs material by changing the anion column and the organic ligand, thereby achieving selective separation and enrichment of the target. By regulating the length of the ligand and the size of the anion column, the optimal adsorption pore size of the phenylurea herbicide can be precisely adjusted, and the fluorine atoms on the titanium hexafluoride anion column form hydrogen bonds with the phenylurea herbicide to achieve high selective enrichment of the phenylurea herbicide in traditional Chinese medicine.

[0006] The MOFs material for adsorption of phenylurea herbicides of the present invention and its preparation and application are achieved by the following technical scheme:

[0007] The first object of the present invention is to provide a MOFs material for adsorption of phenylurea herbicides, the chemical formula of which is [CuL2(TiF6)]·8H2O;

[0008] Among them, Cu 2+ is a metal building block, L is a ligand bipyridine sulfide, TiF6 2- It is an organic connection column;

[0009] And in [CuL2(TiF6)]·8H2O, each Cu 2+ The circumferential direction of the pyridine is coordinated with the nitrogen of four different bipyridyl sulfurs, and the axial ends are respectively coordinated with two different TiF6 2- Coordination, forming a two-dimensional MOF layer with a one-dimensional wavy interlayer channel; and the adjacent two-dimensional MOF layers are connected by guest water molecules and TiF6 2- The multiple hydrogen bonds between the F atoms on the surface are stacked with each other to form a flexible and dynamic three-dimensional structure.

[0010] Furthermore, the pore size of the MOFs material for adsorption of phenylurea herbicides is 0.5-3.5 nm, and the pore volume is 0.08-0.6 cm 3 / g; specific surface area is 40~650m 2 / g.

[0011] The second object of the present invention is to provide a method for preparing the above-mentioned MOFs material for adsorption of phenylurea herbicides, comprising the following steps:

[0012] Step 1: Use Cu as a metal building block 2+ source, and TiF6 as an organic linker 2- The source water is used to prepare a building block solution for use;

[0013] Step 2: prepare bipyridyl sulfide into a ligand solution using an organic solvent, and add the prepared ligand solution dropwise into the building block solution, and allow the ligand in the ligand solution to fully react with the Cu in the building block solution. 2+ and TiF6 2- contact to construct the MOFs material for adsorbing phenylurea herbicides.

[0014] Furthermore, the Cu 2+ The source is copper tetrafluoroborate or copper nitrate;

[0015] The TiF6 2- The source is (NH4)2TiF6.

[0016] Furthermore, in the building element solution, TiF6 2- The concentration is 0.05~6.0mol / L;

[0017] And Cu 2+ With TiF6 2- The molar ratio is 1:1~6.

[0018] Furthermore, the volume ratio of the ligand solution to the building block solution is 1:0.5-6;

[0019] In the ligand solution, the concentration of bipyridyl sulfide is 0.05-8.0 mol / L.

[0020] Furthermore, in step 2, the organic solvent is any one of methanol, ethanol and acetonitrile.

[0021] Furthermore, the standing temperature is 15 to 35° C., and the standing time is 24 to 72 hours.

[0022] The third object of the present invention is to provide an application of the above-mentioned MOFs material for adsorbing phenylurea herbicides in selectively enriching phenylurea herbicides in traditional Chinese medicine.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention uses Cu 2+ As metal building blocks, bipyridyl sulfide as organic ligand, and TiF6 2- For organic connection columns, each Cu 2+ The circumferential direction of the pyridine is coordinated with the nitrogen of four different bipyridyl sulfurs, and the axial ends are respectively coordinated with two different TiF6 2- Coordination, forming a two-dimensional MOF layer with a one-dimensional wavy interlayer channel; and the adjacent two-dimensional MOF layers are connected by guest water molecules and TiF6 2- The multiple hydrogen bonds between the F atoms on the MOFs are stacked to form a flexible and dynamic three-dimensional structure, thereby obtaining the MOFs material for adsorbing phenylurea herbicides of the present invention, whose chemical formula is [CuL2(TiF6)]·8H2O, and whose pore diameter is 0.5-3.5nm and pore volume is 0.08-0.6cm 3 / g, and the specific surface area is 40~650m 2 / g.

[0025] The MOFs material for adsorption of phenylurea herbicides of the present invention can be precisely adjusted to the optimal pore size for adsorption of phenylurea herbicides by regulating the length of the ligand and the size of the anion column, and the fluorine atoms on the titanium hexafluoride anion column form hydrogen bonds with the phenylurea herbicides to achieve high-selective enrichment of phenylurea herbicides in traditional Chinese medicine. The MOFs material for adsorption of phenylurea herbicides of the present invention, i.e., [CuL2(TiF6)]·8H2O, can also be activated under a dynamic vacuum of 298K to remove guest water molecules. After desolventization, the guest-free CuL2(TiF6) shows a reduced interlayer space. When adsorbing phenylurea herbicides, due to the hydrogen bond interaction between the fluorine in the framework and the phenylurea herbicide molecules, the reduced interlayer space can be selectively opened by the phenylurea herbicide molecules, thereby achieving the purpose of highly selective enrichment of phenylurea herbicides.

[0026] The method comprises the following steps: preparing solutions of organic ligand bipyridyl sulfide, metal building blocks and organic connecting columns respectively, and then dropping the prepared ligand solution into the building block solution drop by drop, and allowing the ligand in the ligand solution to fully react with the Cu in the building block solution. 2+ and TiF6 2- Only when the metal building blocks and the organic connecting column are contacted with each other, the MOFs material for adsorbing phenylurea herbicides of the present invention can be successfully prepared, otherwise it cannot be obtained. For example, if bipyridyl sulfide is dissolved with a solvent together with a metal building block and an organic connecting column and then left to stand, the MOFs material for adsorbing phenylurea herbicides of the present invention cannot be obtained; and the MOFs material for adsorbing phenylurea herbicides of the present invention cannot be obtained by dropping the building block solution into the ligand solution.

[0027] The preparation method of the present invention is simple to operate, low in cost and high in efficiency. In addition, the consumption of solvents, adsorbents and organic solvents can be reduced, the extraction capacity can be improved, and the analysis speed can be accelerated while the sensitivity is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural diagram of the MOFs material for adsorption of phenylurea herbicides prepared in Example 1; wherein, Figure 1 a is a schematic diagram of the plane structure. Figure 1 b is a schematic diagram of the cross-sectional structure;

[0029] Figure 2 This is a physical picture of the MOFs material for adsorption of phenylurea herbicides prepared in Example 1;

[0030] Figure 3 This is a scanning electron microscope image of the MOFs material for adsorption of phenylurea herbicides prepared in Example 1;

[0031] Figure 4 This is the XRD pattern of the MOFs material for adsorption of phenylurea herbicides prepared in Example 1;

[0032] Figure 5 The N2 adsorption-desorption isotherm and CO2 adsorption-desorption isotherm of the MOFs material for adsorption of phenylurea herbicides prepared in Example 1;

[0033] Figure 6 This is a picture of a phenylurea herbicide standard product before adsorption by the MOFs material for phenylurea herbicide adsorption prepared in Example 1;

[0034] Figure 7 This is a picture of the standard product of phenylurea herbicides after adsorption by the MOFs material for phenylurea herbicide adsorption prepared in Example 1. DETAILED DESCRIPTION

[0035] This indicates that MOFs with appropriate pore sizes can separate phenylurea herbicides from the matrix in traditional Chinese medicine. Inspired by this, metal-organic framework materials constructed with titanium hexafluoride anion columns have good pore size and strong electrostatic interaction with inorganic anions. Solid-phase microextraction is used as an adsorbent to highly selectively enrich phenylurea herbicides in traditional Chinese medicine. The interaction between the strong recognition sites in the metal-organic framework materials constructed with titanium hexafluoride and phenylurea herbicides is used to further improve the selective adsorption capacity of phenylurea herbicides; a new method for accurate qualitative and quantitative analysis of phenylurea herbicides in traditional Chinese medicine is established using a high-performance liquid chromatography-mass spectrometry system.

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] The present invention provides a MOFs material for adsorbing phenylurea herbicides, and the preparation method thereof is as follows:

[0038] Step 1: Use Cu as a metal building block 2+ source, and TiF6 as an organic linker 2- The source water is used to prepare a building block solution for use;

[0039] It should be noted that the present invention uses copper tetrafluoroborate or copper nitrate as Cu 2+ source to provide Cu 2+ As a metal building block. In the present invention, ammonium titanium hexafluoride (NH4)2TiF6 is used as TiF6 2- Source to provide TiF6 2- As an organic linker.

[0040] Step 2: prepare bipyridyl sulfide into a ligand solution using an organic solvent, and add the prepared ligand solution dropwise into the building block solution, and allow the ligand in the ligand solution to fully react with the Cu in the building block solution. 2+ and TiF62- contacting to construct the MOFs material for adsorbing the phenylurea herbicide;

[0041] It should be noted that the present invention preferably uses bipyridyl sulfide as the organic ligand, and the organic solvent used to prepare the ligand solution of the present invention can be selected from any one of methanol, ethanol and acetonitrile.

[0042] The present invention particularly emphasizes that the organic ligand bipyridyl sulfur must be made into solutions with the metal building blocks and the organic connecting column and then mixed, so that the MOFs material for phenylurea herbicide adsorption of the present invention can be successfully prepared, otherwise it cannot be obtained. For example, if bipyridyl sulfur, the metal building blocks and the organic connecting column are dissolved together with a solvent and then left to stand, the MOFs material for phenylurea herbicide adsorption of the present invention cannot be obtained; and the MOFs material for phenylurea herbicide adsorption of the present invention cannot be obtained by dropping the building block solution into the ligand solution.

[0043] Example 1

[0044] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and the preparation method thereof is as follows:

[0045] Ammonium hexafluorotitanate (NH4)2TiF6 and copper tetrafluoroborate Cu(BF4)2 were dissolved in 1 mL of deionized water at a molar ratio of 1:1, wherein the ammonium hexafluorotitanate was 0.5 mol / L, and stirred at room temperature for 10 min to obtain a building block solution.

[0046] Dissolve bipyridyl sulfur in 2 mL of methanol to form a ligand solution with a bipyridyl sulfur concentration of 1.0 mmol / L; slowly add the ligand solution to the building block solution at a drop rate of 1 mL / min and let stand at room temperature for 48 hours. Filter the resulting mixed solution with suction, wash with methanol to remove impurities on the surface of the filter residue, and dry in an oven to obtain 0.065 g of the product with a yield of 67.0%.

[0047] In this embodiment, the building block solution and the ligand solution undergo self-assembly during standing to form [Cu(dps)2(TiF6)]·8H2O, and the reaction is shown in Formula I.

[0048]

[0049] Example 2

[0050] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and the preparation method thereof is as follows:

[0051] Copper tetrafluoroborate Cu(BF4)2 and ammonium hexafluorotitanate (NH4)2TiF6 were dissolved in 10 mL of deionized water at a molar ratio of 1:2, wherein the concentration of ammonium hexafluorosilicate was 2.0 mol / L, and stirred at room temperature for 10 min to obtain a building block solution.

[0052] Dissolve bipyridyl sulfur in 10 mL of methanol to form a ligand solution with a bipyridyl sulfur concentration of 4.0 mol / L; slowly add the ligand solution to the building block solution at a drop rate of 2 mL / min and let stand for 48 hours. Filter the obtained mixed solution with suction, wash with methanol to remove impurities on the surface of the filter residue, and dry in an oven to obtain 0.071 g of product with a yield of 68.0%.

[0053] Example 3

[0054] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 1 only in that:

[0055] In this embodiment, copper nitrate is used as the Cu metal building block. 2+ source.

[0056] Example 4

[0057] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 1 only in that:

[0058] In this embodiment, in the construction element solution, TiF6 2- The concentration is 0.05mol / L;

[0059] And Cu 2+ With TiF6 2- The molar ratio is 1:1.

[0060] Example 5

[0061] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 1 only in that:

[0062] In this embodiment, in the construction element solution, TiF6 2- The concentration is 6.0 mol / L;

[0063] And Cu 2+ With TiF6 2- The molar ratio is 1:6.

[0064] Example 6

[0065] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 1 only in that:

[0066] In this embodiment, the volume ratio of the ligand solution to the building block solution is 1:0.5;

[0067] And in the ligand solution, the concentration of bipyridyl sulfide is 0.05 mol / L.

[0068] Example 7

[0069] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 1 only in that:

[0070] In this embodiment, the volume ratio of the ligand solution to the building block solution is 1:6;

[0071] And in the ligand solution, the concentration of bipyridyl sulfide is 8.0 mol / L.

[0072] Example 8

[0073] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 1 only in that:

[0074] In step 2 of this embodiment, the organic solvent is ethanol.

[0075] Example 9

[0076] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 1 only in that:

[0077] In step 2 of this embodiment, the organic solvent is acetonitrile.

[0078] Example 10

[0079] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 8 only in that:

[0080] In step 2 of this embodiment, the volume ratio of the ligand solution to the building block solution is 1:6;

[0081] And in the ligand solution, the concentration of bipyridyl sulfide is 8.0 mol / L;

[0082] The MOFs prepared in this embodiment has a pore size of 1.5-3.5 nm and a pore volume of 0.6 cm 3 / g, and the specific surface area is 650m 2 / g.

[0083] Embodiment 11

[0084] This embodiment provides a MOFs material for adsorption of phenylurea herbicides, and its preparation method is different from that of Example 9 only in that:

[0085] In step 2 of this embodiment, the volume ratio of the ligand solution to the building block solution is 1:0.5;

[0086] And in the ligand solution, the concentration of bipyridyl sulfide is 0.05 mol / L;

[0087] According to the test, the pore size of the MOFs material prepared in this embodiment is 0.5-3.0 nm, and the pore volume is 0.05 cm 3 / g, and the specific surface area is 40m 2 / g.

[0088] Comparative Example 1

[0089] The difference between this comparative example and Example 1 is only that:

[0090] In this comparative example, a water solvent and an organic solvent were mixed according to the amounts used in Example 1, and bipyridyl sulfide, metal building blocks, and organic connecting columns were placed therein to dissolve and then allowed to stand.

[0091] In this comparative example, the MOFs material for adsorbing phenylurea herbicides of Example 1 was not obtained.

[0092] Comparative Example 2

[0093] The difference between this comparative example and Example 1 is only that:

[0094] In this comparative example, the building block solution was added dropwise to the ligand solution and then allowed to stand.

[0095] In this comparative example, the MOFs material for adsorbing phenylurea herbicides of Example 1 was not obtained.

[0096] Experimental Section

[0097] (I) Structural test

[0098] The present invention takes the MOFs material prepared in Example 1 as an example, and X-ray single crystal diffraction is used to test its single crystal structure, and the results are shown in Tables 1 and 2. Figure 1 shown.

[0099] The X-ray single crystal diffraction data were collected at 193(2)K on a Bruker-AXS D8 VENTURE diffractometer equipped with a PHOTON-100 / CMOS detector (GaKα, ). Indexing was performed using APEX2, and data integration and reduction were done using SaintPlus 6.01. Absorption correction was performed using the multiscan method implemented in SADABS, and space group determination was performed using XPREP in APEX2.1. The structure was solved using nonlinear least squares methods using F2 (Methods), which includes the SHELXL-97 (APEX2, OLEX2 v1.1.5, and WinGX v1.70.01) program package. The Squeeze program in Platon was used for the treatment of disordered solvent molecules.

[0100] Table 1 Crystal structure data of MOFs materials prepared in Example 1

[0101]

[0102]

[0103] In the table, a R1=Σ|F o -|F c || / Σ|F o |, b R w2 =[Σw(F o 2 -F c 2 )2 / Σw(F o 2 ) 2 ] 1 / 2 .

[0104] It can be seen from Table 1 that the chemical formula of the MOFs material for adsorption of phenylurea herbicides in Example 1 of the present invention is C 20 H 32 CuF6N4S2TiO8, that is [CuL2(TiF6)]·8H2O.

[0105] Figure 1 a is a schematic diagram of the planar structure of the MOFs material for adsorption of phenylurea herbicides in Example 1, Figure 1 b is a schematic diagram of the cross-sectional structure of the MOFs material for adsorption of phenylurea herbicides in Example 1, and is composed of Figure 1 a and Figure 1 b It can be seen that in the MOFs material for adsorption of phenylurea herbicides in Example 1, each Cu 2+ The circumferential direction of the pyridine is coordinated with the nitrogen of four different bipyridyl sulfurs, and the axial ends are respectively coordinated with two different TiF6 2- Coordination, forming a two-dimensional MOF layer with a one-dimensional wavy interlayer channel; and the adjacent two-dimensional MOF layers are connected by guest water molecules and TiF6 2-The multiple hydrogen bonds between the F atoms on the surface are stacked with each other to form a flexible and dynamic structure.

[0106] (II) Surface morphology test

[0107] The present invention takes the MOFs material for adsorption of phenylurea herbicides in Example 1 as an example, and the actual product photo obtained is as follows: Figure 2 shown.

[0108] Depend on Figure 2 It can be seen that the MOFs material for adsorbing phenylurea herbicides in Example 1 of the present invention is a purple powder.

[0109] The MOFs material for adsorption of phenylurea herbicides in Example 1, i.e. the purple powder material, was subjected to scanning electron microscopy testing, and the test results are as follows: Figure 3 shown by Figure 3 It can be seen that the MOFs material for adsorbing phenylurea herbicides in Example 1 is regular cubic particles.

[0110] (III) XRD test

[0111] The present invention takes the MOFs material for adsorption of phenylurea herbicides in Example 1 as an example, and performs XRD test on it, and the results are as follows: Figure 4 As shown, Figure 4 In the figure, the upper curve is the XRD curve of the product prepared in Example 1, and the lower curve is the standard XRD curve obtained by crystal structure simulation.

[0112] And by Figure 4 It can be seen that the XRD peak of the product and the XRD peak of the simulated standard curve can correspond well, indicating that the MOFs material for adsorption of phenylurea herbicides prepared by the present invention has high purity.

[0113] (IV) Pore structure test

[0114] The present invention takes the MOFs material for adsorption of phenylurea herbicides in Example 1 as an example, and tests its pore structure, and the characterization method is as follows:

[0115] Nitrogen and carbon dioxide adsorption isotherms of MOFs materials used to test the adsorption of phenylurea herbicides.

[0116] The test conditions are as follows: N2 gas adsorption and desorption isotherms were measured on ASAP 2460. The sample was degassed at room temperature for 24 hours before analysis to remove the guest molecules in the pores. The experimental temperature was maintained by liquid nitrogen, where the liquid nitrogen was 77K; CO2 gas adsorption and desorption isotherms were measured on ASAP 2460. The sample was degassed at room temperature for 24 hours before analysis to remove the guest molecules in the pores. The experimental temperature was maintained by dry ice-acetone, where the dry ice-acetone was 195K.

[0117] The N2 and CO2 adsorption and desorption isotherms of the MOFs material for phenylurea herbicide adsorption in Example 1 are as follows: Figure 5 shown by Figure 5 It can be seen that the surface area of ​​the MOFs material for adsorption of phenylurea herbicides in Example 1 calculated by CO2 adsorption is 52 m 2 / g, pore volume is 0.06cm 3 / g, and the pore size range is 0.5~3.5nm.

[0118] (V) Adsorption test of phenylurea herbicides

[0119] The present invention uses the MOFs material for adsorption of phenylurea herbicides of Example 1 as the adsorption material, and uses the phenylurea herbicides Fenuron, Monuron, Diuron, Linuron and Pencycuron as the adsorption objects.

[0120] The test instrument is AB Triple TOF 5600 mass spectrometer (AB Sciex). The specific test steps are as follows:

[0121] 15 mg of the MOFs material for phenylurea herbicide adsorption in Example 1 was accurately weighed using a 1 / 10,000 analytical balance (accurate to the fourth decimal place), and then placed in a 1.5 mL centrifuge tube containing 100 ng / ml of phenylurea herbicide standard and shaken for 30 min. Then, centrifuged for 10 min at a speed of 13000 r / min. The supernatant was filtered with a filter membrane and tested by ABTriple TOF 5600. The test results of the MOFs material for phenylurea herbicide adsorption in Example 1 are as follows: Figure 7 shown.

[0122] The control group data was obtained by filtering the membrane with the phenylurea herbicide standard which was not adsorbed by the MOFs material prepared in Example 1. Figure 6 shown.

[0123] By comparison Figure 6 and Figure 7 It can be seen that the MOFs material for adsorbing phenylurea herbicides in Example 1 of the present invention has a high enrichment capacity for the above five phenylurea herbicides, indicating that the MOFs material for adsorbing phenylurea herbicides provided by the present invention can highly selectively adsorb phenylurea herbicides from the traditional Chinese medicine extract and can be used as an enrichment material for phenylurea herbicides.

[0124] It should be noted that in the above embodiments, when conducting the phenylurea herbicide adsorption test, when the MOFs material of Example 1 is placed in the Chinese medicine extract to be enriched and shaken, the shaking speed is preferably 10 to 100 Hz; the stirring temperature is preferably 273K to 313K; and the mass concentration of urea herbicides in the Chinese medicine is preferably 10 ng / mL to 1 mg / mL.

[0125] Obviously, the above embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A MOFs material for adsorption of phenylurea herbicides, characterized in that: Its chemical formula is [CuL2(TiF6)]·8H2O; Among them, Cu 2+ is a metal building block, L is a ligand bipyridine sulfide, TiF6 2- It is an organic connection column; And in [CuL2(TiF6)]·8H2O, each Cu 2+ The circumferential direction of the pyridine is coordinated with the nitrogen of four different bipyridyl sulfurs, and the axial ends are respectively coordinated with two different TiF6 2- Coordination, forming a two-dimensional MOF layer with a one-dimensional wavy interlayer channel; and the adjacent two-dimensional MOF layers are connected by guest water molecules and TiF6 2- The multiple hydrogen bonds between the F atoms on the surface are stacked together to form a flexible three-dimensional structure; The pore size of the MOFs material for adsorption of phenylurea herbicides is 0.5-3.5 nm, and the pore volume is 0.05-0.6 cm 3 / g, and the specific surface area is 40~650m 2 / g.

2. A method for preparing the MOFs material for adsorption of phenylurea herbicides according to claim 1, characterized in that: The following steps are involved: Step 1: Cu as a metal building block 2+ source, and TiF6 as an organic linker 2- The source water is used to prepare a building block solution for use; Step 2: prepare bipyridyl sulfide into a ligand solution using an organic solvent, and add the prepared ligand solution dropwise into the building block solution, and allow the ligand in the ligand solution to fully react with the Cu in the building block solution. 2+ and TiF6 2- contact to construct the MOFs material for adsorbing phenylurea herbicides.

3. The preparation method according to claim 2, characterized in that: The Cu 2+ The source is copper tetrafluoroborate or copper nitrate; The TiF6 2- The source is (NH4)2TiF6.

4. The preparation method according to claim 2, characterized in that: In the building element solution, TiF6 2- The concentration is 0.05~6.0mol / L; And Cu 2+ With TiF6 2- The molar ratio is 1:1~6.

5. The preparation method according to claim 2, characterized in that: The volume ratio of the ligand solution to the building block solution is 1:0.5-6; In the ligand solution, the concentration of bipyridyl sulfide is 0.05-8.0 mol / L.

6. The preparation method according to claim 2, characterized in that: In step 2, the organic solvent is any one of methanol, ethanol and acetonitrile.

7. The preparation method according to claim 2, characterized in that: The standing temperature is 15-35° C., and the standing time is 24-72 hours.

8. Use of the MOFs material for adsorption of phenylurea herbicides according to claim 1 in selectively enriching phenylurea herbicides in traditional Chinese medicine.

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