Amidoxime group modified graphdiyne material as well as preparation method and application thereof
By introducing a terephthaloxime group onto graphyne material, and combining the interaction between π electrons and metal atoms with the pore confinement effect, the problem of poor selectivity of existing materials was solved, and efficient separation and extraction of uranium and vanadium were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2026-03-10
AI Technical Summary
Existing amine oxime materials have poor selectivity for uranium and vanadium, making it difficult to achieve efficient separation of uranium and vanadium from seawater. Furthermore, ordinary adsorbent materials are not effective in extracting uranium from natural seawater.
A methylamine oxime group was introduced into graphyne material by chemical modification. The interaction between the π electrons of graphyne and the metal atoms, as well as the confinement effect of the pores composed of 18 carbon atoms, combined with the affinity of the methylamine oxime group, methylamine oxime modified graphyne material was prepared.
It achieves efficient adsorption and selective extraction of uranium, and efficient separation of uranium and vanadium, especially with a U/V ratio of 69.3 in simulated seawater and 15.0 in natural seawater, which significantly improves the selectivity and adsorption capacity of the material.
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Figure CN121623747A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional materials technology, and relates to a chromamine oxime-modified graphyne material, its preparation method and application; specifically, it relates to the application of chromamine oxime-modified graphyne material in seawater uranium extraction and uranium-vanadium element separation. Background Technology
[0002] Seawater contains vast reserves of uranium; however, efficient extraction from seawater with extremely low uranium concentrations (approximately 3.3 ppb) is extremely difficult. Therefore, improving the uranium ion adsorption selectivity of materials in seawater and shielding against numerous other interfering ions is of great significance for nuclear resource reserves.
[0003] Uranium is a strong electron acceptor, and electron-donating groups have a strong binding affinity to it. Graphdiyne contains sp-C atoms (-C≡CC≡C-), exhibiting electron-rich properties. Its π-electron system has strong interactions with metallic elements, thus facilitating the capture of uranium. Furthermore, the 18-carbon ring molecular channels of graphdiyne... Can react with UO2 in seawater 2+ Dimensions (axial diameter) The presence of Graphdiyne, a high-performance uranium extraction material, allows for selective uranium removal. Furthermore, U(VI), as a "hard" Lewis acid, tends to form complexes with "hard" Lewis bases, such as carboxyl groups containing oxygen and nitrogen donors, phosphates, phosphonates, amino groups, and amine oxime groups. The bonding electrons of the C=N double bond in a amine oxime group and the lone pair electrons on the O in NO make it easy to form stable chelates with uranium; therefore, amine oxime groups exhibit the strongest uranium selectivity among these groups. The -C≡C- and -C≡CH groups present in Graphdiyne can be chemically modified to graft desired functional groups, thereby achieving highly efficient adsorption of uranium.
[0004] Currently, there are reports on research into materials for uranium extraction from seawater. The most effective are poly(ammoxime) materials, such as poly(ammoxime) / graphene oxide composites (Liu T., Zhang R., Chen M., & Wang N. Adv. Funct. Mater. 2022, 32, 2111049); and poly(ammoxime) hydrogel materials (Yan B., Ma C., Gao J., & Wang N. Adv. Funct. Mater. 2022, 32, 2111049). Although these materials exhibit good adsorption performance for uranium and can adsorb uranium from seawater, the ammoxime groups also have a strong affinity for vanadium (V) in seawater, resulting in poor selectivity for uranium and vanadium, making it difficult to separate uranium and vanadium. Highly selective ammoxime adsorbents with a uranium-vanadium ratio greater than 5 in real seawater have not yet been reported. Summary of the Invention
[0005] The purpose of this invention is to provide a chromamine oxime-modified graphyne material, its preparation method, and its application. Specifically, it provides a novel chromamine oxime-modified graphyne material, laying the foundation for improving the performance of graphyne and meeting the requirements for uranium selectivity in actual seawater uranium extraction processes.
[0006] On the one hand, addressing the issue of poor selectivity for uranium and vanadium in polyamine oxime materials, this invention discovers that graphyne, a conjugated structure composed of benzene rings linked by diyne bonds, possesses dispersed terminal alkynes. These alkynes can be chemically modified by grafting amylide oxime groups, with the introduced groups positioned far apart, resulting in a free distribution. The affinity of these free-distributed amylide oxime groups for vanadium is significantly lower than that of polyamine oxime materials with adjacent groups. On the other hand, the low concentration of uranium in seawater makes it difficult for conventional adsorbent materials to effectively extract uranium from natural seawater. This invention utilizes the interaction between the π electrons of graphyne and the empty orbitals of metal atoms, as well as the confinement effect of the pores formed by the 18 carbon atoms of graphyne, combined with the affinity of the amylide oxime groups for uranium, to enhance the material's adsorption capacity for uranium from seawater.
[0007] To achieve this objective, the present invention adopts the following technical solution:
[0008] In a first aspect, the present invention provides a method for preparing a graphyne material modified with a methylamine oxime group.
[0009] Includes the following steps:
[0010] (1) Preparation of Graphdiyne material: The template is placed in a reaction solution containing hexaethynylbenzene, nitrogen-containing ligand, copper salt and dispersant, and Graphdiyne is prepared by in-situ growth on the template.
[0011] (2) In the reaction system in which graphyne was grown on the template in step (1), a modifier with active functional groups, a palladium catalyst, a copper catalyst and an organic base were directly added to react. After the reaction was completed, the cyano-modified graphyne material was obtained by filtration, washing and drying.
[0012] (3) The cyano-modified graphyne material obtained in step (2) is dispersed in a reaction solution to obtain a methylamine oxime-modified graphyne material, that is, the cyano group grafted on the graphyne is converted into a methylamine oxime group through a methylamine oxime reaction. The reaction solution includes hydroxylamine hydrochloride, a base and a dispersant.
[0013] Before the amylated oxime reaction, the cyano-modified graphyne-template composite material obtained in step (2) can be dispersed in an oxidant and the template can be removed by etching with the oxidant.
[0014] The method of this invention allows for the preparation of graphyne materials modified with a methylamine oxime group through in-situ growth followed by chemical modification. This preparation method is mild, simple to operate, and suitable for large-scale production. The prepared graphyne materials modified with a methylamine oxime group can be used for highly selective seawater uranium extraction and efficient separation of uranium and vanadium.
[0015] In addition, the preparation method according to the present invention may also have the following additional technical features:
[0016] According to an embodiment of the present invention, in step 1), the weight ratio of hexaethynylbenzene, template, nitrogen-containing ligand, copper salt, and dispersant is 1:(3-120):(50-550):(0.01-1):(1500-25000). The template chemical composition includes one or more of the following: copper oxide, iron oxide, nickel oxide, cobalt oxide, titanium oxide, silver oxide, niobium oxide, zinc oxide, cerium oxide, tantalum oxide, copper, iron, nickel, titanium, silver, and zinc, forming a multi-metal oxide or multi-metal composition. The resulting graphdiyne-template composite material has the shape of nanoparticles, a two-dimensional planar structure, or a hollow multi-shell structure. The nitrogen-containing ligand can be tetramethylethylenediamine or pyridine; the dispersant is one or more of acetone, pyridine, and N,N-dimethylformamide; the copper salt includes one or more of copper nitrate, copper acetylacetonate, cuprous iodide, and cuprous chloride. Under the protection of inert gas, the reaction temperature is 40-110℃, and the reaction takes 1-4 days. The inert gas includes nitrogen and argon.
[0017] According to an embodiment of the present invention, the cyanoylation modification reaction temperature in step 2) is 40–110°C, and the cyanoylation modification reaction time is 1–3 days. The modifiers with active functional groups in step 2) include 4-ethynylbenzonitrile, 4-ethynylphenylacetonitrile, 4-bromobenzonitrile, 4-bromophenylacetonitrile, 2-bromophenylacetonitrile, bromoacetonitrile, and 3-bromopropionitrile; the palladium catalysts include (1,3-bis(diphenylphosphine)propane)palladium chloride, bis(triphenylphosphine)dipalladium chloride, and 1,2-bis(diphenylphosphine)ethanedipalladium chloride; the copper catalysts include cuprous iodide and cuprous chloride; and the organic bases include diisopropylethylamine, triethylamine, and pyridine. The mass ratio of the modifier with active functional groups, the palladium catalyst, the copper catalyst, and the organic base added to the reaction system is 1:(0.001–0.5):(0.001–0.5):(20–1000).
[0018] According to embodiments of the present invention, the concentration of the oxidant used for template removal is 0.05-1M, and the oxidant includes one or a combination of at least two of concentrated nitric acid, ferric chloride, ferric nitrate, and ferric sulfate. The mass ratio of the oxidant to the graphite-template composite material is (1-100):1. The conditions for oxidative template removal are as follows: stirring at 30-70°C for 10-24 hours, followed by filtration, washing with deionized water and ethanol 2-6 times, and drying at 50-100°C for 5-15 hours to obtain cyano-modified graphite-diene hollow multi-shell material.
[0019] According to an embodiment of the present invention, the amine oxime reaction in step 3) is carried out at a temperature of 50–100°C for 1–3 days. The reaction solution in step 3) comprises hydroxylamine hydrochloride, a base, and a dispersant. The base comprises any one or a combination of at least two of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, and potassium hydroxide. The dispersant comprises any one or a combination of at least two of deionized water, tetrahydrofuran, acetone, and N,N-dimethylformamide. The mass ratio of cyano-modified graphylene, hydroxylamine hydrochloride, base, and dispersant in the reaction system is 1:(2–40):(1–20):(1500–25000).
[0020] A second aspect of the present invention provides a graphyne material modified with a methylamine oxime group.
[0021] According to an embodiment of the present invention, the chromaffin-modified graphyne material is prepared by the method described in the first aspect, and the chromaffin groups introduced on the graphyne by chemical modification are spaced far apart and exhibit a free distribution.
[0022] A third aspect of the present invention provides the application of chromadiene materials modified with a methylamine oxime group as described in the second aspect in the fields of uranium extraction from seawater and uranium-vanadium separation.
[0023] According to embodiments of the present invention, the graphyne material modified with a methylamine oxime group provided by the present invention can be used as a uranium adsorbent to achieve efficient extraction of uranium from seawater; and it has excellent selectivity for uranium, enabling efficient separation of uranium and vanadium from seawater.
[0024] Compared with the prior art, the advantages of the present invention are:
[0025] The preparation method proposed in this invention utilizes the alkyne bonds of graphyne to chemically modify it by grafting ammonia oxime functional groups. Graphyne, with its conjugated structure of benzene rings linked by diyne bonds, has dispersed terminal alkynes. The ammonia oxime groups introduced through chemical modification are widely spaced and exhibit a free distribution. The free distribution of ammonia oxime groups shows a much lower affinity for vanadium than adjacent polyamonia oxime materials, but exhibits excellent selectivity for uranium. Simultaneously, the interaction between the π electrons of graphyne and the empty orbitals of metal atoms, along with the confinement effect of the pores formed by the 18 carbon atoms of graphyne, combined with the affinity of the ammonia oxime groups for uranium, enhances the material's adsorption capacity for uranium from seawater.
[0026] This invention marks the first time that graphdiene materials have been used for uranium extraction from seawater, achieving highly efficient separation of uranium and vanadium. In simulated seawater containing 371.6 mg / L uranium and 108.1 mg / L vanadium, the material adsorbed 130.5 mg / g of uranium, with a record-breaking U / V ratio of 69.3, far exceeding the values reported in the literature under the same conditions. In natural seawater with a uranium content of only 3.55 μg / L, the material can still effectively extract uranium from seawater. After 10 days of adsorption, the material adsorbed 9.0 mg / g of uranium, with a U / V ratio of 15.0. Attached Figure Description
[0027] Figure 1 a is the infrared spectrum of the cyano-modified graphynylene of Example 1 of the present invention. Figure 1 b is the infrared spectrum of the graphyne modified with a methylamine oxime group in Example 1 of this invention.
[0028] Figure 2 This is the Raman spectrum of the Graphdiyne modified with a methylamine oxime group according to Example 1 of the present invention.
[0029] Figure 3 This is the X-ray photoelectron spectrum of the Graphdiyne modified with a methylamine oxime group according to Example 1 of the present invention.
[0030] Figure 4 a is a transmission electron microscope (TEM) image of the chromatinyl-amine oxime-modified graphyne from Example 1 of this invention. Figure 4 b is a transmission electron microscope image of the Graphdiyne modified with a methylamine oxime group in Example 1-1.
[0031] Figure 5 This is a scanning electron microscope image of the Graphdiyne modified with a methylamine oxime group according to Example 1 of the present invention.
[0032] Figure 6 This is a Zeta potential diagram of graphyne and ethanoyl-modified graphyne in water at different pH values according to Example 1 of the present invention.
[0033] Figure 7This is a graph showing the adsorption performance of uranium in simulated seawater by graphyne modified with a methylamine oxime group according to Example 1 of the present invention.
[0034] Figure 8 This is a graph showing the adsorption performance of uranium in natural seawater by the genoamine oxime-modified graphyne of Example 1 of the present invention.
[0035] Figure 9 This is a comparison diagram of the adsorption selectivity of uranium and vanadium elements by the genoamine oxime-modified graphyne of Example 1 of the present invention in simulated seawater.
[0036] Figure 10 This is a comparative diagram showing the adsorption selectivity of uranium and vanadium elements for Graphdiyne modified with a amine oxime group in natural seawater according to Example 1 of the present invention.
[0037] Figure 11 This is a comparison diagram of the U / V ratio of the ethanoyl oxime-modified graphyne of Example 1 of the present invention in simulated seawater with that of materials reported in the literature. Detailed Implementation
[0038] The present invention will now be described in further detail with reference to specific embodiments.
[0039] Example 1
[0040] A method for preparing a chromyne material modified with a amine oxime group includes the following steps:
[0041] (1) Slowly add 25 mL of acetone solution of 1000 mg / L hexaethynylbenzene to 100 mL of acetone solution containing 5 mL of pyridine, 1 mL of tetramethylethylenediamine and 100 mg of hollow multi-shell copper template, and react under nitrogen protection at 50 °C.
[0042] (2) In the reaction system of step (1), after reacting for 4 hours, 180 mg of 4-bromophenylacetonitrile, 80 mg of bis(triphenylphosphine)palladium dichloride, 30 mg of cuprous iodide, and 12 mL of triethylamine were added to the system, and the reaction was carried out at 70 °C for 24 hours. The solid obtained from the reaction was filtered and washed three times with acetone, N,N-dimethylformamide (DMF), ethanol, and deionized water, and dried at 60 °C for 15 hours to obtain a cyano-modified graphdiyne-copper composite material with a hollow multi-shell structure.
[0043] (3) Disperse 70 mg of the hollow multi-shell structured cyano-modified graphyne-copper composite material obtained in step (2) in 70 mL of 0.5 M ferric chloride solution, stir and react at 40 °C for 12 h, filter, wash three times with deionized water and ethanol, and dry at 60 °C for 15 h to obtain the hollow multi-shell structured cyano-modified graphyne material.
[0044] (4) 15 mg of the hollow multi-shell cyano-modified graphyne material obtained in step (3) was dispersed in 50 mL of DMF containing 400 mg hydroxylamine hydrochloride and 200 mg NaOH, and refluxed at 70 °C for 24 h. After filtration, the solid was washed three times with deionized water and ethanol, and dried at 50 °C for 15 h to obtain the hollow multi-shell amine oxime-modified graphyne material.
[0045] The adsorption capacity and selectivity for uranium and vanadium of the seawater uranium extraction material prepared in Example 1 were tested under simulated seawater and natural seawater conditions.
[0046] First, 2 L of simulated seawater was prepared with a sea salt crystal concentration of 70.0 g / L, a uranium concentration of 371.6 μg / L, and a vanadium concentration of 108.2 μg / L. Then, 5 mg of seawater-extracted uranium material was added to the simulated seawater, and the mixture was heated at 1 kW / m³. 2 The adsorption performance was studied under simulated sunlight irradiation and a magnetic stirrer at 300 rpm. The adsorption performance of the seawater uranium extraction material for uranium was calculated using the following formula:
[0047]
[0048] Where, q t (mg / g) represents the amount of uranium or vanadium adsorbed by the material at time t, where C0 and C... t (mg / L) represents the concentration of uranium or vanadium in the solution at adsorption time 0 and t, respectively. V(L) is the total volume of the solution, and m is the mass of the adsorbent material.
[0049] Based on the above formula, the selectivity of the material for uranium is represented by the ratio of the amount of uranium adsorbed to the amount of vanadium adsorbed by the material, U / V.
[0050] Furthermore, the adsorption capacity and selectivity for uranium and vanadium of the seawater uranium extraction material prepared in Example 1 were evaluated in natural seawater.
[0051] The seawater was taken from the Bohai Sea, with a uranium content of only 3.55 μg / L. 100L of seawater was added to a container, and 5mg of seawater was used to extract uranium material, which was then fixed in a packed column. The seawater, driven by a water pump, formed a circulation loop through the container-packed column-container system. The packed column, carrying the uranium material, was placed at a 1kW / m³ pressure. 2 Under simulated solar irradiation, the same formula was used to obtain the adsorption performance of the seawater uranium extraction material for uranium, and the U / V ratio was further calculated to represent the material's selectivity for uranium.
[0052] The infrared spectral characterization results of the obtained cyano-modified hollow multi-shell graphyne are as follows: Figure 1As shown, hollow multi-shell graphyne modified with 4-bromophenylacetonitrile exhibited a clear cyano group signal in its infrared spectrum. Following the cyano group's amine oxime reaction, the infrared spectrum, Raman spectrum, X-ray photoelectron spectrum, and transmission electron microscope (TEM) image of the amine oxime-modified hollow multi-shell graphyne were obtained. Scanning electron microscope (SEM) images are shown below. Figures 1 to 5 As shown in the figure, the modified material still retains its hollow multi-shell structure. Figure 6 The Zeta potential plots show that the hollow multi-shell graphyne grafted with amine oxime groups exhibits a significant change in surface charge compared to graphyne at different pH values in the resulting amine oxime-modified graphyne material. ICP characterization was used to assess the ion concentrations in simulated and natural seawater before and after adsorption. Figure 7 As shown in the figure, after 24 hours of adsorption using this material, the concentration of simulated seawater with an initial uranium concentration of 371.6 μg / L decreased to 45.5 μg / L, and the adsorption capacity reached 130.5 mg / g. Further experiments were conducted with natural seawater containing even lower uranium concentrations, and the adsorption results for uranium by the material are shown in the figure. Figure 8 As shown in the figure, the concentration of uranium in natural seawater is only 3.55 μg / L. After 10 hours of adsorption by the adsorbent material, the concentration decreased to 3.10 μg / L, during which time the material adsorbed 9.0 mg / g of uranium. The selectivity of the material for uranium and vanadium in simulated seawater is shown in the figure. Figure 9 As shown, the ratio of uranium adsorption to vanadium adsorption reached a record high of 69.3 (U / V), with uranium adsorption reaching 130.5 mg / g and vanadium adsorption reaching only 1.88 mg / g. Figure 10 As shown, the U / V ratio of the material in natural seawater reached 15.0. After 10 days of adsorption, the adsorption capacity for uranium was 9.0 mg / g, and the adsorption capacity for vanadium was 0.6 mg / g. Figure 11 As shown, compared with materials reported in other literature, this material obviously has a higher U / V ratio and better selectivity among adsorbents of the amylopyridine group.
[0053] Example 2
[0054] A method for preparing a chromyne material modified with a amine oxime group includes the following steps:
[0055] (1) 25 mL of acetone solution of 2000 mg / L hexaethynylbenzene was slowly added dropwise to 100 mL of acetone solution containing 2 mL of pyridine, 1 mL of triethylamine, 0.5 mg of cuprous iodide and 150 mg of copper nanoparticle template. The reaction was carried out at 60 °C under nitrogen protection for 4 days. After the reaction was completed, graphyne-copper composite material was obtained.
[0056] (2) Four days after the reaction in step (1), 500 mg of 4-bromobenzonitrile, 1 mg of 1,2-bis(diphenylphosphine)ethane palladium dichloride, 1 mg of cuprous iodide, and 15 mL of triethylamine were added, and the mixture was reacted at 40 °C for 24 h. The solid was filtered and washed three times with acetone, N,N-dimethylformamide, ethanol, and deionized water, and dried at 60 °C for 10 h to obtain cyano-modified graphdiyne-copper composite material.
[0057] (3) Disperse 160 mg of the cyano-modified graphyne-copper composite material obtained in step (2) in 50 mL of 0.05 M nitric acid solution, stir and react at 40 °C for 12 h, filter, wash three times with deionized water and ethanol, and dry at 60 °C for 15 h to obtain the cyano-modified graphyne material.
[0058] (4) Disperse 10 mg of the cyano-modified graphyne material obtained in step (3) in 30 mL of DMF containing 30 mg of hydroxylamine hydrochloride and 15 mg of sodium bicarbonate, and reflux at 100 °C for 24 h. After filtration, the solid is washed three times with deionized water and ethanol, and dried at 50 °C for 15 h to obtain the ethano-amine oxime-modified graphyne material.
[0059] Example 3
[0060] A method for preparing a chromyne material modified with a amine oxime group includes the following steps:
[0061] (1) 25 mL of a pyridine solution of hexaethynylbenzene at 900 mg / L was slowly added dropwise to 500 mL of a pyridine solution containing 2.5 g of silver foil template and 20 mg of copper acetylacetonate. The reaction was carried out at 110 °C under argon protection for 1 day. After the reaction was completed, a graphdiyne-silver-copper composite material was obtained.
[0062] (2) One day after the reaction in step (1), 30 mg of 4-bromophenylacetonitrile, 15 mg of bis(triphenylphosphine)palladium dichloride, 15 mg of cuprous chloride, and 35 mL of pyridine were added, and the reaction was carried out at 100 °C for 72 h. After filtration, the solid was washed three times with acetone, N,N-dimethylformamide, ethanol, and deionized water, and dried at 80 °C for 15 h to obtain cyano-modified graphyne-silver composite material.
[0063] (3) 10 mg of the cyano-modified graphyne-silver composite material obtained in step (2) was dispersed in 250 mL of deionized water containing 400 mg of hydroxylamine hydrochloride and 200 mg of sodium carbonate, and refluxed at 60 °C for 36 h. After filtration, the solid was washed three times with deionized water and ethanol, and dried at 50 °C for 15 h to obtain the amine oxime-modified graphyne-silver composite material.
[0064] Example 4
[0065] A method for preparing a chromyne material modified with a amine oxime group includes the following steps:
[0066] (1) 25 mL of acetone solution containing 900 mg / L hexaethynylbenzene was slowly added dropwise to 100 mL of acetone solution containing 700 mg of hollow multi-shell iron oxide template, 10 mL of pyridine, and 2 mL of tetramethylethylenediamine. The reaction was carried out at 55 °C under argon protection for 2 days. After the reaction was completed, hollow multi-shell graphdiyne-iron oxide composite material was obtained.
[0067] (2) After the reaction system in step (1) reacted for 2 days, 40 mg of 3-bromopropionitrile, 10 mg of 1,2-bis(diphenylphosphine)ethane palladium dichloride, 5 mg of cuprous chloride, and 20 mL of diisopropylethylamine were added, and the reaction was carried out at 60 °C for 72 h. After filtration, the solid was washed three times with acetone, N,N-dimethylformamide, ethanol, and deionized water, and dried at 70 °C for 5 h to obtain cyano-modified graphdiyne-iron oxide composite material.
[0068] (3) 60 mg of the cyano-modified hollow multi-shell graphdiyne-iron oxide composite material obtained in step (2) was dispersed in 250 mL of tetrahydrofuran containing 1000 mg hydroxylamine hydrochloride and 400 mg KOH, and refluxed at 50 °C for 72 h. After filtration, the solid was washed three times with deionized water and ethanol, and dried at 50 °C for 15 h to obtain the amine oxime-modified hollow multi-shell graphdiyne-iron oxide composite material.
[0069] Example 5
[0070] A method for preparing a chromyne material modified with a amine oxime group includes the following steps:
[0071] (1) A solution of 25 mL of 1000 mg / L hexaethynylbenzene in acetone was slowly added dropwise to a 100 mL solution of acetone containing 5 mL of pyridine, 2 mL of triethylamine, 3 mg of cuprous iodide, and 500 mg of hollow multi-shell tantalum oxide template. The reaction was carried out at 50 °C under nitrogen protection for 2 days. After the reaction was completed, a hollow multi-shell graphdiyne-tantalum oxide composite material was obtained.
[0072] (2) After reacting for 2 days in step (1), 180 mg of 4-bromophenylacetonitrile, 90 mg of palladium chloride (1,3-bis(diphenylphosphine)propane), 30 mg of cuprous chloride, and 12 mL of triethylamine were added, and the mixture was reacted at 70 °C for 2 days. The solid was filtered and washed three times with acetone, N,N-dimethylformamide, ethanol, and deionized water, and dried at 60 °C for 10 h to obtain cyano-modified hollow multi-shell graphdiyne-tantalum oxide composite material.
[0073] (3) Disperse 80 mg of the cyano-modified hollow multi-shell graphdiyne-tantalum oxide composite material obtained in step (2) in 130 mL of deionized water containing 500 mg hydroxylamine hydrochloride and 250 mg NaOH, and reflux at 90 °C for 36 h. After filtration, the solid is washed three times with deionized water and ethanol, and dried at 60 °C for 15 h to obtain the amine oxime-modified hollow multi-shell graphdiyne-tantalum oxide composite material.
[0074] Comparative Example 1
[0075] The difference between Comparative Example 1 and Example 1 lies in the timing of the addition of 4-bromophenylacetonitrile, bis(triphenylphosphine)palladium dichloride, cuprous iodide, and triethylamine after the acetone solution of hexaethynylbenzene has been added dropwise in step 2. The nitrogen content in the material can be used to estimate the amount of grafted amylopectin groups in the material. As shown in Table 1, increasing the time interval between the addition of bis(triphenylphosphine)palladium dichloride, cuprous iodide, and triethylamine leads to a gradual decrease in the nitrogen content in the hollow multi-shell amylopectin-modified graphyne material. However, if the time interval is too short, as in Comparative Example 1-1, it will affect the formation of the hollow multi-shell structure in the material. Figure 4 As shown in b. Therefore, while ensuring the integrity of the hollow multi-shell structure, the optimal time interval for adding more amine oxime groups is 4 hours.
[0076] Table 1. Time interval between the addition of 4-bromophenylacetonitrile, bis(triphenylphosphine)palladium dichloride, cuprous iodide, and triethylamine and the completion of the addition of the hexaethynylbenzene acetone solution.
[0077]
[0078] Comparative Example 2
[0079] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 is an unmodified hollow multi-shell graphyne material.
[0080] Table 2 shows that Comparative Example 2 demonstrates that graphyne exhibits good adsorption capacity and selectivity for uranium, with a U / V ratio reaching 10.7. Example 1, by combining graphyne with a metallo-oxime group, achieved even better adsorption, demonstrating a significant synergistic effect in uranium adsorption and selectivity.
[0081] Table 2. Uranium adsorption capacity and the ratio of uranium to vanadium adsorption capacity of different materials
[0082] experimental group U adsorption capacity (mg / g) U / V Example 1 130.5 69.3 Comparative Example 2 72.9 10.7
[0083] All aspects not described in detail in this invention can be covered using conventional technical knowledge in the field.
[0084] The applicant declares that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it; that is, they do not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.
Claims
1. A method for preparing an amidoxime-modified graphyne material, comprising the following steps: 1) placing a template in a reaction solution containing hexaethynylbenzene, a nitrogen-containing ligand, a copper salt, and a dispersant, and in situ growing graphyne on the template to prepare a graphyne-template composite material; 2) directly adding a modification agent having an active functional group, a palladium catalyst, a copper catalyst, and an organic base to the reaction system of the graphyne-template composite material obtained in step 1), and reacting to obtain a cyano-modified graphyne material; 3) dispersing the cyano-modified graphyne material obtained in step 2) in a dispersion liquid composed of hydroxylamine hydrochloride, a base, and a dispersant to obtain an amidoxime-modified graphyne material.
2. The production method according to claim 1, characterized by, The cyano-modified graphyne material obtained in step 2) is first dispersed in an oxidizing agent to remove the template, and then the cyano-modified graphyne material from which the template is removed is subjected to amidoximation according to the method of step 3) to convert the cyano group into an amidoxime group.
3. The production method according to claim 1 or 2, characterized by, The chemical composition of the template in step 1) includes one or at least two of copper oxide, iron oxide, nickel oxide, cobalt oxide, titanium oxide, silver oxide, niobium oxide, zinc oxide, cerium oxide, tantalum oxide, copper, iron, nickel, titanium, silver, and zinc to form a multi-metal oxide or a multi-metal; and the shape of the prepared graphyne-template composite material includes nanoparticles, a two-dimensional planar structure, and a hollow multi-shell structure.
4. The production method according to any one of claims 1 to 3, characterized by, The reaction in step 2) is a cyano-modification reaction, the reaction temperature is 40-110°C, and the reaction time is 1-3 days. According to the time of adding the modification agent having an active functional group, the palladium catalyst, the copper catalyst, and the organic base to the system, the content of the cyano group and the integrity of the hollow structure can be controlled.
5. The production method according to any one of claims 1 to 4, characterized by, The modification agent having an active functional group in step 2) includes 4-ethynylbenzonitrile, 4-ethynylphenylacetonitrile, 4-bromobenzonitrile, 4-bromophenylacetonitrile, 2-bromophenylacetonitrile, bromoacetonitrile, and 3-bromopropionitrile; the palladium catalyst includes (1,3-bis(diphenylphosphino)propane) palladium chloride, bis(triphenylphosphine)palladium dichloride, and 1,2-bis(diphenylphosphino)ethane palladium dichloride; the copper catalyst includes cuprous iodide and cuprous chloride; and the organic base includes diisopropylethylamine, triethylamine, and pyridine.
6. The production method according to any one of claims 1 to 5, characterized by, The mass ratio of the modification agent having an active functional group, the palladium catalyst, the copper catalyst, and the organic base in step 2) is 1:(0.001-0.5):(0.001-0.5):(20-1000).
7. The production method according to any one of claims 2 to 6, characterized by, The concentration of the oxidizing agent is 0.05-1M, and the oxidizing agent includes one or a combination of at least two of concentrated nitric acid, ferric chloride, iron nitrate, or iron sulfate; and the mass ratio of the oxidizing agent to the graphyne-template composite material is (1-100):
1.
8. The production method according to any one of claims 1 to 7, characterized by, The reaction in step 3) is an amidoximation reaction of the cyano group, the reaction temperature is 50-100°C, and the reaction time is 1-3 days.
9. The production method according to any one of claims 1 to 8, characterized by, The base in step 3) includes any one or a combination of at least two of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, and potassium hydroxide; and the dispersant includes one or a combination of at least two of deionized water, tetrahydrofuran, acetone, and N,N-dimethylformamide.
10. The production method according to any one of claims 1 to 9, characterized by, In the step 3), the mass ratio of the cyan-modified graphdiyne, hydroxylamine hydrochloride, alkali and dispersant is 1:(2-40):(1-20):(1500-25000).
11. A graphyne material modified with a co-aminoxime group, characterized in that, The amidoxime-modified graphdiyne material is obtained by the preparation method in any one of claims 1-10.
12. The amidoxime-modified graphyne material of claim 11, characterized in that, The amidoxime groups introduced on the graphdiyne are far apart from each other and are in a free state.
13. The use of the amidoxime-modified graphyne material according to claims 11-12 in the field of uranium extraction from seawater and uranium-vanadium element separation, characterized in that, The material has excellent selectivity to uranium and can realize efficient extraction of uranium from seawater and efficient separation of uranium and vanadium.