A W 18 O 49 / Graphene / phosphorylation / amidoxime electrode material and preparation and application

Abstract

This invention belongs to the field of electrode materials and nuclide recovery technology, and discloses a W 18 O 49 / Graphene / Phosphorylated / Methioninated Amine Oxime Electrode Materials and Their Preparation and Application. The preparation method includes the following steps: dispersing ammonium tungstate and graphene in a tris(hydroxymethyl)aminomethane solution, heating and stirring to obtain a mixed solution; then adding dopamine hydrochloride, ethanol, and ammonia water and stirring to react; washing and drying the product to obtain a precursor; and carbonizing the obtained precursor under an inert atmosphere and at a temperature of 600–900°C to obtain W. 18 O 49 / Graphene material, then dispersed in hydroxylamine hydrochloride solution and / or phytic acid solution, stirred and reacted; the product was washed and dried to obtain W. 18 O 49 / Graphene / Phosphorylated / Methamidooxime electrode material. The electrode material obtained by this invention can achieve a selective recovery efficiency of over 95% for uranium ion, and has broad application prospects in the field of uranium recovery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrode materials and nuclide recovery, and particularly relates to a W 18 O 49 / graphene / phosphorylation / amidoxime electrode material and preparation and application. BACKGROUND

[0002] With the rapid development of economy and the rapid growth of social population, the use of non-renewable fossil energy such as coal and oil is increasing day by day, which has caused serious problems to society and environment, the greenhouse effect is becoming more and more serious, and the energy shortage is becoming more and more obvious. Uranium, as an indispensable nuclear fuel for nuclear power operation, its continuous supply is of great significance to the safe development of nuclear industry. In order to realize the sustainable and green development of nuclear energy, it is of great strategic significance to develop a stable, efficient, green and recyclable seawater uranium extraction technology for the development and application of uranium resources.

[0003] At present, scholars at home and abroad have made certain progress in seawater uranium extraction technology, but further efforts are needed to achieve industrialization. For decades, researchers have developed a variety of methods for seawater uranium extraction, such as physical and chemical adsorption, solvent extraction, coprecipitation, biological treatment, ion exchange and membrane separation. But the most widely used way of seawater uranium extraction is physical and chemical adsorption. However, due to the limited surface area of adsorbent materials, the concentration of uranium in seawater is low, the salinity is high and the environment is complex. At the same time, the active sites on the adsorbent material used for adsorbing uranium ions are quickly saturated, which cannot achieve the ideal effect of uranium extraction. These adsorbents have a certain adsorption capacity for uranium ions, but the removal capacity for low-concentration uranium ions is limited, and the adsorbents are easy to cause secondary migration and difficult to regenerate, which limits their application. Therefore, it is of great significance to develop an efficient and selective uranium extraction technology for the sustainable development of nuclear energy.

[0004] Capacitive deionization technology is a new technology based on the theory of capacitive deionization, which has the characteristics of low energy consumption, low cost, environmental friendly, etc. Capacitive deionization technology has wide application prospects in the treatment of domestic sewage, tap water purification, industrial wastewater treatment, etc. The commonly used form of capacitive deionization is double-layer capacitance. When a certain voltage is applied between two electrodes, when the solution flows between the two electrodes, the ions will move to the electrode with opposite polarity under the action of the electric field, and finally be adsorbed on the electrode, so the concentration of the solution flowing out of the ion device will be reduced, realizing the deionization effect. When the ions in the pores of the electrode material reach saturation, the two electrodes are reversely connected, and the ions in the pores are released again, so that the electrode can be regenerated. The commonly used carbon materials have large specific surface area, high electrical conductivity, good electrochemical stability and rich pore structure. However, the existing carbon-based materials capture charged ions through the double-layer mechanism, and the extraction efficiency of uranyl ions is low. The introduction of pseudo-capacitive materials can significantly improve the capacitive deionization capacity. Unlike the porous carbon electrode that stores ions through the double-layer, pseudo-capacitive materials can store ions through electrochemical effects such as ion intercalation and conversion. However, the conversion reaction can easily cause the volume of the electrode to change, resulting in serious electrode degradation and poor stability. The use of ion intercalation reaction can avoid the above shortcomings. This is because the intercalation electrode has a larger interlayer spacing, which can provide more ion storage space, thereby effectively improving the reversible capacity of the electrochemical reaction.

[0005] W 18 O 49 has a higher specific capacitance and a controllable interlayer spacing, which can provide more ion storage space for ion transmission. At the same time, the larger interlayer spacing can also effectively improve the adsorption capacity of ions. At the same time, W 18 O 49 The synthesis process of the material is simple, there is no stacking problem, and the stability is good, and it is not easy to dissolve in acidic or alkaline solution. In addition, W 18 O 49 There are W 4+ , W 5+ and W 6+ various valence states in the crystal lattice, so that the interlayer spacing has too many electrons and lattice distortion. When the third phase cation is inserted, a large number of free electrons are gathered on the surface of the crystal lattice, which is beneficial to the adsorption of cations. However, due to the low conductivity and small specific surface area of single-component W 18 O 49 , it is often limited in capacitive deionization. SUMMARY

[0006] In view of the shortcomings and deficiencies of the prior art, the primary purpose of the present application is to provide a preparation method of W 18 O 49 / graphene / phosphorylation / amidoxime electrode material.

[0007] Another object of the present application is to provide a W 18 O 49 / graphene / phosphorylation / amidoxime electrode material.

[0008] Another object of the present application is to provide the above-mentioned W 18 O 49 / graphene / phosphorylation / amidoxime electrode material in the recovery of nuclear uranium.

[0009] The object of the present application is achieved by the following technical solutions:

[0010] A preparation method of a W 18 O 49 / graphene / phosphorylation / amidoxime electrode material, comprising the following preparation steps:

[0011] (1) dispersing ammonium tungstate and graphene in a trimethylol aminomethane solution and heating and stirring to react, to obtain a mixed solution;

[0012] (2) dispersing dopamine hydrochloride, ethanol and ammonia water into the mixed solution of step (1) in sequence and stirring to react, and the product is washed and dried to obtain a precursor;

[0013] (3) carbonizing the precursor obtained in step (2) in an inert atmosphere and at a temperature of 600-900℃ to obtain a W 18 O 49 / graphene material;

[0014] (4) dispersing the W 18 O 49 / graphene material obtained in step (3) in a hydroxylamine hydrochloride solution and / or a phytic acid solution and stirring to react, and the product is washed and dried to obtain a W 18 O 49 / graphene / phosphorylation / amidoxime electrode material.

[0015] Further, the mass concentration of the trimethylol aminomethane solution in step (1) is 0.1-5 mg / mL.

[0016] Further, the amount of ammonium tungstate added in step (1) is 0.1-4 times the mass of dopamine hydrochloride in step (2).

[0017] Further, the amount of graphene added in step (1) is 0.1-1 times the mass of dopamine hydrochloride in step (2).

[0018] Further, the heating and stirring reaction in step (1) refers to stirring and reacting at 30-80℃ for 0.1-6h.

[0019] Further, the amount of ethanol added in step (2) is 0.1-200 times the mass of ammonium tungstate in step (1), and the addition of ethanol is conducive to the dispersion of ammonium tungstate and graphene.

[0020] Further, the amount of ammonia added in step (2) is 0.1-5 times the mass of ammonium tungstate in step (1), and the addition of ammonia is conducive to the decomposition of ammonium tungstate.

[0021] Further, the stirring reaction in step (2) refers to stirring for 6-24 hours at room temperature; the washing refers to washing with deionized water, and the drying refers to drying at a temperature of 100-140°C.

[0022] Further, the inert atmosphere in step (3) refers to a nitrogen atmosphere or an argon atmosphere; and the carbonization treatment time is 5-500 minutes.

[0023] Further, the mass concentration of the hydroxylamine hydrochloride solution in step (4) is 0.1-5 mg / mL; and the mass concentration of the phytic acid solution is 0.1-200 mg / mL.

[0024] Further, the stirring reaction in step (4) refers to stirring for 6-24 hours at room temperature; the washing refers to washing with deionized water; and the drying refers to drying at a temperature of 100-140°C.

[0025] A W 18 O 49 / graphene / phosphorylation / amidoxime electrode material is prepared by the above method.

[0026] Preferably, the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material is composed of nanospheres with a diameter of 10-50 nm, and the mass ratio of tungsten, oxygen, nitrogen, phosphorus, and carbon is 1-20:1-30:1-40:0.1-10:1-100.

[0027] The above W 18 O 49 / graphene / phosphorylation / amidoxime electrode material is used in the recovery of uranium nuclides.

[0028] Further, the application method is as follows: the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material is used as the negative electrode of a capacitive deionization device, and an activated carbon material is used as the positive electrode, and then uraniumyl ions are recovered through capacitive adsorption.

[0029] Preferably, the voltage of the capacitive adsorption is 0.1-5 V.

[0030] The principle of the present application is: by using ammonium tungstate and graphene to obtain a precursor product through coating of dopamine hydrochloride, and further carbonizing the obtained precursor product under an inert atmosphere to obtain the required W 18 O 49 / graphene, the obtained W 18 O 49 / graphene is adsorbed with hydroxylamine hydrochloride and / or phytic acid to obtain a W 18 O 49 / graphene / phosphorylation / amidoxime electrode, the N and O atoms in the amino and oxime groups in the amidoxime functional group can provide lone pair electrons for the uranium atom with an empty orbital, thereby forming a stable five-membered ring chelate. According to the hard-soft acid-base theory, the amidoxime group belongs to a hard base ligand, which is more suitable for a hard acid uranyl ion. In addition, the phosphoryl group with auxiliary coordination ability can also be introduced at the same time as the amidoxime group. The phosphoryl group is a ternary medium acid, and the phosphate ion has a strong coordination ability, and the hydroxyl group (-OH) in the molecule forms a firm hydrogen bond with the oxygen atom in the uranyl ion, which is conducive to the capture of uranyl ions from water. The obtained electrode material is applied to selective capacitive recovery of uranyl ions, and the recovery efficiency of uranyl ions can reach more than 95%.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] (1) The preparation method of the present application adsorbs hydroxylamine hydrochloride and / or phytic acid on W 18 O 49 / graphene to obtain W 18 O 49 / graphene / phosphorylation / amidoxime electrode material, which has a binding site with affinity for uranyl ions, and can significantly improve the selective adsorption effect of the electrode material on uranyl ions. The selective recovery efficiency of the obtained W 18 O 49 / graphene / phosphorylation / amidoxime electrode material on uranyl ions under a voltage of 1.2V can reach more than 95%.

[0033] (2) The application method of the present application in the recovery of uranyl ions has the advantages of high energy efficiency, environmental friendliness, low cost, etc. compared with the conventional adsorption method, chemical precipitation method, ion exchange method and membrane separation method, and has better cycle stability. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The scanning electron microscope image of the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material prepared in Example 1.

[0035] Figure 2 The W18 O 49 Transmission electron microscopy image of the W

[0036] Figure 3 W 18 O 49 XPS and elemental content distribution image of the W

[0037] Figure 4 W 18 O 49 W 18 O 49 W 18 O 49 Recovery efficiency of the W

[0038] Figure 5 W 18 O 49 W 18 O 49 W 18 O 49 Recovery efficiency of the W

[0039] Figure 6 W 18 O 49 Recovery efficiency of the W DETAILED DESCRIPTION

[0040] The application will be further described in conjunction with the examples below, but the embodiments of the application are not limited thereto.

[0041] Example 1

[0042] One kind of W 18 O 49 / graphene / phosphatization / amidoxime electrode material based on the embodiment, the specific preparation steps are as follows:

[0043] (1) 1.2 g of ammonium tungstate powder and 0.1 g of graphene were weighed and dispersed in 200 mL of 1 mg / mL trihydroxy aminomethane solution, and the mixed solution was obtained by magnetic stirring reaction at 80℃ for 30 minutes.

[0044] (2) Take 0.4 g of dopamine hydrochloride and disperse into the mixed solution above, and then magnetically stir the reaction at room temperature for 2 hours, and then add 160 mL of ethanol and stir the reaction for 2 hours, and finally add 1.2 mL of ammonia water and stir the reaction for 2 hours, and then wash the product after the reaction with deionized water, filter, and dry at 120°C to obtain the precursor 1.

[0045] (3) Put the obtained precursor sample into a tube furnace, and then perform a heating carbonization treatment under an Ar inert atmosphere, wherein the heating carbonization treatment is performed at a temperature of 750°C for 180 minutes, and then obtain the W 18 O 49 / graphene.

[0046] (4) Disperse the obtained W 18 O 49 / graphene into a mixed solution of 90 mL of deionized water and 10 mL of ethanol, and then add 0.1 g of hydroxylamine hydrochloride, and then magnetically stir the reaction at room temperature for 30 minutes, and then add a 0.1 mol / L sodium hydroxide solution to adjust the pH of the solution to 7, and then magnetically stir the reaction at 80°C for 6 hours, and then wash the product after the reaction with deionized water, filter, and obtain the precursor 2.

[0047] (5) Disperse the obtained precursor 2 into a 10% mass fraction of a phytic acid aqueous solution, and then magnetically stir the reaction at room temperature for 10 hours, and then wash the product after the reaction with deionized water, filter, and dry at 120°C to obtain the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material.

[0048] The scanning electron microscope image and the transmission electron microscope image of the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material of the present embodiment are shown in Figure 1 and Figure 2 respectively, and the element distribution diagram of the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material is shown in Figure 3 . It can be seen that the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material obtained by the present application is composed of nanospheres with a diameter of 10-50 nm, and the mass ratio of tungsten, oxygen, nitrogen, phosphorus and carbon is 2.16:12.09:1.56:0.37:83.82.

[0049] The application of the W 18 O 49 / graphene / phosphorylation / amidoxime electrode material obtained by the present embodiment in the recovery of uranyl ions is as follows:

[0050] W obtained 18 O 49 A graphene / phosphorylated / mercaptomethylamine electrode material was used as the negative electrode in a capacitive deionization device, and activated carbon was used as the positive electrode. Under a voltage of 1.2V, the device capacitively adsorbed uranyl ions from uranyl nitrate solutions of different concentrations (10ppm, 30ppm, 50ppm, 70ppm, and 90ppm). The capacitively adsorbed solutions were analyzed by ICP-OES, and the uranyl ion recovery rate was calculated. The test results are as follows: Figure 4 As shown. By Figure 4 The results show that W obtained in this embodiment 18 O 49 The graphene / phosphorylated / mercaptomethylamine electrode material exhibits a recovery efficiency of 99.98% for uranium ions at a concentration of 10 ppm, 99.97% for uranium ions at a concentration of 30 ppm, 99.96% for uranium ions at a concentration of 50 ppm, 99.95% for uranium ions at a concentration of 70 ppm, and 99.94% for uranium ions at a concentration of 90 ppm.

[0051] W obtained 18 O 49 A graphene / phosphorylated / mercaptomethylamine electrode material was used as the negative electrode in the capacitive deionization device, and activated carbon was used as the positive electrode. Uranyl ions in a mixed solution of 10 ppm uranyl nitrate and 100 ppm sodium chloride were capacitively adsorbed under a voltage of 1.2V. The capacitively adsorbed solution was analyzed by ICP-OES, and the uranyl ion recovery rate was calculated. The test results are as follows: Figure 5 As shown. By Figure 5 The results show that W obtained in this embodiment 18 O 49 The graphene / phosphorylated / mercaptooxime electrode material has a uranyl ion recovery efficiency of 99.97%.

[0052] At the same time, the obtained W 18 O 49 A graphene / phosphorylated / mercaptomethylamine electrode material was used as the negative electrode in the capacitive deionization device, and activated carbon was used as the positive electrode. Uranyl ions in a mixed solution of 10 ppm uranyl nitrate and 100 ppm sodium chloride were adsorbed by the capacitor under a voltage of 1.2V. The solutions adsorbed by the capacitor at different cycle numbers were analyzed by ICP-OES, and the uranyl ion recovery rate was calculated. The test results are as follows: Figure 6 As shown. By Figure 6 The results show that W obtained in this embodiment 18 O 49 The graphene / phosphorylated / mercaptooxime electrode material exhibits high and stable recovery efficiency for uranyl ions.

[0053] Example 2

[0054] This embodiment is based on W 18 O 49 The graphene / mercaptooxime material, compared to Example 1, did not adsorb phytic acid molecules during its preparation process. The specific preparation steps are as follows:

[0055] Steps (1) to (3) are the same as in Example 1.

[0056] (4) The obtained W 18 O 49 Graphene was dispersed in a mixture of 90 mL deionized water and 10 mL ethanol, and then 0.1 g of hydroxylamine hydrochloride was added. The mixture was magnetically stirred at room temperature for 30 minutes. The pH of the solution was adjusted to 7 by adding 0.1 mol / L sodium hydroxide, and then the mixture was magnetically stirred at 80 °C for 6 hours. The product was washed with deionized water, filtered, and dried at 120 °C to obtain W. 18 O 49 / Graphene / Amylated oxime electrode material.

[0057] The W obtained in this embodiment 18 O 49 The application of graphene / mercaptomethylamine oxime materials in uranyl ion recovery follows the same method as in Example 1. The capacitively adsorbed solution was tested by ICP-OES to calculate the uranyl ion recovery rate. The test results are as follows: Figure 4 As shown. By Figure 4 The results show that W obtained in this embodiment 18 O 49 The graphene / mercaptomethylamine oxime electrode material exhibits a recovery efficiency of 95.96% for uranyl ions at a concentration of 10 ppm, 95.9% at 30 ppm, 95.85% at 50 ppm, 95.80% at 70 ppm, and 95.77% at 90 ppm. Uranyl ions are capacitively adsorbed in a mixed solution of 10 ppm uranyl nitrate and 100 ppm sodium chloride under a voltage of 1.2 V. The capacitively adsorbed solution is analyzed by ICP-OES, and the uranyl ion recovery rate is calculated. The test results are as follows: Figure 5 As shown. By Figure 5 The results show that W obtained in this embodiment 18 O 49 The graphene / mercaptooxime electrode material has a uranyl ion recovery efficiency of 95.96%.

[0058] The comparison results with Example 1 show that the introduction of phosphorus-containing active sites by adsorbing phytic acid molecules can further improve the recovery rate of uranyl ions by the electrode material.

[0059] Example 3

[0060] This embodiment is based on W 18 O 49 The graphene / phosphorylated material, compared to Example 1, does not require the addition of hydroxylamine hydrochloride in its preparation process. The specific preparation steps are as follows:

[0061] Steps (1) to (3) are the same as in Example 1.

[0062] (4) The obtained W 18 O 49 Graphene was dispersed in a 10% (w / w) phytic acid aqueous solution and reacted magnetically for 10 hours at room temperature. The product was washed and filtered with deionized water and dried at 120°C to obtain W. 18 O 49 / Graphene / Phosphorylated electrode material.

[0063] The W obtained in this embodiment 18 O 49 The application of graphene phosphorylation in uranyl ion recovery follows the same method as in Example 1. The capacitively adsorbed solution was tested by ICP-OES to calculate the uranyl ion recovery rate. The test results are as follows: Figure 4 As shown. By Figure 4 The results show that W obtained in this embodiment 18 O 49 The graphene / phosphorylated electrode material exhibited a recovery efficiency of 96.98% for uranyl ions at a concentration of 10 ppm, 96.89% at 30 ppm, 96.78% at 50 ppm, 96.66% at 70 ppm, and 96.6% at 90 ppm. Uranyl ions were capacitively adsorbed in a mixed solution of 10 ppm uranyl nitrate and 100 ppm sodium chloride under a voltage of 1.2 V. The capacitively adsorbed solution was analyzed by ICP-OES, and the uranyl ion recovery rate was calculated. The test results are shown below. Figure 5 As shown. By Figure 5 The results show that W obtained in this embodiment 18 O 49 The graphene / phosphorylated electrode material has a uranyl ion recovery efficiency of 96.97%.

[0064] The comparison results with Example 1 show that the addition of hydroxylamine hydrochloride to introduce a methylamine oxime group can further improve the recovery rate of uranyl ions by the electrode material.

[0065] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A W 18 O 49 Method for the preparation of a / graphene / phosphorylated / amidoxime electrode material, characterized by, The specific preparation steps are as follows: (1) dispersing ammonium tungstate and graphene in a trimethylol aminomethane solution and stirring and reacting under heating to obtain a mixed solution; (2) dispersing dopamine hydrochloride, ethanol and ammonia water into the mixed solution of step (1) in sequence and stirring and reacting to obtain a product, and then washing and drying the product to obtain a precursor; (3) carbonizing the precursor obtained in step (2) at a temperature of 600-900 °C under an inert atmosphere to obtain W 18 O 49 / graphene material; (4) dispersing the W 18 O 49 / graphene material obtained in step (3) in a hydroxylamine hydrochloride solution and a phytic acid solution in sequence, stirring and reacting, washing the product, drying to obtain a W 18 O 49 / graphene / phosphatization / amidoxime electrode material.

2. A W 18 O 49 A method for preparing a graphene / phosphorylated / amidoxime electrode material, characterized by, In step (1), the mass concentration of the trimethylol aminomethane solution is 0.1-5 mg / mL; the added amount of the ammonium tungstate is 0.1-4 times the mass of the dopamine hydrochloride in step (2); the added amount of the graphene is 0.1-1 times the mass of the dopamine hydrochloride in step (2); and the stirring and reacting under heating refers to stirring and reacting under the condition of 30-80℃ for 0.1-6 h.

3. A W 18 O 49 A method for preparing a / graphene / phosphorylated / amidoxime electrode material, characterized by, In step (2), the added amount of the ethanol is 0.1-200 times the mass of the ammonium tungstate in step (1); the added amount of the ammonia water is 0.1-5 times the mass of the ammonium tungstate in step (1); the stirring and reacting refers to stirring and reacting under the condition of normal temperature for 6-24 h; the washing refers to washing with deionized water; and the drying refers to drying under the condition of 100-140℃.

4. A W 18 O 49 A method for preparing a / graphene / phosphorylated / amidoxime electrode material, characterized by, In step (3), the inert atmosphere refers to a nitrogen atmosphere or an argon atmosphere; and the carbonization treatment time is 5-500 min.

5. A W 18 O 49 A method for preparing a / graphene / phosphorylated / amidoxime electrode material, characterized by, In step (4), the mass concentration of the hydroxylamine hydrochloride solution is 0.1-5 mg / mL; the mass concentration of the phytic acid solution is 0.1-200 mg / mL; the stirring and reacting refers to stirring and reacting under the condition of normal temperature for 6-24 h; the washing refers to washing with deionized water; and the drying refers to drying under the condition of 100-140℃.

6. A W 18 O 49 / graphene / phosphorylated / amidoxime electrode material characterized by, The precursor is prepared by the method of any one of claims 1-5.

7. A W 18 O 49 / graphene / phosphorylated / amidoxime electrode material characterized by, The W 18 O 49 The tungsten / graphene / phosphorylated / amidoxime electrode material is composed of nanospheres with a diameter of 10-50 nm, wherein the mass ratio of tungsten, oxygen, nitrogen, phosphorus and carbon is 1-20: 1-30: 1-40: 0.1-10: 1-100.

8. A W according to claim 6 or 7, wherein the W is a W 18 O 49 Application of graphene / phosphorylated / amidoxime electrode material in the recovery of nuclide uranium.

9. Use according to claim 8, characterized in that, The application method is: W 18 O 49 The graphene / phosphorylation / amidoxime electrode material is used as the negative electrode of the capacitive deionization device, the activated carbon material is used as the positive electrode, and then the uraniumyl ions are recovered through capacitive adsorption.

10. Use according to claim 9, characterized in that, The voltage of the electric double layer capacitor is 0.1-5 V.

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