Preparation of a copper-based nanomaterial for uranium separation and its application in electrochemical uranium extraction.
By preparing copper-based nanomaterial PO4-Cu(B), and utilizing the layered charge separation structure formed by surface doping with boron and phosphate ions, combined with palladium and bismuth loading, the problem of low uranyl ion extraction efficiency in traditional methods was solved, achieving efficient and stable uranyl binding and extraction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTHWEAT UNIV OF SCI & TECH
- Filing Date
- 2023-11-30
- Publication Date
- 2026-06-30
AI Technical Summary
Traditional adsorption methods have low extraction efficiency and unsatisfactory kinetics for uranyl ions in real seawater. Existing electrochemical materials are unstable in complex seawater environments, making it difficult to achieve efficient extraction.
Copper-based nanomaterials PO4-Cu(B) were prepared by doping the surface with boron and phosphate ions to form a layered charge-separated structure, which was then combined with palladium and bismuth loading to enhance the uranyl binding ability. Uranyl was then extracted using an electrochemical method.
The uranium extraction rate reached 95.8% in simulated seawater, and the daily extraction amount in real seawater reached 2.1 mg/g. It has excellent anti-interference and reusability, and the uranyl binding is stable with an extraction rate as high as 98.7%.
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Figure CN117626015B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of uranium separation technology. More specifically, this invention relates to the preparation of a copper-based nanomaterial for uranium separation and its application in electrochemical uranium extraction. Background Technology
[0002] Traditional adsorption methods suffer from kinetic lag and low extraction efficiency in the complex environment of real seawater. As an alternative to adsorption, electrochemical uranium extraction can reduce uranium ions in seawater to insoluble substances. This method offers advantages such as rapid kinetics, stronger resistance to non-reducing interfering ions, and higher uranium extraction efficiency. In electrochemical uranium extraction, efficiency primarily depends on the electrode materials, prompting researchers to explore the rational design of these materials.
[0003] Typically, electrode materials used for electrochemical uranium extraction possess high conductivity and are suitable for binding uranyl (UO2) 2+ The specific sites on the uranium extraction substrate, along with the specific sites on the substrate, ensure the activity of the electrochemical reaction and the selectivity of uranium extraction, respectively. For example, the coupling of Fe-NC single atoms on a conductive carbon support with oxime binding sites achieved an extraction capacity of 1.2 mg / g within 24 hours, enabling electrochemical uranium extraction in real seawater. Another example is a bovine serum albumin-coated carbon fiber mat with carbon fiber as the conductive support and oxygen-containing functional groups as specific sites, exhibiting an extraction capacity of 0.37 mg / g per day. Despite these advancements, the efficiency and kinetics of uranium extraction remain unsatisfactory due to the complex environment of real seawater.
[0004] One promising approach to enhance uranyl binding and reduction is to design the spatial distribution of charges at active sites. Given the electronic structure of uranyl, a stable binding structure requires a negatively charged active site to bind with a U atom in the uranyl group, and a positively charged secondary site to bind with an O atom in the uranyl group. Therefore, layered charge separation is highly desirable for achieving charge-enhanced multi-site binding of uranyl. Summary of the Invention
[0005] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.
[0006] To achieve these objectives and other advantages of the present invention, a method for preparing copper-based nanomaterials from uranium separation is provided, comprising the following steps:
[0007] Step 1: Prepare copper chloride solution and sodium borohydride solution using low-temperature deionized water. Quickly add the copper chloride solution to the sodium borohydride solution and react in an ice-water bath until no more bubbles are generated to obtain a reaction solution. The precipitate in the reaction solution is copper nanomaterials with boron doped on the surface.
[0008] Step 2: Add the disodium hydrogen phosphate solution to the reaction solution containing surface-doped boron copper nanomaterials obtained in Step 1, stir for 10-30 minutes, let stand, collect the precipitate after precipitation is complete, wash and dry to obtain uranium-separated copper-based nanomaterials.
[0009] Preferably, in step one, the temperature of the low-temperature deionized water is 0–5°C; the concentration of the copper chloride solution is 0.3–0.4 mol / L; and the concentration of the sodium borohydride solution is 4–6 mol / L.
[0010] Preferably, in step one, the volume ratio of copper chloride solution to sodium borohydride solution is 1:0.8 to 1.2.
[0011] Preferably, in step two, the concentration of the disodium hydrogen phosphate solution is 0.05–0.1 mol / L.
[0012] Preferably, in step two, the volume ratio of disodium hydrogen phosphate solution to copper chloride solution in step one is 0.8 to 1.2:2.
[0013] Preferably, in step two, the washing method is as follows: wash with water and acetone 2 to 4 times in sequence.
[0014] Preferably, in step two, the drying method is as follows: vacuum drying at 50–80°C for 10–14 hours.
[0015] An application of copper-based nanomaterials prepared by the method described above in electrochemical uranium extraction is characterized by the following steps: copper-based nanomaterials and carbon black are added to anhydrous ethanol, and Nafion solution is added simultaneously. The mixture is sonicated until the solute is evenly distributed to obtain a mixed solution. The mixed solution is then uniformly coated onto a 1×2 cm carbon felt. After the ethanol evaporates, the coating continues until the mixed solution is exhausted, resulting in a sample with copper-based nanomaterials uniformly loaded on the carbon felt. This sample is used as the working electrode in a three-electrode system of an electrochemical workstation. The counter electrode in the three-electrode system is a platinum wire electrode, and the reference electrode is an Ag / AgCl electrode.
[0016] Uranyl nitrate was added to seawater to obtain simulated uranium-rich seawater. The simulated uranium-rich seawater was then added to an electrolytic cell with a three-electrode system, and the voltage was set to -2.0 to -1.5V to extract uranium from the simulated uranium-rich seawater.
[0017] After electrolysis, using sodium sulfate solution as the electrolyte and the sample as the anode, a constant current of 30mA was applied to desorb uranium from the sample into the sodium sulfate solution.
[0018] Preferably, the mass ratio of the copper-based nanomaterial to carbon black is 5:2-4; the concentration of the Nafion solution is 5wt%; and the mass-to-volume ratio of the copper-based nanomaterial, anhydrous ethanol, and Nafion solution is 5mg:1-3mL:30-40μL.
[0019] Preferably, the concentration of U(VI) in the simulated uranium seawater is 3 μg / L to 100 mg / L; and the concentration of sodium sulfate solution is 0.4 to 0.6 mol / L.
[0020] The preparation method of copper-based nanomaterials for uranium separation according to the present invention further includes: in step two, firstly, a surfactant, palladium chloride and bismuth nitrate are added to low-temperature deionized water and stirred evenly to obtain a mixed solution. Then, the mixed solution is added to the reaction solution of copper nanomaterials containing surface-doped boron obtained in step one, and ultrasonically dispersed for 20-40 min. Then, disodium hydrogen phosphate solution is added, stirred for 10-30 min, and allowed to stand. After precipitation is completed, the precipitate is collected, washed, and dried to obtain copper-based nanomaterials for uranium separation.
[0021] Preferably, the surfactant is an anionic surfactant.
[0022] Preferably, in the mixed solution, the concentration of surfactant is 0.5–2 g / L, the concentration of palladium chloride is 0.03–0.07 mol / L, and the concentration of bismuth nitrate is 0.01–0.05 mol / L.
[0023] Preferably, the volume ratio of the mixed solution to the copper chloride solution in step one is 0.8 to 1.2:1.
[0024] Preferably, the ultrasonic power is 500-1500W and the frequency is 30-40KHz.
[0025] This invention includes at least the following beneficial effects: This invention prepares a copper-based nanomaterial PO4-Cu(B) with spatially layered charge separation, while simultaneously combining B atoms and phosphate ions (PO4... 3- Introducing boron (B) atoms into Cu nanoparticles reduces the negative charge on the outer surface of Cu atoms, thereby enhancing the bonding of O atoms in uranyl esters and stabilizing the surface PO4. 3- Site, and PO4 3-The external O atom of the group adds a negative charge, which is beneficial for binding with the U atom in the uranyl group. This enhances uranyl binding through the strengthened O-Cu and UO interaction, thereby facilitating the electrochemical extraction of uranium from seawater. The PO4-Cu(B) of this invention achieves a uranium extraction rate of 95.8% within 400 minutes in simulated seawater. In real seawater experiments, the uranium extraction capacity of PO4-Cu(B) reaches 2.1 mg / g per day. Furthermore, the PO4-Cu(B) of this invention exhibits excellent anti-interference properties and reusability. This invention not only develops a new material for efficient uranium extraction but also provides a constructive strategy for uranyl binding and uranium extraction from real seawater using layered charge separation.
[0026] The addition of surfactants in this invention can control the nucleation and crystal growth rate, effectively avoiding powder agglomeration and growth, which is conducive to the formation of copper-based nanomaterials with consistent morphology, uniform size and good dispersibility. In addition, by loading palladium and bismuth onto the copper surface, the high catalytic activity of palladium and bismuth and the synergistic effect between metals are utilized to further enhance the electrocatalytic activity of copper-based nanomaterials, and the uranium extraction rate reaches 98.7%.
[0027] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description
[0028] Figure 1 for Figure 1 TEM image (a) and HRTEM image (b-c) of PO4-Cu(B) prepared in Example 1;
[0029] Figure 2 XRD patterns of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2;
[0030] Figure 3 FTIR spectra of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2;
[0031] Figure 4 B1s XPS spectra of PO4-Cu(B) prepared in Example 1 and Cu(B) prepared in Comparative Example 1;
[0032] Figure 5 The P 2p XPS spectra of PO4-Cu(B) prepared in Example 1 and PO4-Cu prepared in Comparative Example 2 are shown.
[0033] Figure 6Cu LLM Auger electron spectra of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2.
[0034] Figure 7 Cu L-edge XANES spectra of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2.
[0035] Figure 8 LSV curves of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2;
[0036] Figure 9 A comparison chart of uranium extraction rates of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2.
[0037] Figure 10 A comparison chart of uranium extraction rates of PO4-Cu(B) prepared in Example 1 and PO4-CuPdBi(B) prepared in Example 2;
[0038] Figure 11 The graph shows a comparison of uranium extraction rates of PO4-Cu(B) prepared in Example 1 at different voltages (0V, -1.3V, -1.5V, and -1.7V).
[0039] Figure 12 A comparison chart of uranium extraction rates of PO4-Cu(B) prepared in Example 1 at different initial U(VI) concentrations (8 mg / L, 20 mg / L, 50 mg / L);
[0040] Figure 13 The desorption rate of PO4-Cu(B) uranium prepared in Example 1 in 0.5M Na2SO4 solution after extraction experiment;
[0041] Figure 14 The uranium extraction rate of PO4-Cu(B) prepared in Example 1 during 6 uranium extraction and desorption cycles;
[0042] Figure 15 PO4-Cu(B) prepared in Example 1 was subjected to a single interfering cation (K) + Zn 2+ V 5+ Fe 2+ Ni 2+ Mn 2+ Co 2+ and Pb 2+ uranium extraction rate in the presence of )
[0043] Figure 16 PO4-Cu(B) prepared in Example 1 under single interfering anion (F - CO3 2- Cl - NO3 - and C2O4 2- uranium extraction rate in the presence of )
[0044] Figure 17 The PO4-Cu(B) prepared in Example 1 was subjected to various interfering cations (K). + Zn 2+ V 5+ Fe 2+ Ni 2+ Mn 2+ Co 2+ and Pb 2+ ) Uranium extraction rate under coexistence;
[0045] Figure 18 The image is an HRTEM image of PO4-Cu(B) uranium extraction prepared in Example 1 after the experiment.
[0046] Figure 19 The XRD pattern of PO4-Cu(B) uranium extraction experiment prepared in Example 1;
[0047] Figure 20 The U 4f XPS spectrum of PO4-Cu(B) uranium extraction prepared in Example 1;
[0048] Figure 21 The uranium extraction rate of PO4-Cu(B) prepared in Example 1 in uranium-added real seawater;
[0049] Figure 22 The 8-hour uranium extraction rate and 24-hour uranium extraction capacity of PO4-Cu(B) prepared in Example 1 in real seawater are shown. Detailed Implementation
[0050] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.
[0051] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.
[0052] Example 1
[0053] A method for preparing copper-based nanomaterials from uranium separation includes the following steps:
[0054] Step 1: Prepare a 0.37M copper chloride solution and a 5M sodium borohydride solution using 0℃ deionized water. Quickly add 2mL of copper chloride solution to 2mL of sodium borohydride solution and react in an ice-water bath until no more bubbles are generated to obtain a reaction solution. The precipitate in the reaction solution is copper nanomaterials with boron doped on the surface.
[0055] Step 2: Add 1 mL of 0.085 M disodium hydrogen phosphate solution to the reaction solution obtained in Step 1 (containing copper nanomaterials with boron doped surface), stir for 20 min, let stand, collect the precipitate after precipitation is complete, wash with water and acetone three times in sequence, and dry under vacuum at 60 °C for 12 h to obtain uranium-separated copper-based nanomaterials, namely PO4-Cu(B).
[0056] Example 2
[0057] A method for preparing copper-based nanomaterials from uranium separation includes the following steps:
[0058] Step 1: Prepare a 0.37M copper chloride solution and a 5M sodium borohydride solution using 0℃ deionized water. Quickly add 2mL of copper chloride solution to 2mL of sodium borohydride solution and react in an ice-water bath until no more bubbles are generated to obtain a reaction solution. The precipitate in the reaction solution is copper nanomaterials with boron doped on the surface.
[0059] Step 2: Add sodium dodecyl sulfate, palladium chloride, and bismuth nitrate to deionized water at 0℃ and stir until homogeneous to obtain a mixed solution. Take 2 mL of the mixed solution and add it to the reaction solution obtained in Step 1 (containing copper nanomaterials with boron surface doping). Disperse the mixture in an ultrasonic bath at 1000W power and 35KHz frequency for 30 min. Then add 1 mL of 0.085M disodium hydrogen phosphate solution, stir for 20 min, and let stand. After precipitation is complete, collect the precipitate, wash it three times with water and acetone, and dry it under vacuum at 60℃ for 12 h to obtain uranium-separated copper-based nanomaterials, namely PO4-CuPdBi(B). The concentration of sodium dodecyl sulfate in the mixed solution is 1 g / L, the concentration of palladium chloride is 0.05 mol / L, and the concentration of bismuth nitrate is 0.03 mol / L.
[0060] Comparative Example 1
[0061] A method for preparing boron-doped copper nanomaterials includes: preparing a 0.37M copper chloride solution and a 5M sodium borohydride solution using deionized water at 0℃; rapidly adding 2 mL of copper chloride solution to 2 mL of sodium borohydride solution; reacting in an ice-water bath until no bubbles are generated; filtering; washing three times with water and acetone; and vacuum drying at 60℃ for 12 h to obtain boron-doped copper nanomaterials, i.e., Cu(B).
[0062] Comparative Example 2
[0063] A method for preparing phosphate-doped copper nanomaterials includes the following steps:
[0064] Step 1: Prepare a 0.37M copper chloride solution and a 5M hydrazine hydrate solution using 0℃ deionized water. Quickly add 2mL of copper chloride solution to 2mL of hydrazine hydrate solution and react in an ice-water bath until no more bubbles are generated to obtain the reaction solution. The precipitate in the reaction solution is copper nanomaterial.
[0065] Step 2: Add 1 mL of 0.085 M disodium hydrogen phosphate solution to the reaction solution obtained in Step 1 (containing copper nanomaterials with boron doped surface), stir for 20 min, let stand, collect the precipitate after precipitation is complete, wash with water and acetone three times in sequence, and dry under vacuum at 60 °C for 12 h to obtain copper nanomaterials doped with phosphate groups, namely PO4-Cu.
[0066] Figure 1 TEM (a) and HRTEM (b-c) images of PO4-Cu(B) prepared in Example 1. Figure 1 (a) It can be seen that PO4-Cu(B) is tightly packed in a gel state, which prevents potential leaching during the electrochemical process; Figure 1 (b) It can be seen that in the central region of the gel-like product, the interplanar spacing of the lattice stripes corresponds to the {111} plane of fcc-Cu (0.21nm), which is due to the change in crystal structure caused by surface doping of B. Figure 1 (c) It can be seen that the edge of PO4-Cu(B) has characteristic lattice stripes of Cu2O, indicating that Cu is oxidized on the surface.
[0067] Figure 2 The XRD patterns of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2 are shown. It can be seen that Cu(B), PO4-Cu... 4- Cu and Cu2O phases were observed in Cu and PO4-Cu(B). Regardless of the amount of B doping, the diffraction peak of Cu was located at the same position, which ruled out lattice expansion due to lattice doping and confirmed the surface doping of B. In addition, the diffraction peak of Cu2O in PO4-Cu was the strongest among the three samples, indicating that the doping of B improved the oxidation resistance of Cu nanoparticles, which is beneficial to the conductivity in electrochemical applications.
[0068] Figure 3 The FTIR spectra of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2 are shown. It can be seen that PO4-Cu... 4- Cu and PO4-Cu(B) at 561 cm -1 990cm -1and 1150cm -1 Three new peaks appeared at the point, which are attributed to the phosphate group vibration, PO vibration and P=O vibration on the inner surface, respectively.
[0069] Figure 4 The B1s XPS spectra of PO4-Cu(B) prepared in Example 1 and Cu(B) prepared in Comparative Example 1 show that the spectrum consists of a single peak at 190.7 eV, which is lower than the ~192 eV of the BO bond, ruling out surface adsorption of boron oxide. This indicates that B exists in a neutral or negative valence form. Figure 5 The P 2p XPS spectra of PO4-Cu(B) prepared in Example 1 and PO4-Cu prepared in Comparative Example 2 show that the peak position is located at 133.4 eV, corresponding to the PO bond. PO4-Cu(B) has a wider half-peak width than PO4-Cu, which is attributed to the adjustment of the local electron density of PO4 by the neighboring B doping.
[0070] Figure 6 The Cu LLM Auger electron spectra of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2 show that, due to surface oxidation, the main peak of all three samples is located at 916.1 eV. However, PO4-Cu(B) and Cu(B) exhibit a more pronounced shoulder peak at 918.2 eV compared to PO4-Cu, indicating that the Cu on the surface after B doping... 0 The percentage increase is consistent with the oxidation regions previously observed in HRTEM. Figure 7 The Cu L-edge XANES spectra of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2 show that, compared with the overwhelming surface strength of Cu... + The states are different; the edges of Cu L2 and L3 in the three samples have two Cu atoms. 0 The characteristic peak at 937.0 eV indicates the metallic state of the entire nanoparticle. Considering the two peaks at 934.2 eV and 937.0 eV in the Cu L3 edge region, the peak intensity at 934.2 eV is higher in PO4-Cu, while the peak intensities of Cu(B) and PO4-Cu(B) are opposite. This is because electrons are transferred from Cu atoms to the doped B atoms, leading to an increase in electron energy from 1s to 4s. In summary, the incorporation of B in PO4-Cu(B) reduces surface oxidation and alters the Cu... 0 The overall electron density, which facilitates electrochemical uranium extraction by increasing conductivity and manipulating charge-enhanced uranyl adsorption.
[0071] Uranium extraction experiment: 5 mg PO4-Cu(B) (Cu(B) or PO4-Cu) and 3 mg carbon black were added to 2 mL of anhydrous ethanol, along with 35 μL of 5 wt% Nafion solution. The mixture was sonicated until the solute was evenly distributed, resulting in a mixed solution. This mixed solution was then evenly coated onto a 1×2 cm carbon felt. After the ethanol evaporated, the coating was continued until the mixed solution was exhausted, resulting in a sample of copper-based nanomaterials uniformly loaded on the carbon felt. This sample was used as the working electrode in the three-electrode system of an electrochemical workstation (CHI 660E, China). The counter electrode in the three-electrode system was a platinum wire electrode, and the reference electrode was an Ag / AgCl electrode. Simulated seawater was prepared using uranyl nitrate and sodium sulfate, with a U(VI) concentration of 8 mg / L and a Na2SO4 concentration of 0.5 M. 80 mL of the prepared simulated seawater was used as the electrolyte. The voltage was set to -1.7 V, and the extraction time was 400 min. Azoarsine III was used as the dye, and the concentration of U(VI) in the solution was measured at a wavelength of 651.8 nm using UV-Vis absorption spectroscopy. The U(VI) extraction rate was calculated as follows:
[0072] extraction efficiency(%)=(1-C t / C0)×100%
[0073] In the formula, C0 (mg / L) is the initial concentration of U(VI), C t (mg / L) represents the concentration of U(VI) after reaction time t.
[0074] The linear sweep voltammetry (LSV) curves of PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2 were tested in an electrolyte containing 600 mg / L LU(VI) and 0.5 M Na2SO4. The results are as follows: Figure 8 As shown, compared to Cu(B) and PO4-Cu, PO4-Cu(B) exhibits a smaller negative potential to the U(VI) reduction peak, indicating that B and PO4-Cu have different negative potentials. 3- The introduction of facilitated the electrochemical reduction of U(VI).
[0075] Uranium extraction experiments were performed on PO4-Cu(B) prepared in Example 1, Cu(B) prepared in Comparative Example 1, and PO4-Cu prepared in Comparative Example 2. The results are as follows: Figure 9 As shown, PO4-Cu(B) exhibited an extraction efficiency of up to 95.8% within 400 minutes, which is higher than that of Cu(B) (90.5%) and PO4-Cu (78.9%).
[0076] Uranium extraction experiments were performed on PO4-Cu(B) prepared in Example 1 and PO4-CuPdBi(B) prepared in Example 2. The results are as follows: Figure 10As shown, the uranium extraction rate of PO4-CuPdBi(B) is higher than that of PO4-Cu(B), reaching 98.7%. This is because the addition of surfactants in the reaction can effectively prevent the agglomeration and growth of powders, which is conducive to the formation of copper-based nanomaterials with consistent morphology, uniform size and good dispersibility. In addition, by loading palladium and bismuth on the copper surface, the high catalytic activity of palladium and bismuth and the synergistic effect between metals further improve the uranium extraction rate of copper-based nanomaterials.
[0077] To evaluate the effect of the applied potential, the uranium extraction rate of PO4-Cu(B) was tested at voltages of 0V, -1.3V, -1.5V, and -1.7V. The results are as follows: Figure 11 As shown, the extraction rates at -1.3V and -1.5V were 57.8% and 77.9%, respectively. Further reducing the open circuit potential caused the extraction rate of U(VI) to drop sharply to 5.8%, which proves the key role of electrochemical extraction in uranium extraction, rather than physical or chemical adsorption.
[0078] To evaluate the effect of initial U(VI) concentration in the electrolyte, the uranium extraction rate of PO4-Cu(B) was tested at different initial U(VI) concentrations (8 mg / L, 20 mg / L, and 50 mg / L). The results are as follows: Figure 12 As shown, PO4-Cu(B) exhibited high extraction rates, all above 95%.
[0079] After the uranium extraction experiment, a sample uniformly loaded with copper-based nanomaterials on a carbon felt was used as the anode. A constant current of 30 mA was applied, and 80 mL of 0.5 M Na₂SO₄ solution was used as the electrolyte to desorb uranium from the sample into the 80 mL 0.5 M Na₂SO₄ solution. Figure 13 As shown, uranium extracted from PO4-Cu(B) was rapidly released into the electrolyte within 16 minutes. Figure 14 As shown, through uranium extraction and desorption cycles, the extraction rate of U(VI) of PO4-Cu(B) was greater than 85.0% in all 6 cycles, indicating that PO4-Cu(B) has excellent stability and recyclability.
[0080] To evaluate the impact of various interfering ions in the ocean on the uranium extraction performance of PO4-Cu(B), the anti-interference ability of PO4-Cu(B) against different cations and anions was tested. A single interfering ion was added to simulated seawater according to the ratio of interfering ions to U(VI) concentrations in natural seawater. For example... Figure 15 As shown, in a single interfering cation (K + Zn 2+ V 5+ Fe 2+ Ni 2+ Mn 2+ Co 2+ and Pb 2+ In the presence of PO4-Cu(B), the extraction rate of U(VI) was higher than 84.0%; for example Figure 16 As shown, in the case of a single interfering anion (F - CO3 2- Cl-, NO3 - and C2O4 2- In the presence of PO4-Cu(B), the extraction rate of U(VI) was higher than 89.0%; Figure 17 As shown, in various interfering cations (K + Zn 2+ V 5+ Fe 2+ Ni 2+ Mn 2+ Co 2+ and Pb 2+ Even with the coexistence of these two cations, the extraction rate of U(VI) by PO4-Cu(B) remained above 90.0%, while the extraction rates of other cations were all below 37.0%, indicating that PO4-Cu(B) has excellent anti-interference properties for uranium extraction from seawater.
[0081] PO4-Cu(B) was collected after the uranium extraction experiment and characterized by HRTEM, such as... Figure 18 As shown, the PO4-Cu(B) surface tends to transform into a disordered lattice, which is attributed to the surface covering of uranium. Figure 19 The XRD pattern of PO4-Cu(B) after uranium extraction shows that only one additional peak appears in the spectrum, which is attributed to UO. 2.34 (UO 2+x A special form), indicating that the uranium product crystal is a mixture of low-valent uranium and U(VI), and the U 4f XPS spectrum of PO4-Cu(B) after uranium extraction confirms this result. Figure 20 ), 4f 7 / 2 The U 4f peak is divided into three peaks at 380.7 eV, 381.7 eV, and 382.6 eV, which are attributed to U(IV), U(V), and U(VI), respectively. The different valence states of the uranium products promote the formation of insoluble UO. 2+x The formation of.
[0082] Uranyl nitrate was added as an electrolyte to real seawater, with a U(VI) concentration of 8 mg / L. Uranium extraction experiments were performed on PO4-Cu(B), and the results are as follows: Figure 21 As shown, in real seawater with added uranium, the extraction rate of U(VI) by PO4-Cu(B) reached 84.0% after 8 hours.
[0083] Uranium extraction experiments were conducted on PO4-Cu(B) in 10L of real seawater (U(VI) concentration of 3.3 μg / L), and the results are as follows. Figure 22 As shown, PO4-Cu(B) achieved an electrochemical uranium extraction rate of 75.7% and an extraction amount of 24.9 μg in 10 L of real seawater after 8 h, with a calculated extraction capacity of 2.1 mg / g after 24 h. PO4-Cu(B) demonstrates the potential for electrochemical uranium extraction from real seawater.
[0084] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.
Claims
1. A method for preparing copper-based nanomaterials for uranium separation, characterized in that, Includes the following steps: Step 1: Prepare copper chloride solution and sodium borohydride solution using low-temperature deionized water. Quickly add the copper chloride solution to the sodium borohydride solution and react in an ice-water bath until no more bubbles are generated to obtain a reaction solution. The precipitate in the reaction solution is copper nanomaterials with boron doped on the surface. Step 2: Add the disodium hydrogen phosphate solution to the reaction solution containing surface-doped boron copper nanomaterials obtained in Step 1, stir for 10-30 minutes, let stand, collect the precipitate after precipitation is complete, wash and dry to obtain uranium-separated copper-based nanomaterials.
2. The method for preparing copper-based nanomaterials for uranium separation as described in claim 1, characterized in that, In step one, the temperature of the low-temperature deionized water is 0–5°C; the concentration of the copper chloride solution is 0.3–0.4 mol / L; and the concentration of the sodium borohydride solution is 4–6 mol / L.
3. The method for preparing copper-based nanomaterials for uranium separation as described in claim 1, characterized in that, In step one, the volume ratio of copper chloride solution to sodium borohydride solution is 1:0.8 to 1.
2.
4. The method for preparing copper-based nanomaterials for uranium separation as described in claim 1, characterized in that, In step two, the concentration of the disodium hydrogen phosphate solution is 0.05–0.1 mol / L.
5. The method for preparing copper-based nanomaterials for uranium separation as described in claim 1, characterized in that, In step two, the volume ratio of disodium hydrogen phosphate solution to copper chloride solution in step one is 0.8–1.2:
2.
6. The method for preparing copper-based nanomaterials for uranium separation as described in claim 1, characterized in that, In step two, the washing method is as follows: wash with water and acetone 2 to 4 times in sequence.
7. The method for preparing copper-based nanomaterials for uranium separation as described in claim 1, characterized in that, In step two, the specific drying method is as follows: vacuum drying at 50-80℃ for 10-14 hours.
8. The application of a copper-based nanomaterial prepared by the preparation method according to any one of claims 1 to 7 in electrochemical uranium extraction, characterized in that, Copper-based nanomaterials and carbon black were added to anhydrous ethanol, along with Nafion solution. The mixture was sonicated until the solute was evenly distributed, resulting in a mixed solution. This mixed solution was then uniformly coated onto a 1×2 cm carbon felt. After the ethanol evaporated, the coating was continued until the mixed solution was exhausted, resulting in a sample with copper-based nanomaterials uniformly loaded on the carbon felt. This sample was used as the working electrode in a three-electrode system of an electrochemical workstation. The counter electrode in the three-electrode system was a platinum wire electrode, and the reference electrode was an Ag / AgCl electrode. Uranyl nitrate was added to seawater to obtain simulated uranium-rich seawater. The simulated uranium-rich seawater was then added to an electrolytic cell with a three-electrode system, and the voltage was set to -2.0 to -1.5V to extract uranium from the simulated uranium-rich seawater. After electrolysis, using sodium sulfate solution as the electrolyte and the sample as the anode, a constant current of 30mA was applied to desorb uranium from the sample into the sodium sulfate solution.
9. The application of the copper-based nanomaterials as described in claim 8 in electrochemical uranium extraction, characterized in that, The mass ratio of the copper-based nanomaterial to carbon black is 5:2-4; the concentration of the Nafion solution is 5wt%; and the mass-volume ratio of the copper-based nanomaterial, anhydrous ethanol, and Nafion solution is 5mg:1-3mL:30-40μL.
10. The application of the copper-based nanomaterials as described in claim 8 in electrochemical uranium extraction, characterized in that, The concentration of U(VI) in the simulated uranium seawater was 3 μg / L to 100 mg / L; the concentration of sodium sulfate solution was 0.4 to 0.6 mol / L.