Preparation method of ni-co-fe doped electrode for rapid removal of uranium

Abstract

The application discloses a preparation method of a Ni-Co-Fe doped electrode for rapid removal of uranium and belongs to the technical field of electrochemical functional materials. The preparation method of the Ni-Co-Fe doped electrode for rapid removal of uranium comprises the following steps: using a three-electrode system, taking foamed nickel as a working electrode, first performing anodic oxidation on the foamed nickel, then performing cobalt deposition in an electrolyte containing a cobalt source, and finally performing iron deposition in an electrolyte containing an iron source to obtain the Ni-Co-Fe doped electrode. In the application, foamed nickel is used as a substrate, Co elements are first deposited through an electrodeposition process, and then Fe elements are further deposited to form the Ni-Co-Fe electrode, so that the gradient distribution of metals is realized. The significant potential difference among the three metals forms a built-in electric field, the interface charge transfer is accelerated through the Mott-Schottky effect, the catalytic activity and stability of the electrode are further improved, and the removal effect on uranium is significantly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical functional materials, and more particularly relates to a preparation method of a Ni-Co-Fe doped electrode for rapid removal of uranium. BACKGROUND

[0002] Nuclear energy has the advantages of low carbon emission and high efficiency, and is an irreplaceable energy supply. Uranium is the key raw material for nuclear fission and the main "fuel" for nuclear power. Natural uranium is the material basis for the development of the nuclear industry and an important strategic resource and energy mineral. The reserves of uranium in seawater are abundant, and effective utilization of the reserves is of great significance for the development of nuclear energy. At the same time, uranium, as an element with radioactive toxicity and chemical toxicity, may cause uranium pollution of groundwater or surface water if it enters natural water bodies, thereby posing potential ecological and human health risks. Therefore, the sustainable extraction and recovery of uranium resources are of great strategic significance for guaranteeing the green and sustainable development of nuclear energy and environmental safety.

[0003] Currently, the technologies applied to the extraction and recovery of uranium mainly include chemical precipitation, extraction, and adsorption. The adsorption method is widely used due to its simple operation and low cost. However, the traditional physical and chemical adsorption method faces the challenges of low concentration of uranium in seawater and long adsorption equilibrium time. Electric field adsorption shows great potential due to its large adsorption capacity and fast adsorption rate. However, under the driving of an electric field, coexisting competitive cations such as Na + , K + , Ca 2+ , and Mg 2+ may occupy part of the active sites, and the inevitable competitive hydrogen evolution reaction at high voltage will significantly reduce the adsorption capacity and stability of uranium.

[0004] Therefore, it is of great significance to develop an electric field adsorption method that can realize rapid adsorption and removal of uranium and has high adsorption capacity and stability. SUMMARY

[0005] The purpose of the present application is to provide a preparation method of a Ni-Co-Fe doped electrode for rapid removal of uranium to solve the problems existing in the prior art and significantly improve the efficiency of electrocatalytic uranium extraction.

[0006] To achieve the above purpose, the present application provides the following solutions.

[0007] One of the technical solutions of the present application is to provide a preparation method of a Ni-Co-Fe doped electrode for rapid removal of uranium, which comprises the following steps:

[0008] The three-electrode system is used, the foamed nickel is used as a working electrode, the foamed nickel is first anodized, then cobalt is deposited in an electrolyte containing a cobalt source, and finally iron is deposited in an electrolyte containing an iron source, so that the Ni-Co-Fe doped electrode is obtained.

[0009] The foamed nickel is used as a substrate in the present application, the high specific surface area of the foamed nickel can provide sufficient loading space for the loaded metal, the multi-stage pore structure of the foamed nickel can promote electrolyte permeation and bubble release, and reduce mass transfer resistance. After the anodic oxidation treatment, a NiO / Ni(OH)2 transition layer is formed on the surface, which significantly improves the bonding strength of the substrate and the loaded metal. In the present application, Co element is first deposited on the surface of the oxidized foamed nickel through an electrodeposition process to form a Ni-Co electrode, and then Fe element is further deposited on the basis to form a Ni-Co-Fe electrode, so that the metal potential gradient distribution is realized. The significant potential difference of 0.19V between the three metals forms a built-in electric field, which accelerates the interface charge transfer through the Mott-Schottky effect.

[0010] In the present application, the preparation of the Ni-Co-Fe doped electrode is carried out by the strategy of depositing Co element first and then depositing Fe element, which can ensure the electrode potential gradient distribution and form an intermediate layer with higher conductivity, providing a potential buffer platform for subsequent Fe deposition. The order of depositing Co element and Fe element cannot be exchanged, otherwise the electronic synergistic effect of the Co / Fe heterojunction interface will be destroyed, and the potential gradient distribution will be disordered.

[0011] Preferably, the reagent used for anodic oxidation is potassium hydroxide or potassium hydroxide; the concentration of the reagent used for anodic oxidation is 2-4M; the voltage of anodic oxidation is 2-3V, and the time is 20-30min.

[0012] By controlling the type and concentration of the reagent used for anodic oxidation, and the voltage and time of anodic oxidation, the present application can improve the active sites of the surface and the metal combination, and improve the bonding strength of the foamed nickel substrate and the loaded metal. Exceeding the range will cause the collapse of the porous structure of the foamed nickel and the corrosion of the grain boundary.

[0013] Preferably, when depositing cobalt, the electrolyte is composed of boric acid, ammonium chloride and a cobalt source; in the electrolyte during cobalt deposition, the concentration of boric acid is 0.5-1M, boric acid can improve the uniformity, density and functionality of the coating layer through multiple mechanisms such as buffering pH, complexing metal ions and inhibiting side reactions in electrodeposition; the concentration of ammonium chloride is 1-3M, which can improve the conductivity in electrodeposition, and at the same time, cooperates with boric acid to form a smoother and brighter coating layer; the concentration of the cobalt source is 0.1-0.5M; the cobalt source includes one or more of cobalt nitrate, cobalt sulfate and cobalt chloride.

[0014] Preferably, the current density of the cobalt deposition is 20-40 mA / cm 2 , time is 15 to 20 minutes.

[0015] Preferably, when iron deposition is performed, the electrolyte is composed of boric acid, ammonium chloride and an iron source; in the electrolyte during iron deposition, the concentration of boric acid is 0.5 to 1 M, and boric acid can improve the uniformity, density and functionality of the coating by multiple mechanisms such as buffering pH, complexing metal ions and inhibiting side reactions during electrodeposition; the concentration of ammonium chloride is 1 to 3 M, which can improve conductivity during electrodeposition and synergize with boric acid to form a smoother and brighter coating; the concentration of the iron source is 0.1 to 0.5 M; the iron source includes ferrous chloride and / or ferrous sulfate.

[0016] Preferably, the current density of the iron deposition is 20-40 mA / cm 2 , time is 15 to 20 minutes.

[0017] By controlling the type and concentration of the reagents used in the deposition of cobalt and iron elements, as well as the current density and time during deposition, the present invention can achieve synergistic optimization of the metal active site density, the interfacial electronic coupling effect, and the structural stability. Exceeding this range will lead to the disadvantages of decreased electrode conductivity and dendrite growth.

[0018] Preferably, the step of cleaning the working electrode is further included before the anodic oxidation.

[0019] Furthermore, the cleaning reagent includes hydrochloric acid, and the concentration of the hydrochloric acid is 0.05 to 0.1 M; the cleaning time is 20 to 40 minutes.

[0020] Furthermore, the counter electrode of the three-electrode system includes a platinum electrode, the transverse cross-sectional size of the counter electrode is 1-4 cm×1-4 cm, and the reference electrode includes an Ag / AgCl electrode.

[0021] The second technical solution of the present invention: provides a Ni-Co-Fe doped electrode prepared by the above preparation method.

[0022] The third technical solution of the present invention is to provide the application of the above-mentioned Ni-Co-Fe doped electrode in the field of uranium removal.

[0023] Furthermore, when the Ni-Co-Fe doped electrode is used in the field of uranium removal, the Ni-Co-Fe doped electrode is used as the cathode, graphite is used as the counter electrode, and the Ag / AgCl electrode is used as the reference electrode. The voltage is -0.1 V and the time is 0 to 70 minutes.

[0024] The Ni-Co-Fe doped electrode can remove 100% of uranium within 30 minutes under the condition that the initial concentration of uranium is 50 mg / L.

[0025] The present application discloses the following technical effects:

[0026] 1、The present application adopts a three-dimensional porous nickel foam substrate, which is significantly better than a traditional carbon cloth or flat plate electrode substrate, provides sufficient loading space for metal active material loading, has a high specific surface area and a multi-level pore structure, generates a transition layer on the surface of the nickel foam through anode oxidation pretreatment, and improves the bonding strength of the substrate and the metal active layer, thereby avoiding the peeling problem of the active layer that is prone to occur in the traditional direct deposition process.

[0027] 2、The present application first adopts a step-by-step electrodeposition strategy, deposits Co element to form a Ni-Co core layer, and then deposits Fe element on the Ni-Co core layer to form a Fe shell layer, thereby forming a Ni-Co-Fe doped electrode with gradient metal distribution. Compared with the traditional one-step co-deposition process, the metal distribution uniformity is improved, and the Mott-Schottky heterojunction is formed by using the significant potential difference (DE=0.19V) among Ni, Co and Fe, thereby generating a built-in electric field to drive the rapid migration of interface electrons.

[0028] 3、The Ni-Co-Fe doped electrode can remove 100% of uranium within 30 minutes under the condition that the initial concentration of uranium is 50 mg / L, and the uranium removal efficiency is obviously improved compared with the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a surface electron microscope graph of the original nickel foam of Example 1;

[0030] Figure 2 It is a surface electron microscope graph of the nickel foam after anode oxidation of Example 1;

[0031] Figure 3 It is a surface electron microscope graph of the Ni-Co-Fe doped electrode obtained in Example 1;

[0032] Figure 4 It is a Tafel curve of the Ni-Co doped electrode obtained in Example 1 and the Ni-Fe-Co doped electrode obtained in Example 1;

[0033] Figure 5 It is the adsorption and removal effect of uranium by the nickel foam electrode obtained in Example 1, the nickel foam electrode after anode oxidation obtained in Example 1, the Ni-Co doped electrode obtained in Example 1 and the Ni-Fe-Co doped electrode obtained in Example 1;

[0034] Figure 6The adsorption and removal effect of the Ni-Fe-Co doped electrode obtained in Example 1 on uranium in solutions containing different uranium concentrations;

[0035] Figure 7 This is a surface morphology of the Ni-Fe-Co doped electrode obtained in Example 1 after the adsorption and removal effect test on uranium in a uranium-containing solution is completed;

[0036] Figure 8 This is an X-ray photoelectron spectrum of the Ni-Fe-Co doped electrode obtained in Example 1 after the adsorption and removal effect test on uranium in a uranium-containing solution is completed. DETAILED DESCRIPTION

[0037] The present invention provides a Ni-Co-Fe doped electrode for rapid uranium removal, a preparation method thereof, and its application in the field of uranium removal. The key to the application in the field of uranium removal lies in the field of extracting and recovering uranium from water bodies.

[0038] Uranium mainly exists in water in the form of hexavalent (U(VI)). Hexavalent uranium ions are easily converted from hydroxide ions (OH - ) to seize O 2- , forming uranyl ions (UO2 2+ ). UO2 2+ Under certain conditions, it can be reduced to tetravalent uranium (U(IV)), which is easy to precipitate. Electrocatalysis is a technology that induces redox reactions through electron transfer under the influence of an external electric field. It is a key process for renewable energy conversion and environmental remediation. Combining electrocatalysis with the redox process of uranium can achieve the regeneration of electrode active sites: free UO2 in water 2+ Electrostatic attraction attracts uranium to the negative electrode surface, where it receives electrons and is reduced to relatively fixed U(IV) or electrically neutral uranium species. Electrocatalysis allows for efficient uranium extraction at low voltages, thus avoiding the occurrence of hydrogen evolution reactions.

[0039] Improving the efficiency of electrocatalytic reduction is a key factor in achieving the extraction of uranyl ions. The efficiency of the electrocatalytic reaction mainly depends on the surface structure of the electrocatalyst and the reaction environment near the surface of the electrocatalyst. At present, methods to improve the electrocatalytic efficiency include modifying the catalyst, applying external forces, and optimizing the electrode configuration. It is worth noting that, unlike catalysts, optimizing the electrode configuration can directly affect the reaction kinetics and overall performance of the electrocatalytic process. By introducing different metal hybrid atoms of Ni, Co, and Fe inside and at the interface of the electrode, an electrode potential difference can be formed, driving the electrons near the interface to move toward the electrode in a directional manner, thereby enriching them at the electrode interface. Therefore, optimizing the electrode configuration is crucial to improving the efficiency of electrocatalytic uranium extraction.

[0040] However, the prior art has less research on optimizing electrode configuration, and the conventional optimized configuration is mainly by introducing single metal hybrid atoms in the electrode interior and interface or one-time introduction of multiple different metal hybrid atoms, which still cannot significantly improve the electro-catalytic uranium extraction efficiency.

[0041] Based on the above problems, the present application adopts the strategy of introducing different metal hybrid atoms on the surface of a foam nickel substrate in a specific order to prepare a special structure Ni-Co-Fe doped electrode, which is different from the prior art. The combination strength of the doped metal and the substrate and the uniformity of the distribution of the doped metal are improved, and the Mott-Schottky heterojunction formed by the electrode with the special structure generates a built-in electric field to drive the rapid migration of interface electrons, significantly improving the adsorption and removal efficiency of uranium.

[0042] The various exemplary embodiments of the present application will now be described in detail, which should not be considered as limiting the present application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present application.

[0043] It should be understood that the terms described in the present application are only for describing the specific embodiments, and are not used to limit the present application. In addition, for the numerical range in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value in the stated range, and any other stated value or intermediate value in the stated range, is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In the case of conflict between any document incorporated by reference and the present specification, the present specification will control.

[0045] Many modifications and variations of the specific embodiments of the present application can be made without departing from the scope or spirit of the present application, which will be apparent to those skilled in the art. Other embodiments resulting from the combination of the features of the present application will be apparent to those skilled in the art from the present specification. The present specification and examples are merely illustrative.

[0046] As used herein, "comprise", "comprising", "have", "having", "include", "including", "contain", "containing", and the like, are open-ended terms that are intended to mean including, but not limited to.

[0047] It should be noted that the invention is not detailed in the place, which is the conventional means of operation in the art, and is not the focus of the invention.

[0048] The raw materials used in the following examples and comparative examples of the present application are commercially available products, and the source of the commercially available products does not affect the technical effects of the present application.

[0049] Example 1

[0050] This embodiment provides the preparation of the Ni-Co-Fe doped electrode, and the specific steps are as follows:

[0051] 1) The foam nickel (3cm×3cm×0.3cm) was ultrasonically cleaned in 0.1M HCl for 20min.

[0052] 2) The Ni-Co-Fe doped electrode was prepared by using the conventional two-electrode system in a single-chamber battery, with a platinum electrode (lateral cross-sectional size 2cm×2cm) as the counter electrode, an Ag / AgCl electrode as the reference electrode, and the above-mentioned cleaned foam nickel as the working electrode substrate. The foam nickel was first anodized in 3M KOH at a voltage of 3V for 30min.

[0053] 3) An aqueous solution of 0.65M H3BO3, 1.86M NH4Cl and 0.3M Co(NO3)2 was prepared as an electrolyte, and the anodized foam nickel electrode was electrodeposited at a direct current of 30mA / cm 2 for 15min to obtain a Ni-Co doped electrode.

[0054] 4) An aqueous solution of 0.65M H3BO3, 1.86M NH4Cl and 0.3M FeCl2 was prepared as an electrolyte, and the above-mentioned Ni-Co doped electrode was electrodeposited at a direct current of 30mA / cm 2 for 15min to obtain a Ni-Co-Fe doped electrode.

[0055] The surface of the foam nickel used in Example 1 (original foam nickel), the anodized foam nickel and the obtained Ni-Co-Fe doped electrode were characterized by scanning electron microscopy.

[0056] Figure 1 The surface electron micrograph of the original foam nickel of Example 1 is shown in Figure 1; Figure 2 The surface electron micrograph of the anodized foam nickel of Example 1 is shown in Figure 2; Figure 3 The surface electron micrograph of the Ni-Co-Fe doped electrode obtained in Example 1 is shown in Figure 3.

[0057] From the above results, it can be seen that the Ni-Co-Fe doped electrode prepared in Example 1 has a large specific surface area and a large number of pores, and the surface of the electrode is rough and uneven, which is beneficial to the adsorption of the electrode and the improvement of the electrode performance. Figure 1 and Figure 2It can be seen that the surface roughness of the anodized foamed nickel is significantly increased, the active sites of the surface combined with the metal are increased, and the bonding strength of the foamed nickel substrate and the loaded metal can be improved. Figure 3 It can be seen that the surface of the obtained Ni-Co-Fe doped electrode is obviously deposited with elements, and the active surface area is increased, mainly due to the deposition of Co and Fe elements on the surface.

[0058] Comparative Example 1

[0059] The difference from Example 1 is that the "foamed nickel" is replaced by an equal size "carbon cloth", and the others are the same as Example 1.

[0060] Comparative Example 2

[0061] The difference from Example 1 is that the "foamed nickel" is replaced by an equal size "flat electrode substrate (gold material)", and the others are the same as Example 1.

[0062] Comparative Example 3

[0063] The difference from Example 1 is that the Co element and the Fe element are deposited on the foamed nickel at one time, and the others are the same as Example 1.

[0064] Specifically:

[0065] 1) The foamed nickel (3cm×3cm×0.3cm) was ultrasonically cleaned in 0.1M HCl for 20min.

[0066] 2) A Ni-Co-Fe doped electrode was prepared by using a conventional two-electrode system in a single-chamber battery, with a platinum electrode (lateral cross-sectional size 2cm×2cm) as the counter electrode, an Ag / AgCl electrode as the reference electrode, and the above-mentioned cleaned foamed nickel as the working electrode substrate. The foamed nickel was first anodized in 3M KOH at a voltage of 3V for 30min.

[0067] 3) A water solution of 0.65M H3BO3, 1.86M NH4Cl, 0.3M Co(NO3)2 and 0.3M FeCl2 was configured as an electrolyte, and the anodized foamed nickel electrode was electrodeposited at a direct current of 30mA / cm 2 for 15min to obtain a Ni-Co-Fe doped electrode.

[0068] Comparative Example 4

[0069] The difference from Example 1 is that the deposition order of the Co element and the Fe element is changed, and the others are the same as Example 1.

[0070] Specifically:

[0071] 1) The foamed nickel (3cm×3cm×0.3cm) was ultrasonically cleaned in 0.1M HCl for 20min.

[0072] 2) The Ni-Co-Fe doped electrode was prepared by using the traditional two-electrode system in a single-chamber cell, with a platinum electrode (2 cm x 2 cm in lateral cross-sectional size) as the counter electrode, an Ag / AgCl electrode as the reference electrode, and the above-mentioned cleaned nickel foam as the working electrode substrate. The nickel foam was first anodized in 3 M KOH at a voltage of 3 V for 30 min.

[0073] 3) An aqueous solution of 0.65 M H3BO3, 1.86 M NH4Cl, and 0.3 M FeCl2was configured as the electrolyte, and the anodized nickel foam electrode was electrodeposited at a direct current of 30 mA / cm 2 for 15 min to obtain a Ni-Fe doped electrode.

[0074] 4) An aqueous solution of 0.65 M H3BO3, 1.86 M NH4Cl, and 0.3 M Co(NO3)2was configured as the electrolyte, and the above-mentioned Ni-Fe doped electrode was electrodeposited at a direct current of 30 mA / cm 2 for 15 min to obtain a Ni-Fe-Co doped electrode.

[0075] Comparative Example 5

[0076] The difference from Example 1 is that the anodization conditions of the nickel foam are adjusted, and the others are the same as in Example 1.

[0077] Specifically:

[0078] 1) The nickel foam (3 cm x 3 cm x 0.3 cm) was ultrasonically cleaned in 0.1 M HCl for 20 min.

[0079] 2) The Ni-Co-Fe doped electrode was prepared by using the traditional two-electrode system in a single-chamber cell, with a platinum electrode (2 cm x 2 cm in lateral cross-sectional size) as the counter electrode, an Ag / AgCl electrode as the reference electrode, and the above-mentioned cleaned nickel foam as the working electrode substrate. The nickel foam was first anodized in 1 M NaOH at a voltage of 5 V for 30 min.

[0080] 3) An aqueous solution of 0.65 M H3BO3, 1.86 M NH4Cl, and 0.3 M Co(NO3)2was configured as the electrolyte, and the anodized nickel foam electrode was electrodeposited at a direct current of 30 mA / cm 2 for 15 min to obtain a Ni-Co doped electrode.

[0081] 4) An aqueous solution of 0.65 M H3BO3, 1.86 M NH4Cl, and 0.3 M FeCl2was configured as the electrolyte, and the anodized nickel foam electrode was electrodeposited at a direct current of 30 mA / cm 2The Ni-Co-Fe doped electrode was obtained by electrodeposition of the above Ni-Co doped electrode under the direct current of 30 mA / cm

[0082] Comparative Example 6

[0083] The difference from Example 1 is that the electrodeposition conditions of the electrode were adjusted, and the others were the same as those of Example 1.

[0084] Specifically,

[0085] 1) The nickel foam (3 cm x 3 cm x 0.3 cm) was ultrasonically cleaned in 0.1 M HCl for 20 min.

[0086] 2) The Ni-Co-Fe doped electrode was prepared by using the traditional two-electrode system in a single-chamber battery, with a platinum electrode (lateral cross-sectional size of 2 cm x 2 cm) as the counter electrode, an Ag / AgCl electrode as the reference electrode, and the above cleaned nickel foam as the working electrode substrate. The nickel foam was first anodized in 3 M KOH at a voltage of 3 V for 30 min.

[0087] 3) An aqueous solution of 0.65 M H3BO3, 1.86 M NH4Cl and 0.3 M Co(CO3)2 was prepared as an electrolyte, and the anodized nickel foam electrode was electrodeposited under the direct current of 30 mA / cm 2 to obtain the Ni-Co doped electrode.

[0088] 4) An aqueous solution of 0.65 M H3BO3, 1.86 M NH4Cl and 0.3 M Fe2(SO4)3 was prepared as an electrolyte, and the above Ni-Co doped electrode was electrodeposited under the direct current of 30 mA / cm 2 to obtain the Ni-Co-Fe doped electrode.

[0089] Performance test:

[0090] 1. Test of catalytic activity and stability of the electrode:

[0091] The Ni-Co doped electrode obtained in Example 1 and the Ni-Fe-Co doped electrode obtained in Example 1 were used as working electrodes, a platinum electrode (lateral cross-sectional size of 2 cm x 2 cm) was used as the counter electrode, an Ag / AgCl electrode was used as the reference electrode, and 1 M sodium sulfate solution was used as the electrolyte to determine the Tafel slope, and the results are shown in Figure 4 .

[0092] Figure 4 Tafel curves of the Ni-Co doped electrode obtained in Example 1 and the Ni-Fe-Co doped electrode obtained in Example 1.

[0093] The calculation method of the Tafel curve slope is as follows:

[0094] η = a + b log |j|

[0095] In the formula, η is the overpotential, j is the current density, a is the intercept, and b is the Tafel slope.

[0096] The Tafel slope is used to evaluate the catalytic activity and stability of the electrode, and is calculated by Figure 4 It can be known that the Tafel slope fitting of the Ni-Co-Fe doped electrode is 521 mV / dec, and the Tafel slope fitting of the Ni-Co electrode is 365 mV / dec, proving that the catalytic activity of the synthesized Ni-Co-Fe electrode is obviously improved. In addition, it can be observed that the Tafel slope of the Ni-Co-Fe doped electrode remains stable during the electrochemical test and does not change significantly, indicating that the Ni-Co-Fe doped electrode obtained by the application has high catalytic stability.

[0097] 2. Test of the adsorption and removal effect of uranium in the uranium-containing solution:

[0098] The foam nickel electrode obtained in Example 1, the foam nickel electrode after anodic oxidation obtained in Example 1, the Ni-Co doped electrode obtained in Example 1, and the Ni-Fe-Co doped electrode obtained in Example 1 are respectively used as the working electrode, the platinum electrode (the horizontal cross-sectional size is 2 cm x 2 cm) is used as the counter electrode, and the Ag / AgCl electrode is used as the reference electrode, and the uranium removal experiment is carried out in 0-70 min, and the results are shown in Figure 5 .

[0099] Figure 5 The adsorption and removal effect of uranium of the foam nickel electrode obtained in Example 1, the foam nickel electrode after anodic oxidation obtained in Example 1, the Ni-Co doped electrode obtained in Example 1, and the Ni-Fe-Co doped electrode obtained in Example 1.

[0100] It can be known from Figure 5 that the Ni-Fe-Co doped electrode obtained in Example 1 can significantly improve the uranium extraction efficiency, and can remove 100% of the uranium in 30 min under the condition that the initial concentration of uranium is 50 mg / L.

[0101] The Ni-Fe-Co doped electrode obtained in Example 1 is used as the working electrode, the platinum electrode (the horizontal cross-sectional size is 2 cm x 2 cm) is used as the counter electrode, and the Ag / AgCl electrode is used as the reference electrode, and the uranium removal experiment is carried out in 0-70 min, and the results are shown in Figure 6 .

[0102] Figure 6 The Ni-Fe-Co doped electrode obtained in Example 1 was used to test the uranium removal effect in the solution containing different concentrations of uranium.

[0103] As can be seen from the above table, the Ni-Fe-Co doped electrode obtained in Example 1 can remove more than 95% of uranium within 10 minutes under the condition that the initial concentration of uranium is 20 mg / L. Figure 6

[0104] In addition, in order to verify the uranium removal pathway of the Ni-Fe-Co doped electrode, the surface morphology of the Ni-Fe-Co doped electrode obtained in Example 1 after being treated for 70 minutes under the condition that the initial concentration of uranium is 50 mg / L was characterized, and the results are shown in Figure 7

[0105] Figure 7 The surface morphology of the Ni-Fe-Co doped electrode obtained in Example 1 after the uranium removal effect test in the solution containing uranium was completed.

[0106] As can be seen from the above table, the Ni-Fe-Co doped electrode obtained in Example 1 can remove more than 95% of uranium within 10 minutes under the condition that the initial concentration of uranium is 20 mg / L. Figure 7

[0107] The Ni-Fe-Co doped electrode obtained in Example 1 after being treated for 70 minutes under the condition that the initial concentration of uranium is 50 mg / L was subjected to X-ray photoelectron spectroscopy analysis, and the results are shown in Figure 8

[0108] Figure 8 The X-ray photoelectron spectrogram of the Ni-Fe-Co doped electrode obtained in Example 1 after the uranium removal effect test in the solution containing uranium was completed.

[0109] As can be seen from the above table, the Ni-Fe-Co doped electrode obtained in Example 1 can remove more than 95% of uranium within 10 minutes under the condition that the initial concentration of uranium is 20 mg / L. Figure 8

[0110] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0111] ​​​​​The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a Ni-Co-Fe doped electrode for rapid uranium removal, characterized in that: The steps include: A three-electrode system is used, with nickel foam as the working electrode, which is first anodized, then cobalt is deposited in an electrolyte containing a cobalt source, and finally iron is deposited in an electrolyte containing an iron source to obtain the Ni-Co-Fe doped electrode.

2. The preparation method according to claim 1, characterized in that The reagent used for the anodic oxidation is a potassium hydroxide solution; the concentration of the potassium hydroxide solution is 2-4M.

3. The preparation method according to claim 1, characterized in that The voltage of the anodic oxidation is 2-3V, and the time is 20-30 minutes.

4. The preparation method according to claim 1, characterized in that When cobalt deposition is performed, the electrolyte consists of boric acid, ammonium chloride and a cobalt source; when cobalt deposition is performed, the concentration of boric acid in the electrolyte is 0.5 to 1 M, the concentration of ammonium chloride is 1 to 3 M, and the concentration of the cobalt source is 0.1 to 0.5 M; the cobalt source includes one or more of cobalt nitrate, cobalt sulfate and cobalt chloride.

5. The preparation method according to claim 1, characterized in that The current density of the cobalt deposition is 20-40 mA / cm 2 , time is 15 to 20 minutes.

6. The preparation method according to claim 1, characterized in that When iron deposition is performed, the electrolyte is composed of boric acid, ammonium chloride and an iron source; when iron deposition is performed, the concentration of boric acid in the electrolyte is 0.5 to 1 M, the concentration of ammonium chloride is 1 to 3 M, and the concentration of the iron source is 0.1 to 0.5 M; the iron source includes ferrous chloride and / or ferrous sulfate.

7. The preparation method according to claim 1, characterized in that The current density of the iron deposition is 20-40 mA / cm 2 , time is 15 to 20 minutes.

8. The preparation method according to claim 1, characterized in that The method further includes a step of cleaning the working electrode before the anodic oxidation.

9. A Ni-Co-Fe doped electrode prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the Ni-Co-Fe doped electrode according to claim 9 in the field of uranium removal.

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