Plasma-based manganese dioxide electrode material, method of preparation and use

Abstract

The application provides a kind of plasma-based manganese dioxide electrode material, preparation method and application;The preparation method comprises the following steps: S1, obtaining the mixed solution containing potassium permanganate and reducing agent;S2, the mixed solution is hydrothermally treated, and the product of the hydrothermal treatment is solid-liquid separated, to obtain an intermediate material;The temperature of the hydrothermal treatment is 90-145 DEG C, and the duration of the hydrothermal treatment is 6-24h;S3, the intermediate material is subjected to plasma treatment, to obtain a manganese dioxide electrode material;The gas source of the plasma treatment is inert gas.The application can reduce the manganese dissolution rate on the basis of ensuring the thallium removal rate, thereby improving the cycle performance of the electrode material.

Description

Technical Field

[0001] This invention belongs to the field of manganese electrode material preparation and wastewater treatment, and particularly relates to a plasma-based manganese dioxide electrode material, its preparation method and application. Background Technology

[0002] For a long time, heavy metal pollution has been one of the most serious environmental problems threatening human health and aquatic ecosystems. Thallium (Tl), a highly toxic heavy metal that has received significant attention in recent years, has an extremely low lethal dose for adults, and its toxicity far exceeds that of traditional heavy metals such as Hg, As, Cd, and Pb. Furthermore, due to Tl... + Thallium's high mobility makes it easily and accidentally released into water during the utilization of thallium-containing mineral resources, causing serious thallium pollution incidents. Therefore, thallium pollution in water bodies urgently needs to be addressed. Among numerous treatment technologies, capacitive deionization technology has become a promising water treatment technology due to its advantages of high energy efficiency, environmental friendliness, and low investment cost, and has been widely studied.

[0003] MnO2 is not only inexpensive and abundant, with a high theoretical specific capacity, but also possesses a wider voltage window (around 1 V) compared to transition metal oxides such as NiO and Co3O4, which is beneficial for achieving higher energy densities, making it a current research hotspot in electrode materials. However, with in-depth research, it has been found that its relatively poor ionic properties (10⁻¹³ Scm⁻¹) have led to challenges. -1 ) and electronic conductivity (10 -5 -10 -6 Scm -1 However, the rate performance of MnO2 is not ideal, and the actual measured capacity value differs from the theoretical value, thus limiting the practical application of this material. When it undergoes electrochemical behavior, problems such as dissolution of active materials, low intrinsic conductivity, irreversible phase transition, and structural collapse may occur, leading to a large amount of manganese dissolving during the electrochemical reaction.

[0004] In view of this, it is necessary to provide a plasma-based manganese dioxide electrode material, preparation method and application to solve or at least alleviate the above-mentioned technical defects of large-scale dissolution of manganese during electrochemical reactions. Summary of the Invention

[0005] The main objective of this invention is to provide a plasma-based manganese dioxide electrode material, its preparation method, and its application, aiming to solve or at least alleviate the technical problem of excessive manganese dissolution during electrochemical reactions.

[0006] To achieve the above objectives, the present invention provides a method for preparing a plasma-based manganese dioxide electrode material, comprising the following steps:

[0007] S1, obtaining a mixed solution containing potassium permanganate and a reducing agent;

[0008] S2, performing hydrothermal treatment on the mixed solution, and performing solid-liquid separation on a product of the hydrothermal treatment to obtain an intermediate material;

[0009] The temperature of the hydrothermal treatment is 90-145 DEG C, and the time length of the hydrothermal treatment is 6-24 h;

[0010] S3, performing plasma treatment on the intermediate material to obtain a manganese dioxide electrode material; and the gas source of the plasma treatment is an inert gas.

[0011] Further, the reducing agent comprises one or more of ammonium oxalate, manganese sulfate and hydrochloric acid.

[0012] Further, the molar ratio of the potassium permanganate to the reducing agent is 2:1-6:1.

[0013] The process of obtaining the mixed solution comprises: mixing the potassium permanganate and the reducing agent in a water body to obtain the mixed solution; and the mass-volume ratio of the potassium permanganate to the mixed solution is 0.3 g:45 mL-0.5 g:45 mL.

[0014] Further, the time length of the plasma treatment is 0.5-3.5 min or 6.5-7.5 min.

[0015] Further, the voltage of the plasma treatment is 15-45 V, and the current of the plasma treatment is ≤3 A.

[0016] The application further provides a plasma-based manganese dioxide electrode material prepared by using any of the preparation methods described above.

[0017] The application further provides application of any of the manganese dioxide electrode materials described above in electric adsorption thallium removal.

[0018] The application further provides a method for electric adsorption thallium removal, which comprises: using a substrate material coated with any of the manganese dioxide electrode materials described above as an anode and a cathode of a capacitive deionization device, or using a substrate material coated with any of the manganese dioxide electrode materials described above as a cathode of a capacitive deionization device.

[0019] Then, the capacitive deionization device is used to treat a thallium-containing solution under an applied electric field.

[0020] Further, the concentration of thallium ions in the thallium-containing solution is 0.05-600 mg / L.

[0021] Further, the pH of the thallium-containing solution is 3-11.

[0022] The voltage of the applied electric field is 0.4~1.2 V, and the duration of application of the applied electric field is 0.5~4 h.

[0023] Compared with the prior art, the present invention has at least the following advantages:

[0024] This invention can reduce the manganese leaching rate while ensuring the thallium removal rate, thereby improving the cycle performance of the electrode material. The key to the technical solution of this invention lies in using electrons, ions, photons, excited-state particles generated during plasma modification treatment to bombard the material surface and cause complex physicochemical reactions, thereby improving the physical properties and surface chemical properties of the material, thereby improving the stability of manganese dioxide and increasing surface defects, so that it has high efficiency and stability in the process of electro-adsorption thallium removal.

[0025] Specifically, this invention involves a hydrothermal reaction of potassium permanganate and a reducing agent to obtain modifiable manganese dioxide. Then, low-temperature plasma treatment alters the material's physical and surface chemical properties, creating surface defects that generate more oxygen vacancies and active sites. This enhances the intrinsic properties of the manganese dioxide material, overcoming its defects such as structural collapse, low intrinsic conductivity, and poor cycling behavior in electrochemical processes. Simultaneously, it improves the adsorption performance for thallium. Compared to traditional methods, this invention is more efficient, faster, and cleaner, possessing significant economic and environmental benefits and broad application prospects. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a graph showing the effect of different plasma treatment times on thallium removal rate in Example 2 of the present invention.

[0028] Figure 2 This is a graph showing the effect of different plasma treatment times on manganese leaching in Example 2 of the present invention.

[0029] Figure 3 This is a graph showing the effect of different thallium ion concentrations on thallium adsorption and manganese leaching in Example 3 of the present invention; in the graph, 50ppm, 100ppm, 200ppm, 400ppm, and 600ppm refer to 46.25 mg / L, 97.80 mg / L, 177.80 mg / L, 367.55 mg / L, and 539.10 mg / L in Example 3, respectively.

[0030] Figure 4 This is a fitting curve diagram of the Langmuir and Freundlich models in Embodiment 3 of the present invention;

[0031] Figure 5 This is a data graph showing the effect of different pH values ​​on thallium removal rate in Example 4 of the present invention;

[0032] Figure 6 This is a graph showing the effect of different pH values ​​on manganese leaching in Example 4 of the present invention.

[0033] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0036] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, can be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention. It should be noted that the manganese leaching amount in this invention refers to the concentration of manganese ions in the solution after electro-adsorption removal of thallium. In this invention, since multiple experiments were involved in Examples 2 and 4, the actual concentration of thallium ions may fluctuate slightly when preparing the thallium-containing solution, which is a normal error and does not affect the understanding of the technical effects of this invention by those skilled in the art.

[0037] This invention provides a method for preparing a plasma-based manganese dioxide electrode material, comprising the following steps:

[0038] S1, obtain a mixture containing potassium permanganate and a reducing agent.

[0039] To ensure an increase in thallium removal rate and a decrease in manganese leaching rate, the molar ratio of potassium permanganate to the reducing agent is 2:1 to 6:1.

[0040] As an explanation of the reducing agent, the reducing agent may include one or more of ammonium oxalate, manganese sulfate, and hydrochloric acid.

[0041] As an explanation of the mixture, the process of obtaining the mixture includes: mixing the potassium permanganate and the reducing agent in water to obtain the mixture; the mass-to-volume ratio of the potassium permanganate and the mixture can be 0.3g:45mL to 0.5g:45mL.

[0042] S2, the mixture is subjected to hydrothermal treatment, and the product of the hydrothermal treatment is separated into solid and liquid components to obtain an intermediate material (solid product), wherein the intermediate material is manganese dioxide powder.

[0043] To ensure the acquisition of the intermediate material, the hydrothermal treatment temperature is 90~145℃ and the hydrothermal treatment duration is 6~24 h.

[0044] S3, the intermediate material is subjected to plasma treatment to obtain manganese dioxide electrode material.

[0045] It should be noted that plasma modification technology utilizes plasma to contact the material surface. Under the influence of active particles such as electrons, ions, photons, and free radicals in the plasma, the surface properties of the material can be changed as required by controlling appropriate plasma conditions.

[0046] In order to utilize the electrons, ions, photons, excited-state particles generated during plasma modification to bombard the material surface and cause complex physicochemical reactions, thereby improving the physical properties and surface chemical properties of the material, and thus enhancing the stability of manganese dioxide and increasing surface defects, so as to make it have efficient and stable characteristics in the process of electro-adsorption thallium removal, the present invention uses plasma treatment on the intermediate material, and the gas source of the plasma treatment is an inert gas, specifically argon.

[0047] Thus, this invention enables manganese dioxide to have more oxygen vacancies and active sites, thereby improving the intrinsic properties of manganese dioxide materials and overcoming their defects such as easy structural collapse, low intrinsic conductivity and poor cycling in electrochemical behavior, while simultaneously improving stability and adsorption performance.

[0048] In order to obtain an ideal manganese dioxide electrode material and further reduce the manganese dissolution rate, the plasma treatment time is 0.5~3.5 min or 6.5~7.5 min, preferably 0.5~1.5 min or 6.5~7.5 min.

[0049] In this invention, the plasma treatment is low-temperature plasma, i.e., low-temperature plasma treatment; the voltage of the plasma treatment can be 15~45 V, and the current of the plasma treatment can be ≤3 A, such as 2~3 A.

[0050] As a specific illustration of the plasma treatment process, in this invention, the plasma treatment includes: placing the intermediate material into the discharge region of a plasma generator, continuously introducing inert gas (flow rate can be 40~60 mL / min), adjusting the voltage and current to start discharge etching, processing for a preset time, allowing it to stand for a certain period of time, and then removing it to obtain manganese dioxide electrode material; the temperature is not controlled during the plasma treatment process. In this example of the invention, the plasma generator uses a plasma reaction power supply from Nanjing Suman Plasma Technology Co., Ltd., model CTP-2000, and the quartz reactor used in the plasma generator is from Changsha Dongyan New Materials Co., Ltd., where the material to be treated (such as the intermediate material) is placed.

[0051] The present invention also provides a plasma-based manganese dioxide electrode material, which is prepared using any of the preparation methods described above.

[0052] The present invention also provides an application of manganese dioxide electrode materials as described above in electroadsorption thallium removal.

[0053] The present invention also provides a method for electro-adsorption removal of thallium, comprising: using a substrate material coated with any of the manganese dioxide electrode materials described above as the anode and cathode of a capacitive deionization device; and then treating a thallium-containing solution using the capacitive deionization device under an applied electric field.

[0054] Alternatively, a substrate material coated with any of the manganese dioxide electrode materials described above can be used as the cathode of a capacitive deionization device; then, the capacitive deionization device is used to treat a thallium-containing solution under an applied electric field.

[0055] That is, firstly, the surface of the substrate material is coated with the manganese dioxide electrode material to obtain the electrode to be used; then, both the anode and the cathode are made using the electrode to be used, or only the cathode is made using the electrode to be used (in this case, the anode can be an activated carbon electrode); finally, the thallium-containing solution is placed in the capacitor deionization device, and the external electric field is applied to the capacitor deionization device to electrochemically adsorb thallium ions in the thallium-containing solution.

[0056] In this invention, the substrate material may include a titanium plate; the method of coating the manganese dioxide electrode material onto the substrate material may include: mixing the manganese dioxide electrode material, a conductive material, and a binder material, and then coating the mixture onto the surface of the substrate material; in the experimental process, this invention uses a single-sided coating method, with the coated surface facing the other electrode, and the electrodes used in each experimental process are of the same size. The conductive material may include conductive carbon black, and the binder material may include polyvinylidene fluoride.

[0057] For example, the capacitive deionization device can be composed of a fixed plate, a silicone pad, an anode, a silicone pad, a cathode, a silicone pad, and a fixed plate, which are sequentially fixed and combined to form an internal cavity for reaction; in a specific embodiment of the present invention, a peristaltic pump is used to promote the flow of the thallium-containing solution in the capacitive deionization device.

[0058] The thallium-containing solution may include or be thallium-containing wastewater, and the thallium-containing solution may contain one or more of monovalent thallium and trivalent thallium. Specifically, the thallium-containing solution may contain one or more of TlNO3 and Tl(NO3)3.

[0059] It should be noted that, generally speaking, for conventional manganese dioxide electrodes, the higher the concentration of thallium ions in the thallium-containing solution, the more manganese is dissolved. Therefore, when processing the thallium-containing solution with a higher concentration, the circulation performance of conventional manganese dioxide electrodes is poor. However, the manganese dioxide electrode material provided by the present invention can still ensure that the amount of manganese dissolved is not too large when processing the thallium-containing solution with a higher concentration, thereby improving the circulation performance of the electrode material and reducing manganese loss.

[0060] In this invention, the concentration of thallium ions in the thallium-containing solution can be 0.05~600 mg / L, preferably 0.05~200 mg / L; the pH of the thallium-containing solution can be 3~11; the voltage of the applied electric field can be 0.4~1.2 V, and the duration of application of the applied electric field can be 0.5~4 h.

[0061] The following are specific examples of the present application:

[0062] Example 1

[0063] 1. Preparation of manganese dioxide:

[0064] To obtain 2.5-MnO2: 0.3951 g (2.5 mmol) KMnO4 and 38 μL concentrated hydrochloric acid were added to 45 mL of deionized water to form a precursor solution (the concentration of hydrochloric acid in the precursor solution was 10 mmol / L). The solution was then hydrothermally treated at 140 °C for 12 h in an autoclave. After filtration and washing, the precipitate was dried at 80 °C for 12 h, and this was designated as 2.5-MnO2.

[0065] To obtain 5-MnO2: 0.7902 g (5.0 mmol) KMnO4 and 38 μL concentrated hydrochloric acid were added to 45 mL of deionized water to form a precursor solution (the concentration of hydrochloric acid in the precursor solution was 10 mmol / L). The solution was then hydrothermally treated at 140 °C for 12 h in an autoclave. After filtration and washing, the precipitate was dried at 80 °C for 12 h, and this was recorded as 5-MnO2.

[0066] 2. Electroadsorption thallium removal tests were conducted using 2,5-MnO2 and 5-MnO2 as test materials, as detailed below:

[0067] The test material, conductive carbon black, and polyvinylidene fluoride were mixed in a mass ratio of 8.0:1.5:0.5 to obtain a mixture; 50 mg of the mixture was coated onto an electrode plate (titanium plate) to obtain a manganese dioxide electrode; the cathode and anode of the capacitive deionization device both use this manganese dioxide electrode.

[0068] The above-mentioned capacitor deionization device was used to electro-adsorb 50 mL of thallium-containing solution under an applied electric field. The thallium ion concentration of the thallium-containing solution (thallium nitrate solution) was 107.72 μg / L and the pH was 3.68. The applied electric field voltage was 1.0 V and the electro-adsorption time was 2 h.

[0069] The experimental results of electroadsorption for thallium removal are shown in the table below:

[0070]

[0071] Example 2

[0072] This embodiment provides an application of electroadsorption for thallium removal under different plasma treatment times, as follows:

[0073] 1. Preparation of plasma-based manganese dioxide electrode materials:

[0074] 0.3951 g (2.5 mmol) of KMnO4 and 38 μL of concentrated hydrochloric acid were added to 45 mL of deionized water to form a precursor solution (the concentration of hydrochloric acid in the precursor solution was 10 mmol / L). The solution was then hydrothermally treated at 140 °C for 12 h in an autoclave. After filtration and washing, the precipitate was dried at 80 °C for 12 h to obtain MnO2 material.

[0075] The MnO2 material was placed in the discharge region of the plasma generator, and argon gas was continuously introduced into it (flow rate of 50 mL / min). After adjusting the voltage (40 V) and current (2.5 A), discharge etching (plasma treatment) was started. After treatment for 0-7 min, the material was allowed to stand for 1 min before being removed, resulting in 8 types of manganese dioxide electrode materials (corresponding to different treatment times). That is, the corresponding manganese dioxide electrode materials were obtained at treatment times of 0, 1, 2, 3, 4, 5, 6, and 7 min. Among them, 0 min represents no plasma treatment.

[0076] 2. Eight types of manganese dioxide electrode materials were used as test materials for electroadsorption thallium removal experiments, as detailed below:

[0077] The test material, conductive carbon black, and polyvinylidene fluoride were mixed in a mass ratio of 8.0:1.5:0.5 to obtain a mixture; 50 mg of the mixture was coated onto an electrode plate (titanium plate) to obtain a manganese dioxide electrode; the cathode and anode of the capacitive deionization device both use this manganese dioxide electrode.

[0078] The above-mentioned capacitor deionization device was used to electro-adsorb 50 mL of thallium-containing solution under an applied electric field. The thallium ion concentration of the thallium-containing solution (thallium nitrate solution) was 1200 μg / L and the pH was 4.0. The applied electric field voltage during the electro-adsorption process was 1.0 V and the electro-adsorption time was 2 h.

[0079] Experimental results:

[0080] Reference Figure 1 , Figure 2 According to the results, after 2 hours of electroadsorption, the manganese dioxide electrode materials obtained by plasma treatment for 0, 1, 2, 3, 4, 5, 6, and 7 minutes had thallium removal rates of 98.83%, 99.36%, 99.49%, 99.44%, 99.48%, 99.18%, 99.55%, and 99.50%, respectively.

[0081] After 2 hours of electroadsorption, the manganese dioxide electrode materials obtained by plasma treatment for 0, 1, 2, 3, 4, 5, 6, and 7 minutes had manganese leaching amounts of 123.67 μg / L, 64.48 μg / L, 82.74 μg / L, 89.45 μg / L, 118.66 μg / L, 117.40 μg / L, 100.59 μg / L, and 68.19 μg / L, respectively.

[0082] Example 3

[0083] The manganese dioxide electrode material obtained after 7 min of plasma treatment in Example 2 is denoted as 7-MnO2, and the capacitive deionization device corresponding to 7-MnO2 in Example 2 is obtained. Isothermal kinetic fitting is performed based on the adsorption amount of 7-MnO2 at different thallium concentrations (the adsorption amount is calculated based only on the test material on the cathode, and conductive carbon black and polyvinylidene fluoride are not included). The process is as follows:

[0084] The above-mentioned capacitor deionization device was used to electro-adsorb 50 mL of thallium-containing solution (thallium nitrate solution). The thallium-containing solution had a preset thallium ion concentration and a pH of 4.0. The voltage of the external electric field during the electro-adsorption process was 1.0 V, and the electro-adsorption time was 2 h.

[0085] In this embodiment, the preset thallium ion concentrations are 46.25 mg / L, 97.80 mg / L, 177.80 mg / L, 367.55 mg / L, and 539.10 mg / L, respectively; the above-mentioned electrochemical thallium removal tests are carried out using the above-mentioned preset thallium ion concentrations.

[0086] Reference Figure 3 After 2 h of electroadsorption, the thallium adsorption capacities (7-MnO2) of thallium-containing solutions with thallium ion concentrations of 46.25 mg / L, 97.80 mg / L, 177.80 mg / L, 367.55 mg / L, and 539.10 mg / L were 57.57 mg / g, 121.57 mg / g, 218.63 mg / g, 440.88 mg / g, and 574.57 mg / g, respectively, and the manganese dissolution amounts were 48.17 μg / L, 66.5 μg / L, 68.12 μg / L, 134.89 μg / L, and 168.77 μg / L, respectively.

[0087] The equilibrium adsorption capacity and equilibrium concentration were fitted using the Langmuir and Freundlich models, respectively, with reference to... Figure 4 To understand this, the specific fitting parameters are shown in the table below:

[0088]

[0089] The correlation coefficient of the Langmuir adsorption curve is 0.98, while that of the Freundlich adsorption curve is 0.96, indicating that the reaction process of the 7-MnO2 material conforms more closely to the Langmuir model. This means that the electroadsorption of thallium ions in the solution is mainly a monolayer adsorption process. Fitting the Langmuir model parameters reveals that the maximum adsorption capacity of 7-MnO2 is 591.12 mg / g. The K2 in the Freundlich adsorption model... FThis can describe the interaction strength between thallium ions and the 7-MnO2 electrode, showing that the binding force between them is relatively strong. Furthermore, the parameter n... -1 The electrode coefficient is 0.323, indicating that the adsorption process is easy to carry out, and n>1 indicates that the adsorption process is mainly chemisorption.

[0090] Example 4

[0091] Using 2,5-MnO2 from Example 1 as the test material, electro-adsorption thallium removal experiments were conducted at different pH values ​​to explore the pH range of manganese dioxide material in the electro-adsorption thallium removal process; details are as follows:

[0092] The test material, conductive carbon black, and polyvinylidene fluoride were mixed in a mass ratio of 8.0:1.5:0.5 to obtain a mixture; 50 mg of the mixture was coated onto an electrode plate (titanium plate) to obtain a manganese dioxide electrode; the cathode and anode of the capacitive deionization device both use this manganese dioxide electrode.

[0093] The above-mentioned capacitor deionization device was used to electro-adsorb 50 mL of thallium-containing solution under an applied electric field. The thallium ion concentration of the thallium-containing solution (thallium nitrate solution) was 1100 μg / L. The applied electric field voltage during the electro-adsorption process was 1.0 V, and the electro-adsorption time was 2 h.

[0094] In this embodiment, the pH of the thallium-containing solution was adjusted to 3, 4, 5, 6, 7, 8, 9, 10, and 11, respectively, and the above-mentioned electro-adsorption thallium removal test was carried out at each pH.

[0095] Experimental results:

[0096] Reference Figures 5-6 After 2 hours of electroadsorption, the thallium removal rates of thallium-containing solutions with pH values ​​of 3, 4, 5, 6, 7, 8, 9, 10, and 11 were 99.16%, 98.96%, 98.79%, 98.66%, 98.64%, 98.55%, 99.01%, 98.97%, and 95.05%, respectively.

[0097] After 2 h of electroadsorption, the manganese dissolution amounts corresponding to pH values ​​of thallium-containing solutions 3, 4, 5, 6, 7, 8, 9, 10, and 11 were 171.31 μg / L, 120.91 μg / L, 164.37 μg / L, 137.26 μg / L, 101.22 μg / L, 136.80 μg / L, 119.25 μg / L, 149.28 μg / L, and 224.42 μg / L, respectively.

[0098] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a plasma-based manganese dioxide electrode material, characterized in that, Including the following steps: S1, to obtain a mixture containing potassium permanganate and a reducing agent; S2, the mixture is subjected to hydrothermal treatment, and the product of the hydrothermal treatment is separated into solid and liquid components to obtain an intermediate material; The hydrothermal treatment temperature is 90~145℃, and the hydrothermal treatment duration is 6~24 h; S3, the intermediate material is subjected to plasma treatment to obtain manganese dioxide electrode material; the gas source for plasma treatment is an inert gas.

2. The preparation method according to claim 1, characterized in that, The reducing agent includes one or more of ammonium oxalate, manganese sulfate, and hydrochloric acid.

3. The preparation method according to claim 1, characterized in that, The molar ratio of potassium permanganate to the reducing agent is 2:1 to 6:1; The process of obtaining the mixture includes: mixing the potassium permanganate and the reducing agent in water to obtain the mixture; the mass-volume ratio of the potassium permanganate and the mixture is 0.3g:45mL to 0.5g:45mL.

4. The preparation method according to claim 1, characterized in that, The duration of the plasma treatment is 0.5~3.5 min or 6.5~7.5 min.

5. The preparation method according to any one of claims 1-4, characterized in that, The voltage of the plasma treatment is 15~45 V, and the current of the plasma treatment is ≤3 A.

6. A plasma-based manganese dioxide electrode material, characterized in that, It is prepared using the preparation method described in any one of claims 1-5.

7. The application of the manganese dioxide electrode material as described in claim 6 in electroadsorption thallium removal.

8. A method for removing thallium by electroadsorption, characterized in that, include: The substrate material coated with the manganese dioxide electrode material as described in claim 6 is used as the anode and cathode of the capacitor deionization device, or the substrate material coated with the manganese dioxide electrode material as described in claim 6 is used as the cathode of the capacitor deionization device. Then, the thallium-containing solution is treated using the capacitor deionization device under an applied electric field.

9. The method for removing thallium by electroadsorption according to claim 8, characterized in that, The concentration of thallium ions in the thallium-containing solution is 0.05~600 mg / L.

10. The method for electro-adsorption removal of thallium according to claim 8, characterized in that, The pH of the thallium-containing solution is 3-11; The voltage of the applied electric field is 0.4~1.2 V, and the duration of application of the applied electric field is 0.5~4 h.

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