Process for the preparation of insoluble electrodes

Abstract

The present application provides a method for preparing an insoluble electrode. A substrate is pretreated and immersed in a lead-containing electrolyte to perform a first electrolysis reaction, so that a first lead-containing plating layer is formed on the surface of the substrate. After the first lead-containing plating layer is formed, the substrate is immersed in the lead-containing electrolyte to perform a second electrolysis reaction, so that a second lead-containing plating layer is formed on the surface of the first lead-containing plating layer. After a reaction time, the second lead-containing plating layer is formed on the surface of the first lead-containing plating layer, thereby obtaining an insoluble electrode.

Description

Technical Field

[0001] This invention relates to a method for preparing an insoluble electrode, which improves the sustainability of the preparation of the insoluble electrode. Background Technology

[0002] In conventional processes such as electrolytic oxidation, water electrolysis, and the electrolysis of disinfectant water, insoluble electrodes are typically used. To improve the efficiency of these electrolytic reactions, platinum electrodes with high catalytic activity are widely used in the market. However, while platinum electrodes possess excellent catalytic performance, their high price has become a major bottleneck for large-scale mass production, preventing effective reduction in production costs.

[0003] Therefore, in order to solve the problem of high cost, many researchers are committed to developing alternative electrode materials with lower cost and catalytic activity, including metal electrodes, alloy electrodes and metal oxide electrodes. Among these electrode materials, metal oxide electrodes have gradually become the mainstream choice in the market due to their best catalytic activity. At present, most metal oxide electrode preparation processes involve coating or immersing metal oxide slurry on a substrate, followed by high-temperature sintering to improve the stability and activity of the electrode.

[0004] However, conventional electrode preparation methods have several drawbacks, such as high equipment requirements, as the sintering process of the electrode requires precise equipment and temperature control, which increases manufacturing costs and technical barriers; high energy consumption, as the sintering process requires a continuous high-temperature environment, consuming a large amount of energy; and large carbon emissions, as the high-temperature sintering process generates a large amount of carbon dioxide, which has a negative impact on the environment. In view of the problems of the prior art, the present invention proposes an improved electrode manufacturing process to further optimize the performance of insoluble electrodes and improve the efficiency and sustainability of insoluble electrodes in electrolysis applications. Summary of the Invention

[0005] One objective of this invention is to provide a method for preparing an insoluble electrode, which uses a lead-containing liquid as an electrolyte and performs at least two electrolytic reactions on a substrate to form at least two lead plating layers on the surface of the substrate, thereby obtaining an insoluble electrode.

[0006] One objective of this invention is to provide a method for preparing an insoluble electrode, which uses lead-containing wastewater, treats it into an electrolyte, and then performs at least two electrolytic reactions on the substrate to form at least two lead plating layers on the surface of the substrate, thereby obtaining an insoluble electrode.

[0007] To achieve the aforementioned objectives and effects, the present invention provides a method for preparing an insoluble electrode, comprising: pretreating a substrate; immersing the substrate in a lead-containing electrolyte to perform a first electrolytic reaction, thereby forming a first lead-containing plating layer on the surface of the substrate; after performing the first electrolytic reaction, immersing the substrate in the lead-containing electrolyte to perform a second electrolytic reaction, thereby forming a second lead-containing plating layer on the surface of the first lead-containing plating layer, thus producing an insoluble electrode, wherein the crystal structure of the first lead-containing plating layer is different from that of the second lead-containing plating layer; this method is used to prepare an insoluble electrode with high efficiency and sustainability.

[0008] In one embodiment of the present invention, prior to the step of immersing the substrate in a lead-containing electrolyte to perform a first electrolytic reaction and forming a first lead-containing plating layer on the surface of the substrate, the method further includes the steps of: extracting copper ions from a lead-containing wastewater using a selective copper ion exchange resin to obtain a copper-containing resin and a copper-free wastewater; extracting a metal ion from the copper-free wastewater using a cation exchange resin, and back-extracting the metal ion from the cation exchange resin using a nitric acid solution to obtain a lead-containing nitric acid solution; and concentrating the lead-containing nitric acid solution to a lead concentration of 65000 mg / L to 85000 mg / L and a nitric acid concentration of 6200 mg / L to 62000 mg / L to obtain the lead-containing electrolyte.

[0009] In one embodiment of the present invention, in the step of concentrating the lead-containing nitric acid solution, the lead-containing nitric acid solution is concentrated to a lead concentration of 65,000 mg / L to 85,000 mg / L and a nitric acid concentration of 6,200 mg / L to 62,000 mg / L.

[0010] In one embodiment of the present invention, in the step of pretreatment of a substrate, the substrate is selected from one or a combination of the group consisting of titanium, iron, lead and aluminum.

[0011] In one embodiment of the present invention, in the step of performing a pretreatment on a substrate, the pretreatment is selected from one or a combination of a degreasing treatment and a pickling treatment.

[0012] In one embodiment of the present invention, the first electrolysis reaction and the second electrolysis reaction are carried out sequentially in the same electrolytic cell.

[0013] In one embodiment of the present invention, in the step of immersing the substrate in a lead-containing electrolyte to carry out a first electrolytic reaction, the voltage of the first electrolytic reaction is 2V to 15V.

[0014] In one embodiment of the present invention, in the step of forming a first lead-containing coating on the surface of the substrate, the first lead-containing coating is α-PbO2.

[0015] In one embodiment of the present invention, in the step of performing a second electrolysis reaction in the lead-containing electrolyte in which the substrate is immersed, the reaction time of the second electrolysis reaction is between 0.5 and 4 hours, the temperature of the lead-containing electrolyte is between 20°C and 35°C, and the pH value is between 1 and 5.

[0016] In one embodiment of the present invention, in the step of forming a second lead-containing coating on the surface of the first lead-containing coating, the second lead-containing coating is β-PbO2. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the steps of the method for preparing the insoluble electrode of the present invention. Figure 2 This is a schematic diagram of the wastewater treatment steps in the preparation method of the insoluble electrode of the present invention. Figure 3 This is a schematic diagram of the current change in the insoluble electrode of the present invention; and Figure 4 This is a schematic diagram of the aging of the insoluble electrode of the present invention. [Figure Number Reference Guide] S02: Steps S04: Steps S06: Steps S22: Steps S24: Steps S26: Steps Detailed Implementation

[0018] To provide a better understanding of the structural features and effects achieved by the present invention, preferred embodiments and detailed descriptions are provided below:

[0019] In view of the problems of the prior art, the present invention provides a method for preparing an insoluble electrode, which involves pretreating a substrate and immersing the substrate in a lead-containing electrolyte to sequentially perform at least two electrolytic reactions, thereby forming at least two lead-containing plating layers on the surface of the substrate to obtain an insoluble electrode with high stability, thus solving the problems of high cost and insufficient stability of electrodes prepared by prior art.

[0020] Please see Figure 1 The figure shows a schematic diagram of the steps in preparing the insoluble electrode of the present invention. This embodiment is the first embodiment, and it describes a method for preparing an insoluble electrode, the steps of which include:

[0021] Step S02: Pre-treat the substrate;

[0022] Step S04: Immerse the substrate in a lead-containing electrolyte to perform a first electrolytic reaction, thereby forming a first lead-containing plating layer on the surface of the substrate; and

[0023] Step S06: After the first electrolytic reaction, the substrate is immersed in a lead-containing electrolyte to carry out a second electrolytic reaction, so that a second lead-containing coating is formed on the surface of the first lead-containing coating, thus forming an insoluble electrode.

[0024] Continuing from the above, in step S02, when manufacturing the insoluble electrode, a substrate is first pretreated to clean the surface of the substrate.

[0025] Continuing from the above, in step S04, the substrate is placed in an electrolytic tank and immersed in a lead-containing electrolyte. The substrate is electrically connected to the anode of the power supply, and another electrode is installed and electrically connected to the cathode of the power supply. This allows the substrate to undergo a first electrolytic reaction in the lead-containing electrolyte, forming the first lead-containing plating layer on the surface of the pretreated substrate.

[0026] Following the above, in step S06, the substrate immersed in the lead-containing electrolyte undergoes a second electrolytic reaction, so that a second lead-containing coating is formed on the surface of the first lead-containing coating, at least covering the first lead-containing coating and the second lead-containing coating on the substrate, to obtain an insoluble electrode, wherein the crystal structure of the first lead-containing coating and the crystal structure of the second lead-containing coating are different.

[0027] Continuing from the above, in this embodiment, the substrate undergoes the first electrolytic reaction and the second electrolytic reaction in the same electrolytic cell with the lead-containing electrolyte.

[0028] Continuing from the above, in one embodiment, the second electrolysis reaction is carried out under the conditions that the temperature of the lead-containing electrolyte is between 20°C and 35°C and the pH value of the lead-containing electrolyte is between 1 and 5, and after a period of time, the second lead-containing coating is formed on the surface of the first lead-containing coating.

[0029] In one embodiment, the voltage used in the second electrolytic reaction is preferably 2V to 15V, and the reaction time of the substrate having the first lead-containing plating layer in the lead-containing electrolyte is preferably 0.5h to 4h.

[0030] In one embodiment, the first electrolysis reaction is carried out under the conditions that the temperature of the lead-containing electrolyte is between 10°C and 35°C and the pH value of the lead-containing electrolyte is between 5 and 10, and after a plating time, the first lead-containing plating layer is formed on the surface of the substrate.

[0031] Continuing from the above, the voltage used in the first electrolytic reaction is preferably 2V to 15V, and the plating time of the substrate in the lead-containing electrolyte is preferably 0.5h to 2h.

[0032] In one embodiment, during a pretreatment step of a substrate, the substrate is selected from one or a combination of the group consisting of titanium, iron, lead, and aluminum.

[0033] In one embodiment, in step S02, the pretreatment is selected from one or a combination of a degreasing treatment and an acid washing treatment.

[0034] Continuing from the above, in one embodiment, the degreasing process involves ultrasonically vibrating the substrate in acetone for 1 to 10 minutes.

[0035] Continuing from the above, in one embodiment, the pickling process involves immersing the substrate in a nitric acid solution with a water-to-acid ratio of 1:1, followed by rinsing with water.

[0036] Continuing from the above, in one embodiment, the pretreatment may sequentially perform the degreasing treatment and the pickling treatment to thoroughly clean the surface of the substrate.

[0037] In the above embodiments, the first lead-containing coating is α-PbO2, and the second lead-containing coating is β-PbO2. The substrate is sequentially coated with at least two lead-containing coatings of different crystal types to obtain a highly stable insoluble electrode. The substrate, serving as the anode, undergoes an oxidation reaction to generate the first and second lead-containing coatings, as described in [Chemical 1] and [Chemical 2]. The cathode undergoes a metal reduction reaction, as described in [Chemical 3] and [Chemical 4].

[0038] [Chemical 1]: Pb 2+ +2H₂O→PbO₂+4H + +2e －

[0039] [Chemical 2]: 2H₂O → O₂↑ + 4H₂O + +4e －

[0040] [Chemical 3]: Pb 2+ +2e － →Pb

[0041] [Chemical 4]: 2H + +2e － →H2↑

[0042] The electrode in this embodiment is prepared by electrolysis, which has lower equipment costs than conventional sintering manufacturing technology, as well as lower energy consumption and carbon emissions. It can also be directly combined with wastewater treatment processes to use recycled lead resources, thereby reducing wastewater treatment and electrode production costs and solving the problems of high cost and poor stability of conventional insoluble electrode preparation methods.

[0043] Please see Figure 2 The figure shows a schematic diagram of the wastewater treatment steps in the preparation method of the insoluble electrode of the present invention. As shown in the figure, this embodiment is based on the first embodiment described above. This embodiment, combined with the wastewater treatment process, further includes the following steps before the step of immersing the substrate in a lead-containing electrolyte to perform a first electrolytic reaction and forming a first lead-containing plating layer on the surface of the substrate:

[0044] Step S22: Extract copper ions from lead-containing wastewater using selective copper ion exchange resin to obtain copper-containing resin and copper-free wastewater;

[0045] Step S24: Extract metal ions from copper-free wastewater using a cation exchange resin, and back-extract the metal ions from the cation exchange resin using a nitric acid solution to obtain a lead-containing nitric acid solution; and

[0046] Step S26: Concentrate the lead-containing nitric acid solution to obtain a lead-containing electrolyte.

[0047] Continuing from the above, in step S22, a lead-containing waste liquid is first obtained. The lead-containing waste liquid contains metal ions (such as copper, lead, iron, zinc and nickel), non-metal ions (such as ammonia nitrogen, chloride, sulfate, nitrate and so on), and organic matter. The copper ions in the lead-containing waste liquid are extracted using a selective copper ion exchange resin to obtain a copper-containing resin and a copper-free wastewater. The copper-containing resin is used for subsequent recycling and reuse.

[0048] Continuing from the above, in step S24, a metal ion is extracted from the copper-free wastewater using a cation exchange resin, and the metal ion from the cation exchange resin is back-extracted using a nitric acid solution to obtain a lead-containing nitric acid solution; in this embodiment, the metal ion is a lead ion.

[0049] Continuing from the above, in step S26, the lead-containing nitric acid solution can be concentrated, for example, to a lead concentration of 65,000 mg / L to 85,000 mg / L and a nitric acid concentration of 6,200 mg / L to 62,000 mg / L to obtain the lead-containing electrolyte, which is then placed in the electrolytic cell for the substrate to undergo an electrolytic reaction.

[0050] In one embodiment, the cation exchange resin used in step S24 may be replaced with a chelating resin, and this is not a limitation.

[0051] In one embodiment, other acids, such as sulfuric acid, may also be used to back-extract the metal ions from the cation exchange resin, but this is not a limitation.

[0052] Please see Figure 3 The figure shows a schematic diagram of the current change of the insoluble electrode of the present invention. The current change diagrams during electrolysis in the above embodiments can improve the stability of the electrode. Figure 3As shown, the current change during electrode fabrication is measured with a voltage of 1V to 10V and the temperature of the lead-containing electrolyte is 15℃.

[0053] Please see Figure 4 This is a schematic diagram of the aging process of the insoluble electrode of the present invention. As shown in the figure, the insoluble electrode prepared in the above embodiments can improve the stability of the electrode. Figure 4 For the aging test of the electrodes, a constant current of 100mA / cm was used. 2 Electrolysis was performed, and the voltage (V) and time (h) were recorded. When the voltage reached 10V, it indicated that the electrode had completely failed. The experimental data showed that the insoluble electrodes prepared in the above embodiments could be used stably for at least 80 hours (h) under the target environment of the electrode.

[0054] Following the above, the insoluble electrodes prepared in the above embodiments were subjected to electrolytic oxidation tests, and the results are shown in Table (I).

[0055] Table (1):

[0056] The experimental data show that the insoluble electrodes prepared in the above embodiments can effectively reduce COD content (organic matter is removed) and ammonia nitrogen within 30 minutes after actual electrolytic oxidation test.

[0057] In summary, the present invention provides a method for preparing an insoluble electrode, which involves sequentially electrolytically forming at least two lead-containing plating layers of different crystals on the surface of a substrate to obtain an insoluble electrode with high stability. Furthermore, it can be combined with a wastewater treatment process to utilize recycled lead resources, thereby reducing wastewater treatment and electrode production costs. This method for preparing insoluble electrodes reduces manufacturing equipment costs, energy consumption, and carbon emissions, solving the problems of high cost and poor stability in conventional methods for preparing insoluble electrodes.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent variations and modifications made in accordance with the shape, structure, features and spirit described in the claims of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for preparing an insoluble electrode, characterized in that, The steps include: A pretreatment is performed on a substrate; The substrate is immersed in a lead-containing electrolyte to carry out a first electrolytic reaction, so that a first lead-containing plating layer is formed on the surface of the substrate. as well as After the first electrolytic reaction, the substrate is immersed in the lead-containing electrolyte to carry out a second electrolytic reaction, so that a second lead-containing coating is formed on the surface of the first lead-containing coating, thus forming an insoluble electrode. The crystal structure of the first lead-containing coating is different from that of the second lead-containing coating.

2. The method for preparing the insoluble electrode as described in claim 1, characterized in that, Prior to the step of immersing the substrate in a lead-containing electrolyte to perform a first electrolytic reaction, thereby forming a first lead-containing plating layer on the surface of the substrate, the method further includes the following steps: Copper ions were extracted from a lead-containing waste liquid using a selective copper ion exchange resin to obtain a copper-containing resin and a copper-free wastewater. A metal ion was extracted from the copper-free wastewater using a cation exchange resin, and the metal ion from the cation exchange resin was back-extracted using a nitric acid solution to obtain a lead-containing nitric acid solution, wherein the metal ion was a lead ion. as well as The lead-containing nitric acid solution is concentrated to obtain the lead-containing electrolyte.

3. The method for preparing the insoluble electrode as described in claim 2, characterized in that, In the step of concentrating the lead-containing nitric acid solution, the lead-containing nitric acid solution is concentrated to a lead concentration of 65,000 mg / L to 85,000 mg / L and a nitric acid concentration of 6,200 mg / L to 62,000 mg / L.

4. The method for preparing the insoluble electrode as described in claim 1, characterized in that, In the step of pretreatment of a substrate, the substrate is selected from one or a combination of the group consisting of titanium, iron, lead and aluminum.

5. The method for preparing the insoluble electrode as described in claim 1, characterized in that, In the step of performing a pretreatment on a substrate, the pretreatment is selected from one or a combination of a degreasing treatment and a pickling treatment.

6. The method for preparing the insoluble electrode as described in claim 1, characterized in that, The first electrolysis reaction and the second electrolysis reaction are carried out sequentially in the same electrolytic cell.

7. The method for preparing the insoluble electrode as described in claim 1, characterized in that, In the step of immersing the substrate in a lead-containing electrolyte to carry out a first electrolytic reaction, the voltage of the first electrolytic reaction is 2V to 15V.

8. The method for preparing the insoluble electrode as described in claim 1, characterized in that, In the step of forming a first lead-containing coating on the surface of the substrate, the first lead-containing coating is α-PbO2.

9. The method for preparing the insoluble electrode as described in claim 1, characterized in that, In the step of performing a second electrolysis reaction in the lead-containing electrolyte in which the substrate is immersed, the reaction time of the second electrolysis reaction is between 0.5 and 4 hours, the temperature of the lead-containing electrolyte is between 20°C and 35°C, and the pH value is between 1 and 5.

10. The method for preparing the insoluble electrode according to claim 1, characterized in that, In the step of forming a second lead-containing coating on the surface of the first lead-containing coating, the second lead-containing coating is β-PbO2.

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