A novel inert titanium anode and its preparation method

Abstract

This invention proposes a novel inert titanium anode and its preparation method, belonging to the field of electrochemical technology. The novel inert titanium anode of this invention comprises a titanium substrate and an anode coating. The anode coating is loaded on the surface of the titanium substrate and has a layered structure containing three metal oxides: an inner layer of ruthenium oxide, a middle layer of iridium oxide, and an outer layer of tin oxide. Ruthenium and iridium are deposited sequentially on the surface of the titanium substrate using an electrodeposition method. Then, a tin-containing solution is sprayed onto the surface using a spraying process. Finally, a layered coating containing ruthenium, iridium, and tin oxides is generated in situ on the surface of the titanium substrate using a thermal decomposition method, resulting in the novel inert titanium anode. The novel inert titanium anode prepared by this invention exhibits good electrochemical performance and a long lifespan.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical technology, and particularly relates to a novel inert titanium anode and its preparation method. Background Technology

[0002] Coated titanium anodes, also known as DSA or MMOA, are a new type of high-efficiency and energy-saving electrode. They mainly consist of a titanium metal substrate and an active coating on its surface. Ru and Ir oxides, with their excellent corrosion resistance, conductivity, and catalytic activity, are the main components of the titanium anode coating. SnO2 is an N-type semiconductor material, and its conductivity is enhanced by the generation of free electrons from cation vacancies during heat treatment. Furthermore, Ru, Ir, and Sn all have tetrahedral structures and approximately equal atomic sizes, readily forming substitutional solid solutions of multi-component oxides, leading to increased oxygen vacancies and enhanced catalytic activity. Domestic and international scholars have conducted extensive research and improvement work on ruthenium-based and iridium-based coated titanium anodes, some of which have been successfully applied in the chlor-alkali industry, electrolysis, and electroplating processes. However, problems remain, such as easy detachment of the anode coating in acidic media leading to electrode failure, short lifespan, and low economic efficiency.

[0003] Thermal decomposition is the main method for industrial production of coated titanium anodes. This process has the advantages of mature technology, low cost, and stable products. Currently, the stability of the coating structure is mainly solved by optimizing the coating composition, structure, and preparation process. Patent CN118461064A discloses a method for preparing iridium-ruthenium-tin-titanium coated titanium anodes. The method involves mixing a metal salt solution, coating it onto a titanium substrate, and then heat-treating it to prepare the coated anode. However, the titanium anode coating prepared by this process still suffers from insufficient strength and short service life, making it difficult to meet the catalytic stability requirements in high current densities and acidic solutions. Summary of the Invention

[0004] To address the aforementioned technical problems and further improve the stability and lifespan of coated titanium anodes, this invention proposes a novel inert titanium anode and its preparation method. By combining electrodeposition with spraying processes, a layered coating containing ruthenium, iridium, and tin oxides is generated in situ using a thermal decomposition method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] One of the technical solutions of the present invention:

[0007] A novel inert titanium anode includes a titanium substrate and an anode coating. The anode coating is loaded on the surface of the titanium substrate and has a layered structure containing three metal oxides. The inner layer of the anode coating is ruthenium oxide (RuO2), the middle layer is iridium oxide (IrO2), and the outer layer is tin oxide (SnO2).

[0008] Furthermore, the mass ratio of ruthenium oxide, iridium oxide and tin oxide in the anodic coating is (0.6-1.2):(0.3-0.7):(0.01-0.05).

[0009] The second technical solution of the present invention:

[0010] A method for preparing the novel inert titanium anode involves depositing ruthenium and iridium sequentially on the surface of a titanium plate using an electrodeposition method, followed by spraying a tin-containing solution onto the surface using a spraying process, and finally generating a layered coating containing ruthenium, iridium, and tin oxides in situ on the surface of the titanium plate using a thermal decomposition method, thereby obtaining the novel inert titanium anode.

[0011] Furthermore, the preparation method of the novel inert titanium anode specifically includes the following steps:

[0012] (1) A titanium substrate is obtained by pretreatment of a titanium plate. The titanium substrate is used as the cathode and a platinum sheet is used as the anode. The plate is immersed in a ruthenium-containing solution and ruthenium is electrodeposited on the surface of the titanium plate by electrodeposition to prepare electrode A.

[0013] (2) Using the electrode A obtained in step (1) as the cathode and the metal platinum sheet as the anode, the electrode B is prepared by immersing it in an iridium-containing solution and electrodepositing iridium on the surface of electrode A by electrodeposition.

[0014] (3) The electrode B surface obtained in step (2) is sprayed with a tin-containing solution, then dried and heat-treated to obtain the novel inert titanium anode.

[0015] Furthermore, in step (1), the ruthenium-containing solution comprises RuCl3 at a concentration of 10-15 g / L and NH2SO3H at a concentration of 10 g / L, with a pH of 1-2; and / or

[0016] The solution temperature for the electrodeposition method is 45-50℃, and the current density is 1.0-1.5 A / dm³. 2 The deposition time is 1-2 hours.

[0017] Furthermore, the ruthenium-containing solution is obtained by dissolving RuCl3 in deionized water, then adding NH2SO3H, and sonicating at 20-30 kHz for 10 min.

[0018] Furthermore, in step (2), the iridium-containing solution comprises 10-15 g / L of H2IrCl5·6H2O and 0.01-0.02 mol / L of CH3COOH, with a pH of 4-5; and / or

[0019] The electrodeposition method uses a solution temperature of 85°C and a current density of 1.0-2.0 A / dm³. 2 The deposition time is 1-2 hours.

[0020] Furthermore, all electrodeposition methods are performed in an air atmosphere.

[0021] Furthermore, the iridium-containing solution is obtained by dissolving H2IrCl5·6H2O in deionized water, then adding CH3COOH, and sonicating at 20–30 kHz for 10 min.

[0022] Furthermore, in step (3), the tin-containing solution is a SnCl4 solution with a concentration of 20 g / L; and / or

[0023] The drying is infrared drying; and / or

[0024] The heat treatment is performed at a temperature of 450-550℃ for 1 hour.

[0025] Furthermore, in step (3), the spraying is performed using an electric spraying device with a spray gun nozzle diameter of 0.5-1.5mm.

[0026] Furthermore, in step (3), the tin-containing solution is sprayed multiple times, and the process of spraying tin-containing solution-infrared heat drying-heat treatment is repeated. After spraying the tin-containing solution, infrared heat drying treatment is performed quickly, and then it is transferred to an electric furnace for heat treatment at 450-550℃ for 10 minutes. After cooling, the spraying continues.

[0027] Furthermore, the tin-containing solution is obtained by dissolving SnCl4 in an organic solvent and then sonicating it at 20–30 kHz for 10 min, wherein the organic solvent used is anhydrous ethanol and ethylene glycol in a volume ratio of 1:1.

[0028] Furthermore, in step (1), the titanium plate pretreatment specifically includes the following steps:

[0029] Use an electric grinder or coarse sandpaper to initially polish the titanium plate to remove surface impurities;

[0030] The polished titanium plate was immersed in an alkaline solution, washed, and then immersed in an oxalic acid solution. It was acid etched for 2-3 hours under a gentle boiling state, washed again, and then immersed in anhydrous ethanol for ultrasonic treatment. After washing again, the titanium matrix was obtained.

[0031] Furthermore, during the titanium plate pretreatment process, the alkaline solution is a 5 wt% sodium hydroxide solution or sodium carbonate solution; and / or

[0032] The concentration of the oxalic acid solution is 10-15 wt%.

[0033] Furthermore, during the titanium plate pretreatment process, the ultrasonic treatment time is 10-15 minutes, and the ultrasonic frequency is 20-30 kHz.

[0034] Compared with the prior art, the present invention has the following advantages and technical effects:

[0035] This invention provides a novel inert titanium anode and its preparation method. The novel inert (ruthenium-iridium-tin coated) titanium anode exhibits excellent electrochemical performance and long lifespan. The electrodeposition method sequentially deposits ruthenium and iridium metals on the electrode surface, resulting in a robust structure and good uniformity. Since Ru, Ir, and Sn have identical structures and approximately equal atomic sizes, the in-situ generated oxides are treated through thermal decomposition, allowing the formation of a multi-component oxide substitution solid solution. This increases oxygen vacancies in the coating material, thereby enhancing the coating's lifespan and catalytic activity, especially under acidic conditions and high current densities, where its catalytic stability is excellent. Furthermore, electrospraying maintains coating uniformity and production efficiency. Attached Figure Description

[0036] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0037] Figure 1 Here are schematic diagrams and scanning electron microscope images of the novel inert titanium anode and anode coating prepared in Example 1 of this invention;

[0038] Figure 2 Comparative graphs of cyclic voltammetry tests of titanium anodes prepared in Examples 1-6 and Comparative Examples 1-4;

[0039] Figure 3 The results are from the enhanced life test of the titanium anodes prepared in Examples 1-6 and Comparative Examples 1-4. Detailed Implementation

[0040] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0041] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0042] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0043] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0044] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0045] This invention proposes a novel inert titanium anode, comprising a titanium substrate and an anode coating. The anode coating is loaded on the surface of the titanium substrate and has a layered structure containing three metal oxides: the inner layer of the anode coating is ruthenium oxide (RuO2), the middle layer is iridium oxide (IrO2), and the outer layer is tin oxide (SnO2).

[0046] In a preferred embodiment of the present invention, the mass ratio of ruthenium oxide, iridium oxide and tin oxide in the anodic coating is (0.6-1.2):(0.3-0.7):(0.01-0.05).

[0047] This invention also proposes a method for preparing the novel inert titanium anode. The method involves depositing ruthenium and iridium sequentially on the surface of a titanium plate using electrodeposition, followed by spraying a tin-containing solution onto the surface using a spraying process. Finally, a layered coating containing ruthenium, iridium, and tin oxides is generated in situ on the titanium plate surface via thermal decomposition to obtain the novel inert titanium anode. The method specifically includes the following steps:

[0048] (1) A titanium substrate is obtained by pretreatment of a titanium plate. The titanium substrate is used as the cathode and a platinum sheet is used as the anode. The titanium substrate is immersed in a ruthenium-containing solution, and ruthenium is electrodeposited on the surface of the titanium plate to prepare electrode A.

[0049] (2) Using the electrode A obtained in step (1) as the cathode and the metal platinum sheet as the anode, immerse it in an iridium-containing solution and electrodeposit iridium on the surface of electrode A to prepare electrode B;

[0050] (3) The electrode B surface obtained in step (2) is sprayed with a tin-containing solution, then dried and heat-treated to obtain the novel inert titanium anode.

[0051] This invention employs electrodeposition to sequentially deposit ruthenium and iridium metals on the electrode surface, which has the advantages of robust structure and good uniformity. Since Ru, Ir, and Sn have the same structure and approximately equal atomic sizes, the oxides generated in situ by the thermal decomposition process can form a substitution solid solution of multi-component oxides, increasing oxygen vacancies in the coating material and thus increasing the catalytic activity of the coating. Furthermore, the use of electrospraying can maintain the uniformity of the coating and production efficiency.

[0052] In step (1) of the preferred embodiment of the present invention, the ruthenium-containing solution comprises RuCl3 at a concentration of 10-15 g / L and NH2SO3H at a concentration of 10 g / L, and has a pH of 1-2; and / or

[0053] The electrodeposition solution temperature is 45-50℃, and the current density is 1.0-1.5 A / dm³. 2 Time: 1-2 hours; and / or

[0054] The ruthenium-containing solution is obtained by dissolving RuCl3 in deionized water, then adding NH2SO3H, and sonicating at 20-30 kHz for 10 min.

[0055] In step (2) of the preferred embodiment of the present invention, the iridium-containing solution comprises 10-15 g / L of H2IrCl5·6H2O and 0.01-0.02 mol / L of CH3COOH, with a pH of 4-5; and / or

[0056] The electrodeposition solution temperature is 85℃, and the current density is 1.0-2.0 A / dm³. 2 Time: 1-2 hours; and / or

[0057] The iridium-containing solution is obtained by dissolving H2IrCl5·6H2O in deionized water, then adding CH3COOH, and sonicating at 20–30 kHz for 10 min.

[0058] In a preferred embodiment of the present invention, the electrodeposition method is performed in an air atmosphere.

[0059] In step (3) of the preferred embodiment of the present invention, the tin-containing solution is a SnCl4 solution with a concentration of 20 g / L; and / or

[0060] The drying is infrared drying; and / or

[0061] The heat treatment is performed at a temperature of 450-550℃ for 1 hour; and / or

[0062] The tin-containing solution is obtained by dissolving SnCl4 in an organic solvent and then sonicating it at 20-30 kHz for 10 min. The solvent used is anhydrous ethanol and ethylene glycol in a volume ratio of 1:1.

[0063] In step (3) of the preferred embodiment of the present invention, the spraying is carried out using an electric spraying device with a spray gun diameter of 0.5-1.5mm, preferably 0.9mm, and a flow rate of 300mL / min.

[0064] In step (3) of the preferred embodiment of the present invention, the tin-containing solution is sprayed multiple times, and the process of spraying tin-containing solution-infrared heat drying-heat treatment is repeated. The tin-containing solution is sprayed and quickly subjected to infrared heat drying treatment, and then transferred to an electric furnace for heat treatment at 450-550°C for 10 minutes. After cooling, the spraying continues.

[0065] In step (1) of the preferred embodiment of the present invention, the titanium plate pretreatment specifically includes the following steps:

[0066] Use an electric grinder or coarse sandpaper to initially polish the titanium plate to remove surface impurities;

[0067] The polished titanium plate is immersed in an alkaline solution, washed, and then immersed in an oxalic acid solution for acid etching at a gentle boil for 2-3 hours. After washing, it is immersed in anhydrous ethanol for ultrasonic treatment, and washed again to obtain the titanium matrix. The alkaline solution is a 5 wt% sodium hydroxide solution or sodium carbonate solution; and / or

[0068] The concentration of the oxalic acid solution is 10-15 wt%; and / or

[0069] The ultrasonic treatment time is 10-15 minutes, and the ultrasonic frequency is 20-30 kHz.

[0070] All raw materials used in the embodiments of this invention were purchased commercially.

[0071] The technical solution of the present invention will be further illustrated by the following embodiments.

[0072] Example 1

[0073] A novel method for preparing an inert titanium anode includes the following steps:

[0074] (1) The titanium plate was initially polished with an electric grinder (3000r / min, grinding disc diameter 125mm, sandpaper 150 mesh) to remove surface impurities. Then it was soaked in a 5wt% sodium hydroxide solution at 60℃ for 1h. After rinsing with deionized water, it was soaked in a 10wt% oxalic acid solution and acid etched for 2h under a slight boiling state. After rinsing with deionized water, it was soaked in anhydrous ethanol and ultrasonically treated at 30kHz for 10min. After cleaning with deionized water, a titanium substrate with a rough and clean surface was obtained.

[0075] (2) Using the titanium substrate obtained in step (1) as the cathode and a platinum sheet as the anode, the substrate is immersed in a ruthenium-containing solution (containing 10 g / L RuCl3, 10 g / L NH2SO3H, pH 2). Ruthenium is electrodeposited on the surface of the titanium plate using an electrodeposition method. The solution temperature for the electrodeposition method is 50 °C and the current density is 1.0 A / dm³. 2 Electrode A was prepared by deposition time of 1 hour;

[0076] (3) Using electrode A obtained in step (2) as the cathode and a platinum sheet as the anode, immerse it in an iridium-containing solution (containing 15 g / L H2IrCl5·6H2O and 0.015 mol / L CH3COOH, pH 5). Electrodeposit iridium on the surface of electrode A using an electrodeposition method. The solution temperature for the electrodeposition method is 85℃ and the current density is 1.5 A / dm³. 2 Electrode B was prepared by deposition time of 1 hour;

[0077] (4) Spray a 20 g / L SnCl4 solution (spray gun diameter is 0.9 mm, flow rate is 300 mL / min) onto the surface of electrode B obtained in step (3), and dry it by infrared irradiation for 15 min. Then place it in an electric furnace for heat treatment at 500℃ for 10 min. Repeat the above operation 5 times. The last heat treatment is at 500℃ for 1 h. After cooling, a new type of inert titanium anode is obtained.

[0078] The structural schematic diagram and scanning electron microscope image of the novel inert titanium anode and anode coating prepared in Example 1 of this invention are shown below. Figure 1 As can be seen, the novel inert titanium anode comprises a titanium substrate and an anode coating. The total length of the novel inert titanium anode plate is 158 mm, with an effective working length of 138 mm and a width of 75 mm (length and width only indicate the specifications of the titanium anode plate prepared and tested; only the mesh portion has a coating, which constitutes the effective working area). The coating mainly consists of a three-layer structure: SnO2, IrO2, and RuO2, with strong bonding between the layers. Furthermore, the scanning electron microscope image shows that the anode coating surface is uniformly porous, a structure that helps increase the effective coating area and improve the electrode's electrochemical performance.

[0079] Example 2

[0080] A novel method for preparing an inert titanium anode is the same as in Example 1, except that the electrodeposition time in step (2) is 2 hours.

[0081] Example 3

[0082] A novel method for preparing an inert titanium anode is the same as in Example 1, except that the electrodeposition time in step (3) is 2 hours.

[0083] Example 4

[0084] A novel method for preparing an inert titanium anode is the same as in Example 1, except that the electrodeposition time in step (2) is 2 hours and the electrodeposition time in step (3) is 2 hours.

[0085] Example 5

[0086] (1) The titanium plate was initially polished with an electric grinder to remove surface impurities. Then it was soaked in a 5 wt% sodium hydroxide solution at 60°C for 1 hour. After rinsing with deionized water, it was soaked in a 15 wt% oxalic acid solution and acid etched for 3 hours under a slight boiling state. After rinsing with deionized water, it was soaked in anhydrous ethanol and ultrasonically treated at 30 kHz for 10 minutes. After cleaning with deionized water, a titanium substrate with a rough and clean surface was obtained.

[0087] (2) Using the titanium substrate obtained in step (1) as the cathode and a platinum sheet as the anode, the substrate is immersed in a ruthenium-containing solution (containing 15 g / L RuCl3, 10 g / L NH2SO3H, pH 1). Ruthenium is electrodeposited on the surface of the titanium plate using an electrodeposition method. The solution temperature for the electrodeposition method is 50 °C and the current density is 1.5 A / dm³. 2 Electrode A was prepared by deposition time of 1 hour;

[0088] (3) Using electrode A obtained in step (2) as the cathode and a platinum sheet as the anode, immerse it in an iridium-containing solution (containing 15 g / L H2IrCl5·6H2O and 0.01 mol / L CH3COOH, pH 5). Electrodeposit iridium on the surface of electrode A using an electrodeposition method. The electrodeposition solution temperature is 85℃ and the current density is 2.0 A / dm³. 2 Electrode B was prepared by deposition time of 1 hour;

[0089] (4) Spray a 20 g / L SnCl4 solution (spray gun diameter is 0.9 mm, flow rate is 300 mL / min) onto the surface of electrode B obtained in step (3), and dry it by infrared irradiation for 15 min. Then place it in an electric furnace for heat treatment at 550℃ for 10 min. Repeat the above operation 5 times. The last heat treatment is at 500℃ for 1 h. After cooling, a new type of inert titanium anode is obtained.

[0090] Example 6

[0091] (1) The titanium plate was initially polished with coarse sandpaper (specification: less than 400 mesh) to remove surface impurities. Then it was soaked in a sodium carbonate solution with a concentration of 5wt% at 60℃ for 1 hour. After rinsing with deionized water, it was soaked in an oxalic acid solution with a concentration of 10wt% and acid etched for 2 hours under a slight boiling state. After rinsing with deionized water, it was soaked in anhydrous ethanol and ultrasonically treated at 20kHz for 15 minutes. After cleaning with deionized water, a titanium substrate with a rough and clean surface was obtained.

[0092] (2) Using the titanium substrate obtained in step (1) as the cathode and a platinum sheet as the anode, the substrate is immersed in a ruthenium-containing solution (containing 10 g / L RuCl3, 10 g / L NH2SO3H, pH 2). Ruthenium is electrodeposited on the surface of the titanium plate using an electrodeposition method. The solution temperature for the electrodeposition method is 45 °C and the current density is 1.0 A / dm³. 2 Electrode A was prepared by deposition time of 2 hours;

[0093] (3) Using electrode A obtained in step (2) as the cathode and a platinum sheet as the anode, immerse it in an iridium-containing solution (containing 10 g / L H2IrCl5·6H2O and 0.02 mol / L CH3COOH, pH 4). Electrodeposit iridium onto the surface of electrode A using an electrodeposition method. The solution temperature for the electrodeposition method is 85℃ and the current density is 1.0 A / dm³. 2 Electrode B was prepared by deposition time of 2 hours.

[0094] (4) Spray a 20 g / L SnCl4 solution (spray gun diameter is 0.9 mm, flow rate is 300 mL / min) onto the surface of electrode B obtained in step (3), and dry it by infrared irradiation for 15 min. Then place it in an electric furnace for heat treatment at 450 °C for 10 min. Repeat the above operation 5 times. The last heat treatment is at 500 °C for 1 h. After cooling, a new type of inert titanium anode is obtained.

[0095] Comparative Example 1

[0096] The titanium substrate with a rough and clean surface is prepared by the same method as step (1) in Example 1.

[0097] Comparative Example 2

[0098] Same as Example 1, except that in step (2), the solution temperature for electrodeposition is 80°C and the current density is 2A / dm³. 2 The deposition time was 0.5 h.

[0099] Comparative Example 3

[0100] Same as Example 1, except that in step (3), the solution temperature for electrodeposition is 60°C and the current density is 0.5 A / dm³. 2 The deposition time was 0.5 h.

[0101] Comparative Example 4

[0102] Same as Example 1, except that in step (4), the surface of electrode B obtained in step (3) is sprayed with 50 g / L SnCl4 solution, and then placed in an electric furnace for heat treatment at 500°C for 1 h. After cooling, an inert titanium anode is obtained.

[0103] The proportions of each element in the anode coating of the novel inert titanium anodes prepared in Examples 1-6 and Comparative Examples 1-4 were determined and compared with the titanium substrate of Comparative Example 1. The results are shown in Table 1.

[0104] Table 1. Proportion of elements in the anodic coatings of Examples 1-6 and Comparative Examples 1-4

[0105] Element content / g Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 <![CDATA[RuO2]]> 0.665 1.200 0.662 1.196 0.788 0.814 0 0.682 0.662 0.663 <![CDATA[IrO2]]> 0.332 0.340 0.660 0.663 0.462 0.462 0 0.331 0.341 0.331 <![CDATA[SnO2]]> 0.02 0.021 0.019 0.042 0.027 0.021 0 0.022 0.019 0.02

[0106] Performance testing

[0107] Cyclic voltammetry and enhanced lifetime tests were performed on the titanium anodes prepared in Examples 1-6 and Comparative Examples 1-4.

[0108] The cyclic voltammetry curve test conditions are: potential range -0.7V to 0.7V, scan rate 10mV / s.

[0109] The enhanced life test conditions were as follows: a DC regulated power supply was used at room temperature, with a coated titanium anode and a titanium mesh cathode, and a current density of 2 A / cm². 2 The electrode spacing is 2 cm, the electrolyte is 1 mol / L H2SO4 solution, and the cell voltage rises to 10V, indicating electrode failure.

[0110] Comparison of cyclic voltammetry results for titanium anodes prepared in Examples 1-6 and Comparative Examples 1-4 is shown in the figure. Figure 2 The size of the image area in the cyclic voltammetry test results clearly indicates that the plate surface has good catalytic performance. This is consistent with Table 1 and... Figure 2It can be seen that the composition of the effective substance in the anode coating varies significantly under different conditions. The catalytic activity of the coated titanium anode is significantly higher than that of the uncoated anode. The uncoated anode is prone to forming a dense oxide film on its surface in acidic solutions, which significantly reduces the electrode conductivity and catalytic performance, leading to a sharp increase in anode voltage and failure, resulting in the shortest lifespan. The cyclic voltammetry curves of Examples 1-6 all have large areas, with the cyclic voltammetry curve corresponding to Example 4 having the largest enclosed area, indicating that the novel inert coated titanium anode prepared by this method has excellent catalytic active sites. Comparative Example 1, because it has no catalytic coating on its surface, has a significantly smaller number of catalytic active sites on the anode surface than the coated examples. In addition, the novel inert titanium anode with coating (Examples 1-6) has a lower oxygen evolution overpotential and higher current efficiency, and its corrosion resistance is better due to the coating protection. The uncoated anode (Comparative Example 1) has a relatively higher oxygen evolution overpotential, which leads to lower current efficiency. The lack of surface coating protection has caused an oxide film to form on the surface of the titanium electrode, reducing conductivity and shortening its lifespan. Comparing Examples 1-4, it can be seen that the catalytic performance of the coated anode is mainly affected by the quality of the active material, the electroplating process, and the heat treatment process. Adjusting the electroplating process can significantly change the amount of metal oxides in the coating, while the coating quality can directly affect the catalytic activity and lifespan of the anode. In comparison, the more coating applied, the longer the anode lifespan. IrO2 can significantly reduce the overall oxygen evolution potential of the anode.

[0111] The enhanced life test results of titanium anodes in Examples 1-6 and Comparative Examples 1-4 are shown in the figure. Figure 3 ,Depend on Figure 3 It can be seen that the anode lifetime prepared in the embodiments of the present invention is significantly higher than that of the uncoated titanium anode (Comparative Example 1). Based on the coating composition table in Table 1, it can be inferred that increasing the content of Ru and Ir can significantly improve the catalytic performance of the anode, while increasing the content of Sn and Ru helps to enhance the stability of the electrode coating and improve the overall performance of the electrode. By comparing Examples 1, 5, 6 and Comparative Example 1, it can be seen that the surface process of the titanium substrate mainly affects the lifespan of the coating. Appropriate roughness of the titanium substrate surface can significantly increase the surface area of ​​the titanium substrate, increase the adhesion between the coating and the titanium substrate, and improve stability; however, excessive acid etching will lead to the opposite result. The coating electrodeposition process is affected by temperature, current density, and time, directly affecting the metal oxide composition in the coating. Comparative analysis of the test results of Comparative Examples 1, 2, 3, 4 and Examples 2, 3, 4 shows that the electrodeposition process significantly affects the coating lifetime. Based on the analysis in Table 1, it can be determined that the deposition process affects the electrochemical performance and lifespan of the coated anode from both the quality of the active components of the coating oxide and the coating structure. Therefore, each stage of the process in preparing the coated titanium anode can affect its performance. Overall analysis... Figure 3 The influence of each condition on the coating performance is not significant and the results of the titanium anodizing test are the result of the combined effect of various process conditions.

[0112] In summary, the novel inert titanium anode prepared by the method of the present invention has good stability and electrochemical performance.

[0113] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A novel inert titanium anode comprising a titanium substrate and an anodic coating, characterized in that, The anode coating is loaded on the surface of the titanium substrate, and the anode coating is a layered structure containing three metal oxides, the inner layer of the anode coating is ruthenium oxide, the middle layer is iridium oxide, and the outer layer is tin oxide; The mass ratio of ruthenium oxide, iridium oxide and tin oxide in the anode coating is (0.6-1.2):(0.3-0.7):(0.01-0.05); The preparation method of the novel inert titanium anode comprises the following steps: (1) The titanium plate is pretreated to obtain a titanium substrate, the titanium substrate is used as a cathode, a platinum metal sheet is used as an anode, and the titanium plate is immersed in a solution containing ruthenium, and ruthenium is electrodeposited on the surface of the titanium plate by using an electrodeposition method to obtain an electrode A; (2) The electrode A obtained in step (1) is used as a cathode, a platinum metal sheet is used as an anode, and the electrode A is immersed in a solution containing iridium, and iridium is electrodeposited on the surface of the electrode A by using an electrodeposition method to obtain an electrode B; (3) A solution containing tin is sprayed on the surface of the electrode B obtained in step (2), and then dried and heat treated to obtain the novel inert titanium anode; In step (1), the solution containing ruthenium comprises RuCl3 at a concentration of 10-15 g / L and NH2SO3H at a concentration of 10 g / L, with a pH of 1-2; the solution temperature of the electrodeposition method is 45-50°C, the current density is 1.0-1.5 A / dm 2 , and the deposition time is 1-2 h. In step (1), the solution containing ruthenium comprises RuCl3 at a concentration of 10-15 g / L and NH2SO3H at a concentration of 10 g / L, with a pH of 1-2; the solution temperature of the electrodeposition method is 45-50°C, the current density is 1.0-1.5 A / dm 2 , and the deposition time is 1 In step (2), the iridium-containing solution comprises H2IrCl5·6H2O at a concentration of 10-15 g / L and CH3COOH at a concentration of 0.01-0.02 mol / L, with a pH of 4-5; the solution temperature of the electrodeposition method is 85°C, the current density is 1.0-2.0 A / dm2, and the deposition time is 1-2 h. 2 ​ In step (3), the solution containing tin is a SnCl4 solution with a concentration of 20 g / L; the drying is infrared drying; and the heat treatment is performed at a temperature of 450-550 DEG C for 1 h.

2. A method of producing the novel inert titanium anode as claimed in claim 1, characterized by, The novel inert titanium anode is obtained by using an electrodeposition method to successively deposit ruthenium and iridium on the surface of a titanium plate, then using a spraying process to spray a solution containing tin on the surface, and finally using a thermal decomposition method to in-situ generate a layered structure coating containing ruthenium, iridium and tin oxides on the surface of the titanium plate, and the mass ratio of ruthenium oxide, iridium oxide and tin oxide in the layered structure coating is (0.6-1.2):(0.3-0.7):(0.01-0.05); and the preparation method specifically comprises the following steps: (1) The titanium plate is pretreated to obtain a titanium substrate, the titanium substrate is used as a cathode, a platinum metal sheet is used as an anode, and the titanium plate is immersed in a solution containing ruthenium, and ruthenium is electrodeposited on the surface of the titanium plate by using an electrodeposition method to obtain an electrode A; (2) The electrode A obtained in step (1) is used as a cathode, a platinum metal sheet is used as an anode, and the electrode A is immersed in a solution containing iridium, and iridium is electrodeposited on the surface of the electrode A by using an electrodeposition method to obtain an electrode B; (3) A solution containing tin is sprayed on the surface of the electrode B obtained in step (2), and then dried and heat treated to obtain the novel inert titanium anode; In step (1), the solution containing ruthenium comprises RuCl3 with a concentration of 10-15 g / L and NH2SO3H with a concentration of 10 g / L, and the pH is 1-2; and / or The solution temperature of the electrodeposition method is 45-50°C, the current density is 1.0-1.5 A / dm 2 , and the deposition time is 1-2 h. In step (2), the solution containing iridium comprises H2IrCl5·6H2O with a concentration of 10-15 g / L and CH3COOH with a concentration of 0.01-0.02 mol / L, and the pH is 4-5; and / or The solution temperature of the electrodeposition method is 85°C, the current density is 1.0-2.0 A / dm 2 , and the deposition time is 1-2 h. In step (3), the solution containing tin is a SnCl4 solution with a concentration of 20 g / L; and / or The drying is infrared drying; and / or The heat treatment is performed at a temperature of 450-550 DEG C for 1 h.

3. The method of producing a novel inert titanium anode according to claim 2, characterized by, In step (1), the pretreatment of the titanium plate specifically comprises the following steps: After the titanium plate is polished, it is immersed in an alkaline solution, washed, immersed in an oxalic acid solution, continuously washed, then immersed in anhydrous ethanol and ultrasonically treated, and washed again to obtain the titanium substrate.

4. The method of producing a novel inert titanium anode according to claim 3, characterized by, The alkali solution is a sodium hydroxide solution or a sodium carbonate solution with a concentration of 5wt%; and / or The concentration of the oxalic acid solution is 10-15wt%.

5. The method of producing a novel inert titanium anode according to claim 3, characterized by, The ultrasonic treatment time is 10-15min, and the ultrasonic frequency is 20-30kHz.

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