Preparation method and application of coated titanium anode

Abstract

The invention provides a preparation method and application of a coated titanium anode, and relates to the technical field of electrode preparation. According to the method, an electrochemical oxidation step is introduced into the preparation of an electrode material, a PbO2 layer with a uniform microstructure and fewer cracks can be formed on a titanium plate substrate in situ, and the process is carried out along with electrolysis, so that the connection effect between the PbO2 layer and the substrate is effectively enhanced, and the PbO2 layer is prevented from falling off. By means of the mode, the defects that in the traditional electro-deposition technology, stripping is prone to occurring, the specific surface area is small, the production cost is high, and large-scale production cannot be achieved due to the fact that electro-deposition equipment and speed are limited are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of electrode preparation, and in particular to a preparation method of a coated titanium anode and application thereof. Background Art

[0002] Lead dioxide (PbO2) anodes are widely used in the electrochemical industry due to their excellent conductivity, high overpotential, corrosion resistance, and electrocatalytic activity, such as electrolytic production of chlorate, electrolytic production of fluorine, electrolytic organic synthesis, and electrochemical wastewater treatment. Currently, the main methods for preparing PbO2 electrodes include brush coating, electrodeposition, thermal decomposition, and sol-gel methods. However, these traditional methods all have certain limitations, which affect the performance and lifespan of PbO2 anodes in large-scale industrial applications.

[0003] In the known brush coating process, the slurry is brushed onto the titanium substrate by hand printing or screen printing, and then directly sintered at high temperature. The precursor substances such as chloric acid and chloride in the slurry are directly converted into oxides under high temperature conditions, and the bound water and chlorine elements in the precursor substances generate gases and escape. The gas escape can easily cause the catalytic layer on the electrode surface to crack. Once the electrode surface cracks, the titanium plate is exposed and cannot be completely covered. During use, the titanium substrate is quickly passivated, causing the electrode to fail quickly and the operating voltage to increase rapidly. Generally, the number of layers is increased by brushing multiple times to cover the cracks in the coating and protect the titanium substrate in order to reduce the risk of failure. However, multiple brushing will lead to an increase in the thickness of the coating, and the increase in material load will lead to an increase in the production cost of the coated titanium anode. The traditional brush coating process cannot reduce the production cost of the coated titanium anode while ensuring that the coated titanium anode has sufficient and stable quality and performance, which limits its actual production application. At present, the electrodeposition method is the mainstream technology for preparing PbO2 electrodes, but it has the following defects: (1) easy to peel off and poor mechanical stability; (2) low specific surface area and limited catalytic activity; (3) process limitations and difficulty in large-scale production.

[0004] In view of this, it is necessary to design an improved preparation method of coated titanium anode and its application to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a coated titanium anode and application thereof.

[0006] To achieve the above-mentioned object of the invention, on the one hand, the present invention provides a method for preparing a coated titanium anode, comprising the following steps:

[0007] S1. Coating an anti-oxidation layer on the surface of the titanium plate;

[0008] S2. At 200-400° C., spraying electrode slurry onto the surface of the titanium plate coated with the anti-oxidation layer in step S1 to form a deposition layer on the surface of the anti-oxidation layer;

[0009] S3, sintering the titanium plate containing the anti-oxidation layer and the deposition layer obtained in step S2, and then subjecting it to electrochemical oxidation treatment to obtain a coated titanium anode.

[0010] Preferably, in step S3, the electrochemical oxidation treatment is carried out as follows: immersing the sintered titanium plate containing the anti-oxidation layer and the deposition layer in an electrolyte at a voltage of 2-3.5 V and a current density of 10-50 mA / cm 2 Electrolysis was carried out under the following conditions and the electrolysis time was 3-4h.

[0011] Preferably, in step S3, the sintering treatment is performed at a temperature of 400-450° C. and for a time of 0.5-3 h.

[0012] Preferably, the electrolyte is a mixture of nitric acid and lead acetate, wherein the concentration of lead nitrate in the mixture is 0.5-1.5M and the concentration of nitric acid is 0.1-0.5M.

[0013] Preferably, in step S1, the anti-oxidation layer is a conductive metal oxide film.

[0014] Preferably, in step S1, the anti-oxidation layer is a conductive glass film, specifically one of ATO, ITO, and FTO.

[0015] Preferably, the anti-oxidation layer is formed in the following manner: a conductive glass film is sprayed on the surface of the titanium plate, and then heated to solidify the conductive glass film. The solidification temperature is 300-500° C. and the time is 5-30 minutes.

[0016] On the other hand, the present invention also provides a coated titanium anode, comprising:

[0017] titanium plate;

[0018] At least one anti-oxidation layer, which is closely attached to the surface of the titanium plate, is formed of a conductive metal oxide and has a thickness of 0.2-3 μm;

[0019] At least one sediment layer is closely attached to the surface of the anti-oxidation layer and is composed of lead dioxide. The coated titanium anode can be used for electrolysis of organic wastewater and reduction of COD in the organic wastewater.

[0020] The beneficial effects of the present invention are:

[0021] 1. The method for preparing a coated titanium anode provided by the present invention, by introducing an electrochemical oxidation step into the preparation of the electrode material, can in situ form a PbO2 layer with a uniform microstructure and fewer cracks on a titanium plate substrate. Because this process occurs during electrolysis, it effectively strengthens the connection between the PbO2 layer and the substrate, preventing the PbO2 layer from falling off. This approach overcomes the shortcomings of traditional electrodeposition technology, such as easy flaking, low specific surface area, high production costs, and the inability to scale production due to limitations in electrodeposition equipment and speed.

[0022] 2. The preparation method provided by this invention precisely controls the thickness of the PbO2 layer by controlling the thickness of the precursor coating and the sintering time. By spraying the electrode slurry to form the deposited layer, atomization is more uniform, quickly covering a large area at one time, and forming nano- or micron-sized particles, improving production efficiency and increasing material utilization. The PbO2 layer generated through in-situ growth is less susceptible to flaking. Controlling the electrolysis current density and electrolyte composition facilitates the formation of highly active β-PbO2. Using the preparation method proposed by this invention, a coated titanium anode with high electrochemical stability and excellent catalytic activity can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a process flow chart of the method for preparing the coated titanium anode proposed in the present invention;

[0024] Figure 2 Surface SEM images of the coated titanium anodes prepared in Examples 1-5 of the present invention at a magnification of 100 times;

[0025] Figure 3 Surface SEM images of the coated titanium anodes prepared in Examples 1-5 of the present invention at a magnification of 1000 times;

[0026] Figure 4 The cyclic voltammetry curves of the coated titanium anodes prepared in Examples 1-5 of the present invention are shown;

[0027] Figure 5 LSV curves of the coated titanium anodes prepared in Examples 1-5 of the present invention;

[0028] Figure 6 This is a graph showing the COD changes when the electrodes prepared in Examples 1-5 of the present invention treat wastewater;

[0029] Figure 7 The COD change diagram of the electrodes prepared in Example 1 of the present invention and Comparative Example 1 when treating wastewater. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] It should also be noted here that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0032] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0033] In one aspect, the present invention provides a coated titanium anode comprising:

[0034] titanium plate;

[0035] At least one anti-oxidation layer, which is closely attached to the surface of the titanium plate, and is formed of a conductive metal oxide and has a thickness of 0.2-3 μm;

[0036] At least one deposition layer is closely attached to the surface of the anti-oxidation layer and is composed of lead dioxide.

[0037] On the other hand, see Figure 1 As shown, the present invention provides a method for preparing a coated titanium anode, comprising the following steps:

[0038] S1. Coating an anti-oxidation layer on the surface of the titanium plate;

[0039] S2. At 200-400° C., spraying electrode slurry onto the surface of the titanium plate coated with the anti-oxidation layer in step S1, the electrode slurry is cracked under the action of high temperature to form an initial metal oxide deposition layer;

[0040] S3, sintering the titanium plate containing the anti-oxidation layer and the deposition layer obtained in step S2, and then subjecting it to electrochemical oxidation treatment to obtain a coated titanium anode.

[0041] In some embodiments, in step S1, the anti-oxidation layer is a conductive metal oxide film, specifically a conductive glass film, including ATO, ITO or FTO, which is formed by spraying the conductive glass film on the surface of the titanium plate and then heating it to solidify the conductive glass film. The curing temperature is 300-500°C and the time is 5-30 minutes. In particular, in some embodiments, before preparing the anti-oxidation layer on the surface of the titanium plate, it needs to be pretreated as follows: the titanium substrate is cut and sandblasted to remove the surface oxide layer, then soaked in a 20% hydrochloric acid solution for 16 hours, and finally placed in a slightly boiling 10% oxalic acid solution for etching for 2 hours. After etching, it is rinsed with deionized water and dried to obtain a pretreated titanium plate.

[0042] In some embodiments, in step S2, the electrode slurry is formed by dissolving a lead precursor in an organic solvent, wherein the organic solvent is one or more of isopropyl alcohol, butanol, and ethanol. Specifically, in some embodiments, the electrode slurry is a mixed solution of lead acetate and ethanol, wherein the concentration of lead triacetate in the mixed solution is 0.2-0.5 mol / L.

[0043] In some embodiments, in step S2, the electrode slurry is formed by atomization spraying, such as an atomizer such as an airbrush, and the atomization spraying speed is 0.5-2 mL / (min﹒m 2 ).

[0044] In some embodiments, in step S3, the sintering process is performed at a temperature of 400-450° C. and for a time of 0.5-3 h.

[0045] In some embodiments, in step S3, the electrochemical oxidation treatment is performed as follows: immersing the sintered titanium plate in an electrolyte at a voltage of 2-3.5 V and a current density of 10-50 mA / cm 2 Electrolysis is carried out under the above conditions, and the electrolysis time is 3-4h. Through the above treatment method, the initial metal oxide deposition layer composed of lead tetroxide can be oxidized to lead dioxide. Among them, the electrolyte is a mixture of nitric acid and lead acetate, the concentration of lead acetate in the mixture is 0.5-1.5M, and the concentration of nitric acid is 0.1-0.5M. The voltage here is 2-3.5V, which can provide the electrode potential required for electrodeposition, so that the anode reaction is sufficient to oxidize lead tetroxide. If the voltage is too low, the deposition rate will be low, and it will be difficult to form a complete and continuous film layer. It may only generate lead oxide and lead tetroxide; if the weak voltage is too high, oxygen evolution reaction will easily occur, generating bubbles, resulting in holes, bulging, and decreased adhesion in the deposition layer. The current density determines the deposition rate per unit area per unit time, affecting the grain size, crystal form, density, etc. If the current density is too small (<10mA / cm 2 ), the deposition rate is slow, the grains are easy to grow, resulting in loose film, low conductivity, poor corrosion resistance, and moderate current density (10-30mA / cm 2 ), the deposition is more uniform, the structure is dense, which is conducive to the formation of β-PbO2, good crystallization, high catalytic activity, and high current density (>50mA / cm 2 ) The deposition rate is fast, oxygen is easily released, holes and cracks are easily generated, the film adhesion is poor, and it may even peel off; however, it can be used to prepare electrodes with large roughness and high specific surface area.

[0046] The preparation method and application of the coated titanium anode provided by the present invention are further described below with reference to specific embodiments:

[0047] Example 1

[0048] This embodiment prepares a coated titanium anode, including the following steps:

[0049] The titanium substrate was first cut and sandblasted to remove the surface oxide layer, then immersed in a 20% hydrochloric acid solution for 16 hours, and finally etched in a slightly boiling 10% oxalic acid solution for 2 hours. After etching, it was rinsed with deionized water and dried to obtain a titanium plate (length × width × height = 10 cm × 10 cm × 0.05 cm). A 0.5 μm thick conductive glass film (ATO) was applied to the surface of the pretreated titanium plate and dried in a 400°C oven for 10 minutes to form an anti-oxidation layer on the surface of the titanium plate.

[0050] Maintaining the temperature at 200°C, use an atomizer (airbrush) to spray 10 mL of electrode slurry (deposition layer thickness is 0.5 mm) onto the surface of the titanium plate treated in the above step. After spraying, place it in a muffle furnace and calcine at 450°C until it presents orange-red Pb3O4. The electrode slurry is a mixed solution of lead acetate and ethanol. The concentration of lead triacetate in the mixed solution is 0.3 mol / L. The number of spraying times is 5, and the spraying rate is 2 mL / min.

[0051] The treated titanium plate was electrolyzed in an electrolyte solution at a controlled voltage of 2.50 V for 60 minutes to produce a coated titanium anode. The electrolyte was prepared by mixing nitric acid and lead acetate, with a nitric acid concentration of 1 mol / L and a lead acetate concentration of 0.1 mol / L. It should be noted that, unless otherwise specified, the reagents and raw materials used in the examples of the present invention can be obtained commercially.

[0052] Example 2

[0053] This embodiment prepares a coated titanium anode, including the following steps:

[0054] The titanium substrate was first cut and sandblasted to remove the surface oxide layer, then immersed in a 20% hydrochloric acid solution for 16 hours, and finally etched in a slightly boiling 10% oxalic acid solution for 2 hours. After etching, it was rinsed with deionized water and dried to obtain a titanium plate (length × width × height = 10 cm × 10 cm × 0.05 cm). A 0.5 μm thick conductive glass film (ATO) was applied to the surface of the pretreated titanium plate and dried in a 400°C oven for 10 minutes to form an anti-oxidation layer on the surface of the titanium plate.

[0055] Maintaining the temperature at 300°C, use an atomizer (airbrush) to spray 10 mL of electrode slurry (deposition layer thickness is 0.5 mm) onto the surface of the titanium plate treated in the above step. After spraying, place it in a muffle furnace and calcine at 450°C until it presents orange-red Pb3O4. The electrode slurry is a mixed solution of lead acetate and ethanol. The concentration of lead triacetate in the mixed solution is 0.1 mol / L. The number of spraying times is 5, and the spraying rate is 2 mL / min.

[0056] The treated titanium plate was placed in an electrolyte solution with a controlled voltage of 2.50 V for electrolysis for 60 minutes to obtain a coated titanium anode; wherein the electrolyte was obtained by mixing nitric acid and lead acetate, with a nitric acid concentration of 1 mol / L and a lead acetate concentration of 0.1 mol / L in the electrolyte.

[0057] Example 3

[0058] This embodiment prepares a coated titanium anode, including the following steps:

[0059] The titanium substrate was first cut and sandblasted to remove the surface oxide layer, then immersed in a 20% hydrochloric acid solution for 16 hours, and finally etched in a slightly boiling 10% oxalic acid solution for 2 hours. After etching, it was rinsed with deionized water and dried to obtain a titanium plate (length × width × height = 10 cm × 10 cm × 0.05 cm). A 0.5 μm thick conductive glass film (ATO) was applied to the surface of the pretreated titanium plate and dried in a 400°C oven for 10 minutes to form an anti-oxidation layer on the surface of the titanium plate.

[0060] Maintaining the temperature at 300°C, use an atomizer (airbrush) to spray 10 mL of electrode slurry (deposition layer thickness is 0.5 mm) onto the surface of the titanium plate treated in the above step. After spraying, place it in a muffle furnace and calcine at 450°C until it presents orange-red Pb3O4. The electrode slurry is a mixed solution of lead acetate and ethanol. The concentration of lead triacetate in the mixed solution is 0.3 mol / L. The number of spraying times is 5, and the spraying rate is 2 mL / min.

[0061] The treated titanium plate was placed in an electrolyte solution with a controlled voltage of 2.50 V for electrolysis for 60 minutes to obtain a coated titanium anode; wherein the electrolyte was obtained by mixing nitric acid and lead acetate, with a nitric acid concentration of 1 mol / L and a lead acetate concentration of 0.1 mol / L in the electrolyte.

[0062] Example 4

[0063] This embodiment prepares a coated titanium anode, including the following steps:

[0064] The titanium substrate was first cut and sandblasted to remove the surface oxide layer, then immersed in a 20% hydrochloric acid solution for 16 hours, and finally etched in a slightly boiling 10% oxalic acid solution for 2 hours. After etching, it was rinsed with deionized water and dried to obtain a titanium plate (length × width × height = 10 cm × 10 cm × 0.05 cm). A 0.5 μm thick conductive glass film (ATO) was applied to the surface of the pretreated titanium plate and dried in a 400°C oven for 10 minutes to form an anti-oxidation layer on the surface of the titanium plate.

[0065] Maintaining the temperature at 200°C, use an atomizer (airbrush) to spray 10 mL of electrode slurry (deposition layer thickness is 0.5 mm) onto the surface of the titanium plate treated in the above step. After spraying, place it in a muffle furnace and calcine at 450°C until it presents orange-red Pb3O4. The electrode slurry is a mixed solution of lead acetate and ethanol. The concentration of lead triacetate in the mixed solution is 0.5 mol / L. The number of spraying times is 5, and the spraying speed is 2 mL / min.

[0066] The treated titanium plate was placed in an electrolyte solution with a controlled voltage of 2.50 V for electrolysis for 60 minutes to obtain a coated titanium anode; wherein the electrolyte was obtained by mixing nitric acid and lead acetate, with a nitric acid concentration of 1 mol / L and a lead acetate concentration of 0.1 mol / L in the electrolyte.

[0067] Example 5

[0068] This embodiment prepares a coated titanium anode, including the following steps:

[0069] The titanium substrate was first cut and sandblasted to remove the surface oxide layer, then immersed in a 20% hydrochloric acid solution for 16 hours, and finally etched in a slightly boiling 10% oxalic acid solution for 2 hours. After etching, it was rinsed with deionized water and dried to obtain a titanium plate (length × width × height = 10 cm × 10 cm × 0.05 cm). A 0.5 μm thick conductive glass film (ATO) was applied to the surface of the pretreated titanium plate and dried in a 400°C oven for 10 minutes to form an anti-oxidation layer on the surface of the titanium plate.

[0070] Maintaining the temperature at 400°C, use an atomizer (airbrush) to spray 10 mL of electrode slurry (deposition layer thickness is 0.5 mm) onto the surface of the titanium plate treated in the above step. After spraying, place it in a muffle furnace and calcine at 450°C until it presents orange-red Pb3O4; the electrode slurry is a mixed solution of lead acetate and ethanol, the concentration of lead triacetate in the mixed solution is 0.3 mol / L, the number of spraying times is 5, and the spraying rate is 2 mL / min;

[0071] The treated titanium plate was placed in an electrolyte solution with a controlled voltage of 2.50 V for electrolysis for 60 minutes to obtain a coated titanium anode; wherein the electrolyte was obtained by mixing nitric acid and lead acetate, with a nitric acid concentration of 1 mol / L and a lead acetate concentration of 0.1 mol / L in the electrolyte.

[0072] The surface SEM images of the coated titanium anodes obtained in Examples 1 to 5 at a magnification of 100 times are as follows: Figure 2 As shown, the surface SEM image of the coated titanium anode at a magnification of 1000 times is as follows Figure 3 As shown, Figure 2 and Figure 3Figures (a)-(e) correspond to Examples 1 to 5, respectively. The results show that a relatively dense titanium dioxide coating is formed on the surface of the coated titanium anode prepared under the conditions of Example 1 (electrode slurry spraying temperature of 200°C). At this time, since the titanium surface temperature during spraying is not sufficient to allow lead acetate to evaporate instantly, no nanoparticles are formed on the surface; tiny particles are formed on the surface of the coating of Example 2, and a large number of gaps can be observed in the coating at a magnification of 1000 times, indicating that the formation of the coating effectively increases the active area of ​​the titanium plate; more obvious surface pores can be observed on the surface of the coated titanium anode of Example 3 than in Examples 1-2, and small particles of lead tetroxide are generated after spraying and pyrolysis, and the active area is the largest at this time; compared with Example 3, after increasing the lead acetate concentration in Example 4, the formation of nanoparticles is suppressed, and the generated lead particles are larger; Figure 2-3 Figure (e) in FIG. 5 shows that nano-sized particles are also formed in Example 5.

[0073] Comparative Example 1

[0074] This comparative example adopts the preparation method in CN107779847A to prepare the coated titanium anode, and the specific steps are as follows:

[0075] A titanium plate (1 cm × 2 cm) was polished using 240# alumina water-abrasive sandpaper until a metallic luster appeared on the surface of the titanium plate. The plate was then rinsed three times with an alkaline solution containing sodium carbonate, rinsed with deionized water, and then placed in 10 wt% oxalic acid and etched for 2 h. After etching, the plate was rinsed with deionized water and dried to obtain a pretreated titanium plate. A 0.5 μm thick conductive glass film (ATO) was applied to the surface of the pretreated titanium plate, which was then baked in a 400°C oven for 10 min and dried in a 400°C oven for 10 min to form an anti-oxidation layer on the surface of the titanium plate.

[0076] Maintaining the temperature at 250°C, use an airbrush to spray 10 mL of electrode slurry onto the treated titanium plate. After spraying, the plate is sintered at 600°C for 3 hours to produce a titanium anode with an iridium dioxide coating. The electrode slurry is a mixture of 7 mmol / L iridium trichloride and 3 mmol / L tin chloride in isopropanol.

[0077] The cyclic voltammetry curves of the coated titanium anodes obtained in Examples 1 to 5 are shown in FIG. Figure 4 As shown in the cyclic voltammetry curve, there is an obvious oxidation peak at about +1.8V relative to the Ag / AgCl electrode, which indicates that the lead dioxide-coated titanium anode has a higher oxygen evolution potential, fewer side reactions, and a higher treatment depth; the LSV curves of the coated titanium anodes prepared in Examples 1 to 5 are shown in FIG. Figure 5 As shown, the results show that the lead dioxide coating prepared under the conditions of Example 3 (electrode slurry spraying temperature of 300° C., lead acetate solution concentration of 0.3 mol / L) has a higher oxygen evolution potential. Figure 6The treatment results of Examples 1 to 5 of the present invention for electrolysis of organic wastewater at a constant voltage of 4V are shown. The COD concentration of the raw water is about 1000mg / L. The lead dioxide-coated titanium anodes prepared in Examples 1 to 5 can effectively remove COD, with the highest reduction of COD being about 96%. Under the above conditions, the anode materials of Example 1 and Comparative Example 1 are used for electrolysis of organic wastewater, and the treatment results are shown in FIG. Figure 7 As shown, the results show that the iridium dioxide coated titanium anode of Comparative Example 1 has a worse treatment effect than that of Example 1.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a coated titanium anode, characterized in that: The steps include: S1. Coating an anti-oxidation layer on the surface of the titanium plate; S2. At 200-400° C., spraying electrode slurry onto the surface of the titanium plate coated with the anti-oxidation layer in step S1 to form a deposition layer on the surface of the anti-oxidation layer; S3, sintering the titanium plate containing the anti-oxidation layer and the deposition layer obtained in step S2, and then subjecting it to electrochemical oxidation treatment to obtain a coated titanium anode.

2. The preparation method according to claim 1, characterized in that In step S3, the electrochemical oxidation treatment is carried out as follows: the sintered titanium plate containing the anti-oxidation layer and the deposition layer is immersed in an electrolyte at a voltage of 2-3.5 V and a current density of 10-50 mA / cm 2 Electrolysis was carried out under the following conditions and the electrolysis time was 3-4h.

3. The preparation method according to claim 1, characterized in that In step S3, the sintering temperature is 400-450° C. and the sintering time is 0.5-3 hours.

4. The preparation method according to claim 2, characterized in that The electrolyte is a mixture of nitric acid and lead acetate, wherein the concentration of lead nitrate in the mixture is 0.5-1.5M and the concentration of nitric acid is 0.1-0.5M.

5. The preparation method according to claim 1, characterized in that In step S1 , the anti-oxidation layer is a conductive metal oxide film.

6. The preparation method according to claim 1, characterized in that In step S1 , the anti-oxidation layer is a conductive glass film, specifically one of ATO, ITO, and FTO.

7. The preparation method according to claim 6, characterized in that The anti-oxidation layer is formed in the following manner: a conductive glass film is sprayed on the surface of the titanium plate, and then heated to solidify the conductive glass film. The solidification temperature is 300-500° C. and the time is 5-30 minutes.

8. A coated titanium anode, characterized in that: Prepared by the preparation method according to any one of claims 1 to 7, comprising: titanium plate; At least one anti-oxidation layer, which is closely attached to the surface of the titanium plate, is formed of a conductive metal oxide and has a thickness of 0.2-3 μm; At least one deposition layer is closely attached to the surface of the anti-oxidation layer and is composed of lead dioxide.

9. Use of the coated titanium anode according to claim 8 in electrolysis of organic wastewater.

10. Use of the coated titanium anode according to claim 8 in reducing COD in organic wastewater.

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