Quantum dot modified anode material and preparation method thereof

Abstract

This invention discloses a quantum dot-modified anode material and its preparation method, relating to the field of electrochemical technology. It fully utilizes the advantages of quantum dots, such as good crystallinity, excellent conductivity, tunable particle size, diverse quantum dot types, and ease of organic or inorganic modification of nanoparticle surfaces, providing abundant anchoring sites and active sites for noble metal oxides in the electrode, thus maximizing the electrocatalytic performance of the electrode. The introduced quantum dots offer the possibility of improving the conductivity of the composite material and promoting electron transfer between the catalyst active sites and the electron surface, thereby greatly enhancing the electrocatalytic water oxidation performance. This results in the quantum dot-modified anode material of this invention exhibiting excellent electrochemical activity and lifespan, significantly improving the electrocatalytic OER activity and stability of the electrode, and possessing highly efficient wastewater treatment capabilities.

Description

Technical Field

[0001] This invention relates to the field of electrochemical technology, and in particular to a quantum dot modified anode material and its preparation method. Background Technology

[0002] With the rapid development of industry, the volume of wastewater discharge is increasing, and its composition is becoming more complex. Simultaneously, stricter emission standards have made efficient wastewater treatment methods increasingly important. Electrochemical wastewater treatment technology using DSA electrodes (titanium-based active oxide coated electrodes) has gained widespread attention due to its advantages such as strong oxidizing properties without the need for strong oxidants, no secondary pollution during the treatment process, and high efficiency in treating toxic, high-concentration, and recalcitrant wastewater.

[0003] Electrodes are the most critical factor affecting wastewater treatment efficiency, and the performance of the anode material in a DSA electrode determines the development of electrochemical wastewater treatment technology. However, traditional anode materials suffer from low catalytic efficiency and instability, limiting their development. Therefore, improving the catalytic performance and stability of electrodes has become a current research hotspot. Quantum dots, as a novel type of nanomaterial with abundant surface functional groups and the ability to induce charge redistribution, have become an important candidate material for improving the electrocatalytic performance of transition metal-based materials due to their inherent physical and chemical properties. In addition, the abundant functional groups on the surface of quantum dots provide rich anchoring sites and active sites for the engineering of multi-component high-performance composite materials. Summary of the Invention

[0004] The purpose of this invention is to provide a quantum dot-modified anode material and its preparation method. Quantum dots are prepared using chemical solution growth, epitaxial growth, and electric field confinement methods, and then combined with thermal decomposition, sol-gel, and electrodeposition methods to achieve the preparation of a quantum dot composite coating. On a titanium substrate, the main components are noble metal oxides, and the doped quantum dots adhere to these oxides. Utilizing their high specific surface area, numerous surface active centers, and the ability of quantum dots to act as both electron donors and acceptors, the grain size of the active coating is reduced, thereby improving the electrocatalytic performance and stability of the electrode.

[0005] The solution of the present invention is:

[0006] A method for preparing quantum dot modified anode materials includes the following steps:

[0007] 1) Titanium plate pretreatment: polish the titanium plate, wash it with alkaline solution, etch it with oxalic acid solution, and then put it in anhydrous ethanol for later use.

[0008] 2) Quantum dot selection, quantum dot preparation, and surface modification using elements;

[0009] 3) Preparation of quantum dot modified coating anode: The quantum dots in 2) are used to prepare a coating liquid with noble metal salt compounds. The coating liquid is applied to the surface of the titanium plate treated in 1) to prepare a quantum dot modified anode material.

[0010] As a preferred technical solution, the quantum dot in 2) is one of carbon quantum dots, silicon quantum dots, PbS quantum dots, GeS quantum dots, cadmium sulfide quantum dots, germanium quantum dots, and Mo2C-MoO2 quantum dots; the preparation and surface modification using elements in 2) includes microwave strengthening technology, chemical solution growth method, epitaxial growth method, and electric field confinement method.

[0011] As a preferred technical solution, the element in 2) is one of nitrogen, phosphorus, and boron.

[0012] As a preferred technical solution, the noble metal salt compound in 3) is one or more of RuCl3, TaCl5, H2IrCl6, and SnCl4.

[0013] As a preferred technical solution, the method by which the intermediate coating liquid in step 3) is applied to the surface of the titanium plate treated in step 1) is one of the following: thermal decomposition, sol-gel method, electrodeposition method, electroplating method, and magnetron sputtering method.

[0014] As a preferred technical solution, the quantum dot modified anode material is N-CQDs-RuO2-TiO. 2、 One of the following: SQDs-IrO2-Ta2O5-TiO2, Mo2C / MoO2QDs-RuO2-TiO2-SnO2, PbSQDs-TiO2-RuO2, GeQDs-TiO2-RuO2-SnO2, and CdSQDs-TiO2-RuO2-PbO2.

[0015] As a preferred technical solution, in step 3), applying the coating liquid to the surface of the titanium plate treated in step 1) involves uniformly brushing the prepared coating liquid onto the surface of the treated titanium plate with a fine brush, followed by drying and calcination. The plate is then removed and allowed to cool naturally. This process is repeated ≥15 times. When the drying process is completed in the last cycle, calcination is replaced by sintering. After sintering, a quantum dot modified anode material is obtained.

[0016] As a preferred technical solution, the drying temperature is 100-120℃ and the drying time is 10-15 min; the calcination temperature is 450-500℃ and the processing time is 10-20 min; the final sintering time is 60 min and the sintering temperature is 450-500℃.

[0017] As a preferred technical solution, in step 1), the alkaline washing solution is 10g of analytical grade NaOH dissolved in 90mL of distilled water, the alkaline washing temperature is 50℃, and the treatment time is 30min; the acid washing solution is 10g of analytical grade oxalic acid dissolved in 90mL of distilled water, the acid etching temperature is 80℃, and the time is 120min. The purpose of polishing the titanium plate is to increase its roughness and remove surface stains and oxide layers.

[0018] The present invention also discloses a quantum dot modified anode material, characterized in that: the surface of the titanium plate is coated with a layer containing quantum dots and noble metal oxides.

[0019] The preparation method of quantum dot modified anode material includes the following steps: 1) Titanium plate pretreatment: the titanium plate is polished and washed with alkaline solution, etched with oxalic acid solution, and then placed in anhydrous ethanol for later use; 2) Quantum dot selection: quantum dots are prepared and surface is modified using elements; 3) Quantum dot modified coating anode preparation: a coating liquid is prepared using the quantum dots in 2) and noble metal salt compounds, and the coating liquid is applied to the surface of the titanium plate treated in 1) to prepare quantum dot modified anode material.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The quantum dot-modified anode material prepared in this invention fully utilizes the high specific surface area, numerous surface active centers, and the ability of quantum dots to act as both electron donors and acceptors to improve the electrocatalytic performance and stability of the electrode while reducing grain size. Quantum doping generates a large number of vacancy defects on the surface of the composite coating, reducing the loading of Ru, Ir, and Ta rare and precious metals on the coating surface during anode preparation. Furthermore, it gradually reduces the width and depth of cracks on the coating surface, and the reduced crystal size effectively improves the surface charge capacity and corrosion resistance of the anode.

[0022] In the degradation of organic pollutant wastewater (such as phenol), the addition of quantum dots can increase the electron transfer rate of the degradation reaction, thereby generating more... This promotes the oxidation of oxidants The generation, and Phenol is oxidized to produce CO2+H2O, thereby further improving the degradation efficiency of phenol. Attached Figure Description

[0023] Figure 1 SEM image of the N-CQDs-IrO2-RuO2-TiO2 composite coating;

[0024] Figure 2 The degradation rates of phenol and COD with different CQDs contents are shown in (a) phenol degradation rate and (b) COD degradation rate. Detailed Implementation

[0025] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0026] Example 1

[0027] The preparation method of N-doped carbon quantum dot modified anode material includes the following steps (in this example, the noble metal elements are Ir, Ru, and Ti):

[0028] (1) Cut the TA2 titanium plate into 10mm×10mm pieces using a shearing machine, then use sandpaper to polish the cut titanium plate to remove the oxide layer and stains on the surface of the titanium plate, and then rinse the surface of the titanium plate with distilled water to remove the residual powder on the surface of the titanium plate.

[0029] (2) Dissolve 10g of analytical grade NaOH in 90mL of distilled water and stir at 600r / min for 10min on a magnetic stirrer to fully dissolve the NaOH particles. Then heat the water bath to 50℃ and put the titanium plate rinsed in step (1) into it. Keep it warm for 30min and then rinse off the NaOH droplets on the surface of the titanium plate with distilled water.

[0030] (3) Dissolve 10g of analytical grade oxalic acid in 90mL of distilled water, stir at 600r / min for 10min on a magnetic stirrer to fully dissolve the oxalic acid particles, then heat to 80℃ in a water bath, put the titanium plate rinsed in step (2) into it, keep it warm for 60min, then rinse off the oxalic acid droplets on the surface of the titanium plate with distilled water, and put it in anhydrous ethanol for later use.

[0031] (4) Dissolve 3g of analytical grade glucose and 3g of urea in 97mL of distilled water. Stir on a magnetic stirrer at 600r / min for 30min until fully dissolved. Then place in a microwave oven and heat at a rate of 12℃ / min for 15min. Then keep at 180℃ for 60min. After cooling naturally in the microwave oven, remove the solution, pour it out, centrifuge at 10000r / min for 30min, and then filter through a 0.22µm membrane. The final result is a brown nitrogen-doped carbon quantum dot solution.

[0032] (5) The freeze-dried N-CQDs powder was decomposed into 1.72 mL of n-butanol at mass fractions of 3.4%, 6.7%, 9.7%, and 12.2%, respectively, and then 0.7 mL of hydrochloric acid (concentration of 36%) was added. The mixture was then dissolved in water at a molar ratio of n(Ir). 4+ ): n(Ru 4 + ): n(Ti4+ The coating solution was prepared by adding chloroiridium acid (H2IrCl6.6H2O), ruthenium trichloride (RuCl3.3H2O), and tetrabutyl titanate to the solution with a ratio of 36:38:26.

[0033] (6) Apply the coating solution prepared in step (5) evenly to the surface of the titanium plate treated in step (3) using a fine brush, then dry it in a drying oven at 120°C for 10 minutes, and then transfer it to a muffle furnace at 500°C for 10 minutes. After removing it and allowing it to cool naturally, apply the solution again, dry and calcine, repeating this process more than 15 times until the coating solution is used up. For the last coating, sinter it at 500°C for 1 hour. After removing it and cooling it, a carbon quantum dot coated anode (Ti / N-CQDs-IrO2-RuO2-TiO2) is obtained. The SEM image of the N-CQDs powder with a doping content of 3.4% is shown in the figure. Figure 1 As shown in the figure, the addition of N-CQDs significantly reduced the number of microcracks. The results of degradation of a high-concentration phenol solution (1 g / L) are as follows... Figure 2 As shown, when the N-CQDs powder doping amount is 12.2%, the degradation rate of phenol within 1 hour is increased by 102.12% compared with the traditional Ti / TiO2-IrO2-RuO2 anode, and the degradation rate of COD is increased by 57.75%. Moreover, with the increase of N-CQDs powder doping amount, the degradation rate of COD is further improved.

[0034] Example 2

[0035] The preparation method of silicon quantum dot modified anode material specifically includes the following steps (in this example, the noble metal elements are Ir and Ta):

[0036] (1) Cut the TA2 titanium plate into 10mm×10mm pieces using a shearing machine, then use sandpaper to polish the cut titanium plate to remove the oxide layer and stains on the surface of the titanium plate, and then rinse the surface of the titanium plate with distilled water to remove the residual powder on the surface of the titanium plate.

[0037] (2) Dissolve 10g of analytical grade NaOH in 90mL of distilled water and stir at 600r / min for 10min on a magnetic stirrer to fully dissolve the NaOH particles. Then heat the water bath to 60℃ and put the titanium plate rinsed in step (1) into it. Keep it warm for 60min and then rinse off the NaOH droplets on the surface of the titanium plate with distilled water.

[0038] (3) Dissolve 15g of analytical grade oxalic acid in 90mL of distilled water, stir at 600r / min for 20min on a magnetic stirrer to fully dissolve the oxalic acid particles, then heat to 90℃ in a water bath, put the titanium plate rinsed in step (2) into it, keep it warm for 60min, then rinse off the oxalic acid droplets on the surface of the titanium plate with distilled water, and put it in anhydrous ethanol for later use.

[0039] (4) Dissolve 4 mL of silane coupling agent in 16 mL of water and stir magnetically for 30 min; add 5 mL of 0.1 M ascorbic acid solution and continue stirring until the solution turns clear and slightly yellow. Transfer the mixture to a hydrothermal reactor and react at 180 °C for 10 h. Cool to room temperature to obtain silicon quantum dot solution (SQDs), and store at 4 °C for later use. Freeze-dry a certain volume of the solution to obtain solid silicon quantum dots;

[0040] (5) Decompose the freeze-dried SQDs powder into 1.72 mL of n-butanol at a certain mass fraction, then add 0.7 mL of hydrochloric acid (concentration of 36%), and then add the solution at a molar ratio of n(Ir) 4+ ): n(Ta 5+ A coating solution was prepared by adding chloroiridium acid (H2IrCl6.6H2O) and tantalum pentachloride (TaCl5) to a solution with a ratio of 7:3.

[0041] (6) The coating solution prepared in step (5) is evenly brushed onto the surface of the titanium plate treated in step (3) with a fine brush, and then placed in a drying oven at 120°C for 10 min. After that, it is transferred to a muffle furnace at 500°C for 10 min. After being taken out and allowed to cool naturally, the coating solution is applied again, dried, and sintered. This process is repeated more than 15 times until the coating solution is used up. The last coating is sintered at 500°C for 1 h. After being taken out and cooled, a silicon quantum dot anode (Ti / IrO2-Ta2O5-SQDs) is obtained. By degrading a high-concentration phenol solution with a content of 1 g / L, the results show that the degradation rate of phenol within 1 h is 95% higher than that of the traditional Ti / IrO2-Ta2O5 anode, and the degradation rate of COD is 45% higher.

[0042] Example 3

[0043] The preparation method of PbS quantum dot modified anode material specifically includes the following steps (in this example, the noble metal elements are Ru and Ti):

[0044] (1) Cut the TA2 titanium plate into 10mm • 10mm pieces using a shearing machine, then polish the cut titanium plate with sandpaper to remove the oxide layer and stains on the surface of the titanium plate, and then rinse the surface of the titanium plate with distilled water to remove the residual powder on the surface of the titanium plate.

[0045] (2) Dissolve 15g of analytical grade NaOH in 90mL of distilled water and stir at 600r / min for 15min on a magnetic stirrer to fully dissolve the NaOH particles. Then heat the water bath to 60℃ and put the titanium plate rinsed in step (1) into it. Keep it warm for 40min and then rinse off the NaOH droplets on the surface of the titanium plate with distilled water.

[0046] (3) Dissolve 10g of analytical grade oxalic acid in 90mL of distilled water, stir at 600r / min for 15min on a magnetic stirrer to fully dissolve the oxalic acid particles, then heat to 90℃ in a water bath, put the titanium plate rinsed in step (2) into it, keep it warm for 60min, then rinse off the oxalic acid droplets on the surface of the titanium plate with distilled water, and put it in anhydrous ethanol for later use.

[0047] (4) Dissolve 0.04 mol of lead nitrate (Pb(NO3)2) in ethanol, and then add ethanolamine (C2H7NO) dropwise to prepare a cation solution. Dissolve 0.04 mol of sodium sulfide (Na2S) in deionized water to prepare an anion solution. Then immerse the cleaned conductive glass plate (fluorine-doped tin oxide) in the cation solution, and then rinse the glass plate with ethanol to remove loosely bound ions; the cations and sulfide ions adsorbed by immersing it in the anion solution react to form PbS quantum dots (PbS QDs).

[0048] (5) Dissolve 3.5g of citric acid in 25ml of anhydrous ethanol and heat and stir at 60℃ for 3h. Then dissolve RuCl3 and tetrabutyl titanate in anhydrous ethanol at a molar ratio of n(Ru):n(Ti) = 3:7, and add the solution dropwise at a rate of 1 drop / s, stirring at 60℃ for a period of time to ensure thorough mixing and evaporation of excess anhydrous ethanol. After cooling, add the prepared PbSQDs solution and stir, then let stand for 24h.

[0049] (6) The coating solution prepared in step (5) is evenly brushed onto the surface of the titanium plate treated in step (3) with a fine brush, and then placed in a drying oven at 100°C for 10 min. After that, it is transferred to a muffle furnace at 500°C for 10 min. After being taken out and allowed to cool naturally, the coating solution is applied again, dried and calcined, and this process is repeated more than 15 times until the coating solution is used up. The last coating is sintered at 500°C for 1 h. After being taken out and cooled, a PbS quantum dot-doped anode (Ti / TiO2-RuO2-PbSQDs) is obtained. By degrading a high-concentration phenol solution with a content of 1 g / L, the results show that the degradation rate of phenol within 1 h is 102% higher than that of the traditional Ti / TiO2-RuO2 anode, and the degradation rate of COD is 63% higher. Example 4

[0050] The preparation method of the germanium quantum dot anode composite coating includes the following steps (in this example, the noble metal elements are Ru, Ti, and Sn):

[0051] (1) Cut the TA2 titanium plate into 10mm • 10mm pieces using a shearing machine, then polish the cut titanium plate with sandpaper to remove the oxide layer and stains on the surface of the titanium plate, and then rinse the surface of the titanium plate with distilled water to remove the residual powder on the surface of the titanium plate.

[0052] (2) Dissolve 15g of analytical grade NaOH in 90mL of distilled water and stir at 600r / min for 15min on a magnetic stirrer to fully dissolve the NaOH particles. Then heat the water bath to 60℃ and put the titanium plate rinsed in step (1) into it. Keep it warm for 40min and then rinse off the NaOH droplets on the surface of the titanium plate with distilled water.

[0053] (3) Dissolve 10g of analytical grade oxalic acid in 90mL of distilled water, stir at 600r / min for 15min on a magnetic stirrer to fully dissolve the oxalic acid particles, then heat to 90℃ in a water bath, put the titanium plate rinsed in step (2) into it, keep it warm for 60min, then rinse off the oxalic acid droplets on the surface of the titanium plate with distilled water, and put it in anhydrous ethanol for later use.

[0054] (4) Add 92 µL of GeCl4 and 1.5 g of tetraoctylammonium bromide (TOAB) solution to 100 mL of anhydrous toluene and stir for 24 h to ensure complete and uniform formation of reverse micelles. Add 0.63 µL of LiAlH4 (reducing agent) to the solution and stir vigorously for 3 h. Quench excess LiAlH4 with anhydrous MeOH. Add 40 µL of H2PtCl6 and 2.0 mL of allylamine to the quantum dots; react until the solution stops producing hydrogen gas. Remove from the glove box and evaporate the liquid. After drying, resuspend the particles in deionized water and filter through a 0.2 µm pore filter. Finally, GeQDs are obtained;

[0055] (5) Dissolve 3g of citric acid in 20ml of anhydrous ethanol and heat and stir at 60℃ for 3.5h. Then dissolve RuCl3, tetrabutyl titanate and SnCl4 in anhydrous ethanol at a molar ratio of n(Ru):n(Ti):n(Sn) = 2:2:6, and add the solution dropwise at a rate of 1 drop / s, stirring at 60℃ for a period of time to ensure thorough mixing and volatilization of excess anhydrous ethanol. After cooling, add the prepared GeQDs solution and stir, then let stand for 24h.

[0056] (6) The coating solution prepared in step (5) is evenly brushed onto the surface of the titanium plate treated in step (3) with a fine brush, and then placed in a drying oven at 100°C for 10 min. After that, it is transferred to a muffle furnace at 500°C for 10 min. After being taken out and allowed to cool naturally, the coating solution is applied again, dried and calcined, and this process is repeated more than 15 times until the coating solution is used up. The last coating is sintered at 500°C for 1 h. After being taken out and cooled, a GeQDs quantum dot-doped anode (Ti / TiO2-RuO2-SnO2-GeQDs) is obtained. By degrading a high-concentration phenol solution with a content of 1 g / L, the results show that the degradation rate of phenol within 1 h is 112% higher than that of the traditional Ti / TiO2-RuO2-SnO2 anode, and the degradation rate of COD is 50% higher.

[0057] Example 5

[0058] The preparation method of the cadmium sulfide quantum dot anode composite coating includes the following steps (in this example, the noble metal elements are Ru, Ti, and Pb):

[0059] (1) Cut the TA2 titanium plate into 10mm • 10mm pieces using a shearing machine, then polish the cut titanium plate with sandpaper to remove the oxide layer and stains on the surface of the titanium plate, and then rinse the surface of the titanium plate with distilled water to remove the residual powder on the surface of the titanium plate.

[0060] (2) Dissolve 12g of analytical grade NaOH in 90mL of distilled water and stir at 650r / min for 15min on a magnetic stirrer to fully dissolve the NaOH particles. Then heat the water bath to 65℃ and put the titanium plate rinsed in step (1) into it. Keep it warm for 40min and then rinse off the NaOH droplets on the surface of the titanium plate with distilled water.

[0061] (3) Dissolve 15g of analytical grade oxalic acid in 90mL of distilled water. Stir at 600r / min for 15min on a magnetic stirrer to fully dissolve the oxalic acid particles. Then heat the water bath to 90℃ and place the titanium plate rinsed in step (2) into it. Keep it warm for 85min. Then rinse off the oxalic acid droplets on the surface of the titanium plate with distilled water and place it in anhydrous ethanol for later use.

[0062] (4) A solution of 1.5 g of 3.5 mmol CdO, 7 mL of oleic acid, and 7 mL of 1-octadecene (ODE) was heated to 230 °C under a N2 atmosphere. Subsequently, 3.5 g of sulfur powder was dissolved in 5 mL of oleylamine to form an S-OAm solution, which was then transferred to the precursor solution to generate CdS quantum dots (CdS QDs).

[0063] (5) Dissolve 3g of citric acid in 20ml of anhydrous ethanol and heat and stir at 60℃ for 3.5h. Then dissolve RuCl3, tetrabutyl titanate and PbCl4 in anhydrous ethanol at a molar ratio of n(Ru):n(Ti):n(Pb) = 2:2:6, and add the solution dropwise at a rate of 1 drop / s, stirring at 60℃ for a period of time to ensure thorough mixing and volatilization of excess anhydrous ethanol. After cooling, add the prepared CdS QDs solution and stir, then let stand for 24h.

[0064] (6) The coating solution prepared in step (5) is evenly brushed onto the surface of the titanium plate treated in step (3) with a fine brush, and then placed in a drying oven at 100°C for 10 min. After drying, it is transferred to a muffle furnace at 450°C for 10 min. After being taken out and allowed to cool naturally, the coating solution is applied again, dried and calcined, and this process is repeated more than 15 times until the coating solution is used up. The last coating is sintered at 500°C for 1 h. After cooling, a cadmium sulfide quantum dot-doped anode (Ti / TiO2-RuO2-PbO2-CdS QDs) is obtained. By degrading a high-concentration phenol solution with a content of 1 g / L, the results show that the degradation rate of phenol within 1 h is 115% higher than that of the traditional Ti / TiO2-RuO2-PbO2 anode, and the degradation rate of COD is 71% higher.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. The application of a quantum dot modified anode material in the degradation of a high-concentration phenol solution with a concentration of 1 g / L, characterized in that, The preparation method of the quantum dot modified anode material specifically includes the following steps: (1) Cut the TA2 titanium plate into 10mm×10mm pieces using a shearing machine, then use sandpaper to polish the cut titanium plate to remove the oxide layer and stains on the surface of the titanium plate, and then rinse the surface of the titanium plate with distilled water to remove the residual powder on the surface of the titanium plate. (2) Dissolve 10g of analytical grade NaOH in 90mL of distilled water and stir at 600r / min for 10min on a magnetic stirrer to fully dissolve the NaOH particles. Then heat the water bath to 60℃ and put the titanium plate rinsed in step (1) into it. Keep it warm for 60min and then rinse off the NaOH droplets on the surface of the titanium plate with distilled water. (3) Dissolve 15g of analytical grade oxalic acid in 90mL of distilled water, stir at 600r / min for 20min on a magnetic stirrer to fully dissolve the oxalic acid particles, then heat to 90℃ in a water bath, put the titanium plate rinsed in step (2) into it, keep it warm for 60min, then rinse off the oxalic acid droplets on the surface of the titanium plate with distilled water, and put it in anhydrous ethanol for later use. (4) Dissolve 4 mL of silane coupling agent in 16 mL of water and stir magnetically for 30 min; add 5 mL of 0.1 M ascorbic acid solution and continue stirring until the solution turns clear and slightly yellow. Transfer the mixture to a hydrothermal reactor and react at 180 °C for 10 h. Cool to room temperature to obtain silicon quantum dot solution SQDs. Store at 4 °C for later use. Freeze-dry a certain volume of the solution to obtain solid silicon quantum dots. (5) The freeze-dried SQDs powder was decomposed into 1.72 mL of n-butanol at a certain mass fraction, and then 0.7 mL of hydrochloric acid with a concentration of 36% was added. The mixture was then added in a molar ratio of n(Ir) 4+ ): n(Ta 5+ The coating solution was prepared by adding chloroiridium acid (H₂IrCl₆·6H₂O) and tantalum pentachloride (TaCl₅) to the solution in a ratio of 7:

3. (6) Apply the coating liquid prepared in step (5) evenly to the surface of the titanium plate treated in step (3) with a fine brush, then put it into a drying oven at 120°C for 10 min, and then transfer it to a muffle furnace at 500°C for 10 min. After taking it out and letting it cool naturally, apply the liquid again, dry it, and sinter it. Repeat this process more than 15 times until the coating liquid is used up. For the last coating, sinter it at 500°C for 1 h. After taking it out and cooling it, a silicon quantum dot modified anode Ti / IrO2-Ta2O5-SQDs is obtained. The degradation of a high-concentration phenol solution with a concentration of 1 g / L was carried out, and the results showed that the degradation rate of phenol within 1 hour was increased by 95% compared with the traditional Ti / IrO2-Ta2O5 anode, and the degradation rate of COD was increased by 45%.

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