Electrocatalytic composite anode and preparation method and application thereof

Abstract

The application discloses an electro-catalytic composite anode, which comprises a titanium plate, a SnO2-Sb2O5 coating layer formed on the surface of the titanium plate, and a boron-modified PbO2-CeO2 active surface layer formed on the surface of the SnO2-Sb2O5 coating layer by electro-deposition. The electro-catalytic composite anode provided by the application improves the catalytic ability and service life of the titanium-based PbO2 coating electrode by optimizing the active components of the anode material and adding the SnO2-Sb2O5 intermediate layer. Based on the electro-catalytic composite anode, the application further provides a preparation method of the electro-catalytic composite anode and an application of the electro-catalytic composite anode in degradation of high-concentration dye wastewater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrochemical oxidation, in particular to an electro-catalytic composite anode and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of modern industry, the total amount of industrial wastewater discharged annually is increasing, and the proportion of dye wastewater is large. High-concentration dye wastewater has high colority and great toxicity, which can cause harm to the environment and human health, so it must be treated by effective means before being discharged. At present, the treatment of dye wastewater can be divided into biological method, physical method and chemical method according to the principle. The three methods have advantages and disadvantages, and considering the factors such as operation convenience, complete degradation, mild conditions, etc., the electrochemical oxidation method has become one of the most promising water treatment methods due to its energy saving, environmental protection, green and pollution-free, mild conditions, simple device, strong operability and easy automation.

[0003] The DSA electrode (Dimensionally Stable Anode) constructed with PbO2 as the main active component has the outstanding advantages of low use cost, strong corrosion resistance, small change of electrode distance, high catalytic activity, etc., and replaces the traditional insoluble graphite anode, and is widely used in chemical industry, metallurgy, electroplating, water treatment, environmental protection, ocean, cathodic protection and other fields. However, the titanium-based PbO2 coating electrode has the problems of easy peeling of the coating, easy formation of TiO2 passivation film on the substrate, resulting in poor conductivity of the electrode, short service life, etc. Especially when facing different types of high-concentration dye wastewater, the electro-catalytic oxidation efficiency is low and the degradation is not complete, which greatly limits the application range of this type of electrode.

[0004] Therefore, it is necessary to provide a new electrode material to solve the above technical problems. SUMMARY

[0005] The technical problem to be solved by the present application is to provide an electro-catalytic composite anode, which improves the catalytic ability and service life of the titanium-based PbO2 coating electrode by optimizing the active component of the anode material and adding a SnO2-Sb2O5 intermediate layer.

[0006] The technical scheme of the present application is as follows:

[0007] An electro-catalytic composite anode comprises a titanium plate, a SnO2-Sb2O5 coating layer formed on the surface of the titanium plate, and a boron-modified PbO2-CeO2 active surface layer formed on the surface of the SnO2-Sb2O5 coating layer by electrodeposition.

[0008] Further, the thickness of the SnO2-Sb2O5 coating layer is 60-80 μm; and the thickness of the boron-modified PbO2-CeO2 active surface layer is 25-35 μm.

[0009] The application further provides a preparation method of the electro-catalytic composite anode.

[0010] Step S1, titanium plate pretreatment;

[0011] Step S2, SnO2-Sb2O5 coating is prepared on the surface of the titanium plate, and the step specifically comprises the following steps:

[0012] Step S21, 1-butanol is used as a solvent, SnCl4·5H2O, SbCl3 and appropriate concentrated HCl are sequentially added, and a mixed solution A is prepared by fully stirring;

[0013] Step S22, the mixed solution A is coated on the surface of the titanium plate, and after drying, calcination is performed at 450-600 DEG C for 10-30 min; specifically, the calcination temperature can be 450 DEG C, 500 DEG C, 550 DEG C or 600 DEG C, or other temperature values in the range;

[0014] Step S23, step S228 is repeated for 12 times, and the SnO2-Sb2O5 coating is prepared on the titanium plate; the coating times of the mixed solution A are related to the thickness of the SnO2-Sb2O5 coating, and can be adjusted according to the thickness requirement in actual application;

[0015] Step S3, a boron-modified PbO2-CeO2 active surface layer is deposited on the surface of the SnO2-Sb2O5 coating by electrodeposition, and the step specifically comprises the following steps:

[0016] Step S31, boron powder is taken into acetone, and after being uniformly dispersed by magnetic stirring, solvent thermal reaction is performed at 160-200 DEG C for 12-24 h, and then ultrasonic dispersion, centrifugation and collection of the upper-layer boronene nanosheet dispersion liquid are performed; specifically, the solvent thermal reaction temperature can be 160 DEG C, 180 DEG C or 200 DEG C, or other temperature values in the range; the reaction time can be 12 h, 16 h, 20 h or 24 h, or other time values in the range;

[0017] Step S32, Pb(NO3)2, Ce(NO3)3 and NaF are taken in appropriate amounts and added into deionized water, stirred until fully dissolved, then concentrated nitric acid is added to adjust the pH to 2-3, to prepare solution C, and then appropriate boronene nanosheet dispersion liquid is added to obtain solution D;

[0018] Step S33, the electrode piece prepared in step S2 is used as an anode, a stainless steel piece is used as a cathode, and solution D is used as an electroplating solution, and the electroplating is performed at 20-40 DEG C using 10-30 mA / cm 2Mode electrodeposition 1-2h; specifically, the electrodeposition temperature can be 20℃, 25℃, 30℃, 35℃ or 40℃, or other temperature values in the range;

[0019] Step S34, the electrode piece is taken out after the reaction, washed, and dried at room temperature to obtain a boron-modified Ti / SnO2-Sb2O5 / PbO2-CeO2 electrocatalytic composite anode.

[0020] Further, in step S2, the mass ratio of SnCl4·5H2O to SbCl3 is 10:1.

[0021] Further, in step S3, the concentration of Pb(NO3)2 in the plating solution is 0.3 mol / L, the concentration of Ce(NO3)3 is 1.5 g / L, the concentration of NaF is 0.4 g / L, the concentration of concentrated nitric acid is 16 mol / L, and the concentration of boron nanosheet dispersion solution is 0.8 mg / mL.

[0022] Further, in step S1, the titanium plate pretreatment process comprises:

[0023] Step S11, the titanium plate is placed in a NaOH solution and immersed at 70-100℃ for 20-60min, and then washed with deionized water; specifically, the alkaline temperature can be 70℃, 80℃, 90℃ or 100℃, or other temperature values in the range; the immersion time can be 20min, 30min, 40min, 50min or 60min, or other values in the range.

[0024] Step S12, the titanium plate is placed in an oxalic acid solution and etched at 80-100℃ for 2-3h, and then washed with deionized water; specifically, the oxalic acid solution etching temperature can be 80℃, 85℃, 90℃, 95℃ or 100℃, or other temperature values in the range.

[0025] Preferably, the concentration of the NaOH solution is 14 mol / L, and the solubility of the oxalic acid solution is 1 mol / L.

[0026] The application also provides a use of the electrocatalytic composite anode in degrading high-concentration dye wastewater.

[0027] Further, the electrocatalytic composite anode is used for degrading high-concentration dye wastewater, comprising the following steps:

[0028] Step S1, acid / alkali is added to the anion / cation type dye wastewater respectively, the pH value is adjusted to 1-3 or 12-14, stirred uniformly, aged for 36-72h, then filtered, and the bottom precipitate is removed to obtain a supernatant;

[0029] Step S2, adding sodium sulfate as electrolyte in the supernatant of step S1, using the above composite anode as anode, using stainless steel plate as cathode, and using 10-30mA / cm 2 The electrochemical oxidation treatment is performed in a constant current mode for 1-3h to obtain degraded dye wastewater.

[0030] Further, in step S2, the concentration of sodium sulfate is 0.012mol / L.

[0031] Compared with the prior art, the electro-catalytic composite anode provided by the application, the preparation method and application thereof have the beneficial effects that:

[0032] Firstly, the electro-catalytic composite anode provided by the application forms SnO2-Sb2O5 coating and boron-modified PbO2-CeO2 active surface layer on the surface of the titanium plate in sequence, optimizes the components of the active layer on the surface of the electrode, and increases the intermediate protective layer to improve the catalytic ability and service life of the titanium-based PbO2 coating electrode, thereby effectively improving the degradation ability of the electrode to high-concentration dye wastewater. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1 is an optical photo of the titanium plate in different processing processes;

[0035] Figure 2 is an XRD spectrum of the titanium plate in different processing processes;

[0036] Figure 3 is an SEM photo of the titanium plate in different processing processes;

[0037] Figure 4 is an optical photo and TEM photo of the boronene nanosheet dispersion liquid;

[0038] Figure 5is an electrochemical LSV curve chart of different coating electrodes;

[0039] Figure 6 is a photo of the process of electrocatalytic degradation of methyl orange dye solution by the composite titanium plate;

[0040] Figure 7 is a UV absorption spectrum chart of methyl orange dye solution before and after electrocatalytic degradation;

[0041] Figure 8 is a photo of the process of electrocatalytic degradation of methylene blue dye solution by the composite titanium plate;

[0042] Figure 9 is a UV absorption spectrum chart of methylene blue dye solution before and after electrocatalytic degradation;

[0043] Figure 10 is a photo of the process of electrocatalytic degradation of neutral red dye solution by the composite titanium plate;

[0044] Figure 11 is a UV absorption spectrum chart of neutral red dye solution before and after electrocatalytic degradation;

[0045] Figure 12 is a photo of the process of electrocatalytic degradation of methyl orange, methylene blue, neutral red dye solution by the electrocatalytic anode of Comparative Example 1. DETAILED DESCRIPTION

[0046] In order to make the technical solutions in the embodiments of the present application better understood by those skilled in the art, and make the above-mentioned purposes, characteristics and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are further described below.

[0047] It should be noted that the description of these embodiments is used to help understand the present application, but does not constitute a limitation of the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0048] Example 1

[0049] A kind of electrocatalytic composite anode, its preparation method includes the following steps:

[0050] Step S1, titanium plate pretreatment, as follows:

[0051] 280g of NaOH was weighed into 220mL of deionized water, stirred evenly, fully dissolved, to obtain a NaOH solution;

[0052] The 50×50×1mm titanium plate was polished with sandpaper, washed with deionized water to remove the surface oxide film, then placed in a NaOH solution, heated to 80℃ for 30min, and then washed with deionized water to remove the surface alkali solution;

[0053] Then the titanium plate was vertically placed in a 20% H2C2O4 solution (m%), etched under boiling conditions for 2-3h, washed again with deionized water, and then stored in anhydrous ethanol for use.

[0054] Step S2, preparing a SnO2-Sb2O5 coating layer on the surface of the titanium plate, specifically including the following steps:

[0055] Step S21, preparing a mixed solution A by adding SnCl4·5H2O, SbCl3 and appropriate concentrated HCl in sequence in 1-butanol as a solvent, and fully stirring; specifically:

[0056] 20g of SnCl4·5H2O and 2g of SbCl3 were added to 95mL of 1-butanol, 5mL of concentrated HCl was added, and the mixture was stirred and dissolved to obtain solution A.

[0057] Step S22, applying the mixed solution A to the surface of the titanium plate, drying the surface in an oven at 110℃, then applying to the other side, and after drying, transferring to a muffle furnace, heating to 500℃ at 5° / min, and calcining for 10min;

[0058] Step S23, repeating the process of step S22 9 times after cooling, and annealing and calcining in the muffle furnace for 60min the last time, to prepare a SnO2-Sb2O5 coating layer on the titanium plate, with a coating layer thickness of 70μm;

[0059] Step S3, depositing a boron-modified PbO2-CeO2 active surface layer on the surface of the SnO2-Sb2O5 coating layer by electrodeposition, specifically including the following steps:

[0060] Step S31, adding 100mg of boron powder (AR, Sigma-aldrich) to 100mL of CH3COCH3, magnetically stirring and dispersing uniformly, transferring the dispersion to a polytetrafluoroethylene-lined reaction kettle, and performing a solvothermal reaction at 200℃ for 24h, then performing probe ultrasonic dispersion at 225W for 2h, and centrifuging at 6000-8000rpm for 15min to collect the upper layer of boronene nanosheet dispersion;

[0061] Step S32, 29.8 g of Pb(NO3)2, 0.5 g of Ce(NO3)3, and 0.2 g of NaF were weighed into 270 mL of deionized water, stirred until uniform, and fully dissolved, and then 1 mL of concentrated HNO3 was added to adjust the pH to 2 to obtain solution C; then the boron-ene nanosheet dispersion was added to make the concentration 0.8 mg / mL, and mixed uniformly to obtain solution D;

[0062] Step S33, the titanium plate prepared in step S2 was used as the anode, a 50×50×1 mm stainless steel plate was used as the cathode, solution D was used as the electroplating solution, the plate spacing was 2 cm, a constant current power supply was connected at 25°C, and the current density was 20 mA / cm 2 The electrodeposition was performed for 1 h;

[0063] Step S34, after the electrodeposition was completed, the titanium plate was rinsed to remove residual substances, and then air-dried at 25°C to obtain a boron-modified Ti / SnO2-Sb2O5 / PbO2-CeO2 electrocatalytic composite anode, and the thickness of the boron-modified PbO2-CeO2 active layer was 30 μm.

[0064] Please refer to Figure 1 , which are optical photographs of the titanium plates at different processing stages, wherein Figure 1 a represents the titanium plate after pretreatment, Figure 1 b represents the titanium plate with a SnO2-Sb2O5 coating, Figure 1 c represents the boron-modified composite titanium plate. From Figure 1 it can be seen that the surface of the titanium plate after pretreatment is rough, which increases the specific surface area; after the introduction of the SnO2-Sb2O5 intermediate layer Figure 1 (b) and the modified active layer Figure 1 (c), the surface of the plate presents a dense coating of different colors, respectively, which confirms that the two types of coatings are tightly combined with the Ti substrate.

[0065] Please refer to Figure 2 , which are XRD patterns of the titanium plates at different processing stages. From Figure 2 it can be seen that the diffraction peaks of the XRD pattern of the SnO2-Sb2O5 intermediate layer confirm that SnO2-Sb2O5 is successfully introduced, the diffraction peaks of the XRD pattern of the boron-modified active layer correspond to β-PbO2 with good crystallinity, and boron-ene and CeO2 do not have obvious characteristic diffraction peaks due to the influence of the crystallinity of the product and the doping amount.

[0066] Please refer to Figure 3 , which are SEM photographs of the titanium plates at different processing stages, wherein Figure 3 a represents the titanium plate with a SnO2-Sb2O5 coating, Figure 3 b represents the boron-modified composite titanium plate. From Figure 3It can be seen that the boron-modified composite titanium electrode has better surface density and uniform crystal size. During the electrocatalysis process, it is less likely to have problems such as coating peeling and titanium matrix oxidation, which is beneficial to improving the electrocatalytic efficiency of the electrode and extending its life.

[0067] Please see Figure 4 These are optical and TEM images of a boronene nanosheet dispersion. Figure 4 'a' indicates its optical photograph. Figure 4 b indicates its TEM image. (By...) Figure 4 It can be seen that the boronene nanosheet dispersion exhibits a significant Tyndall effect. Figure 4 a) This indicates that the dispersion has colloidal properties, as shown in the TEM image ( Figure 4 b) confirms that the product prepared by the liquid-phase exfoliation method is a two-dimensional sheet. The boronene nanosheets possess good electrical conductivity, and their electron-deficient nature allows them to bond tightly with the electrodeposited PbO2-CeO2 coating at the anode when used as a dopant. This is beneficial for increasing the oxygen evolution potential of the electrode, thereby improving the electrode catalytic efficiency. Please refer to [link to relevant documentation]. Figure 5 These are electrochemical LSV curves for electrodes with different coatings. Figure 5 This indicates that the oxygen evolution potential of the boron-modified composite titanium electrode is higher than that of the Ti / SnO2-Sb2O5 and Ti / SnO2-Sb2O5 / PbO2 electrodes, which is beneficial to reduce the evolution of O2 at the anode during electrolysis and improve electrode life and catalytic efficiency.

[0068] Example 2

[0069] The boron-modified Ti / SnO2-Sb2O5 / PbO2-CeO2 electrocatalytic composite anode from Example 1 was applied to the degradation of high-concentration dye wastewater. The specific method is as follows:

[0070] Weigh 0.5g of methyl orange and add it to 500mL of deionized water. Stir thoroughly until completely dissolved. Add 1mL of concentrated HCl to adjust the pH to 2. Stir for 60min, let stand for 48h, filter the precipitate, and obtain 300mL of supernatant.

[0071] Add 0.5g of sodium sulfate as an electrolyte to the obtained supernatant, stir well and dissolve completely.

[0072] Using the composite electrode prepared in Example 1 as the anode and a stainless steel plate as the cathode, with a 2 cm gap between the two electrodes, the electrode was placed vertically in the solution. Under an external DC power supply at 30 mA / cm², 2 Electrochemical oxidation was performed in constant current mode for 30 minutes. After the reaction was completed, the power was turned off and the treated solution was collected.

[0073] Please refer to the following: Figure 6 and Figure 7 ,in Figure 6is the photo of the process of electrocatalytic degradation of methyl orange dye solution by the composite titanium plate, wherein Figure 6 a represents the initial methyl orange dye solution, Figure 6 b represents the methyl orange dye solution after aging for 48 hours, Figure 6 c represents the methyl orange dye solution after electrocatalytic degradation; Figure 7 is the ultraviolet absorption spectrum of the methyl orange dye solution before and after electrocatalytic degradation. Figure 6 It is shown that the solution produces a precipitate after aging, and the supernatant has no obvious color change after electrocatalytic degradation, and the color is basically faded to colorless; Figure 7 The ultraviolet spectrum results of the solution before and after electrolysis also confirm this.

[0074] Example 3

[0075] The boron-modified Ti / SnO2-Sb2O5 / PbO2-CeO2 electrocatalytic composite anode of Example 1 is applied to the degradation of high-concentration dye wastewater, and the specific method is as follows:

[0076] In Example 2, replace the methyl orange with an equal amount of methylene blue, add 2.5 mL of 12 mol / L NaOH to the prepared dye solution to adjust the pH to 13, and the other steps are the same as in Example 1 to obtain the corresponding solution after degradation.

[0077] Please refer to Figure 8 and Figure 9 , wherein Figure 8 is the photo of the process of electrocatalytic degradation of methylene blue dye solution by the composite titanium plate, Figure 8 a represents the initial methylene blue dye solution, Figure 8 b represents the methylene blue dye solution after aging for 48 hours, Figure 8 c represents the methylene blue dye solution after electrocatalytic degradation; Figure 9 is the ultraviolet absorption spectrum of the methylene blue dye solution before and after electrocatalytic degradation. Figure 8 It is shown that the solution produces a precipitate after aging, and the supernatant has no obvious color change after electrocatalytic degradation, and the color is faded to colorless, Figure 9 The ultraviolet spectrum results of the solution before and after electrolysis also confirm this.

[0078] Example 4

[0079] The boron-modified Ti / SnO2-Sb2O5 / PbO2-CeO2 electrocatalytic composite anode of Example 1 is applied to the degradation of high-concentration dye wastewater, and the specific method is as follows:

[0080] In Example 2, replace the methyl orange with an equal amount of neutral red, add 2.5 mL of 12 mol / L NaOH to the prepared dye solution to adjust the pH to 13, and the other steps are the same as in Example 1 to obtain the corresponding solution after degradation.

[0081] Please refer to Figure 10 and Figure 11 wherein Figure 10 is a photo of the process of electrocatalytic degradation of neutral red dye solution by the composite titanium electrode plate, wherein Figure 10 a represents the initial neutral red dye solution, Figure 10 b represents the neutral red dye solution after aging for 48 hours, Figure 10 c represents the neutral red dye solution after electrocatalytic degradation; Figure 11 is the ultraviolet absorption spectrum of the neutral red dye solution before and after electrocatalytic degradation. Figure 10 It is shown that the solution produces a precipitate after aging, and the supernatant has no obvious color change, and the color fades to colorless after electrocatalytic degradation, Figure 11 The ultraviolet spectrum results of the solution before and after electrolysis also confirm this.

[0082] The TOC change values of the anode electrocatalytic degradation of different types of dyes in Example 1 are shown in Table 1:

[0083] Table 1: TOC change values (in mg / L) before and after electrocatalytic degradation of different types of dyes

[0084]

[0085] From the data in Table 1, it can be seen that for high-concentration methyl orange, methylene blue, and neutral red dye wastewater, electrocatalytic degradation using the composite electrode of the present application significantly reduces the TOC value, indicating that it has a significant degradation effect on different types of high-concentration dye wastewater.

[0086] Comparative Example 1

[0087] Based on Example 1, the step of preparing a SnO2-Sb2O5 coating on the surface of the titanium electrode plate is cancelled, and in the active surface layer preparation process, the step of adding the boronene nanosheet dispersion to solution C is omitted. The obtained electrocatalytic anode includes a titanium electrode, a PbO2-CeO2 active surface layer formed on the surface of the titanium electrode, and the active surface layer is not modified with boron.

[0088] The electrocatalytic anode of Comparative Example 1 is applied to the degradation of high-concentration methyl orange, methylene blue, and neutral red dye wastewater, and the method is the same as Examples 2-4.

[0089] Please refer to Figure 12are photos of the process of electrocatalytic degradation of methyl orange, methylene blue, neutral red dye solution by the electrode of Comparative Example 1, wherein the first group represents the process of electrocatalytic degradation of methyl orange dye, the second group represents the process of electrocatalytic degradation of methylene blue dye, and the third group represents the process of electrocatalytic degradation of neutral red dye. It can be seen from the photos of the process of degradation of the three types of high-concentration dye wastewater by the electrocatalytic anode (simple titanium-based PbO2 electrode) of Comparative Example 1 that the electrocatalytic degradation effect is poor, which is related to the factors such as the absence of the intermediate layer and the insufficient density of the active layer, further illustrating that the boron-modified Ti / SnO2-Sb2O5 / PbO2-CeO2 electrocatalytic composite anode has a good catalytic effect when facing different types of high-concentration dye wastewater.

[0090] The TOC change values of the anode of Comparative Example 1 before and after electrocatalytic degradation of different types of dyes are shown in Table 2.

[0091] Table 2: TOC change values (unit: mg / L) before and after electrocatalytic degradation of different types of dyes

[0092]

[0093] It can be seen from the data in Table 2 that when the electrode of Comparative Example 1 is used for electrocatalytic degradation of high-concentration methyl orange, methylene blue, and neutral red dye wastewater, the TOC value after catalysis decreases significantly less than that of the composite electrode of Example 1, which illustrates that the electrode without an intermediate layer and not modified by boron has a low electrocatalytic efficiency, which is consistent with the results of the foregoing figures.

[0094] Comparative Example 2

[0095] In the preparation process of Example 1, it is found in practice that the number of times of brushing the SnO2-Sb2O5 coating and the concentration of the boronene nanosheet dispersion liquid in the modification process have a relatively obvious influence on the properties of the composite electrode. While keeping the remaining steps unchanged, the number of times of brushing the coating and the concentration of the boronene nanosheet dispersion liquid are changed in turn to obtain titanium electrode pieces prepared under different process parameters by using the single-factor variable control idea.

[0096] It is found through experiments that when the number of times of brushing is less than 8, the intermediate coating in the electrode is relatively thin, and the tank voltage rises rapidly during electrolysis, which is related to the oxidation of the titanium electrode plate and forms effective protection. When the number of times of brushing is more than 15, the local coating area is whitened and broken during calcination, so that an integrated coating cannot be formed, and the titanium electrode plate cannot be effectively protected.

[0097] For the boronene nanosheet dispersion liquid for modification, when the concentration is more than 1.5 mg / mL, the local concentration is too high, which causes the boronene nanosheet to settle, the electrode coating cannot be effectively modified, and the preparation cost is relatively high. When the concentration is less than 0.5 mg / mL, the dispersion liquid is limited by the concentration, the potential is low, and effective doping cannot be formed in the anode.

[0098] The pole piece prepared by the above process is subjected to comprehensive evaluation of morphology and electrochemical degradation effect, and the composite anode electrocatalytic degradation effect is optimal when the brushing times are 9, and the concentration of the boronene nanosheet dispersion liquid is 0.8 mg / mL.

[0099] The above describes the embodiments of the present application in detail, but the present application is not limited to the described embodiments. Various changes, modifications, replacements and variations of the embodiments made by those skilled in the art without departing from the principles and spirits of the present application still fall within the protection scope of the present application.

Claims

1. A method for preparing an electrocatalytic composite anode, characterized in that, It comprises the following steps: Step S1, titanium plate pretreatment; Step S2, SnO2-Sb2O5 coating is prepared on the surface of the titanium plate, which comprises the following steps: Step S21, 1-butanol is used as a solvent, SnCl4·5H2O, SbCl3 and appropriate concentrated HCl are sequentially added, and the mixed solution A is prepared by fully stirring; Step S22, the mixed solution A is coated on the surface of the titanium plate, and after drying, it is calcined at 450-600℃ for 10-30min; Step S23, step S22 is repeated 8-12 times to prepare SnO2-Sb2O5 coating on the titanium plate, and the thickness of the SnO2-Sb2O5 coating is 60-80μm; Step S3, a boron-modified PbO2-CeO2 active surface layer is deposited on the surface of the SnO2-Sb2O5 coating by electrodeposition, which comprises the following steps: Step S31, boron powder is added to acetone, and after being uniformly dispersed by magnetic stirring, solvent thermal reaction is carried out at 160-200℃ for 12-24h, followed by ultrasonic dispersion, centrifugation, and collection of the upper layer of boronene nanosheet dispersion liquid; Step S32, Pb(NO3)2, Ce(NO3)3 and NaF are appropriately added to deionized water, stirred until fully dissolved, then concentrated nitric acid is added to adjust the pH to 2-3, to prepare solution C, then an appropriate amount of boronene nanosheet dispersion liquid is added to obtain solution D, and the concentration of the boronene nanosheet dispersion liquid is 0.5-1.5mg / mL; Step S33, using the electrode sheet prepared in step S2 as an anode, using a stainless steel sheet as a cathode, using solution D as an electroplating solution, using a mode of 10-30 mA / cm 2 at 20-40 °C for 1-2 h to obtain a boron-modified PbO2-CeO2 active surface layer with a thickness of 25-35 μm; Step S34, the electrode piece is taken out after the reaction is completed, washed and dried at room temperature to obtain a boron-modified Ti / SnO2-Sb2O5 / PbO2-CeO2 electrocatalytic composite anode.

2. The method of claim 1, wherein the electrocatalytic composite anode is prepared by the steps of: In step S2, the mass ratio of SnCl4·5H2O to SbCl3 is 10:

1.

3. The method of claim 2, wherein the electrocatalytic composite anode is prepared by the steps of: In step S3, the concentration of Pb(NO3)2 in the plating solution is 0.3 mol / L, the concentration of Ce(NO3)3 is 1.5 g / L, the concentration of NaF is 0.4 g / L, the concentration of concentrated nitric acid is 16 mol / L, and the concentration of boronene nanosheet dispersion liquid is 0.8mg / mL.

4. The method of claim 3, wherein the electrocatalytic composite anode is prepared by the steps of: In step S1, the titanium plate pretreatment process comprises: Step S11, the titanium plate is immersed in NaOH solution at 70-100℃ for 20-60min, and then washed with deionized water; Step S12, the titanium plate is placed in oxalic acid solution and etched at 80-100℃ for 2-3h, and then washed with deionized water.

5. The method of claim 4, wherein the electrocatalytic composite anode is prepared by the steps of: The concentration of NaOH solution is 14 mol / L, and the concentration of oxalic acid solution is 1 mol / L.

6. An electrocatalytic composite anode prepared according to the method of any one of claims 1 to 5, characterized in that, It comprises a titanium plate, a SnO2-Sb2O5 coating formed on the surface of the titanium plate, and a boron-modified PbO2-CeO2 active surface layer formed on the surface of the SnO2-Sb2O5 coating by electrodeposition, wherein the thickness of the SnO2-Sb2O5 coating is 60-80μm; and the thickness of the boron-modified PbO2-CeO2 active surface layer is 25-35μm.

7. The use of the electrocatalytic composite anode of claim 1 in degrading high-concentration dye wastewater.

8. Use according to claim 7, characterized in that, The electrocatalytic composite anode is used for degrading high-concentration dye wastewater, and comprises the following steps: In step S1, acid / alkali is added to the anion / cation type dye wastewater respectively, the pH value is adjusted to 1-3 or 12-14, after stirring and aging for 36-72 hours, the supernatant is obtained by filtering and removing the bottom precipitate; Step S2, adding sodium sulfate as electrolyte in the supernatant of step S1, using the composite anode of claim 1 as anode, using stainless steel plate as cathode, carrying out electrochemical oxidation treatment at 10-30 mA / cm 2 The electrochemical oxidation treatment is carried out in a constant current mode for 1-3 h to obtain the degraded dye wastewater.

9. Use according to claim 8, characterized in that, In step S2, the concentration of sodium sulfate is 0.012 mol / L.

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