Electrodes, their preparation methods and applications

Abstract

This invention provides an electrode, its preparation method, and its applications, belonging to the field of electrochemical technology. The electrode preparation method includes: placing an electrode substrate in a solution containing metal ions for a hydrothermal reaction to obtain an electrode substrate coated with a precursor; heating the precursor-coated electrode substrate to 500-800°C within 5-10 seconds, sintering for 80-200 seconds, and then cooling it to 30-60°C within 5-20 seconds to obtain the electrode. The electrode preparation method provided by this invention has a short heating time and a simple production process, which can significantly reduce electrode manufacturing time and save labor costs. The prepared electrodes have uniform quality control and stable performance, and can be well applied in wastewater treatment, drinking water purification, environmental protection, food processing, medical care, and fruit and vegetable preservation. It is particularly effective in algae removal and can remove toxic substances produced by algae, making it suitable for various aquatic environments.

Description

Technical Field

[0001] This invention relates to the field of electrochemical technology, and more specifically, to an electrode, its preparation method, and its application. Background Technology

[0002] With rapid societal development, environmental pollution has become increasingly severe, with large quantities of nitrogen- and phosphorus-rich wastewater being discharged, leading to excessive algae growth in these eutrophic water bodies. Traditional methods for algae removal, such as ozone treatment and chemical flocculation, are inefficient and costly. Electrochemical algae removal methods, due to their ease of operation, have been widely adopted in recent years.

[0003] Electrochemical algae removal utilizes strong oxidizing substances generated by electrodes to remove algae. It is generally divided into diaphragm-type and diaphragm-less types. Diaphragm-type algae removal prevents the strong oxidizing substances generated at the cathode from being rapidly reduced, thus achieving higher algae removal efficiency. However, it suffers from insufficient contact between the diaphragm and electrode, and typically requires catalyst composite onto the diaphragm, a complex and costly process that limits its application. Diaphragm-less electrochemical algae removal devices are simpler, lower in cost, and more practical. The electrode, as a key component in diaphragm-less electrochemical algae removal devices, directly affects the efficiency of the process. However, applying existing electrodes to diaphragm-less electrochemical algae removal devices results in poor performance stability, and the algae removal efficiency needs further improvement. Summary of the Invention

[0004] To address the aforementioned problems, the main objective of this invention is to provide an electrode, its preparation method, and its application. This method features short heating time, simple production process, significant reduction in electrode manufacturing time, and reduced labor costs. The prepared electrodes exhibit uniform quality control, stable performance, excellent algae removal capabilities, and the ability to remove toxic substances produced by algae, making them suitable for various aquatic environments.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] The first aspect of this invention provides a method for preparing an electrode, comprising:

[0007] The electrode substrate is placed in a solution containing metal ions for a hydrothermal reaction to obtain an electrode substrate coated with the precursor.

[0008] The electrode substrate coated with the precursor is heated to 500-800°C within 5-10 seconds, sintered for 80-200 seconds, and then cooled to 30-60°C within 5-20 seconds to obtain the electrode.

[0009] According to an embodiment of the present invention, the metal ion is at least one selected from ruthenium ion, iridium ion, tin ion, antimony ion, platinum ion, tantalum ion, or nickel ion.

[0010] According to an embodiment of the present invention, the metal ion is a combination of tin ions, antimony ions and platinum ions.

[0011] According to an embodiment of the present invention, the molar ratio of tin ions, antimony ions and platinum ions is (100-200):(5-30):(0.1-1), preferably 9:1:0.03.

[0012] According to an embodiment of the present invention, the solution containing metal ions further includes a pH adjuster, which is suitable for inhibiting the hydrolysis reaction of the metal ions;

[0013] According to an embodiment of the present invention, the pH adjuster comprises hydrochloric acid, preferably a combination of hydrochloric acid and citric acid.

[0014] According to an embodiment of the present invention, the total concentration of the metal ions in the solution containing metal ions is 0.2 to 2.0 mol / L.

[0015] According to an embodiment of the present invention, the temperature of the hydrothermal reaction is 150–180°C, and the reaction time is 3–8 hours.

[0016] According to an embodiment of the present invention, the electrode substrate is a titanium mesh or a titanium sheet.

[0017] A second aspect of the present invention provides an electrode, said electrode being prepared by any of the methods described above.

[0018] A third aspect of the present invention provides an electrolysis apparatus comprising at least one of the electrodes described above.

[0019] The fourth aspect of the present invention provides the application of the above-mentioned electrode or the above-mentioned electrolysis device in the fields of wastewater treatment, drinking water purification, environmental protection, food processing, medical care or fruit and vegetable preservation, especially in electrochemical algae removal.

[0020] According to embodiments of the present invention, a high-performance electrode is prepared by coating a catalyst precursor onto the surface of an electrode substrate, followed by rapid heating, holding, and rapid cooling. The rapid heating and cooling significantly reduces reaction time, prevents continuous catalyst crystal growth, effectively limits catalyst particle size, results in more uniform and fine catalyst particles, increases the specific surface area of ​​the catalyst, and improves reaction activity. Simultaneously, the catalyst prepared by this method exhibits good anisotropy, exposing numerous defect sites and high-index crystal planes, which effectively improves the catalyst's resistance to poisoning and its stability. The electrode preparation method provided by this invention features short heating time, a simple production process, and can significantly reduce electrode fabrication time and save labor costs.

[0021] According to embodiments of the present invention, the electrodes prepared by the method provided by the present invention exhibit uniform quality control and stable performance, and can be well applied in wastewater treatment, drinking water purification, environmental protection, food processing, medical care, and fruit and vegetable preservation. In particular, they demonstrate excellent performance in algae removal and can remove toxic substances produced by algae, making them suitable for various aquatic environments. Attached Figure Description

[0022] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0023] Figure 1 This is a scanning electron microscope image of the electrode prepared in Example 3 of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0025] Research revealed that existing diaphragm-less electrochemical algae removal devices exhibit poor electrode performance stability, and the algae removal efficiency needs further improvement. During the development of this invention, it was discovered that the temperature change rate during the sintering process of the catalyst precursor significantly impacts the algae removal performance of the electrode. Therefore, a method was proposed to prepare a high-performance electrode by coating the catalyst precursor onto the electrode substrate surface and then sintering it using a rapid heating, holding, and rapid cooling process.

[0026] Specifically, according to an embodiment of the present invention, an electrode preparation method is provided, comprising: placing an electrode substrate in a solution containing metal ions for a hydrothermal reaction to obtain an electrode substrate coated with a precursor; heating the electrode substrate coated with the precursor to 500-800°C within 5-10s, sintering it for 80-200s, and then cooling it to 30-60°C within 5-20s to obtain an electrode.

[0027] According to embodiments of the present invention, the heating time can be 5s, 5.5s, 6s, 6.5s, 7s, 7.5s, 8s, 8.5s, 9s, 9.5s or 10s, and the temperature can be raised to 500℃, 550℃, 600℃, 620℃, 650℃, 680℃, 700℃, 750℃ or 800℃. The sintering time can be 80s, 90s, 100s, 110s, 120s, 130s, 140s, 143s, 145s, 148s, 150s, 160s, 170s, 180s, 190s or 200s. The cooling time can be 5s, 6s, 7s, 8s, 10s, 12s, 15s, 18s or 20s. Preferably, the electrode substrate coated with the precursor is heated to 600°C within 7 seconds, sintered for 100 seconds, and then cooled to 40°C within 10 seconds.

[0028] According to an embodiment of the present invention, the device used for rapid heating, heat preservation, and rapid cooling is a Joule heating device heating platform. It should be noted that other devices capable of achieving the technical parameters of the present invention can also be used in this invention.

[0029] According to embodiments of the present invention, a high-performance electrode is prepared by coating a catalyst precursor onto the surface of an electrode substrate, followed by rapid heating, holding, and rapid cooling. The rapid heating and cooling significantly reduces reaction time, prevents continuous catalyst crystal growth, effectively limits catalyst particle size, results in more uniform and fine catalyst particles, increases the specific surface area of ​​the catalyst, and improves reaction activity. Simultaneously, the catalyst prepared by this method exhibits good anisotropy, exposing numerous defect sites and high-index crystal planes, which effectively improves the catalyst's resistance to poisoning and its stability.

[0030] According to embodiments of the present invention, the preparation method provided by the present invention has a short heating time, a simple production process, can significantly reduce electrode manufacturing time, save labor costs, produce electrodes with uniform quality control, stable performance, excellent algae removal performance, and can remove toxic substances produced by algae, making it suitable for various aquatic environments.

[0031] According to embodiments of the present invention, the metal ion is at least one selected from ruthenium ion, iridium ion, tin ion, antimony ion, platinum ion, tantalum ion, or nickel ion.

[0032] According to an embodiment of the present invention, the preferred metal ions are subjected to a hydrothermal reaction to generate a precursor coated on the surface of the electrode substrate. Then, through rapid heating, holding, and rapid cooling, an oxide coated on the surface of the electrode substrate is generated, which further improves the stability and catalytic effect of the electrode.

[0033] According to an embodiment of the present invention, the metal ion is a combination of tin ions, antimony ions and platinum ions.

[0034] According to an embodiment of the present invention, the molar ratio of tin ions, antimony ions and platinum ions is (100-200):(5-30):(0.1-1), preferably 9:1:0.03.

[0035] According to an embodiment of the present invention, when the metal ions are a combination of tin ions, antimony ions and platinum ions, in the final formed electrode, platinum exists in the form of single atoms in the composite oxide of tin and antimony, further improving the technical effect of algae removal.

[0036] According to an embodiment of the present invention, the solution containing metal ions further includes a pH adjuster, which is suitable for inhibiting the hydrolysis reaction of metal ions;

[0037] According to embodiments of the present invention, the pH adjuster includes hydrochloric acid, preferably a combination of hydrochloric acid and citric acid.

[0038] According to an embodiment of the present invention, when the pH adjuster is a combination of hydrochloric acid and citric acid, the hydrolysis of metal ions can be further inhibited. Citric acid can also inhibit hydrolysis by chelating with metal ions and increase the viscosity of the solution containing metal ions, thus ensuring the smooth progress of the hydrothermal reaction.

[0039] According to an embodiment of the present invention, the total concentration of metal ions in the solution containing metal ions is 0.2 to 2.0 mol / L.

[0040] According to embodiments of the present invention, the concentration of metal ions may be 0.2 mol / L, 0.5 mol / L, 0.8 mol / L, 1.0 mol / L, 1.3 mol / L, 1.5 mol / L, 1.8 mol / L or 2.0 mol / L, preferably 1.0 mol / L.

[0041] According to an embodiment of the present invention, if the metal ion concentration is too high, the purity of the generated precursor is low, the grain development is incomplete, and there are many impurities and structural defects after sintering; if the metal ion concentration is too low, the hydrothermal reaction rate is slow and the reaction is incomplete.

[0042] According to an embodiment of the present invention, the hydrothermal reaction temperature is 150–180°C, and the reaction time is 3–8 hours.

[0043] According to embodiments of the present invention, the temperature of the hydrothermal reaction can be 150°C, 160°C, 165°C, 170°C, or 180°C, preferably 160°C. The reaction time can be 3h, 4h, 5h, 5.5h, 6h, 7h, or 8h, preferably 6h.

[0044] According to an embodiment of the present invention, if the temperature of the hydrothermal reaction is too high, the reaction rate is too fast, the purity of the generated precursor is low, the grain development is incomplete, and there are many impurities and structural defects after sintering; if the temperature of the hydrothermal reaction is too low, the reaction is incomplete and the reaction rate is low.

[0045] According to an embodiment of the present invention, the electrode substrate is a titanium mesh or a titanium sheet.

[0046] According to embodiments of the present invention, a preferred electrode substrate can further improve the stability of the electrode, resulting in a uniform electrode quality.

[0047] According to an embodiment of the present invention, an electrode is provided, which is prepared by any of the methods described above.

[0048] According to an embodiment of the present invention, an electrolysis apparatus is provided, comprising at least one of the electrodes described above.

[0049] According to an embodiment of the present invention, the electrolysis apparatus includes two electrodes disposed opposite to each other, the area of ​​which can be 10 to 30 cm². 2 The electrode spacing can be 4 to 20 mm.

[0050] According to embodiments of the present invention, the above-described electrode or electrolysis device is provided for applications in wastewater treatment, drinking water purification, environmental protection, food processing, medical care, or fruit and vegetable preservation, especially for electrochemical algae removal.

[0051] According to embodiments of the present invention, the electrodes prepared by the method provided by the present invention exhibit uniform quality control and stable performance, and can be well applied in wastewater treatment, drinking water purification, environmental protection, food processing, medical care, and fruit and vegetable preservation. In particular, they demonstrate excellent performance in algae removal and can remove toxic substances produced by algae, making them suitable for various aquatic environments.

[0052] It should be noted that, according to the embodiments of the present invention, the titanium-based substrate used is degreased, cleaned, polished, and acid-washed using hot sodium hydroxide.

[0053] It should be noted that the electrode substrate also undergoes pretreatment before use. The pretreatment involves degreasing the electrode substrate with hot sodium hydroxide, cleaning, polishing, and acid pickling. The acid pickling involves immersing the substrate in a 10% oxalic acid solution at 105°C for 2 hours.

[0054] The following detailed description provides several specific embodiments to illustrate the technical solution of the present invention. It should be noted that the specific embodiments described below are merely examples and are not intended to limit the scope of the invention.

[0055] Example 1

[0056] This embodiment provides a method for preparing an electrode, the specific steps of which are as follows:

[0057] Step 1: Dissolve 0.018 mol ruthenium chloride and 0.007 mol chloroiridium acid in 50 mL deionized water, then add 1 mL concentrated hydrochloric acid and stir to dissolve for 1 hour.

[0058] Step 2: Transfer the solution prepared in Step 1 to a 100mL reaction vessel, then place the pretreated titanium mesh inside, and react at a constant temperature of 160℃ for 6 hours.

[0059] Step 3: After the reaction vessel in Step 2 has cooled naturally to room temperature, remove the titanium mesh and rinse it with deionized water. Then, vacuum dry it at 60°C to obtain the titanium mesh coated with the precursor.

[0060] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 600°C in 7 seconds, hold it at that temperature for 100 seconds, and then cool it down to below 40°C in 10 seconds. After cooling down, remove the electrode.

[0061] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 With an electrode spacing of 6 mm, the algae were electrolyzed at a constant current of 1.2 A for 60 minutes in 100 ml of water containing a certain amount of algae. The algae inactivation efficiency was found to be 99.1%.

[0062] The experimental setup is a 1L device, equipped with a magnetic stirrer and heating device, and the electrode module is placed in it for constant current operation.

[0063] Microcystis aeruginosa was used in the experiment. The experimental temperature was 24±1℃. The algal solution in the logarithmic growth phase was diluted with deionized water to a concentration of approximately 1.0×10⁻⁶. 9 The algae removal rate was calculated by taking samples and measuring the initial concentration (e.g., cells / L) before the experiment. The control group was kept static for 90 minutes, and samples were taken and cultured for one day to calculate the final concentration. The experimental group was reacted in the electrolysis device for 60 minutes, then allowed to stand for 30 minutes, and samples were taken and cultured for one day to calculate the actual concentration. The algae removal rate was calculated by dividing (control group concentration - experimental group concentration) by the control group concentration.

[0064] Example 2

[0065] This embodiment provides a method for preparing an electrode, the specific steps of which are as follows:

[0066] Step 1: First, weigh 5g of citric acid and dissolve it in 50mL of deionized water, then add 1mL of concentrated hydrochloric acid, followed by 0.045mol of tin tetrachloride and 0.005mol of antimony trichloride. Stir to dissolve.

[0067] Step 2: Transfer the solution prepared in Step 1 to the reaction vessel, then place the pretreated titanium mesh inside, and react at a constant temperature of 180℃ for 8 hours.

[0068] Step 3: After the reaction vessel in Step 2 has cooled naturally to room temperature, remove the titanium mesh and rinse it with deionized water. Then, vacuum dry it at 60°C to obtain the titanium mesh coated with the precursor.

[0069] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 500°C in 5 seconds, hold it at that temperature for 100 seconds, and then cool it down to below 40°C in 5 seconds. After cooling down, remove the electrode.

[0070] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 1.2 A for 60 minutes. The algae inactivation efficiency was found to be 99.4%. The experimental setup and method were the same as in Example 1.

[0071] Example 3

[0072] This embodiment provides a method for preparing an electrode, the specific steps of which are as follows:

[0073] Step 1: Weigh 5g of citric acid and dissolve it in 50mL of deionized water, then add 1mL of concentrated hydrochloric acid. Next, add 0.045mol of tin tetrachloride and 0.005mol of antimony trichloride, and stir to dissolve. The molar ratio of tin to antimony is 9:1. Stir until dissolved. Then add 0.0015mol of chloroplatinic acid and continue stirring for 1 hour.

[0074] Step 2: Transfer the solution prepared in Step 1 to the reaction vessel, then place the pretreated titanium mesh inside, and react at a constant temperature of 180℃ for 8 hours.

[0075] Step 3: After the reaction vessel in Step 2 has cooled naturally to room temperature, remove the titanium mesh and rinse it with deionized water. Then, vacuum dry it at 60°C to obtain the titanium mesh coated with the precursor.

[0076] Step 4: Place the titanium mesh coated with the precursor on the heating plate of the Joule heating apparatus, then adjust the current to heat to 550℃ in 7 seconds, hold for 120 seconds, and then cool to below 50℃ in 15 seconds. After cooling, remove the electrode. The prepared electrode is then examined using a scanning electron microscope (SEM). See the SEM images for details. Figure 1 ,Depend on Figure 1 It can be seen that the prepared electrode surface is coated with a uniformly distributed catalytic material.

[0077] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 1.2 A for 60 minutes. The algae inactivation efficiency was found to be 99.5%. The experimental setup and method were the same as in Example 1.

[0078] Example 4

[0079] This embodiment provides a method for preparing an electrode, the specific steps of which are as follows:

[0080] Step 1: Dissolve 0.0375 mol ruthenium chloride and 0.0125 mol chloroplatinic acid in 50 mL of deionized water, add 1 mL of concentrated hydrochloric acid, and stir to dissolve for 1 hour.

[0081] Step 2: Transfer the solution prepared in Step 1 to the reaction vessel, then place the pretreated titanium mesh inside, and react at a constant temperature of 150℃ for 3 hours.

[0082] Step 3: After the reaction vessel in Step 2 has cooled naturally to room temperature, remove the titanium mesh and rinse it with deionized water. Then, vacuum dry it at 60°C to obtain the titanium mesh coated with the precursor.

[0083] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 800°C in 10 seconds, hold it at that temperature for 200 seconds, and then cool it down to below 30°C in 10 seconds. After cooling down, remove the electrode.

[0084] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​10 cm². 2 With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 1.0 A for 60 minutes. The algae inactivation efficiency was found to be 98.3%. The experimental setup and method were the same as in Example 1.

[0085] Example 5

[0086] This embodiment provides a method for preparing an electrode, the specific steps of which are as follows:

[0087] Step 1: Add 1 mL of concentrated hydrochloric acid to 50 mL of deionized water, then add 0.0175 mol of chloroiridic acid and 0.0075 mol of tantalum chloride, and stir to dissolve for 1 hour.

[0088] Step 2: Transfer the solution prepared in Step 1 to the reaction vessel, then place the pretreated titanium mesh inside, and react at a constant temperature of 180℃ for 6 hours.

[0089] Step 3: After the reaction vessel in Step 2 has cooled naturally to room temperature, remove the titanium mesh and rinse it with deionized water. Then, vacuum dry it at 60°C to obtain the titanium mesh coated with the precursor.

[0090] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 520°C in 7 seconds, hold it at that temperature for 80 seconds, and then cool it down to below 50°C in 10 seconds. After cooling down, remove the electrode.

[0091] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​15 cm². 2 With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 1.5 A for 60 minutes. The algae inactivation efficiency was found to be 98.7%. The experimental setup and method were the same as in Example 1.

[0092] Example 6

[0093] This embodiment provides a method for preparing an electrode, the specific steps of which are as follows:

[0094] Step 1: Dissolve 0.05 mol ruthenium chloride, 0.0005 mol nickel chloride and 0.015 mol chloroplatinic acid in 50 mL of deionized water, then add 1 mL of concentrated hydrochloric acid and stir to dissolve for 1 hour.

[0095] Step 2: Transfer the solution prepared in Step 1 to the reaction vessel, then place the pretreated titanium mesh inside, and react at a constant temperature of 160℃ for 6 hours.

[0096] Step 3: After the reaction vessel in Step 2 has cooled naturally to room temperature, remove the titanium mesh and rinse it with deionized water. Then, vacuum dry it at 60°C to obtain the titanium mesh coated with the precursor.

[0097] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 600°C in 7 seconds, hold it at that temperature for 100 seconds, and then cool it down to below 60°C in 20 seconds. After cooling down, remove the electrode.

[0098] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​10 cm². 2 With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 2.0 A for 60 minutes. The algae inactivation efficiency was found to be 99.3%. The experimental setup and method were the same as in Example 1.

[0099] Comparative Example 1

[0100] This comparative example provides a method for preparing an electrode, the specific steps of which are as follows:

[0101] Steps one through three are the same as in Example 1 and will not be repeated here.

[0102] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 480°C in 4 seconds, hold it at that temperature for 210 seconds, and then cool it down to below 40°C in 4 seconds. After cooling down, remove the electrode.

[0103] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 1.2 A for 60 minutes. The algae inactivation efficiency was found to be 95.1%. The experimental setup and method were the same as in Example 1.

[0104] Comparative Example 2

[0105] This comparative example provides a method for preparing an electrode, the specific steps of which are as follows:

[0106] Steps one through three are the same as in Example 1 and will not be repeated here.

[0107] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 810°C in 11s, hold it at that temperature for 75s, and then cool it down to below 40°C in 22s. After cooling down, remove the electrode.

[0108] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 1.2 A for 60 minutes. The algae inactivation efficiency was found to be 94.5%. The experimental setup and method were the same as in Example 1.

[0109] Comparative Example 3

[0110] This comparative example provides a method for preparing an electrode, the specific steps of which are as follows:

[0111] Steps one through three are the same as in Example 1 and will not be repeated here.

[0112] Step 4: Place the titanium mesh covering the precursor on the heating plate of the Joule heating device, then adjust the current to heat it to 600℃ in 15s, hold it at that temperature for 100s, and then cool it down to below 40℃ in 25s. After cooling down, remove the electrode.

[0113] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 With an electrode spacing of 6 mm, the sample was placed in 100 ml of water containing a certain amount of algae and electrolyzed at a constant current of 1.2 A for 60 minutes. The algae inactivation efficiency was found to be 95.9%. The experimental setup and method were the same as in Example 1.

[0114] Comparative Example 4

[0115] This comparative example provides a method for preparing an electrode, the specific steps of which are as follows:

[0116] Steps one through three are the same as in Example 1 and will not be repeated here.

[0117] Step 4: Place the titanium mesh coated with the precursor in a muffle furnace, heat it to 600°C in 30 minutes, hold it at that temperature for 100 seconds, and then cool it down to below 40°C in 60 minutes. After cooling down, remove the electrode.

[0118] Two prepared electrode sheets were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 The electrodes were spaced 6 mm apart and placed in 100 ml of water containing a certain amount of algae. Electrolysis was performed at a constant current of 1.2 A for 60 minutes, and the algae inactivation efficiency was found to be 90%. The experimental setup and method were the same as in Example 1.

[0119] Experimental Example 1

[0120] Two electrode sheets prepared in Example 1 were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 With an electrode spacing of 6 mm, the algae were placed in 100 ml of water containing a certain amount of algae and continuously electrolyzed at a constant current of 1.2 A for 90 minutes. The algal solution at different time points was repeatedly freeze-thawed and extracted, and then concentrated to determine the total microcystin concentration and the extracellular microcystin concentration. This allowed for the calculation of changes in intracellular microcystin concentration, which in turn determined the gradual breakup of algae during the reaction. The removal rate of total microcystin concentration reached 85.6% after 90 minutes.

[0121] Experimental Example 2

[0122] Two electrode sheets prepared in Example 1 were assembled into an electrolysis module, with each electrode having an area of ​​12 cm². 2 With an electrode spacing of 6mm, it was placed in 100ml of water with a certain amount of algae and electrolyzed at a constant current of 1.2A for 60 minutes. After that, 100ml of algae solution of a certain concentration was replaced and the solution was run at a constant current of 1.2A. After 30 consecutive solution replacements, the algae inactivation efficiency reached 90.2% in the 30th test. There was no obvious coating peeling or damage on the electrode surface. The electrode can be enlarged for algae removal, such as in aquariums and landscape ponds.

[0123] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an electrode, comprising: subjecting an electrode substrate to a hydrothermal reaction in a solution containing metal ions to obtain a coated precursor electrode substrate; sintering the coated precursor electrode substrate at 500-800℃ for 80-200s, and then cooling to 30-60℃ within 5-20s to obtain an electrode; wherein the metal ions are at least one of ruthenium ions, iridium ions, tin ions, antimony ions, platinum ions, tantalum ions or nickel ions; the electrode substrate is a titanium mesh or a titanium sheet.

2. The method of claim 1, wherein, the metal ions are a combination of tin ions, antimony ions and platinum ions; the molar ratio of the tin ions, the antimony ions and the platinum ions is (100-200):(5-30):(0.1-1).

3. The method of claim 2, wherein, the molar ratio of the tin ions, the antimony ions and the platinum ions is 9:1:0.

03.

4. The method of claim 1, wherein, the solution containing metal ions further comprises a pH adjuster, and the pH adjuster is suitable for inhibiting the hydrolysis reaction of the metal ions. the pH adjuster comprises hydrochloric acid.

5. The method of claim 4, wherein, the pH adjuster is a combination of hydrochloric acid and citric acid.

6. The method of claim 1, wherein, in the solution containing metal ions, the concentration of the metal ions is 0.2-2.0 mol / L.

7. The method of claim 1, wherein, the temperature of the hydrothermal reaction is 150-180℃, and the reaction time is 3-8h. 8.An electrode prepared by the method of any one of claims 1-7. 9.An electrochemical device comprising at least one electrode of claim 8. 10.Use of the electrode of claim 8 or the electrochemical device of claim 9 in the field of wastewater treatment, fish tank treatment, drinking water purification, environmental protection, food processing, medical care or fruit and vegetable preservation.

11. Use according to claim 10, wherein, the use is in electrochemical algae removal.

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