A method for preparing and applying a co-doped modified Ti4O7 electrode.

Abstract

This application relates to the field of electrochemical oxidation, specifically disclosing a method for preparing a co-doped modified Ti4O7 electrode. The preparation method includes the following steps: Step 1: Mixing Ti4O7 powder, a metal source, and a non-metal source, and ball milling to obtain a mixed powder; Step 2: Adding a binder and an organic dispersant to the mixed powder, ultrasonicating, heating and stirring, drying, and sintering to obtain the co-doped modified Ti4O7 electrode. The co-doped modified Ti4O7 electrode prepared in this application has excellent chlorine evolution sterilization performance and can be applied to the purification treatment of wastewater containing ammonia nitrogen pollutants, as well as the long-term disinfection and sterilization of small water bodies such as circulating water, landscape water, and ballast water.

Description

Technical Field

[0001] This application relates to the field of electrochemical oxidation, and more specifically, it relates to a method for preparing a co-doped modified Ti4O7 electrode, its application, and the electrode itself. Background Technology

[0002] The electrochemical chlorine evolution reaction can utilize Cl in the solution. - The process converts chlorine into active chlorine and prepares chlorine gas through hydrolysis to produce hypochlorous acid. This process not only has excellent treatment effects on ammonia nitrogen wastewater, but also endows it with excellent bactericidal and disinfection effects due to its ability to generate active chlorine in situ, showing broad application prospects. The key to the electrochemical chlorine evolution performance lies in the chlorine evolution electrode, which determines the working efficiency of the entire unit. Currently, the commonly used chlorine evolution electrode on the market is the traditional ruthenium-iridium stabilizing electrode. However, long-term use has gradually exposed technical problems that urgently need to be solved, such as the dissolution of active materials, mechanical corrosion from severe bubbles, the formation of insulating oxides on the electrode substrate, and chemical dissolution caused by chlorine generation or acid washing. These problems greatly test the stability and service life of the electrode. At the same time, the limited reserves of precious metal resources and the high application cost have prompted us to seek and develop a new type of sustainable chlorine evolution electrode that is more efficient, stable, and inexpensive.

[0003] Titanium suboxide (Ti n O 2n-1 Ti4O7 is a novel environmentally friendly ceramic film electrode material with significant research and application value. Among these materials, Ti4O7 exhibits the best conductivity and possesses advantages such as high chemical stability, high corrosion resistance, and high oxygen evolution potential. It demonstrates good chlorine evolution selectivity and high chlorine evolution activity potential, and is expected to be used stably in harsh chlorine evolution environments for a long time. In particular, its cost is significantly lower than that of commercially available ruthenium-iridium stabilized electrodes. However, there is still considerable room for improvement in the chlorine evolution performance of a single Ti4O7 electrode. Summary of the Invention

[0004] To improve the chlorine evolution performance of Ti4O7 electrodes, this application provides a method for preparing a co-doped modified Ti4O7 electrode, its application, and the electrode itself.

[0005] In a first aspect, this application provides a method for preparing a co-doped modified Ti4O7 electrode, employing the following technical solution:

[0006] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0007] Step 1: Mix Ti4O7 powder, metal source, and non-metal source, and ball mill to obtain mixed powder;

[0008] Step 2: Add binder and organic dispersant to the mixed powder, sonicate, heat and stir, dry, and sinter to obtain co-doped modified Ti4O7 electrode.

[0009] Preferably, the amount of the metal source is 1-3 wt% of Ti4O7 powder, and the amount of the non-metal source is 5-9 wt% of Ti4O7 powder.

[0010] Preferably, the metal source is one or more of ruthenium chloride, cobalt chloride or cobalt nitrate, cerium chloride, europium chloride or europium acetate, tin chloride and antimony chloride, and the non-metal source is one or more of boric acid, phosphoric acid, sodium fluoride and sodium sulfide.

[0011] By adopting the above technical solution, the doped metal source can reduce the electron density of Ti centers in the Ti4O7 electrode, which is beneficial to the nucleophile Cl. - The proximity of the electrodes is beneficial to improving the activity of the chlorine evolution reaction and also to improving the stability of the Ti4O7 electrode. Meanwhile, the doping of non-metallic sources can effectively increase the number of unsaturated oxygen sites in the Ti4O7 electrode, which is conducive to the efficient adsorption and conversion of intermediate active substances in chlorine evolution on the electrode and greatly improves the chlorine evolution selectivity of the electrode.

[0012] Preferably, the Ti4O7 powder has a particle size of 20–45 μm.

[0013] By adopting the above technical solution, the appropriate particle size helps the Ti4O7 powder to make close contact between each other, which can ensure the compactness of the final product and thus ensure the stability of the electrode.

[0014] Preferably, the amount of the binder is 5-7 wt% of the Ti4O7 powder.

[0015] Preferably, the binder is a nitrogen-containing heterocyclic zinc-based metal-organic framework nanoparticle.

[0016] By adopting the above technical solution, nitrogen-containing heterocyclic zinc-based metal-organic framework nanoparticles have a large specific surface area and porosity. After being added to the system, they can effectively adsorb and bind various raw material components, thereby improving the stability of the electrode. At the same time, after high-temperature sintering, nitrogen-containing heterocyclic zinc-based metal-organic framework nanoparticles can be transformed into metal-organic framework-derived nitrogen-doped carbon, which can significantly improve the electron transport efficiency of the electrode. In addition, the unsaturated oxygen atoms bound to the carbon defect sites will also become important adsorption active sites for chlorine intermediates in the chlorine evolution process, effectively improving the chlorine evolution function of the electrode.

[0017] Preferably, the organic dispersant is selected from one or more of isopropanol, ethanol, and acetone.

[0018] Preferably, it also includes sheet graphene and spherical graphene, wherein the amount of sheet graphene is 2-3 wt% of Ti4O7 powder and the amount of spherical graphene is 3-5 wt% of Ti4O7 powder; the mesh size of sheet graphene is 1500-2000 mesh and the mesh size of spherical graphene is 4000-5000 mesh.

[0019] By adopting the above technical solution, the combination of sheet graphene and spherical graphene can enable the raw materials to effectively contact and pack tightly in the system. After sintering, the number of reactive sites on the electrode surface can be increased, thereby further improving the performance of the electrode.

[0020] Preferably, the ball milling process is as follows: rotation speed is 1100-1400 r / min, and time is 20-30 min;

[0021] The ultrasonic time is 30-50 min, the heating and stirring temperature is 50-70℃, the stirring speed is 200-300 r / min, the drying temperature is 70-90℃, and the drying time is 15-24 h;

[0022] The sintering process is as follows: sintering heating rate 40-70℃ / min, sintering temperature 1100-1200℃, sintering time 15-30min, and high pressure condition 2-4MPa.

[0023] By adopting the above technical solutions and selecting appropriate sintering processes, the quality of the finished products can be effectively ensured.

[0024] Secondly, this application provides a co-doped modified Ti4O7 electrode, employing the following technical solution:

[0025] A co-doped modified Ti4O7 electrode was prepared using a specific method.

[0026] Thirdly, this application provides an application of a co-doped modified Ti4O7 electrode, employing the following technical solution:

[0027] An application of a co-doped modified Ti4O7 electrode for water treatment.

[0028] In summary, this application has the following beneficial effects:

[0029] 1. This application distorts the Ti4O7 lattice by doping with a metal source and adjusts the unsaturated oxygen atom state by doping with a non-metal source. With the help of the synergistic regulation of the electronic structure of the Ti4O7 electrode by binary, ternary or multi-element metal and non-metal co-doping, the activity and selectivity of the electrode for chlorine evolution reaction are significantly enhanced.

[0030] 2. This application uses metal-organic framework nanoparticles as a binder to prepare Ti4O7 electrodes, which makes Ti4O7 electrodes have higher electron transport efficiency. At the same time, the electrodes formed by high-temperature sintering and pressing have good mechanical stability, and Ti4O7 itself has excellent acid and alkali resistance, which are all conducive to the long-term repeated stable use of the electrodes in harsh chlorine evolution environments.

[0031] 3. Compared with commercially available stable electrodes commonly used in the chlor-alkali industry, the co-doped modified Ti4O7 electrode prepared in this application has superior overall chlorine evolution performance and a significant cost advantage. It can be flexibly applied to the efficient and harmless treatment of wastewater containing ammonia nitrogen pollutants, as well as the long-term disinfection and sterilization of small water bodies such as landscape water, circulating water, and ballast water. Its market promotion and application prospects are very broad. Attached Figure Description

[0032] Figure 1 This is a low-magnification scanning electron microscope image of the electrode in Example 1;

[0033] Figure 2 This is a high-magnification scanning electron microscope image of the electrode prepared in Example 1;

[0034] Figure 3 These are the linear sweep voltammetry curves of the electrodes prepared in Examples 1-3 and Comparative Example 1;

[0035] Figure 4 These are the electrochemical impedance spectra of the electrodes prepared in Examples 1-3 and Comparative Example 1;

[0036] Figure 5 This is a comparison chart of the Faraday efficiency of the electrodes prepared in Examples 1-3 and Comparative Examples 1-4. Detailed Implementation

[0037] The present application will be further clarified and described below with reference to embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The nitrogen-containing heterocyclic zinc-based metal-organic framework nanoparticles used in this application were prepared according to Example 1 in published patent 201811036011X.

[0039] Example 1

[0040] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0041] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0042] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0043] Example 2

[0044] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0045] 2g of Ti4O7 powder with a diameter of 35μm, 0.04g of europium chloride and 0.14g of sodium fluoride were mixed and ball-milled at 1300r / min for 30min to obtain a mixed powder.

[0046] 0.12 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of acetone were added to the mixed powder, sonicated for 50 min, heated to 70 °C, stirred at 300 r / min until nearly dry, and then dried at 80 °C for 20 h under vacuum. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 60 °C / min, a sintering temperature of 1200 °C, a sintering time of 15 min, and a high pressure of 3 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0047] Example 3

[0048] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0049] 2g of Ti4O7 powder with a diameter of 45μm, 0.06g of tin chloride and 0.18g of phosphoric acid were mixed and ball-milled at 1400r / min for 30min to obtain a mixed powder.

[0050] 0.14 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of ethanol were added to the mixed powder, sonicated for 40 min, heated to 60 °C, stirred at 200 r / min until nearly dry, and then dried at 90 °C under vacuum for 18 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 70 °C / min, a sintering temperature of 1200 °C, a sintering time of 20 min, and a high pressure of 4 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0051] Example 4

[0052] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0053] 2g of Ti4O7 powder with a diameter of 20μm, 0.04g of ruthenium chloride and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0054] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0055] Example 5

[0056] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0057] 2g of Ti4O7 powder with a diameter of 20μm, 0.06g of ruthenium chloride and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0058] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0059] Example 6

[0060] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0061] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride and 0.14g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0062] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0063] Example 7

[0064] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0065] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride and 0.18g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0066] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0067] Example 8

[0068] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0069] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride, 0.04g of 1500-mesh sheet graphene, 0.06g of 4000-mesh spherical graphene and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0070] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0071] Example 9

[0072] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0073] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride, 0.06g of 2000-mesh sheet graphene, 0.1g of 5000-mesh spherical graphene and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0074] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0075] Example 10

[0076] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0077] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride, 0.1g of 1500-mesh sheet graphene and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0078] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0079] Example 11

[0080] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0081] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride, 0.1g of 4000-mesh spherical graphene and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0082] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0083] Example 12

[0084] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0085] 2g of Ti4O7 powder with a diameter of 20μm, 0.1g of ruthenium chloride and 0.1g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0086] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0087] Example 13

[0088] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0089] 2g of Ti4O7 powder with a diameter of 20μm, 0.02g of ruthenium chloride and 0.04g of boric acid were mixed and ball-milled at 1100r / min for 20min to obtain a mixed powder.

[0090] 0.1 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of isopropanol were added to the mixed powder, sonicated for 30 min, heated at 50 °C, stirred at 200 r / min until nearly dry, and then dried at 70 °C under vacuum for 24 h. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 40 °C / min, a sintering temperature of 1100 °C, a sintering time of 30 min, and a high pressure of 2 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0091] Comparative Example 1

[0092] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0093] 2g of Ti4O7 powder with a diameter of 20μm and 0.06g of ruthenium chloride were mixed and ball-milled at 1400r / min for 30min to obtain a mixed powder.

[0094] 0.14 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of acetone were added to the mixed powder, sonicated for 40 min, heated to 60 °C, stirred at 200 r / min until nearly dry, and then dried at 90 °C for 18 h under vacuum. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 70 °C / min, a sintering temperature of 1100 °C, a sintering time of 20 min, and a high pressure of 4 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0095] Comparative Example 2

[0096] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0097] 2g of Ti4O7 powder with a diameter of 20μm and 0.14g of boric acid were mixed and ball-milled at 1300r / min for 30min to obtain a mixed powder.

[0098] 0.12 g of nitrogen-containing zinc-based metal-organic framework nanoparticles and 30 ml of acetone were added to the mixed powder, sonicated for 50 min, heated to 70 °C, stirred at 300 r / min until nearly dry, and then dried at 80 °C for 20 h under vacuum. Finally, the mixture was sintered under high temperature and high pressure using spark plasma sintering at a heating rate of 50 °C / min, a sintering temperature of 1200 °C, a sintering time of 15 min, and a high pressure of 3 MPa. The resulting co-doped modified Ti4O7 electrode was then obtained.

[0099] Comparative Example 3

[0100] A method for preparing a co-doped modified Ti4O7 electrode includes the following steps:

[0101] 2g of Ti4O7 powder with a diameter of 35μm, 0.04g of cobalt chloride and 0.14g of sodium sulfide were mixed and ball-milled at 1300r / min for 30min to obtain a mixed powder.

[0102] Sintering was carried out by spark plasma sintering under high temperature and high pressure. The sintering heating rate was 60℃ / min, the sintering temperature was 1100℃, the sintering time was 20min, and the high pressure condition was 4MPa. After the sintering was completed, a co-doped modified Ti4O7 electrode was obtained.

[0103] Comparative Example 4

[0104] A commercially available ruthenium-iridium electrode with a diameter of 20 mm was used as a comparative example.

[0105] Performance testing

[0106] 1. Morphological analysis

[0107] The electrode structure in Example 1 was observed using a scanning electron microscope, such as... Figure 1 As shown, the Ti4O7 electrode exhibits good sintering properties, resulting in a micron-sized porous structure. Figure 2 As shown, nitrogen-containing heterocyclic zinc-based metal-organic framework nanoparticles are distributed among the particles in the Ti4O7 electrode, indicating that the nitrogen-containing heterocyclic zinc-based metal-organic framework nanoparticles play an excellent binding role and can effectively improve the conductivity of the electrode.

[0108] 2. Chlorine evolution performance test

[0109] Electrodes prepared in Examples 1-3 and Comparative Example 1 were used as test electrodes, with Ag / AgCl electrode as reference electrode and platinum electrode as counter electrode. The performance was tested and recorded.

[0110] A sample was taken, and the polarization curve of the working electrode was determined using linear voltammetry. The electrolyte was 0.3M NaCl solution, the scan rate was 20 mV / s, and the voltage range was 0-1.6 V. This was used to evaluate the chlorine evolution activity of the electrode. The polarization curve is shown below. Figure 3 As shown, compared with Comparative Example 1, the electrodes prepared in Examples 1-3 exhibited superior chlorine evolution performance; the chlorine evolution current increased rapidly, reaching 10 mA / cm². 2 Under the current density conditions, the overpotential of the electrodes in Examples 1-3 is significantly lower than that in Comparative Example 1, indicating that the co-doping modification of Ti4O7 electrodes using metal and non-metal sources in this application can effectively reduce the overpotential of the chlorine evolution reaction of Ti4O7 electrodes and enhance the chlorine evolution activity.

[0111] Electrochemical impedance spectroscopy was performed on the sample, and the results are as follows: Figure 4 As shown, the AC impedance of the electrodes in Examples 1-3 is significantly lower than that of the electrode in Comparative Example 1, indicating that the electrodes in Examples 1-3 have higher electron transport efficiency and faster reaction kinetics in the chlorine evolution reaction.

[0112] Samples were taken, and the Faraday efficiency of the electrode was tested using the iodometric method to evaluate its chlorine evolution selectivity. The electrolyte was a 0.3 M NaCl solution, and the current density was 30 mA / cm². 2 The result is as follows Figure 5 As shown, the electrodes in Examples 1-3 exhibit better chlorine evolution selectivity, less oxygen evolution side reaction, and higher current utilization.

[0113] 3. Ammonia nitrogen oxidation degradation performance test

[0114] Using the sample as the anode and a pure Ti4O7 electrode as the cathode, ammonia nitrogen wastewater was simulated for electro-oxidation treatment. The initial concentration of ammonia nitrogen was 100 mg / L, and the current density was 30 mA / cm². 2 The chloride ion concentration was 2000 mg / L, and the ammonia nitrogen removal rate was measured after 90 min. The results are shown in Table 1.

[0115] Table 1. Test results of ammonia nitrogen oxidation degradation performance

[0116]

[0117]

[0118] Referring to Table 1, compared with Comparative Examples 1-4, the electrodes in Examples 1-3 showed better removal of ammonia nitrogen, indicating that co-doping the Ti4O7 electrode with metal and non-metal sources can effectively improve the chlorine evolution performance of the electrode.

[0119] By combining Examples 1, 4-7, 12 and 13, limiting the amount of metal and non-metal sources can effectively ensure that the electrode has a better chlorine evolution effect; by combining Examples 1 and 8-11, the combined use of sheet graphene and spherical graphene can improve the performance of the electrode to a certain extent.

[0120] 4. Sterilization performance test

[0121] The sample was used as the anode, and a pure Ti4O7 electrode sheet was used as the cathode. 100 mL of solutions containing Staphylococcus aureus and Escherichia coli (both bacterial concentrations were 1.2 × 10⁻⁶) were used. 7 The bactericidal and disinfection performance of 0.3M NaCl electrolyte (CFU / mL) was tested. After 3 minutes of reaction, the content of Staphylococcus aureus and Escherichia coli in the solution was detected. The results are shown in Table 2.

[0122] Table 2. Sterilization performance test results

[0123]

[0124]

[0125] As can be seen from Table 2, compared with Comparative Examples 1-4, the electrodes in Examples 1-3 have better sterilization effects, indicating that the electrodes prepared according to the preparation method in this application have excellent chlorine sterilization effects.

[0126] In addition, the present invention also provides the modified Ti4O7 electrode prepared by the above-mentioned co-doped modified Ti4O7 electrode and the application of the prepared modified Ti4O7 electrode in water treatment. Specifically, the electrode has high efficiency in chlorine evolution reaction activity and selectivity, and can be widely used in the purification treatment of wastewater containing ammonia nitrogen pollutants, as well as the long-term disinfection and sterilization of small water bodies such as circulating water, landscape water, and ballast water.

[0127] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a co-doped modified Ti407 electrode, characterized in that, The method comprises the following steps: Step 1: mixing Ti4O7 powder, metal source, non-metal source, flaky graphene and spherical graphene, ball milling to obtain mixed powder; Step 2: adding binder and organic dispersant to the mixed powder, ultrasonic treatment, heating and stirring, drying, sintering to obtain co-doped modified Ti4O7 electrode; The amount of the metal source is 1-3wt% of the Ti4O7 powder, and the amount of the non-metal source is 5-9wt% of the Ti4O7 powder; The metal source is one or more of ruthenium chloride, cobalt chloride or cobalt nitrate, cerium chloride, europium chloride or europium acetate, tin chloride and antimony chloride, and the non-metal source is one or more of boric acid, phosphoric acid, sodium fluoride and sodium sulfide; The amount of the binder is 5-7wt% of the Ti4O7 powder, and the binder is nitrogen-containing heterocyclic zinc-based metal-organic framework nanoparticles; The amount of the flaky graphene is 2-3wt% of the Ti4O7 powder, and the amount of the spherical graphene is 3-5wt% of the Ti4O7 powder; the mesh number of the flaky graphene is 1500-2000 mesh, and the mesh number of the spherical graphene is 4000-5000 mesh.

2. The method for preparing a co-doped modified Ti4O7 electrode according to claim 1, characterized in that: The particle size of the Ti4O7 powder is 20-45μm.

3. The method for preparing a co-doped modified Ti4O7 electrode according to claim 1, characterized in that: The organic dispersant is one or more of isopropyl alcohol, ethanol and acetone.

4. The method for preparing a co-doped modified Ti4O7 electrode according to claim 1, characterized in that: The ball milling process is at a speed of 1100-1400r / min for 20-30min; The ultrasonic treatment time is 30-50min, the heating and stirring temperature is 50-70℃, the stirring speed is 200-300r / min, the drying temperature is 70-90℃, and the drying time is 15-24h; The sintering process is at a sintering heating rate of 40-70℃ / min, a sintering temperature of 1100-1200℃, a sintering time of 15-30min, and a high pressure of 2-4MPa.

5. A co-doped modified Ti407 electrode characterized by: The method is prepared by the method of any one of claims 1-4.

6. The use of a co-doped modified Ti407 electrode according to claim 5, characterized in that: It is used for water treatment.

Images