Preparation method of Ti4O7-doped C3N4 electrode material and application thereof

Abstract

The application provides a preparation method of a Ti4O7 doped C3N4 electrode material, which comprises the following steps: adding tetrabutyl titanate and glacial acetic acid into anhydrous ethanol to obtain solution A; mixing deionized water, glacial acetic acid and anhydrous ethanol to obtain solution B; adding solution B into solution A drop by drop and stirring to obtain a sol; after hydrothermal reaction at 180 DEG C, centrifugation, washing and drying, a crystal substance is obtained; after grinding, calcination at 520 DEG C under an air atmosphere and grinding again, TiO2 powder is obtained; after reduction under H2 atmosphere at 1050 DEG C, Ti4O7 powder is obtained; under N2 atmosphere, melamine powder is calcined at a temperature increasing rate of 2 DEG C / min to 500 DEG C to obtain C3N4 powder; after oscillation mixing of the Ti4O7 powder and the C3N4 powder and sintering in a double-power vacuum plasma sintering furnace, the Ti4O7 doped C3N4 electrode material is obtained. The application is also provided, and is used for degrading imidacloprid. The electrode has a high oxygen evolution potential, generates more hydroxyl radicals, improves the electrochemical characteristics, and has a good degradation effect on imidacloprid in pollutants.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrode materials, and particularly relates to a preparation method of Ti4O7 doped C3N4 electrode material and application thereof. BACKGROUND

[0002] The Ti4O7 electrode has excellent electrochemical characteristics and is widely used in fuel cells, water treatment, photocatalysis and the like.

[0003] However, the pure Ti4O7 electrode has a low oxygen evolution potential, which leads to a reduction in the production of hydroxyl radicals. SUMMARY

[0004] The technical problem to be solved by the application is to provide a preparation method of Ti4O7 doped C3N4 electrode material and application thereof, which can improve the electrochemical characteristics and the degradation effect of imidacloprid in pollutants.

[0005] To solve the above technical problem, the application adopts the technical scheme of a preparation method of Ti4O7 doped C3N4 electrode material.

[0006] S1, tetrabutyl titanate and glacial acetic acid are added to anhydrous ethanol, and the mixture is stirred at room temperature for 1 h to obtain solution A;

[0007] S2, deionized water, glacial acetic acid and anhydrous ethanol are uniformly mixed to obtain solution B;

[0008] S3, under the condition of magnetic stirring, solution B obtained in S2 is added dropwise to solution A obtained in S1, and stirring is continued for 2 h after the dropwise addition is completed to obtain a sol;

[0009] S4, the sol obtained in S3 is reacted under hydrothermal conditions at a temperature of 180 DEG C for 10 h, and then naturally cooled to room temperature; after centrifugation, the precipitate is washed with anhydrous ethanol for 3 times and then with deionized water for 3 times, and then dried at a temperature of 60 DEG C to obtain a crystalline material;

[0010] S5, the crystalline material obtained in S4 is ground for 5 min, and then calcined in a muffle furnace at a temperature of 520 DEG C for 3 h under an air atmosphere, and then ground into powder after naturally cooled to room temperature to obtain TiO2 powder;

[0011] S6, the TiO2 powder obtained in S5 is reduced at a temperature of 1050 DEG C for 40 min under an H2 atmosphere to obtain a Ti4O7 powder;

[0012] S7, the melamine powder is heated to 500 DEG C at a heating rate of 2 DEG C / min in a tube furnace under an N2 atmosphere, and then is kept at the temperature for 3 h, and then is cooled to room temperature to obtain a C3N4 powder;

[0013] S8, the Ti4O7 powder obtained in S6 and the C3N4 powder obtained in S7 are mixed uniformly by shaking, and then are placed in a graphite mold, and then are sintered in a double-power vacuum plasma sintering furnace, and then are taken out to obtain a Ti4O7-doped C3N4 electrode material; the sintering system is as follows: under a vacuum condition with a pressure of 5 MPa, the temperature is raised from room temperature to 600 DEG C at a heating rate of 114 DEG C / min, then is raised from 600 DEG C to 1000 DEG C at a heating rate of 50 DEG C / min, and then is raised from 1000 DEG C to 1100 DEG C at a heating rate of 25 DEG C / min, and then is kept at the temperature for 20 min, and then is naturally cooled to room temperature under the condition with a pressure of 5 MPa.

[0014] Preferably, the volume ratio of tetrabutyl titanate, glacial acetic acid and anhydrous ethanol in the solution A in S1 is 5:2:12.

[0015] Preferably, the volume ratio of deionized water, glacial acetic acid and anhydrous ethanol in the solution B in S2 is 2:3:3.

[0016] Preferably, the volume ratio of the solution B and the solution A in the sol in S3 is 8:19.

[0017] Preferably, the average particle size of the TiO2 powder in S5 is 25.26 mu m.

[0018] Preferably, the mass ratio of the Ti4O7 powder and the C3N4 powder in S8 is 1.47:0.03.

[0019] The application further provides application of the Ti4O7-doped C3N4 electrode material prepared by the method.

[0020] Compared with the prior art, the application has the following advantages:

[0021] 1. The anode material prepared by doping the C3N4 powder into the Ti4O7 powder has a higher oxygen evolution potential than the pure Ti4O7 electrode, so that more hydroxyl radicals are generated, and the electrochemical properties are improved, and the degradation effect on imidacloprid in the pollutants is good.

[0022] 2、The application first uses a sol-hydrothermal method to prepare TiO2 powder, then prepares Ti4O7 powder through high-temperature hydrogen reduction, then prepares C3N4 powder through a tube furnace in a nitrogen atmosphere, and finally mixes the two materials (Ti4O7 and C3N4) in powder form, and sintering is performed by using a double-power vacuum plasma sintering furnace, so that the purity of the two materials can be ensured, and the Ti4O7 powder is mainly used, and a small amount of C3N4 powder is doped in the Ti4O7 powder, so that the advantages of Ti4O7 and C3N4 can be exerted. In terms of performance, the prepared electrode material is directly sintered in powder form, the two materials are combined closely, and there is no problem of falling off in the reaction process, and the stability is more advantageous.

[0023] The application will be further described in detail below in combination with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is an electron microscope picture of the Ti4O7 doped C3N4 electrode material prepared in Example 1 of the application.

[0025] Figure 2 It is an XRD spectrum of the Ti4O7 doped C3N4 electrode material prepared in Example 1 of the application.

[0026] Figure 3 It is a linear sweep voltammogram of the Ti4O7 doped C3N4 electrode material prepared in Example 1 of the application.

[0027] Figure 4 It is an electrochemical impedance spectrum of the Ti4O7 doped C3N4 electrode material prepared in Example 1 of the application.

[0028] Figure 5 It is the degradation situation of the Ti4O7 doped C3N4 electrode material prepared in Example 1 of the application for imidacloprid. DETAILED DESCRIPTION

[0029] Example 1

[0030] The preparation method of the Ti4O7 doped C3N4 electrode material of the application is as follows:

[0031] S1, 5mL of tetrabutyl titanate, 2mL of glacial acetic acid are added to 12mL of anhydrous ethanol, and stirring and mixing are performed at room temperature for 1h to obtain solution A;

[0032] S2, 2mL of deionized water, 3mL of glacial acetic acid and 3mL of anhydrous ethanol are mixed uniformly to obtain solution B;

[0033] S3. Under magnetic stirring, add 8 mL of solution B obtained in S2 dropwise to 19 mL of solution A obtained in S1. After the addition is completed, continue stirring for 2 hours to obtain a sol.

[0034] S4. The sol obtained in S3 was reacted under hydrothermal conditions at 180℃ for 10 hours, then naturally cooled to room temperature, centrifuged, and the precipitate was washed three times with anhydrous ethanol and then three times with deionized water. It was then dried at 60℃ to obtain crystalline substance.

[0035] S5. After grinding the crystalline substance obtained in S4 for 5 minutes, calcine it in a muffle furnace at 520°C for 3 hours in an air atmosphere. After naturally cooling to room temperature, grind it into powder to obtain TiO2 powder with an average particle size of 25.26 μm.

[0036] S6. Under H2 atmosphere, the TiO2 powder obtained in S5 is reduced at 1050℃ for 40 min to obtain Ti4O7 powder.

[0037] S7. Under N2 atmosphere, melamine powder is placed in a tube furnace and heated to 500°C at a heating rate of 2°C / min, calcined at a constant temperature for 3 hours, and then cooled to room temperature to obtain C3N4 powder.

[0038] S8. After thoroughly mixing 1.47g of Ti4O7 powder obtained in S6 and 0.03g of C3N4 powder obtained in S7 by shaking, the mixture is placed in a graphite mold and sintered in a dual-power vacuum plasma sintering furnace. The resulting cylindrical Ti4O7-doped C3N4 electrode material with a diameter of 20mm and a thickness of 1.5mm is obtained. The sintering process is as follows: under a vacuum of 5MPa, the temperature is increased from room temperature to 600℃ at a heating rate of 114℃ / min, then increased from 600℃ to 1000℃ at a heating rate of 50℃ / min, and then increased from 1000℃ to 1100℃ at a heating rate of 25℃ / min. The temperature is held constant for 20min, and then naturally cooled to room temperature under a pressure of 5MPa.

[0039] like Figure 1 As shown in (a), the surface of a pure Ti4O7 electrode (the Ti4O7 powder prepared in S6 is sintered in a graphite mold, and the sintering method is the same as step S8 in this embodiment) shows that the surface is somewhat rough and there are gaps between the particles. Figure 1 (b) The electrode surface of the Ti4O7-doped C3N4 electrode material prepared in this embodiment is shown. Three-dimensional particles with rhomboid shapes (the structure of C3N4) can be seen on the surface, and gaps still exist between the particles.

[0040] The XRD pattern of pure Ti4O7 electrode (Ti4O7 electrode sintered from Ti4O7 powder obtained in step S6 of the present embodiment), Ti4O7 / C3N4 electrode (electrode made of Ti4O7 doped with C3N4 electrode material prepared in the present embodiment) is shown in Figure 2 As can be seen, all characteristic diffraction peaks of pure Ti4O7 electrode are observed. The diffraction peaks of Ti4O7 / C3N4 electrode and pure Ti4O7 electrode are not much different, but the intensity of the diffraction peaks is lower.

[0041] The linear sweep voltammogram of pure Ti4O7 electrode (Ti4O7 electrode sintered from Ti4O7 powder obtained in step S6 of the present embodiment), Ti4O7 / C3N4 electrode (electrode made of Ti4O7 doped with C3N4 electrode material prepared in the present embodiment) is shown in Figure 3 As can be seen, the oxygen evolution potential of Ti4O7 is 1.86 V, and the oxygen evolution potential of Ti4O7 doped with C3N4 is 2.54 V, which is conducive to the generation of hydroxyl radicals and inhibits the oxygen evolution side reaction on the electrode surface.

[0042] The electrochemical impedance spectrogram of pure Ti4O7 electrode (Ti4O7 electrode sintered from Ti4O7 powder obtained in step S6 of the present embodiment), Ti4O7 / C3N4 electrode (electrode made of Ti4O7 doped with C3N4 electrode material prepared in the present embodiment) is shown in Figure 4 As can be seen in the EIS graph, the EIS radius of Ti4O7 doped with C3N4 electrode is much smaller than that of Ti4O7 electrode, which means that the interfacial charge transfer resistance is lower, and its electrochemical performance is better.

[0043] The present embodiment also provides the use of the above-prepared Ti4O7 doped with C3N4 electrode as an anode for the degradation of imidacloprid.

[0044] The degradation of imidacloprid by the Ti4O7 doped with C3N4 electrode prepared in the present experiment is shown in Figure 5As shown, the degradation rates of Ti4O7, Ti4O7 / C3N4 electrodes on the imidacloprid were 83.2% and 88.2% respectively. It can be seen that the Ti4O7 electrode doped is better than the undoped electrode and the degradation of Ti4O7 doped C3N4 electrode is faster, because the oxygen evolution potential of Ti4O7 / C3N4 electrode is higher than that of Ti4O7, which is beneficial to the generation of hydroxyl radicals and the degradation of imidacloprid. Experimental conditions: 100 mL of 50 mg / L imidacloprid aqueous solution was measured, 0.5682 g of Na2SO4 electrolyte was added, and then poured into the electrolysis cell. Ti4O7, Ti4O7 / C3N4 were used as anode respectively, the same size of pure titanium mesh with 400 cc sandpaper polishing surface was used as cathode, double electrode system constant current density 8 mA / cm 2 , magnetic stirring rate 750 r / min, room temperature conditions for 60 min.

[0045] The above is only a preferred embodiment of the present application, not any limitation on the present application. Any simple modification, change and equivalent change of the above embodiment according to the technical essence of the present application still belongs to the protection scope of the technical scheme of the present application.

Claims

1. Use of a Ti407-doped C3N4 electrode material, characterized in that, The electrode material of Ti4O7-doped C3N4 is used for degrading imidacloprid. S1, tetrabutyl titanate and glacial acetic acid are added to anhydrous ethanol, and the mixture is stirred at room temperature for 1 h to obtain solution A; S2, deionized water, glacial acetic acid and anhydrous ethanol are mixed uniformly to obtain solution B; S3, under the condition of magnetic stirring, solution B obtained in S2 is added dropwise into solution A obtained in S1, and after the dropwise addition is completed, stirring is continued for 2 h to obtain a sol; S4, after the sol obtained in S3 is reacted under hydrothermal conditions at a temperature of 180 ℃ for 10 h, it is naturally cooled to room temperature, centrifuged, and the precipitate is washed with anhydrous ethanol for 3 times and then with deionized water for 3 times, and dried at a temperature of 60 ℃ to obtain a crystalline material; S5, the crystalline material obtained in S4 is ground for 5 min, calcined in a muffle furnace at a temperature of 520 ℃ for 3 h under air atmosphere, and then ground into powder after being naturally cooled to room temperature to obtain TiO2 powder; S6, the TiO2 powder obtained in S5 is reduced under H2 atmosphere at a temperature of 1050 ℃ for 40 min to obtain Ti4O7 powder; S7, melamine powder is heated to 500 ℃ at a heating rate of 2 ℃ / min in a tube furnace under N2 atmosphere, and then calcined at constant temperature for 3 h, and then cooled to room temperature to obtain C3N4 powder; S8, the Ti4O7 powder obtained in S6 and the C3N4 powder obtained in S7 are mixed uniformly by shaking and then placed in a graphite mold, and then sintered in a double-power vacuum plasma sintering furnace to obtain the electrode material of Ti4O7-doped C3N4; the sintering schedule is as follows: under the condition of vacuum at a pressure of 5 MPa, the temperature is increased from room temperature to 600 ℃ at a heating rate of 114 ℃ / min, then increased from 600 ℃ to 1000 ℃ at a heating rate of 50 ℃ / min, and then increased from 1000 ℃ to 1100 ℃ at a heating rate of 25 ℃ / min, and kept at constant temperature for 20 min, and then naturally cooled to room temperature under the condition of a pressure of 5 MPa.

2. The use of a Ti407-doped C3N4 electrode material according to claim 1, characterized in that, The volume ratio of tetrabutyl titanate, glacial acetic acid and anhydrous ethanol in the solution A in S1 is 5:2:

12.

3. The use of a Ti407-doped C3N4 electrode material according to claim 1, characterized in that, The volume ratio of deionized water, glacial acetic acid and anhydrous ethanol in the solution B in S2 is 2:3:

3.

4. The use of a Ti407-doped C3N4 electrode material according to claim 1, characterized in that, The volume ratio of solution B and solution A in the sol in S3 is 8:

19.

5. The use of a Ti407-doped C3N4 electrode material according to claim 1, characterized in that, The average particle size of the TiO2 powder in S5 is 25.26 μm.

6. The use of a Ti407-doped C3N4 electrode material according to claim 1, characterized in that, The mass ratio of the Ti4O7 powder and the C3N4 powder in S8 is 1.47:0.03.

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