Iodine corrosion Ti4O7 electrode material and preparation method and application thereof

Abstract

The application belongs to the technical field of electrode materials, and particularly relates to an iodine etching Ti4O7 electrode material and a preparation method and application thereof. The Ti4O7 is mixed with iodine powder through ball milling, an alcohol solution is added, and the mixed iodine is dissolved by ultrasonic oscillation, the alcohol solution is completely volatilized in the form of natural evaporation drying at room temperature, and then the obtained powder is put into a high-pressure reaction kettle for reaction, the iodine sublimates under heating in the reaction kettle, the iodine vapor corrodes the Ti4O7, the surface structure of the Ti4O7 changes, and finally the iodine etching Ti4O7 anode is prepared by performing spark plasma sintering (SPS). The surface structure of the Ti4O7 is changed, defects are generated, the surface oxygen vacancies are increased, the active sites on the electrode surface are increased, and higher ·OH production is obtained. The preparation method can significantly improve the catalytic activity of the Ti4O7 anode.

Description

TECHNICAL FIELD

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

[0002] With the continuous development of industry and agriculture, more and more pollutants enter the environment, which brings great harm to the environment. Perfluorinated compounds are a kind of persistent pollutants with high thermal stability and chemical stability, which can exist in the environment for a long time and are difficult to be biodegraded. It is undoubtedly very important to seek an effective degradation method for perfluorinated compounds.

[0003] Current studies show that electrochemical oxidation is a very effective method for degrading perfluorinated compounds. There are two main ways for electrochemical oxidation to degrade perfluorinated compounds. One is that hydroxyl radicals generated on the surface of the anode enter the water body and undergo electron transfer with the pollutants. The other is that the pollutants undergo direct electron transfer on the anode, so as to achieve the purpose of degrading the pollutants. Ti4O7 has high electrical conductivity and corrosion resistance, high oxygen evolution potential, wide environmental benefits and low manufacturing cost. Using Ti4O7 as an anode to electrolytically oxidize pollutants has been considered as one of the most effective methods for degrading perfluorinated compounds in complex water bodies. However, the interfacial charge transfer rate of pure Ti4O7 is low, and the ·OH yield is not as good as that of traditional non-active anode materials, so that the degradation efficiency of fluorides is not ideal. SUMMARY

[0004] Therefore, the application provides an iodine-corroded Ti4O7 electrode material and a preparation method and application thereof. The iodine-corroded Ti4O7 electrode material prepared by the preparation method provided in the application has a surface containing more oxygen vacancies, which can improve the ·OH yield, thereby improving the catalytic activity of the Ti4O7 anode and facilitating the improvement of the fluorine degradation efficiency.

[0005] To solve the above technical problems, the application provides a preparation method of an iodine-corroded Ti4O7 electrode material, which comprises the following steps:

[0006] Mixing Ti4O7 powder, iodine and an alcohol solution to obtain a mixed solution;

[0007] After removing the solvent from the mixed solution, sequentially performing iodine corrosion reaction and sintering to obtain the Ti4O7 electrode material.

[0008] Preferably, the mixing comprises the following steps:

[0009] Firstly mixing Ti4O7 powder and iodine to obtain a mixed powder;

[0010] Secondly, the mixed powder and the alcohol solution are mixed to obtain a mixed solution.

[0011] Preferably, the mass percentage of the iodine in the mixed powder is 1-15%.

[0012] Preferably, the first mixing is carried out under ball milling, the rotating speed of the ball mill is 1200-1500 r / min, and the time is 15-25 min.

[0013] Preferably, the mass concentration of the alcohol solution is greater than or equal to 90%, and the mass of the mixed powder to the volume of the alcohol solution is 1 g: 0.6-0.8 mL.

[0014] The second mixing is carried out under ultrasonic condition, the power of the ultrasonic is 220-260 W, the frequency of the ultrasonic is 35-45 kHz, and the time of the ultrasonic is more than 30 min.

[0015] Preferably, the average particle size of the Ti4O7 powder is 100 nm-1 μm.

[0016] Preferably, the temperature of the iodine corrosion reaction is 80-110 ℃, and the time of the iodine corrosion reaction is not less than 36 h.

[0017] Preferably, the sintering is spark plasma sintering, the pressure of the spark plasma sintering is 4-6 MPa, the temperature of the spark plasma sintering is 1000-1200 ℃, the time of the spark plasma sintering is 20-30 min, and the heating rate for heating to the temperature required by the spark plasma sintering is 50-60 ℃ / min.

[0018] The application further provides a Ti4O7 electrode material prepared by the preparation method.

[0019] The application further provides application of the Ti4O7 electrode material in electrochemical oxidation degradation of perfluorinated compounds.

[0020] The application provides a preparation method of an iodine-corroded Ti4O7 electrode material, which comprises the following steps: mixing Ti4O7 powder, iodine and an alcohol solution to obtain a mixed solution; and carrying out iodine corrosion reaction and sintering on the mixed solution after removing the solvent to obtain the Ti4O7 electrode material. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A comparison point-line graph of the degradation rate of RhB of Example 3 and Comparative Example 1;

[0022] Figure 2 A comparison point-line graph of the degradation ability of TCH of Example 3 and Comparative Example 1;

[0023] Figure 3 A comparison point-line graph of the degradation ability of PFOA of Example 1, 3, 6 and Comparative Example 1;

[0024] Figure 4 A comparison point-line graph of the degradation ability of SMX of Example 3 and Comparative Example 1;

[0025] Figure 5 A comparison point-line graph of the degradation ability of COU of Example 3 and Comparative Example 1;

[0026] Figures 1-5 The ordinate is the ratio of the pollutant concentration in the pollutant solution at different reaction times and the initial concentration of the pollutant in the pollutant solution;

[0027] Figure 6 An XRD spectrum of the electrode material prepared by Example 3 and Comparative Example 1;

[0028] Figure 7 A Raman spectrum of the electrode material prepared by Example 3 and Comparative Example 1;

[0029] Figure 8 An XPS spectrum of the electrode material prepared by Example 3 and Comparative Example 1. DETAILED DESCRIPTION

[0030] The present application provides a preparation method of iodine corrosion Ti4O7 electrode material, comprising the following steps:

[0031] Mixing Ti4O7 powder, iodine and alcohol solution to obtain a mixed solution;

[0032] After removing the solvent from the mixed solution, sequentially performing iodine corrosion reaction and sintering to obtain the Ti4O7 electrode material.

[0033] The present application mixes Ti4O7 powder, iodine and alcohol solution to obtain a mixed solution. In the present application, the mixing preferably comprises the following steps:

[0034] Firstly mixing Ti4O7 powder and iodine to obtain a mixed powder;

[0035] Secondly mixing the mixed powder and alcohol solution to obtain a mixed solution.

[0036] The Ti4O7 powder and iodine are first mixed to obtain a mixed powder. In the present application, the average particle size of the Ti4O7 powder is preferably 100 nm to 1 μm, more preferably 300 to 800 nm; the average particle size of the iodine is preferably 0.5 to 2 mm, more preferably 1 to 1.5 mm. In the present application, the purity of the iodine is preferably ≥ 95%, more preferably 99 to 99.8%. In the present application, the mass percentage of iodine in the mixed powder is preferably 1 to 15%, more preferably 2 to 9%, and more preferably 3 to 7%.

[0037] In the present application, the first mixing is preferably carried out under ball milling, the rotation speed of the ball milling is preferably 1200 to 1500 r / min, more preferably 1250 to 1300 r / min; the time of the ball milling is preferably 15 to 25 min, more preferably 15 to 20 min.

[0038] After obtaining the mixed powder, the mixed powder and an alcohol solution are second mixed to obtain a mixed liquid. In the present application, the alcohol solution includes a methanol solution or an ethanol solution, more preferably a methanol solution. In the present application, the mass concentration of the alcohol solution is preferably ≥ 90%, more preferably 95 to 99.5%. In the present application, the mass of the mixed powder and the volume of the alcohol solution are preferably 1 g: 1.6 to 2 mL, more preferably 1 g: 1.7 to 1.8 mL.

[0039] In the present application, the second mixing is preferably carried out under ultrasonic condition, the power of the ultrasonic is preferably 220 to 260 W, more preferably 240 to 250 W; the frequency of the ultrasonic is preferably 35 to 45 kHz, more preferably 40 kHz; the time of the ultrasonic is preferably 30 min or more, more preferably 30 to 50 min. In the present application, the ultrasonic is preferably preceded by stirring; the stirring has no special requirement in the present application as long as it can mix uniformly. In the present application, the iodine is dissolved in the alcohol solution under the conditions of stirring and ultrasonic, which is conducive to the uniform mixing of iodine and Ti4O7.

[0040] After obtaining the mixed liquid, the mixed liquid is desolventized, and then subjected to iodine etching reaction and sintering in sequence to obtain the Ti4O7 electrode material. In the present application, the desolventization is preferably natural evaporation drying of the mixed liquid at room temperature. In the present application, the temperature of the room temperature is preferably 20 to 30 °C, more preferably 25 to 28 °C. The time of the evaporation drying has no special limitation in the present application as long as the alcohol solution can be removed. After the desolventization of the mixed liquid, the present application preferably includes grinding the solid obtained after the desolventization. The grinding has no special requirement in the present application and can be carried out by using conventional methods in the art.

[0041] In the present application, the temperature of the iodine etching reaction is preferably 80-110 DEG C, more preferably 100-110 DEG C; the time of the iodine etching reaction is preferably no less than 36 h, more preferably 36-40 h. In the present application, the iodine etching reaction is preferably carried out in a high-temperature reaction kettle.

[0042] In the present application, the sintering is preferably spark plasma sintering, the pressure of the spark plasma sintering is preferably 4-6 MPa, more preferably 5 MPa; the temperature of the spark plasma sintering is preferably 1000-1200 DEG C, more preferably 1050-1100 DEG C; the heating rate for heating to the temperature required for the spark plasma sintering is preferably 50-60 DEG C / min, more preferably 55 DEG C / min; the time of the spark plasma sintering is preferably 20-30 min, more preferably 20-25 min. In the present application, the sintering is preferably carried out in a mold, and the shape and size of the mold are preferably designed according to the shape and size required for the Ti4O7 electrode material. In the present application, the mold is preferably cylindrical, and the Ti4O7 electrode material is preferably in the shape of a round sheet.

[0043] In the present application, the sintering is preferably spark plasma sintering, the pressure of the spark plasma sintering is preferably 4-6 MPa, more preferably 5 MPa; the temperature of the spark plasma sintering is preferably 1000-1200 DEG C, more preferably 1050-1100 DEG C; the heating rate for heating to the temperature required for the spark plasma sintering is preferably 50-60 DEG C / min, more preferably 55 DEG C / min; the time of the spark plasma sintering is preferably 20-30 min, more preferably 20-25 min. In the present application, the sintering is preferably carried out in a mold, and the shape and size of the mold are preferably designed according to the shape and size required for the Ti4O7 electrode material. In the present application, the mold is preferably cylindrical, and the Ti4O7 electrode material is preferably in the shape of a round sheet.

[0044] The present application mixes Ti4O7 with iodine powder by ball milling, adds an alcohol solution, and dissolves the mixed iodine by ultrasonic oscillation, completely volatilizes the alcohol solution in the form of natural evaporation and drying at room temperature, and then puts the obtained powder into a high-pressure reaction kettle for reaction. Iodine sublimates under heating in the reaction kettle, and iodine vapor corrodes Ti4O7, causing changes in the surface structure of Ti4O7. Finally, discharge plasma sintering (SPS) is carried out to prepare iodine-etched Ti4O7 anodes. The present application changes the surface structure of Ti4O7 to produce defects, increases the surface oxygen vacancies, and increases the active sites on the electrode surface, thereby obtaining higher ·OH production. The preparation method provided by the present application can significantly improve the catalytic activity of Ti4O7 anodes, and is conducive to promoting the large-scale application of Ti4O7 in the remediation of polluted water bodies.

[0045] The present application also provides a Ti4O7 electrode material prepared by the preparation method according to the above technical solution, wherein the surface of the Ti4O7 electrode material contains oxygen vacancies, providing more defects.

[0046] The present application also provides the use of the Ti4O7 electrode material according to the above technical solution in the electrochemical oxidative degradation of perfluorinated compounds. In the present application, the Ti4O7 electrode material is used as an anode for the electrochemical oxidative degradation of perfluorinated compounds in wastewater.

[0047] In order to further illustrate the present application, the technical solutions provided by the present application are described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.

[0048] Example 1

[0049] The Ti4O7 powder 5.94 g and the iodine element with a purity of 99.8% 0.06 g were uniformly ball-milled to obtain a mixed powder with a mass fraction of iodine of 1%; the ball-milling speed was 1250 r / min, and the ball-milling time was 15 min;

[0050] The mixed powder and 10 mL of a methanol solution with a mass concentration of 99.5% were stirred and uniformly mixed, and then placed in an ultrasonic cleaning instrument to be ultrasonically treated at 240 W and 40 kHz for 30 min, and then naturally evaporated and dried in a fume hood;

[0051] The solid obtained after evaporative drying was ground into powder and then placed in a high-temperature reaction kettle to be iodine etched at 110℃ for 36 h, and then the product after iodine etching was subjected to spark plasma sintering, and then naturally cooled to 25℃ to obtain a Ti4O7 electrode material etched by iodine, which is denoted as Ti4O7-1%I; the pressure for spark plasma sintering was 5 MPa, the temperature was 1100℃, the heating rate was 55℃ / min, and the time was 20 min.

[0052] Examples 2-6

[0053] The Ti4O7 electrode material was prepared according to the method of Example 1, except that the specific composition of the mixed powder was different, and the specific conditions were referred to Table 1.

[0054] Table 1 Composition of the mixed powder of Examples 2-6

[0055]

[0056] Comparative Example 1

[0057] The Ti4O7 electrode material was prepared according to the method of Example 3, except that no iodine element was added, and the methanol solution was replaced by deionized water, and the specific conditions were as follows:

[0058] The 6 g Ti4O7 powder was ball-milled at a speed of 1250 r / min for 15 min, and then stirred and uniformly mixed with 10 mL of deionized water, and then placed in an ultrasonic cleaning instrument to be ultrasonically treated at 240 W and 40 kHz for 30 min, and then naturally evaporated and dried in a fume hood;

[0059] The solid obtained after evaporation drying was ground into powder and placed in a high-temperature reaction kettle at 110°C for 36h of heat preservation, and then spark plasma sintering was performed, and the product was naturally cooled to 25°C to obtain a Ti4O7 electrode material, denoted as Ti4O7. The pressure for spark plasma sintering was 5MPa, the temperature was 1100°C, the heating rate was 55°C / min, and the time was 20min.

[0060] Comparative Example 2

[0061] The Ti4O7 electrode material was prepared according to the method of Example 3, except that the methanol solution was replaced by deionized water, specifically as follows:

[0062] The Ti4O7 powder 5.82g and iodine element 0.18g were uniformly ball-milled to obtain a mixed powder with a mass fraction of 3% of iodine; the ball-milling speed was 1250r / min, and the ball-milling time was 15min.

[0063] The mixed powder and 10mL of deionized water were stirred and mixed uniformly, and then placed in an ultrasonic cleaning instrument under the conditions of 240W and 40kHz for 30min of ultrasonic treatment, and then naturally evaporated and dried in a fume hood.

[0064] The solid obtained after evaporation drying was ground into powder and placed in a high-temperature reaction kettle at 110°C for 36h of heat preservation, and then spark plasma sintering was performed, and the product was naturally cooled to 25°C to obtain a Ti4O7 electrode material, denoted as Ti4O7. The pressure for spark plasma sintering was 5MPa, the temperature was 1100°C, the heating rate was 55°C / min, and the time was 20min.

[0065] Comparative Example 3

[0066] The Ti4O7 electrode material was prepared according to the method of Example 3, except that no iodine element was added, specifically as follows:

[0067] The Ti4O7 powder 5.82g and iodine element 0.18g were uniformly ball-milled to obtain a mixed powder with a mass fraction of 3% of iodine; the ball-milling speed was 1250r / min, and the ball-milling time was 15min.

[0068] The solid obtained after evaporation drying was ground into powder and placed in a high-temperature reaction kettle at 110°C for 36h of heat preservation, and then spark plasma sintering was performed, and the product was naturally cooled to 25°C to obtain a Ti4O7 electrode material, denoted as Ti4O7. The pressure for spark plasma sintering was 5MPa, the temperature was 1100°C, the heating rate was 55°C / min, and the time was 20min.

[0069] The electrode materials prepared in Examples 1-6 and Comparative Examples 1-3 were subjected to performance detection according to the following method:

[0070] The electrode material prepared in Examples 1-6 and Comparative Examples 1-3 was used as an anode, two pieces of stainless steel electrode pieces were used as cathodes, and 50 mM / L sodium sulfate solution was used as an electrolyte. The anode was activated by applying current at a current density of 20 mA / cm 2 for 12 h. The stainless steel electrode was used as a cathode, and the activated anode was used to perform electrochemical oxidation experiments on different pollutant solutions at a current density of 20 mA / cm 2 for 120 min. The pollutant solutions were rhodamine B (RhB) solution with a concentration of 10 mg / L, coumarin (COU) solution with a concentration of 10 mg / L, tetracycline hydrochloride (TCH) solution with a concentration of 10 mg / L, perfluorooctanoic acid (PFOA) solution with a concentration of 10 mg / L, and sulfamethoxazole (SMX) solution with a concentration of 10 mg / L. During the electrochemical oxidation experiment, samples were taken every 10 min, and the samples were detected and the detection results were recorded. The results are shown in Table 2.

[0071] Table 2 Degradation rate of organic matter after electrochemical oxidation with different electrode materials as anodes

[0072]

[0073]

[0074] As can be seen from Table 2, the reaction of RhB and ·OH will cause the absorbance of the system to decrease. The absorbance of the solution can be measured by ultraviolet spectrophotometry, which can directly reflect the ability of the anode to oxidize and degrade RhB. COU and ·OH can freely react to generate hydroxyl coumarin, and the decrease rate of the concentration of COU can reflect the generation rate of ·OH, i.e., the ability to generate ·OH. The decrease rate of the concentrations of TCH, PFOA, and SMX can reflect the actual situation of the iodine-etched Ti4O7 electrode in oxidizing and degrading organic pollutants in the experiment. The degradation rate of organic matter is the ability of the anode to oxidize and degrade organic matter.

[0075] The degradation rates of RhB, COU, TCH, PFOA, and SMX in Table 2 can directly reflect the ability of the iodine-etched Ti4O7 electrode to generate ·OH, i.e., the greater the degradation rate, the stronger the ability to generate hydroxyl radicals. Compared with Comparative Examples 1-3, the ability of Example 1 to generate ·OH and degrade organic matter is significantly stronger than that of Comparative Examples 1-3, which fully demonstrates that the electrocatalytic activity of the anode prepared by the present application has been improved, and the ability to degrade organic pollutants is stronger than that of the original Ti4O7 anode.

[0076] As can be seen from Examples 1-6, adjusting the ratio of Ti4O7 powder to elemental I in the preparation method will significantly change the anode performance of the iodine-etched Ti4O7. Compared with Comparative Examples 1-3, the anode pollutant degradation performance of Examples 1-6 is higher than that of Comparative Examples 1-3. Therefore, using different contents of iodine to etch Ti4O7 will improve the anode performance of Ti4O7 to varying degrees. Within a wide range of Ti4O7 to iodine ratios, the anode performance of iodine-etched Ti4O7 can be improved, which fully demonstrates that the preparation method of the present invention can improve the electrocatalytic performance of Ti4O7 anodes.

[0077] Based on the detection results of the electrochemical oxidation experiment, the following plot was drawn. Figures 1-5 The vertical axis represents the ratio of the concentration of pollutants in the pollutant solution to the initial concentration of pollutants in the pollutant solution at different reaction times; Figures 1-5 In this context, k represents the first-order kinetic rate of degradation of the target pollutant, and R... 2 The coefficient represents the degree of curve fit; the closer it is to 1, the better the fit.

[0078] Figure 1 This is a line graph comparing the reaction rates of RhB (i.e., the ·OH production capacity) between Example 3 and Comparative Example 1. The figure shows the experimental results of adding methanol (MeOH) to quench the hydroxyl groups during the electrochemical degradation of RhB using Ti4O7-3%I as the anode material. It is clear from the graph that the degradation rate of RhB by the iodine-etched Ti4O7 anode (Ti4O7-3%I, Example 3) is significantly higher than that of the pure Ti4O7 electrode. More than 80% of the RhB was degraded after 1 hour of oxidation, exceeding twice the degradation rate of the pure Ti4O7 anode (Comparative Example 1). The degradation effect of Ti4O7-3%I-MeOH is far lower than that of Ti4O7-3%I and Ti4O7, indicating that ·OH plays a major role in the degradation process.

[0079] Figure 2 This is a line graph comparing the TCH degradation capabilities of Example 3 and Comparative Example 1. The degradation rate of TCH by the iodine-etched Ti4O7 anode is significantly better than that of the pure Ti4O7 anode. The TCH degradation rate in 1 hour is close to 1.5 times that of the pure Ti4O7 anode.

[0080] Figure 3 This is a line graph comparing the PFOA degradation capabilities of Examples 1, 3, and 6 with Comparative Example 1. The degradation rates of PFOA shown by Ti4O7 anodes etched with different iodine contents are not entirely the same, but they are all better than those of pure Ti4O7 anodes, indicating that the catalytic oxidation capability of iodine-etched Ti4O7 anodes is improved.

[0081] Figure 4is a comparison point-line graph of the degradation ability of SMX of Example 3 and Comparative Example 1, and the iodine-etched Ti4O7 anode has a stronger degradation ability of SMX than the pure Ti4O7 anode, and the average degradation rate in 1h is close to 1.7 times of the pure Ti4O7 anode;

[0082] Figure 5 is a comparison point-line graph of the reaction rate of Example 3 and Comparative Example 1 and COU, that is, the comparison of the ·OH production ability, and it can be seen from the graph that the ·OH production ability of the iodine-etched Ti4O7 anode is stronger than that of the pure Ti4O7 electrode, and the average rate of ·OH production is increased by about 1.3 times;

[0083] The electrode materials prepared in Example 3 and Comparative Example 1 are subjected to XRD detection, and the XRD graph is shown in Figure 6 It can be seen from Figure 6 that the diffraction peak intensity of the iodine-etched Ti4O7 and the pure Ti4O7 at different diffraction angles changes, indicating that the crystal lattice of the iodine-etched Ti4O7 changes compared with the pure Ti4O7;

[0084] The electrode materials prepared in Example 3 and Comparative Example 1 are subjected to Raman detection, and the Raman graph is shown in Figure 7 It can be seen from Figure 7 that the Raman graph of Example 3 and the Raman peak of Comparative Example 1 are shifted to the high wave number direction, and the half-height width of the Raman peak is widened, indicating that the spatial structure of the iodine-etched Ti4O7 changes compared with the original Ti4O7.

[0085] Figure 8 is the XPS spectrum of the electrode materials of Example 3 and Comparative Example 1, and it can be seen from Figure 8 that the C 1s peak of Comparative Example 1 appears at 295 and 297eV, which is due to the pollution of the material during preparation. The Ti 2p peak of Example 3 and Comparative Example 1 is consistent, indicating that the Ti of the electrode materials prepared in Example 3 and Comparative Example 1 does not change. In the O1s spectrum, the peak at 530.7eV of Comparative Example 1 corresponds to the lattice oxygen in Ti4O7, and the peak at 532.2eV corresponds to the adsorbed oxygen or oxygen vacancy. In the O1s spectrum of Example 3, the oxygen peak appears at 531.4eV compared with Comparative Example 1, indicating that the surface structure of the iodine-etched Ti4O7 changes, and the shift and combination of the oxygen peak are due to the appearance of more oxygen vacancies in the crystal structure.

[0086] The iodine-etched Ti4O7 electrode material obtained by the preparation method provided by the present application can change the surface structure of Ti4O7, greatly improve the reaction active site of the Ti4O7 anode, increase the ·OH production, and improve the catalytic degradation performance of the organic pollutants such as perfluorinated compounds, in addition, the manufacturing process of the iodine-etched Ti4O7 anode is simple, and the cost is low, so it is expected to be widely used in the treatment of sewage.

[0087] Although the above embodiments have been described in detail, they are only some embodiments of the present application, not all embodiments. Other embodiments can be obtained on the basis of the above embodiments without creativity, which are within the protection scope of the present application.

Claims

1. A method for preparing an iodine etched Ti407 electrode material, characterized in that, The method comprises the following steps: mixing Ti4O7 powder, iodine and an alcohol solution to obtain a mixed solution; removing the solvent from the mixed solution, and then sequentially performing iodine etching reaction and sintering to obtain the Ti4O7 electrode material.

2. The preparation method according to claim 1, characterized in that, The mixing comprises the following steps: first mixing Ti4O7 powder and iodine to obtain a mixed powder; second mixing the mixed powder and an alcohol solution to obtain a mixed solution.

3. The preparation method according to claim 2, characterized in that, The mass percentage of iodine in the mixed powder is 1-15%.

4. The preparation method according to claim 2, characterized in that, The first mixing is performed under ball milling, the rotation speed of the ball milling is 1200-1500 r / min, and the time is 15-25 min.

5. The preparation method according to claim 2, characterized in that, The mass concentration of the alcohol solution is ≥90%, and the mass of the mixed powder to the volume of the alcohol solution is 1g:0.6-0.8 mL. The second mixing is performed under ultrasonic condition, the power of the ultrasonic is 220-260 W, the frequency of the ultrasonic is 35-45 kHz, and the time of the ultrasonic is more than 30 min.

6. The method of claim 1 or 2, wherein the compound is prepared by the method of claim 1 or 2. The average particle size of the Ti4O7 powder is 100 nm-1 μm.

7. The method of claim 1 or 2, wherein the method is carried out at a temperature of from 20°C to 30°C. The temperature of the iodine etching reaction is 80-110 ℃, and the time of the iodine etching reaction is not less than 36 h.

8. The method of claim 1 or 2, wherein the method is carried out at a temperature of from 20°C to 30°C. The sintering is spark plasma sintering, the pressure of the spark plasma sintering is 4-6 MPa, the temperature of the spark plasma sintering is 1000-1200 ℃, the time of the spark plasma sintering is 20-30 min, and the heating rate for heating to the temperature required by the spark plasma sintering is 50-60 ℃ / min.

9. The Ti407 electrode material prepared according to the method of any one of claims 1 to 8, characterized in that The surface of the Ti4O7 electrode material contains oxygen vacancies.

10. Application of the Ti4O7 electrode material in claim 9 to electrochemical oxidative degradation of perfluorinated compounds in water.

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