Iron oxide homologous heterogeneous photoelectric self-fenton electrode material and preparation method and application thereof

Abstract

The application relates to an iron oxide homogenous phase photoelectric self-Fenton electrode material and a preparation method and application thereof. The self-Fenton electrode material comprises a carbon fiber cloth substrate and active alpha / beta-Fe2O3 homojunctions in-situ grown on the carbon fiber cloth, and the structure is expressed as alpha / beta-Fe2O3 / CC. The alpha / beta-Fe2O3 homojunctions are composed of alpha-Fe2O3 and beta-Fe2O3 two-phase composites. The alpha / beta-Fe2O3 / CC has oxygen vacancies. The preparation method is as follows: the pretreated carbon fiber cloth substrate is soaked in a previously prepared alpha / beta-Fe2O3 precursor solution and reacts, after the reaction is completed, FeOOH / CC is obtained through post-treatment; the FeOOH / CC is calcined, and alpha / beta-Fe2O3 / CC is obtained after cooling; the alpha / beta-Fe2O3 / CC can introduce oxygen vacancies through sodium borohydride aqueous solution reduction activation treatment. Compared with the prior art, the application can generate H2O2 in-situ, enhance the sustainable circulation of Fe 3+ Fe 2+ The application promotes the generation of hydroxyl radicals in the self-Fenton reaction, greatly improves the degradation reaction speed and efficiency of organic pollutants, especially antibiotics.

Description

Technical Field

[0001] This invention relates to the field of environmental pollution control technology, and in particular to a homogeneous and heterogeneous iron oxide photoelectric self-Fenton electrode material, its preparation method, and its application. Background Technology

[0002] Antibiotics play a vital role in clinical medicine, agriculture, and animal husbandry. Ibuprofen (IBF), oxytetracycline (OTC), and sulfamethoxazole (SD) antibiotics account for approximately 30.52% of antibiotic usage. In recent years, antibiotic contamination has garnered widespread global attention, posing significant risks to ecosystems and human health. Traditional physical, chemical, and biological treatment methods for antibiotics remain challenging due to their poor antibacterial and biodegradability.

[0003] The Fenton reaction, as a well-studied advanced oxidation process, has demonstrated impressive capabilities in degrading persistent organic pollutants due to its low operating cost, high mineralization efficiency, and controllable degradation kinetics. However, Fe... 2+ The addition of hydrogen peroxide can easily generate iron sludge, causing additional environmental problems. Furthermore, traditional Fenton reactions require the continuous consumption of large amounts of hydrogen peroxide, making transportation and storage another safety concern. From the perspectives of energy economy, sustainable development, and environmental protection, the self-Fenton reaction is an ideal choice for efficient oxygen production and green degradation of pollutants. In the self-Fenton reaction process, hydrogen peroxide can be generated in situ on the cathode surface via a direct two-electron pathway and rapidly converted by Fe. 2+ The base electrode is activated, thereby improving the utilization efficiency of the generated hydroxyl radicals.

[0004] Due to its high natural abundance, low cost, non-toxicity, and narrow band gap (1.9-2.1 eV), Fe₂O₃ has become one of the most widely used electrochemical catalysts. Furthermore, because of the empty d orbitals in the electronic structure of iron, it can form various unique chemisorption bonds with activated molecules, thereby lowering the activation energy barrier and enhancing electrocatalytic activity. And because of its low band gap, it can also effectively absorb sunlight, thus becoming one of the most promising photoelectrocatalytic materials.

[0005] Fe2O3 includes α-Fe2O3 and β-Fe2O3. Among them, α-Fe2O3, due to its narrow band gap (1.9-2.1 eV) and low cost, is often used in photo-Fenton systems to degrade dyes (such as RhB and MB) and antibiotics. For example, Chinese patent CN108212192A prepared a photo-Fenton catalyst, which was obtained by combining α-Fe2O3 and g-C3N4. At 30℃, pH=3, and an initial concentration of methyl orange of 10 mg / L, the prepared α-Fe2O3 / g-C3N4 composite photocatalyst material can achieve a degradation rate of over 96% for simulated methyl orange wastewater. However, it still requires the addition of exogenous H2O2 to initiate the Fenton reaction and is dependent on the control of temperature and pH. The degradation efficiency still needs to be improved. Summary of the Invention

[0006] The purpose of this invention is to provide a homogeneous and heterogeneous photoelectric self-Fenton electrode material of iron oxide, its preparation method and application. The prepared photoelectric self-Fenton electrode material realizes the self-circulation of the Fenton reaction and can be used for efficient degradation of antibiotics.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] One objective of this invention is to provide a homogeneous self-Fenton electrode material for iron oxide photoelectric applications, comprising a carbon fiber cloth matrix and an active α / β-Fe2O3 homojunction grown in situ on the carbon fiber cloth matrix, the structure of which is represented as α / β-Fe2O3 / CC.

[0009] Preferably, the α / β-Fe2O3 / CC has oxygen vacancies, which are introduced by reduction and activation treatment with sodium borohydride aqueous solution.

[0010] Preferably, the activated structure is represented as α / β-Fe2O 3-xR / CC, where x is 1 / 3 of the concentration of sodium borohydride aqueous solution, and the value of x ranges from 1 to 5.

[0011] More preferably, the structure of the self-Fenton electrode material is α / β-Fe2O 3-3R / CC, x = 3.

[0012] More preferably, α / β-Fe2O 3-xR In / CC, R represents the reduction and activation of α / β-Fe2O3 / CC by sodium borohydride aqueous solution.

[0013] More preferably, the α / β-Fe2O3 homojunction is composed of two phases, α-Fe2O3 and β-Fe2O3.

[0014] More preferably, in the α / β-Fe2O3 homojunction, the atomic ratio of α-Fe2O3 to β-Fe2O3 is (1-1.8):1.

[0015] More preferably, the atomic ratio of α-Fe2O3 to β-Fe2O3 is 1.31:1.

[0016] Preferably, the content of active α / β-Fe2O3 homojunctions grown in situ on the carbon fiber matrix is ​​10-20 wt%.

[0017] The second objective of this invention is to provide a method for preparing the aforementioned iron oxide homogeneous self-Fenton electrode material, comprising the following steps:

[0018] S1: Pretreatment of carbon fiber fabric matrix;

[0019] S2: Prepare α / β-Fe2O3 precursor solution;

[0020] S3: The pretreated carbon fiber fabric matrix obtained in step S1 is immersed in the α / β-Fe2O3 precursor solution obtained in step S2 and reacted. After the reaction is completed, FeOOH / CC is obtained through post-treatment.

[0021] S4: Calcine the FeOOH / CC obtained in step S3 and cool it to obtain α / β-Fe2O3 / CC.

[0022] Preferably, in step S1, the pretreatment includes the following steps: the carbon fiber cloth matrix is ​​ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 40-80 minutes each, then acid-washed in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for 10-14 hours, and dried at 80-120°C for 10-14 hours to obtain the pretreated carbon fiber cloth matrix.

[0023] More preferably, in step S1, the volume ratio of concentrated sulfuric acid to concentrated nitric acid in the mixed solution of concentrated sulfuric acid and concentrated nitric acid is 0.8-1.2:1, and even more preferably 1:1.

[0024] Preferably, in step S2, the preparation of the α / β-Fe₂O₃ precursor solution specifically includes the following steps: adding ferric chloride hexahydrate and sodium nitrate to deionized water, stirring to dissolve and obtain a mixed solution, then adding hydrochloric acid to adjust the pH of the mixed solution to 1-3, wherein, in the mixed solution, Fe 3+ The concentration is 0.05-0.15 mol / L.

[0025] More preferably, in step S2, the concentration of sodium nitrate in the mixed solution is 0.5 mol / L-1.5 mol / L.

[0026] Preferably, in step S3, the reaction temperature is 110-130℃ and the reaction time is 12-14h.

[0027] More preferably, in step S3, the pretreated carbon fiber matrix obtained in step S1 needs to be completely immersed in the α / β-Fe2O3 precursor solution obtained in step S2.

[0028] More preferably, in step S3, the post-treatment refers to washing and drying the carbon fiber cloth matrix after the reaction to obtain FeOOH / CC.

[0029] Preferably, in step S4, the calcination is carried out in a mixed atmosphere containing N2 and H2, the gas flow rate of the mixed atmosphere is 900-1100 sccm, the gas volume ratio of N2 and H2 is (96-98):(2-4), the calcination temperature is 400-600℃, the calcination time is 1-4 hours, and the calcination heating rate is 2℃ / min-5℃ / min.

[0030] Preferably, the method further includes step S5: immersing the α / β-Fe₂O₃ / CC obtained in step S4 in an aqueous sodium borohydride solution for reduction and activation, to obtain the α / β-Fe₂O₃ / CC. 3-xR / CC, wherein the concentration of the sodium borohydride aqueous solution is 1-10 mol / L, and the soaking time is 2-4 h.

[0031] More preferably, in step S5, after the soaking, reduction, and activation are completed, the carbon fiber cloth matrix is ​​removed, rinsed with deionized water, and vacuum dried at 50-70°C to obtain the α / β-Fe2O. 3-xR / CC.

[0032] More preferably, the preparation method of the iron oxide homogeneous self-Fenton electrode material includes the following steps:

[0033] (1) Pretreatment of CC (carbon fiber cloth) matrix electrode: The carbon fiber cloth was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then the carbon cloth (carbon fiber cloth) was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a 100°C drying oven for 12 hours to obtain the pretreated CC.

[0034] (2) Add ferric chloride hexahydrate and sodium nitrate to deionized water and stir until completely dissolved to obtain Fe. 3+A clear and transparent solution with a concentration of 0.1 mol / L was prepared by adding hydrochloric acid to adjust the pH value of the solution to 1.9. The pretreated CC obtained in (1) was transferred to a hydrothermal reactor and reacted at 110-130 degrees Celsius for 12-14 hours. The resulting carbon cloth was washed and dried to obtain FeOOH / CC.

[0035] (3) Construction of α / β-Fe2O3 homogeneous structure: The FeOOH / CC obtained in (2) was calcined in a tube furnace at 400-600 degrees Celsius for 1-4 hours under a mixed gas atmosphere of nitrogen and H2 (gas flow rate 1000 sccm, nitrogen / hydrogen ratio 97:3) and then cooled to room temperature to obtain α / β-Fe2O3 / CC.

[0036] (4) Activation of α / β-Fe2O3 homojunction: The α / β-Fe2O3 / CC obtained in (3) was immersed in a sodium borohydride aqueous solution with a concentration range of 1-10 mol / L for 3 hours to obtain highly active α / β-Fe2O3 homojunction. 3-xR / CC (x represents 1 / 3 of the concentration of sodium borohydride aqueous solution).

[0037] The third objective of this invention is to provide an application of the aforementioned iron oxide homogeneous self-Fenton electrode material in the degradation of organic pollutants.

[0038] Preferably, the organic pollutant includes antibiotics, and the iron oxide homogeneous photoelectric self-Fenton electrode material can be used for antibiotic degradation.

[0039] More preferably, the antibiotics include ibuprofen (IBF), oxytetracycline (OTC), and sulfamethoxazole (SD).

[0040] Preferably, the photoelectric self-Fenton electrode material is used for antibiotic degradation, specifically including the following steps:

[0041] a: Using KOH aqueous solution as the electrolyte solution, add the antibiotic to be degraded and continuously purify the solution with oxygen.

[0042] b: Using the photoelectric self-Fenton electrode as the working electrode and the counter electrode, and the Hg / HgO electrode as the reference electrode, the electrodes are placed in an electrolyte solution.

[0043] c: Apply voltage to both the working electrode and the counter electrode, and simultaneously apply light to excite the photoelectric Fenton effect, thereby performing photoelectrocatalytic degradation of antibiotics. The supernatant is then removed at regular intervals.

[0044] d: Immediately analyze the supernatant obtained from the sample using a UV-Vis spectrometer (Agilent Cary 5000) to determine the concentration of the antibiotics after degradation at different time points.

[0045] Preferably, the concentration of the KOH aqueous solution is 0.05-0.15M, and more preferably 0.1M.

[0046] Preferably, the concentration of the antibiotic to be degraded in the electrolyte solution is 8-12 mg / L, more preferably 10 mg / L.

[0047] Preferably, the working area of ​​the photoelectric self-Fenton electrode is 1 cm². 2 .

[0048] Preferably, the applied voltage is 0.1-1V, more preferably 0.5V.

[0049] Preferably, the light source used to apply the illumination is a deuterium lamp with a wavelength of 200-800nm.

[0050] Studies have shown that α-Fe₂O₃ possesses high stability and a wide band gap, while β-Fe₂O₃ exhibits higher light absorption and catalytic activity due to its smaller band gap (1.9 eV) and longer light absorption band edge (up to 650 nm). However, β-Fe₂O₃ is a pressure-stable phase, prone to phase transitions in practical applications, leading to insufficient stability. Therefore, improving its pressure stability is crucial for its large-scale application. However, single-phase materials often struggle to balance stability and activity.

[0051] This invention provides an iron oxide homogeneous photoelectric self-Fenton electrode material for degrading antibiotics, with a structure of α / β-Fe₂O₃ / CC. This material is an active α / β-Fe₂O₃ homojunction grown in situ on carbon cloth. This α / β-Fe₂O₃ homojunction is composed of two phases, α-Fe₂O₃ and β-Fe₂O₃, combining the advantages of both phases while exhibiting high stability and light absorption. Furthermore, α / β-Fe₂O₃ / CC can be further activated by reduction with sodium borohydride to obtain α / β-Fe₂O₃ with abundant oxygen vacancies. 3-3R / CC. This invention combines advantageous band alignment and oxygen vacancy engineering to generate H2O2 under low voltage and visible light irradiation, achieving a self-circulating Fenton reaction and accelerating the degradation of antibiotics.

[0052] This invention provides an optimal ratio between the atomic ratios of α and β phases. Heating at 500°C for 1 h, 2 h, and 4 h yielded atomic ratios of 1.73, 1.31, and 1.06 for α-Fe₂O₃ and β-Fe₂O₃, respectively. In α / β-Fe₂O₃ homojunction materials, the atomic ratio of the α and β phases significantly affects the catalytic performance of the material. An atomic ratio of 1.31:1 for α-Fe₂O₃ / β-Fe₂O₃ exhibits optimal catalytic degradation performance. Furthermore, this ratio of α / β-Fe₂O₃... 3-3RFurthermore, it can more efficiently generate H2O2 in situ during the Fenton reaction, further enhancing its ability to degrade organic pollutants. Therefore, controlling the atomic ratio of the α to β phases to an intermediate value is an ideal strategy for achieving efficient catalytic degradation. This invention, by studying the relationship between the atomic ratio of α-Fe2O3 / β-Fe2O3 and its catalytic performance, determined that the best catalytic effect is obtained when the ratio is 1.31.

[0053] This invention also provides an optimal concentration of oxygen vacancies for the catalytic reaction. The concentration of oxygen vacancies is controlled by adjusting the concentration of sodium borohydride solution (NaBH4), and the optimal concentration is determined by comparing the catalytic effects. When x = 3, after activation treatment, α / β-Fe2O 3-3R / CC further enhances the degradation rate of antibiotics. This self-derived α / β-Fe2O 3-3R The / CC homojunction combines favorable band alignment and oxygen vacancy engineering, through its interaction with the O2 adsorption energy (E) of α-Fe2O3. a A comparison of the adsorption energy E of α / β-Fe₂O₃ for O₂ (=0.022 eV) revealed that the adsorption energy E of α / β-Fe₂O₃ for O₂ is... a = -0.15 eV, while α / β-Fe2O after activation and introduction of oxygen vacancies 3-3R Homojunctions exhibit a larger negative adsorption energy E a = -0.47eV, indicating that it has a stronger adsorption capacity for oxygen.

[0054] This invention provides a self-derived homojunction material with an iron oxide heterostructure, which significantly improves electron transport efficiency. It achieves efficient self-Fenton reaction by inducing in-situ H2O2 generation through an oxygen reduction reaction. This material system not only generates H2O2 in-situ through photocatalysis but also through Fe... 3+ To Fe 2+ The sustainable cycle promotes the continuous generation of hydroxyl radicals (·OH), thereby significantly improving the degradation efficiency of antibiotics. This design overcomes the limitations of traditional Fenton reactions, which rely on external H2O2 addition and iron sludge formation, achieving green, efficient, and sustainable antibiotic degradation. The main reaction mechanism is as follows: Figure 15 As shown, the details are as follows:

[0055] O2 + 2H2O + 2e - +α / β-Fe2O 3-3R →H₂O₂ + 2OH⁻ - (Eq.1)

[0056] α / β-Fe2O 3-3R +hν→α / β-Fe2O 3-3R (h + +e -(Eq.2)

[0057] Fe 3+ +e - (α / β-Fe2O 3-3R )→Fe 2+ (Eq.3)

[0058] Fe 2+ +H₂O₂→Fe 3+ +OH - +·OH (Eq.4)

[0059] Fe 3+ +H₂O₂→Fe 2+ +·OOH+H + (Eq.5)

[0060] H2O2+e - (α / β-Fe2O 3-3R )→OH - +·OH (Eq.6)

[0061] O2+e - (α / β-Fe2O 3-3R → O2 - (Eq.7)

[0062] ·OH+H + +·O2 - +Organic pollutants→CO2+H2O+others (Eq.8)

[0063] This invention synergistically improves H2O2 production through the combined effects of light, oxygen vacancies, and a robust homogeneous interface, thereby enhancing the completion of the spontaneous Fenton reaction. The H2O2 yield reaches as high as 3.51 mmol / g·h under relatively low voltage (0.5V) and visible light irradiation. The in-situ generated H2O2 directly acts as an oxidant, accelerating the subsequent degradation of antibiotics in the Fenton reaction.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] (1) This invention provides an iron oxide homogeneous photoelectric self-Fenton electrode material by growing α / β-Fe2O3 homojunction in situ on carbon cloth. The α / β-Fe2O3 homojunction is composed of two phases, α-Fe2O3 and β-Fe2O3. The electrode material prepared can generate H2O2 in situ, realize the self-circulation of Fenton reaction, and be used for efficient degradation of antibiotics.

[0066] (2) This invention, through advantageous band arrangement combined with oxygen vacancy engineering, can generate high-yield H2O2 under low voltage and visible light irradiation. Specifically, this invention can generate 3.51 mmol / g·h of H2O2 under a low voltage of 0.5V and visible light irradiation. It realizes the self-circulation of the Fenton reaction, achieves in-situ regeneration of Fe3+, reduces H2O2 dependence, and enables the green degradation of antibiotics.

[0067] (3) Based on a band structure strategy, this invention constructs an α / β-Fe₂O₃ homojunction, solving the problems of wide band structure and narrow light absorption range of single α-Fe₂O₃, and low stability of single β-Fe₂O₃. Furthermore, the catalytic performance of the material can be adjusted by modifying the atomic (phase) ratio of the α and β phases, thus obtaining the desired α / β-Fe₂O₃ homojunction. 3-3R It also exhibits high stability and activity.

[0068] (4) This invention introduces oxygen vacancies through the reduction and activation of sodium borohydride. Using the sodium borohydride reduction method, oxygen vacancies are directionally introduced onto the α / β-Fe2O3 surface to prepare α / β-Fe2O3. 3-xR Furthermore, the concentration of oxygen vacancies can be controlled by adjusting the concentration of the sodium borohydride solution (NaBH4) to prepare α / β-Fe2O3. 3-3R Homojunctions have a larger oxygen adsorption energy (Ea = -0.47 eV), which is more conducive to enhancing the cycle efficiency of Fe3+→Fe2+.

[0069] (5) This invention can achieve highly efficient degradation of organic pollutants, especially antibiotics, without the need to introduce exogenous H2O2, and is independent of temperature and pH regulation. When α / β-Fe2O 3-3R / CC is used as the working electrode. When oxytetracycline is degraded at room temperature, the degradation rate can reach 98.5% within 90 minutes, demonstrating a strong antibiotic degradation ability. Attached Figure Description

[0070] Figure 1 The α / β-Fe2O prepared in Example 5 3-3R TEM images of / CC, including (a) transmission electron microscopy (TEM) image and (b) high-resolution transmission electron microscopy (TEM) image.

[0071] Figure 2 α / β-Fe2O in Example 5 3-3R XRD spectra of / CC, α / β-Fe2O3 / CC in Example 2, α-Fe2O3 / CC in Comparative Example 1, and β-Fe2O3 / CC in Comparative Example 2.

[0072] Figure 3X-ray diffraction patterns (a) and atomic ratios (b) of α / β-Fe2O3 / CC prepared in Examples 1-3 at different calcination times are shown.

[0073] Figure 4-6 The graphs show the degradation efficiency of α / β-Fe2O3 / CC prepared in Examples 1-3 for different calcination times on different antibiotics under light and no light.

[0074] Figure 7-9 The α / β-Fe2O prepared in Examples 4-6 are respectively 3-R / CC、α / β-Fe2O 3-3R / CC、α / β-Fe2O 3-5R Degradation efficiency of α / β-Fe2O3 / CC prepared in Example 2 for different antibiotics under light irradiation.

[0075] Figure 10 and Figure 11 The figures show the degradation of IBF, OTC, and SD by α-Fe2O3 / CC in Comparative Example 1 and β-Fe2O3 / CC in Comparative Example 2 under light and non-light conditions, respectively.

[0076] Figure 12 The graph shows the H2O2 production rate of Example 5 under different applied voltages and with or without light.

[0077] Figure 13 α / β-Fe2O prepared in Example 5 3-3R ESR graph of / CC.

[0078] Figure 14 This is the photoelectron transfer model of the α / β-Fe2O3 homojunction of the present invention.

[0079] Figure 15 This is a schematic diagram illustrating the mechanism by which the present invention degrades antibiotics. Detailed Implementation

[0080] This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiment.

[0081] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0082] A homogeneous self-Fenton electrode material for iron oxide photoelectric applications includes a carbon fiber cloth matrix and an active α / β-Fe2O3 homojunction grown in situ on the carbon fiber cloth matrix. Its structure is represented as α / β-Fe2O3 / CC, wherein the α / β-Fe2O3 homojunction is composed of two phases, α-Fe2O3 and β-Fe2O3.

[0083] The α / β-Fe₂O₃ / CC also possesses oxygen vacancies, which are introduced through reduction and activation treatment with sodium borohydride aqueous solution. The activated structure is represented as α / β-Fe₂O₃. 3-xR / CC, where x is 1 / 3 of the concentration of sodium borohydride aqueous solution, and the value of x ranges from 1 to 5.

[0084] The aforementioned iron oxide homogeneous self-Fenton electrode material is obtained through the following preparation method:

[0085] S1: Pretreatment of carbon fiber fabric matrix;

[0086] S2: Prepare α / β-Fe2O3 precursor solution;

[0087] S3: The pretreated carbon fiber fabric matrix obtained in step S1 is immersed in the α / β-Fe2O3 precursor solution obtained in step S2 and reacted. After the reaction is completed, FeOOH / CC is obtained through post-treatment.

[0088] S4: Calcine the FeOOH / CC obtained in step S3 and cool it to obtain α / β-Fe2O3 / CC.

[0089] S5: The α / β-Fe2O3 / CC obtained in step S4 is immersed in an aqueous solution of sodium borohydride for reduction and activation to obtain the α / β-Fe2O3 / CC. 3-xR / CC, wherein the concentration of the sodium borohydride aqueous solution is 1-10 mol / L, and the soaking time is 2-4 h.

[0090] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0091] Table 1. Preparation parameters of Examples 1-6 and Comparative Examples 1-2

[0092]

[0093] Examples 1-6 and Comparative Examples 1-2 were prepared according to the parameters in Table 1, as detailed below:

[0094] Example 1

[0095] (1) Carbon fiber cloth (CC) was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then, the carbon cloth was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours to obtain CC.

[0096] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing solution is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0097] (3) The dried precursor was placed in a tube furnace and heated to 500°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 1 hour. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black α / β-Fe2O3 coating on the surface.

[0098] (4) The prepared self-supporting electrode material α / β-Fe2O3 / CC was used for antibiotic degradation. A three-electrode system was adopted, and the tests were performed using an Autolab PGSTAT302N electrochemical workstation. The α / β-Fe2O3 / CC electrode served as both the counter electrode and the working electrode, while the Hg / HgO electrode was used as the reference electrode. The working area of ​​α / β-Fe2O3 / CC as the working electrode was approximately 1 cm². 2 Oxygen was continuously bubbled into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, to degrade OTC, IBF, and SD via photoelectrocatalytic reactions. The degradation efficiency was then tested. (Applied voltage: 0.5V; Light source: deuterium; wavelength: 200-800 nm)

[0099] Example 2

[0100] (1) Carbon fiber cloth (CC) was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then, the carbon cloth was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours to obtain CC.

[0101] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing liquid is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0102] (3) The dried precursor was placed in a tube furnace and heated to 500°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 2 hours. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black α / β-Fe2O3 coating on the surface.

[0103] (4) The prepared self-supporting electrode material α / β-Fe2O3 / CC was used for antibiotic degradation. A three-electrode system was adopted, and the tests were performed using an Autolab PGSTAT302N electrochemical workstation. The α / β-Fe2O3 / CC electrode served as both the counter electrode and the working electrode, while the Hg / HgO electrode was used as the reference electrode. The working area of ​​α / β-Fe2O3 / CC as the working electrode was approximately 1 cm². 2 Oxygen was continuously bubbled into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, to degrade OTC, IBF, and SD via photoelectrocatalytic reactions. The degradation efficiency was then tested. (Applied voltage: 0.5V; Light source: deuterium; wavelength: 200-800 nm)

[0104] Example 3

[0105] (1) Carbon fiber cloth (CC) was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then, the carbon cloth was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours to obtain CC.

[0106] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing solution is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0107] (3) The dried precursor was placed in a tube furnace and heated to 500°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 4 hours. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black α / β-Fe2O3 coating on the surface.

[0108] (4) The prepared self-supporting electrode material α / β-Fe2O3 / CC was used for antibiotic degradation. A three-electrode system was adopted, and the tests were performed using an Autolab PGSTAT302N electrochemical workstation. The α / β-Fe2O3 / CC electrode served as both the counter electrode and the working electrode, while the Hg / HgO electrode was used as the reference electrode. The working area of ​​α / β-Fe2O3 / CC as the working electrode was approximately 1 cm². 2 Oxygen was continuously bubbled into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, to degrade OTC, IBF, and SD via photoelectrocatalytic reactions. The degradation efficiency was then tested. (Applied voltage: 0.5V; Light source: deuterium; wavelength: 200-800 nm)

[0109] Example 4: α / β-Fe2O 3-R / CC:

[0110] (1) Carbon fiber cloth (CC) was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then, the carbon cloth was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours to obtain CC.

[0111] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing liquid is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0112] (3) The dried precursor was placed in a tube furnace and heated to 500°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 2 hours. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black α / β-Fe2O3 coating on the surface.

[0113] (4) The carbon cloth with α / β-Fe₂O₃ grown on it was immersed in a 3M sodium borohydride solution for 3 hours for activation. After activation, the carbon cloth was removed, rinsed with deionized water, and vacuum dried at 60°C to obtain the target product α / β-Fe₂O₃. 3-R / CC.

[0114] (5) The prepared self-supporting electrode material α / β-Fe2O 3-R / CC was used for antibiotic degradation, employing a three-electrode system and tested using an Autolab PGSTAT302N electrochemical workstation, where α / β-Fe2O 3-R The / CC electrodes are the counter electrode and working electrode, respectively, and the Hg / HgO electrode is the reference electrode. α / β-Fe2O 3-R The working area of ​​ / CC when used as a working electrode is approximately 1cm². 2 Oxygen was continuously bubbled into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, to degrade OTC, IBF, and SD via photoelectrocatalytic reactions. The degradation efficiency was then tested. (Applied voltage: 0.5V; Light source: deuterium; wavelength: 200-800 nm)

[0115] Example 5: α / β-Fe2O 3-3R / CC

[0116] (1) Carbon fiber cloth (CC) was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then, the carbon cloth was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours to obtain CC.

[0117] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing liquid is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0118] (3) The dried precursor was placed in a tube furnace and heated to 500°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 2 hours. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black α / β-Fe2O3 coating on the surface.

[0119] (4) The carbon cloth with α / β-Fe₂O₃ grown on it was immersed in a 9M sodium borohydride solution for 3 hours for activation. After activation, the carbon cloth was removed, rinsed with deionized water, and vacuum dried at 60°C to obtain the target product α / β-Fe₂O₃. 3-3R / CC.

[0120] (5) The prepared self-supporting electrode material α / β-Fe2O 3-3R / CC was used for antibiotic degradation, employing a three-electrode system and tested using an Autolab PGSTAT302N electrochemical workstation, where α / β-Fe2O 3-3R The / CC electrodes are the counter electrode and working electrode, respectively, and the Hg / HgO electrode is the reference electrode. α / β-Fe2O 3-3R The working area of ​​ / CC when used as a working electrode is approximately 1cm². 2 Oxygen was continuously bubbled into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, to degrade OTC, IBF, and SD via photoelectrocatalytic reactions. The degradation efficiency was then tested. (Applied voltage: 0.5V; Light source: deuterium; wavelength: 200-800 nm)

[0121] Example 6: α / β-Fe2O 3-5R / CC

[0122] (1) After ultrasonic cleaning of carbon fiber cloth (CC) in acetone, anhydrous ethanol and deionized water for 60 minutes each, the carbon cloth was then acid-washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours. The resulting CC was then placed in a vacuum drying oven and dried at 60℃ for later use.

[0123] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing liquid is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0124] (3) The dried precursor was placed in a tube furnace and heated to 500°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 2 hours. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black α / β-Fe2O3 coating on the surface.

[0125] (4) The carbon cloth with α / β-Fe₂O₃ grown on it was immersed in a 15M sodium borohydride solution for 3 hours for activation. After activation, the carbon cloth was removed, rinsed with deionized water, and vacuum dried at 60°C to obtain the target product α / β-Fe₂O₃. 3-5R / CC.

[0126] (5) The prepared self-supporting electrode material α / β-Fe2O 3-5R / CC was used for antibiotic degradation, employing a three-electrode system and tested using an Autolab PGSTAT302N electrochemical workstation, where α / β-Fe2O 3-5R The / CC electrodes are the counter electrode and working electrode, respectively, and the Hg / HgO electrode is the reference electrode. α / β-Fe2O 3-5R The working area of ​​ / CC when used as a working electrode is approximately 1cm². 2 Oxygen was continuously bubbled into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, to degrade OTC, IBF, and SD via photoelectrocatalytic reactions. The degradation efficiency was then tested. (Applied voltage: 0.5V; Light source: deuterium; wavelength: 200-800 nm)

[0127] Comparative Example 1: α-Fe2O3 / CC

[0128] The preparation method is as follows:

[0129] (1) Carbon fiber cloth (CC) was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then, the carbon cloth was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours to obtain CC.

[0130] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing solution is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0131] (3) The dried precursor was placed in a tube furnace and heated to 400°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 2 hours. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black α-Fe2O3 coating on the surface.

[0132] (4) The prepared self-supporting electrode material α-Fe2O3 / CC was used for antibiotic degradation. A three-electrode system was adopted, and the tests were performed using an Autolab PGSTAT302N electrochemical workstation. The α-Fe2O3 / CC electrode served as both the counter electrode and the working electrode, while the Hg / HgO electrode was used as the reference electrode. The working area of ​​α-Fe2O3 / CC as the working electrode was approximately 1 cm². 2 Oxygen was continuously bubbled into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, to degrade OTC, IBF, and SD via photoelectrocatalytic reactions. The degradation efficiency was then tested. (Applied voltage: 0.5V; Light source: deuterium; wavelength: 200-800 nm)

[0133] Comparative Example 2: β-Fe2O3 / CC

[0134] The preparation method is as follows:

[0135] (1) Carbon fiber cloth (CC) was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 60 minutes each. Then, the carbon cloth was acid washed in concentrated sulfuric acid: concentrated nitric acid = 1:1 for 12 hours and dried in a drying oven at 100℃ for 12 hours to obtain CC.

[0136] (2) Weigh 0.973 g of ferric chloride hexahydrate and 5.099 g of sodium nitrate, add them to 60 mL of deionized water, and stir until completely dissolved to obtain a clear and transparent solution. Add 150 μL of hydrochloric acid to the solution to adjust the pH to 1.9, and immerse the pretreated carbon cloth in the solution, ensuring complete immersion. Transfer the mixed solution and carbon cloth to a high-pressure reactor, seal it, and place it in an oven for hydrothermal reaction at 100 °C for 12 hours. After the reaction, remove the carbon cloth and wash it repeatedly with deionized water until the washing liquid is colorless and transparent. Place the washed carbon cloth in a vacuum drying oven and dry it at 60 °C to obtain the FeOOH / CC precursor.

[0137] (3) The dried precursor was placed in a tube furnace and heated to 600°C at a heating rate of 5°C / min under a mixed gas atmosphere (gas flow rate 1000 sccm, nitrogen / hydrogen volume ratio 97:3), and held for 2 hours. After calcination, it was naturally cooled to room temperature to obtain carbon cloth with a black β-Fe2O3 surface.

[0138] (4) The prepared self-supporting electrode material β-Fe2O3 / CC was used for antibiotic degradation. A three-electrode system was adopted, and the tests were performed using an Autolab PGSTAT302N electrochemical workstation. The β-Fe2O3 / CC electrode served as both the counter electrode and the working electrode, while the Hg / HgO electrode was used as the reference electrode. The working area of ​​β-Fe2O3 / CC as the working electrode was approximately 1 cm². 2 Oxygen was continuously introduced into 0.1M KOH electrolyte solutions containing 10 mg / L of OTC, IBF, and SD, respectively, and the degradation of OTC, IBF, and SD was carried out through photoelectrocatalytic reaction. The degradation effect was then tested.

[0139] Figure 1 The α / β-Fe2O prepared in Example 5 3-3R TEM images and lattice fringe analysis revealed two distinct lattice spacings: 0.36 nm and 0.27 nm, clearly observed by high-resolution TEM (HRTEM). These correspond to the (012) crystal plane of α-Fe₂O₃ (JCPDS No. 33-0664) and the (222) crystal plane of β-Fe₂O₃ (JCPDS No. 39-0238), respectively. The coherent interface between the two phases indicates the successful construction of the α / β-Fe₂O₃ homojunction.

[0140] Figure 2 α / β-Fe2O in Example 5 3-3R The XRD spectra of α / β-Fe₂O₃ / CC in Example 2, α-Fe₂O₃ / CC in Comparative Example 1, and β-Fe₂O₃ / CC in Comparative Example 2 show that the prepared α / β-Fe₂O₃ / CC...3-3R Both α / β-Fe2O3 / CC and α / β-Fe2O3 / CC exhibit XRD characteristic peaks of the α and β phases, indicating that the α / β-Fe2O3 homojunction was successfully prepared.

[0141] Figure 3 The X-ray diffraction patterns and atomic ratios of α / β-Fe₂O₃ / CC prepared in Examples 1-3 at different calcination times are shown in the figures. It can be seen from the figures that α-Fe₂O₃ gradually transforms into β-Fe₂O₃ with increasing calcination time. Calcination at 500℃ for 1 h, 2 h, and 4 h yielded atomic ratios of 1.73, 1.31, and 1.06 for α-Fe₂O₃ and β-Fe₂O₃, respectively.

[0142] Figure 4-6 The graphs show the degradation efficiencies of α / β-Fe₂O₃ / CC prepared in Examples 1-3 for different calcination times against different antibiotics under both light and dark conditions. The comparison reveals that, except for the α / β-Fe₂O₃ / CC prepared with a calcination time of 4 hours, the degradation efficiencies of the other materials under light catalysis are greater than those without light, demonstrating the superiority of the photoelectro-Fenton reaction. The graphs also show that a calcination time of 2 hours, i.e., an atomic ratio of α-Fe₂O₃ to β-Fe₂O₃ of 1.31, yields the optimal catalytic degradation performance.

[0143] Figure 7-9 The α / β-Fe2O prepared in Examples 4-6 are respectively 3-R / CC、α / β-Fe2O 3-3R / CC、α / β-Fe2O 3-5R The degradation efficiency of α / β-Fe₂O₃ / CC prepared in Example 2 against different antibiotics under light irradiation is shown in the graph. The comparison reveals that α / β-Fe₂O₃ / CC prepared by activation and reduction with sodium borohydride introduces oxygen vacancies. 3-xR The catalytic degradation performance of α / β-Fe₂O₃ / CC is greater than that of α / β-Fe₂O₃ / CC without oxygen vacancies, where x=3, i.e., α / β-Fe₂O₃ / CC. 3-3R / CC exhibits optimal catalytic degradation performance. When used for the degradation of oxytetracycline (OTC), it achieves a degradation rate of 98.5% within 90 minutes.

[0144] Figure 10 and Figure 11 The graphs show the degradation efficiency of α-Fe₂O₃ / CC in Comparative Example 1 and β-Fe₂O₃ / CC in Comparative Example 2 for IBF, OTC, and SD under both light and non-light conditions. As can be seen from the graphs, their degradation efficiency is far lower than that of α / β-Fe₂O₃ / CC and α / β-Fe₂O₃ / CC in this invention. 3-xR / CC.

[0145] Figure 12The graph shows the H2O2 production rate of Example 5 under different applied voltages and with and without light irradiation. As can be seen from the graph, compared to the electro-Fenton reaction alone, the photo-Fenton reaction, in conjunction with the electro-Fenton reaction, further enhances the H2O2 production rate under visible light irradiation. Under visible light irradiation and the optimal applied voltage of 0.5V, 3.51 mmol / g·h of H2O2 can be produced. This indicates that the present invention can achieve self-circulation of the Fenton reaction, realize in-situ regeneration of Fe3+, reduce H2O2 dependence, and achieve green degradation of antibiotics.

[0146] Figure 13 α / β-Fe2O prepared in Example 5 3-3R The ESR plot of / CC shows that ·OH and h + The characteristic signal is stronger, while ·O 2- The peak values ​​are relatively weak. Taking the degradation of IBF as an example, this result indicates that during the catalytic process, ·OH and h + It will preferentially attack the O sites of IBF and play a major catalytic degradation role.

[0147] Figure 14 The photoelectron transfer model of the α / β-Fe₂O₃ homojunction in this invention is shown in the figure. As can be seen, electrons transfer from β-Fe₂O₃ to α-Fe₂O₃, resulting in the accumulation of positive charges in the β-Fe₂O₃ portion and negative charges on the α-Fe₂O₃ side, thus widening the B-IEF of α-Fe₂O₃. This widening of the B-IEF indicates an increased driving force for charge transfer, accelerating the charge transfer rate and promoting the faster generation of ·OH, thereby accelerating the self-Fenton reaction and improving the efficiency of antibiotic degradation.

[0148] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A homogeneous and heterogeneous self-Fenton electrode material for iron oxide photoelectric applications, characterized in that, It includes a carbon fiber fabric matrix and an active α / β-Fe2O3 homojunction grown in situ on the carbon fiber fabric matrix, the structure of which is represented as α / β-Fe2O3 / CC; The α / β-Fe2O3 / CC has oxygen vacancies, which are introduced by reduction and activation treatment with sodium borohydride aqueous solution; The preparation method includes the following steps: S1: Pretreatment of carbon fiber fabric matrix; S2: Prepare α / β-Fe2O3 precursor solution; S3: The pretreated carbon fiber fabric matrix obtained in step S1 is immersed in the α / β-Fe2O3 precursor solution obtained in step S2 and reacted. After the reaction is completed, FeOOH / CC is obtained through post-treatment. S4: Calcine the FeOOH / CC obtained in step S3 and cool it to obtain α / β-Fe2O3 / CC; In step S2, the preparation of the α / β-Fe2O3 precursor solution specifically includes the following steps: adding ferric chloride hexahydrate and sodium nitrate to deionized water, stirring to dissolve and obtain a mixed solution, and then adding hydrochloric acid to adjust the pH of the mixed solution.

2. The iron oxide homogeneous self-Fenton electrode material according to claim 1, characterized in that, The α / β-Fe2O3 homojunction is composed of two phases, α-Fe2O3 and β-Fe2O3.

3. The iron oxide homogeneous self-Fenton electrode material according to claim 2, characterized in that, In the α / β-Fe2O3 homojunction, the atomic ratio of α-Fe2O3 to β-Fe2O3 is (1-1.8):1, and the content of active α / β-Fe2O3 homojunctions grown in situ on the carbon fiber matrix is ​​10-20wt%.

4. The iron oxide homogeneous self-Fenton electrode material according to claim 1, characterized in that, In step S1, the pretreatment includes the following steps: the carbon fiber cloth matrix is ​​ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 40-80 min each, then acid-washed in a mixed solution of concentrated sulfuric acid and concentrated nitric acid for 10-14 h, and dried at 80-120℃ for 10-14 h to obtain the pretreated carbon fiber cloth matrix.

5. The iron oxide homogeneous self-Fenton electrode material according to claim 1, characterized in that, In step S2, hydrochloric acid is added to adjust the pH of the mixed solution to 1-3, wherein the mixed solution contains Fe. 3+ The concentration is 0.05-0.15 mol / L.

6. The iron oxide homogeneous self-Fenton electrode material according to claim 1, characterized in that, In step S3, the reaction temperature is 110-130℃ and the reaction time is 12-14h; In step S4, the calcination is carried out in a mixed atmosphere containing N2 and H2, the gas flow rate of the mixed atmosphere is 900-1100 sccm, the gas volume ratio of N2 to H2 is (96-98):(2-4), the calcination temperature is 400-600℃, the calcination time is 1-4 hours, and the calcination heating rate is 2℃ / min-5℃ / min.

7. The iron oxide homogeneous self-Fenton electrode material according to claim 1, characterized in that, The process also includes step S5: immersing the α / β-Fe₂O₃ / CC obtained in step S4 in an aqueous solution of sodium borohydride for reduction and activation, to obtain α / β-Fe₂O₃. 3-xR / CC, wherein the concentration of the sodium borohydride aqueous solution is 3-15 mol / L, and the soaking time is 2-4h; x is 1 / 3 of the concentration of the sodium borohydride aqueous solution, and the value of x ranges from 1 to 5; R represents the reduction and activation of α / β-Fe2O3 / CC by the sodium borohydride aqueous solution.

8. The application of an iron oxide homogeneous self-Fenton electrode material as described in any one of claims 1-7 in the degradation of organic pollutants.

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