A method for treating antibiotic wastewater using a metal-organic framework derivative-semiconductor hybrid photoelectrode

Abstract

The present invention discloses a method for treating antibiotic wastewater by using a metal organic framework derivative-semiconductor hybrid photoelectrode. The method uses a metal organic framework derivative hybrid semiconductor photoelectrode as an anode to treat antibiotic wastewater through a photoelectrocatalytic reaction, wherein anatase TiO2-NTs is used as a conductive substrate, and ZrO2, a derivative of NH2-UiO-66(Zr), is loaded in the TiO2-NTs. The photoelectrode ZrO2 / Ti is prepared by high-temperature engraving and reduction in argon gas. 3+ The method of the present invention not only has the advantages of good removal effect, high circulation efficiency, good stability, and strong applicability, but also has the advantages of good recyclability and no secondary pollution. It is a treatment method that can be widely adopted and can effectively remove antibiotics, and has high use value and application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of photoelectrocatalytic anode preparation, relates to treating antibiotic wastewater, and specifically relates to a method for treating antibiotic wastewater by utilizing a metal organic framework derivative-semiconductor hybrid photoelectrode. Background Art

[0002] Emerging contaminants, antibiotics, have attracted widespread attention for their potential negative impacts on human health and the risk of generating resistance genes in ecosystems. The low concentrations and high toxicity of antibiotics hinder their effective removal through traditional wastewater purification methods, such as coagulation, sedimentation, chlorination, disinfection, biodegradation, physical adsorption, and chemical oxidation. Furthermore, the accumulation of antibiotics often leads to ineffective degradation. Therefore, there is an urgent need to develop advanced and innovative strategies for the effective and rapid degradation of antibiotics in water.

[0003] The new photoelectrocatalytic (PEC) technology has been widely regarded as a green and efficient alternative to electrochemical assisted photocatalytic systems. In this technology, by applying a certain anode bias, photogenerated electrons move through the circuit to the counter electrode, resulting in a potential gradient inside the electrode, which effectively promotes the reaction between photogenerated electrons and holes (e - and h + ) separation. However, there are few reports on the practical application of photoelectrocatalysis technology. The key is that the electrode must meet the following conditions: (1) participate in the reaction in a non-powdered state to avoid difficulties in catalyst recovery; (2) excite the photosensitivity and optical response range of the electrode; (3) the catalyst must be stably bonded to the conductive substrate and the active component yield must be high.

[0004] For traditional photoelectrocatalytic electrodes, powdered materials are typically coated onto a conductive substrate. However, the coated powdered material is not firmly bonded to the substrate and easily falls off. Furthermore, coating the electrode reduces the mass transfer rate between the material and the conductive substrate. Therefore, it is necessary to find a substrate with a unique structure that effectively bonds with the catalytic material. In recent years, studies have shown that nanostructures can be grown in situ on three-dimensional substrates without affecting the catalytic performance of the photosensitizer while maintaining its stability and conductivity. As a semiconducting metal oxide, TiO2 is easily synthesized into shape-tunable TiO2-NTs. TiO2-NTs prepared by anodization can precisely control their structural parameters (pore size, wall thickness, and length) by adjusting the oxidation conditions. The ordered and tightly packed nanotubes provide a solid support structure to allow for the loading of specific electroactive materials and reduce light reflection losses caused by multiple radiation scatterers. However, due to the large band gap of TiO2, which results in low visible light utilization, it is not an ideal electrode substrate.

[0005] MOFs are a class of crystalline porous materials with periodic network structures formed by self-assembly of inorganic metal centers and organic ligands. Due to their porosity, large surface area, multiple metal sites, and semiconductor-like properties, MOFs exhibit excellent photosensitivity and visible light sensing performance. Currently, MOFs are rarely used in photoelectrocatalytic systems. Most MOF materials have poor photocatalytic activity and complex synthesis processes, and existing research is still limited to constructing photoanodes by coating powdered catalysts on conductive glass. Furthermore, research on in situ growth of MOFs onto substrates is limited, and existing MOF composite materials are primarily in powder form, making them difficult to recycle and prone to secondary pollution. These issues significantly limit their widespread application in the environment. Therefore, addressing the challenges and shortcomings of MOFs to develop a photoelectrocatalytic anode that is simple to synthesize, easy to operate, and exhibits excellent performance is crucial for the treatment of antibiotics in wastewater. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a photoelectric electrode of a metal organic framework derivative hybrid semiconductor with good recyclability, high removal efficiency, good cycle performance and strong practical application for treating antibiotic wastewater.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for treating antibiotic wastewater using a metal-organic framework derivative-semiconductor hybrid photoelectrode, characterized by comprising: a metal-organic framework derivative and a semiconductor hybrid to generate a photoelectrode, mixing the photoelectrode with the antibiotic wastewater, irradiating the photoelectrode with visible light and applying an external bias voltage to achieve efficient treatment of the antibiotics in the wastewater; the photoelectrode uses anatase TiO2-NTs as a conductive substrate; the metal-organic framework derivative is ZrO2, which is derived from the metal-organic framework NH2-UiO-66 (Zr); and the semiconductor is TiO2.

[0009] The above method is further improved, and the method for preparing the photoelectric electrode of the metal organic framework derivative hybrid semiconductor comprises the following steps:

[0010] S1. Immerse the titanium foil in acetone and anhydrous ethanol for 15 minutes, then immerse it in a mixed solution of hydrofluoric acid, nitric acid and ultrapure water for 30 seconds of polishing and ultrasonication.

[0011] S2, immersing the titanium foil cleaned in step S1 into an electrolyte containing sodium sulfate and sodium fluoride, stirring, and performing anodization using graphite as a counter electrode to obtain TiO2 nanotubes (TiO2-NTs);

[0012] S3, calcining the oxidized electrode obtained in step S2 at 450° C. for 3 h to obtain anatase TiO2-NTs;

[0013] S4, using a three-electrode standard system, the TiO2-NTs obtained in step S3 were electrochemically reduced in sodium sulfate and ammonium sulfate solutions to obtain Ti 3+ -TiO2 electrode, the electrode is immersed in a 45℃ zirconium chloride solution for pulse electrodeposition;

[0014] S5, immersing the electrode obtained in step S4 in a mixed solution of an organic solvent, 2-aminoterephthalic acid, nitric acid, and hydrofluoric acid for a hydrothermal reaction, maintaining the temperature at 160° C. for 24 hours;

[0015] S6. The electrode obtained in step S5 is cleaned and dried, and reduction-engraved at 450° C. for 2 h in an argon atmosphere to obtain a hybrid semiconductor MOFs derivative photoelectrode.

[0016] The above method is further improved, in step S1, the ratio of hydrofluoric acid: nitric acid: ultrapure water is 1:3:6, and after polishing, the electrode is immersed in ultrapure water and ultrasonically cleaned for 10 minutes to 15 minutes.

[0017] The above method is further improved, in step S2, the sodium sulfate concentration is 100 mmol / L to 500 mmol / L, the mass fraction of ammonium fluoride is 0.5 wt% to 0.8 wt%, the stirring rate is 200 r / min to 250 r / min, the oxidation time is 5 h to 6 h, and the oxidation DC voltage is 15 V to 20 V.

[0018] The above method is further improved in that in step S3, the calcination heating rate is 5°C to 7°C.

[0019] The above method is further improved, wherein in step S4, the standard three-electrode system uses the electrode obtained in step S2 as the working electrode, the platinum sheet as the counter electrode, and the Ag / AgCl electrode as the reference electrode; the concentration of sodium sulfate is 100 mmol / L to 500 mmol / L, the concentration of ammonium sulfate is 500 mmol / L to 1000 mmol / L, and the concentration of zirconium chloride is 32 mmol / L to 40 mmol / L; the sodium sulfate reduction voltage is -1.3 V to -1.5 V, 20 min; the ammonium sulfate reduction voltage is -1.5 V, 3 s; pulse electrodeposition is adopted: the anode voltage is 0.25 mA, 10 ms; the cathode voltage is -0.25 mA, 3 ms; and the dwell current is 0 mA, 1 s.

[0020] The above method is further improved, wherein in step S5, the organic solvent is N-N dimethylformamide, the concentration of 2-aminoterephthalic acid is 66 mmol / L to 70 mmol / L, and the amounts of nitric acid and hydrofluoric acid used are 0.27 ml / 50 mL and 0.35 ml / 50 mL respectively.

[0021] The above method is further improved in that in step S6, anhydrous ethanol and ultrapure water are used for cleaning, the drying temperature is 60° C. to 80° C., and the drying time is 15 min to 30 min.

[0022] The above method is further improved, wherein the antibiotic in the wastewater is tetracycline hydrochloride; the antibiotic concentration is 10 mg / L to 30 mg / L; and the pH of the antibiotic wastewater is 5 to 7.

[0023] The above method is further improved, wherein the antibiotic undergoes a catalytic reaction under photoelectric conditions, the antibiotic wastewater contains sodium sulfate at a concentration of 0.5 mol / L to 1.0 mol / L; the pH of the antibiotic wastewater is 5 to 7; the applied external voltage is 2.0 V, and the catalytic time is 18 minutes.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] (1) The present invention provides a method for treating antibiotic wastewater using a metal-organic framework derivative-semiconductor hybrid photoelectrode. Using a standard three-electrode system, the metal-organic framework derivative hybrid semiconductor photoelectrode is used as the working electrode, a platinum sheet is used as the counter electrode, and an Ag / AgCl electrode is used as the reference electrode. The system is placed in antibiotic wastewater containing a sodium sulfate electrolyte to carry out a photoelectrocatalytic reaction, thereby achieving efficient degradation of the antibiotic. Using tetracycline hydrochloride as the target pollutant, the degradation rate and degradation efficiency of the metal-organic framework derivative hybrid semiconductor photoelectrode treatment were increased by 31.1 times and 7.4 times, respectively, compared to unmodified TiO2-NTs. After six cycles, the degradation rate of tetracycline in wastewater by the metal-organic framework derivative hybrid semiconductor photoelectrode remained above 80%. For tetracycline hydrochloride in different actual water bodies, the degradation efficiency of the metal-organic framework derivative hybrid semiconductor photoelectrode treatment was as high as 90%. The method of the present invention not only has the advantages of good removal effect, fast removal rate, high circulation efficiency, strong practicality, etc., but also has the advantages of good recyclability, no secondary pollution, and good stability. It is a treatment method for achieving efficient catalytic degradation of antibiotics and has good application prospects.

[0026] (2) The present invention uses a photoelectrode of a metal organic framework derivative hybrid semiconductor, wherein anatase TiO2-NTs is used as a conductive electrode and ZrO2 is loaded in the TiO2-NTs. In the present invention, Ti is formed by electrochemical reduction.3+ Self-doping greatly improves the utilization efficiency of visible light; at the same time, the applied voltage causes the excited photogenerated electrons to flow from the photoelectrode to the counter electrode, reducing the separation of photogenerated electrons and holes. On this basis, the ZrO2 formed by the high-temperature engraving reduction of NH2-UiO-66(Zr) loaded on the anatase TiO2-NTs conductive electrode is 3+ -TiO2 forms a heterostructure. On the one hand, the heterostructure forms an internal electric field and energy band bending, which greatly promotes the photogenerated - / h + On the other hand, heterostructures produce 1 O2、O2 - and h + Active substances such as ZrO2 greatly enhance the redox ability of the photoelectrode. At the same time, ZrO2 grows tightly inside TiO2-NTs, showing good stability, which is conducive to improving the recycling performance of the material. Compared with the existing technology, the photoelectrode of the metal organic framework derivative hybrid semiconductor of the present invention has the advantages of good structural stability, excellent catalytic performance, high visible light sensitivity and a wide range. It solves the problem that semiconductor TiO2 can only absorb ultraviolet light, can effectively avoid the recombination of photogenerated electrons and holes, and the photoelectric synergistic effect can efficiently treat antibiotics in wastewater; at the same time, the electrode can be easily recycled and has high promotion value and good application prospects.

[0027] (3) In the present invention, for the first time, an in-situ growth method and argon high-temperature engraving reduction were used to excite MOFs derivatives to form an S-type heterojunction for a semiconductor-like hybrid semiconductor. Zr was deposited into anatase TiO2-NTs using an electrochemical method of pulsed electrodeposition. By optimizing the deposition time and deposition temperature, the prepared metal organic framework derivative hybrid semiconductor photoelectrode had an appropriate amount of Zr deposited, thereby enabling the photoelectrode to produce stronger visible light utilization capabilities and catalytic performance. In particular, the best catalytic performance was achieved when the deposition time was 5 minutes and the deposition temperature was 45°C.

[0028] (4) In the present invention, the TiO2-NTs generated by anodic oxidation have a hollow tubular structure, and the surface of the photoelectrode of the metal organic framework derivative hybrid semiconductor forms a dense octahedral structure, which has the advantages of uniform deposition, convenient recovery, easy operation, good stability, good catalytic performance, and strong applicability. It is suitable for large-scale preparation and is conducive to industrial utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0030] Figure 1 The scanning electron microscope and transmission electron microscope images of different prepared electrodes in the process of preparing the photoelectrode of the metal organic framework derivative hybrid semiconductor in Example 1 of the present invention, where (a) is a TiO2-NTs electrode and (b) is a Zr-Ti 3+ -TiO2 electrode, (c) NH2-UiO-66 / Ti 3+ -TiO2 electrode, (de) is ZrO2 / Ti 3+ -TiO2 electrode, (fh) is ZrO2 / Ti 3+ -Transmission electron microscopy images of TiO2 electrodes, (i) ZrO2 / Ti 3+ -Diffraction image of a selected area of a TiO2 electrode.

[0031] Figure 2 These are X-ray diffraction patterns of different prepared electrodes during the process of preparing the metal organic framework derivative hybrid semiconductor photoelectrode in Example 1 of the present invention.

[0032] Figure 3 This is the X-ray photoelectron spectra of different prepared electrodes in the process of preparing the metal organic framework derivative hybrid semiconductor photoelectrode in Example 1 of the present invention.

[0033] Figure 4 These are the catalytic degradation effect diagrams and corresponding reaction rate diagrams of differently prepared electrodes in the process of preparing the photoelectric electrode of the metal organic framework derivative hybrid semiconductor in Example 1 of the present invention, where (a) is the degradation effect diagram and (b) is the reaction rate diagram.

[0034] Figure 5 These are the degradation effect diagrams of tetracycline hydrochloride by the metal-organic framework derivative hybrid semiconductor photoelectrode under different photoelectric conditions and the corresponding reaction rate diagrams in Example 2 of the present invention, where (a) is the degradation effect diagram and (b) is the reaction rate diagram.

[0035] Figure 6 The photoelectrode ZrO2 / Ti of the metal organic framework derivative hybrid semiconductor in Example 3 of the present invention 3+ -TiO2 degradation effect diagram of tetracycline hydrochloride at different voltages and the corresponding reaction rate diagram, where (a) is the degradation effect diagram and (b) is the reaction rate diagram.

[0036] Figure 7 The photoelectrode ZrO2 / Ti of the metal organic framework derivative hybrid semiconductor in Example 4 of the present invention 3+ -Degradation effect of TiO2 on tetracycline hydrochloride at different pH values.

[0037] Figure 8The photoelectrode ZrO2 / Ti of the metal organic framework derivative hybrid semiconductor in Example 1 of the present invention 3+ -Photocurrent decay curve and cycling effect diagram of TiO2. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the scope of protection of the present invention is not limited thereby.

[0039] The raw materials and instruments used in the following examples are all commercially available. In the following examples, unless otherwise specified, the data obtained are the average values of more than three repeated experiments.

[0040] Example 1

[0041] A method for treating antibiotic wastewater using a metal organic framework derivative-semiconductor hybrid photoelectrode, specifically treating tetracycline hydrochloride in the wastewater through a photoelectrocatalytic reaction using a metal organic framework derivative hybrid semiconductor photoelectrode as an anode, comprising the following steps:

[0042] A photoelectrode of a metal-organic framework derivative hybrid semiconductor was used as the anode, a platinum sheet was used as the counter electrode, and an Ag / AgCl electrode was used as the reference electrode. 100 mL of tetracycline hydrochloride wastewater containing sodium sulfate (the concentration of sodium sulfate in the wastewater was 0.5 mol / L, the concentration of antibiotics was 20 mg / L, and the pH was 5.0) was placed in the solution for a photoelectrocatalytic reaction for 20 minutes. The reaction was carried out under visible light at a voltage of 2.0 V.

[0043] In this example, the photoelectrode ZrO2 / Ti is a hybrid semiconductor of a metal organic framework derivative. 3+ -TiO2 uses anatase TiO2-NTs as a conductive substrate, and the TiO2-NTs are loaded with a metal organic framework derivative ZrO2. After high-temperature carving and reduction by argon gas, ZrO2 and Ti 3+ -TiO2 is tightly combined to form an S-type heterojunction.

[0044] A method for preparing a photoelectrode of a metal organic framework derivative hybrid semiconductor of the present embodiment comprises the following steps:

[0045] (1) 3.2×3.2cm 2 Titanium foil (thickness 0.2 mm) was ultrasonically treated in acetone and anhydrous ethanol for 15 min in sequence, then ultrasonically polished in a polishing solution of HF:HNO3:H2O=1:3:6 for 30 s, and finally ultrasonically treated in ultrapure water for 15 min.

[0046] (2) The electrode in step (1) was used as the anode and graphite was used as the counter electrode. Electrochemical anodic oxidation was performed in a mixed solution of 0.5 wt% sodium fluoride and 0.5 mol / L sodium sulfate (130 mL) at a constant voltage of 20 V for 5 h.

[0047] (3) The electrode in step (2) was placed in a crucible, and the temperature was raised to 450°C at a heating rate of 5°C / min and maintained for 3 h to obtain a conductive substrate containing anatase TiO2-NTs.

[0048] (4) Prepare 0.1 mol / L sodium sulfate solution, 1.0 mol / L ammonium sulfate solution, and 32 mmol / L zirconium chloride solution, use the electrode in step (3) as the working electrode, the platinum electrode as the counter electrode, and the Ag / AgCl electrode as the reference electrode, electrochemically reduce the solution at -1.3 V for 20 min, electrochemically reduce the solution at -1.5 V for 3 s in ammonium sulfate solution, and pulse electrodeposit the solution at 45°C for 5 min in zirconium chloride solution.

[0049] (5) Prepare a hydrothermal solution by mixing 0.6 g of 2-aminoterephthalic acid, 50 ml of NN-dimethylformamide, 0.27 mL of nitric acid, and 0.35 mL of hydrofluoric acid. Immerse the electrode obtained in step (4) in the solution and hydroheat at 160° C. for 24 h.

[0050] (6) The hydrothermal electrode obtained in step (5) was washed three times with anhydrous ethanol and ultrapure water, heated to 450°C at 5°C / min in an argon atmosphere, and calcined at high temperature for 2 h to obtain a photoelectrode of a metal organic framework derivative hybrid semiconductor, named ZrO2 / Ti 3+ -TiO2.

[0051] Figure 1 The scanning electron microscope images and transmission electron microscope images of different prepared electrodes in the process of preparing the photoelectrode of the metal organic framework derivative hybrid semiconductor in Example 1 of the present invention, wherein (a) is a TiO2-NTs electrode, and (b) is a Zr-Ti 3+ -TiO2 electrode, (c) NH2-UiO-66 / Ti 3+ -TiO2 electrode, (de) is ZrO2 / Ti 3+ -TiO2 electrode, (fh) is ZrO2 / Ti 3+ -Transmission electron microscopy images of TiO2 electrodes, (i) ZrO2 / Ti 3+ -Diffraction image of a selected area of a TiO2 electrode. Figure 1 As can be seen in a, TiO2-NTs do not show a highly ordered structure and vertical upward characteristics, which may be related to collapse; after electrochemical pulse deposition, nano Zr particles are distributed on the nanotube matrix and grow from the bottom to the tube wall and surface ( Figure 1 b); After hydrothermal acidification, the electrode interior presents a regular directional structure ( Figure 1 c); After argon engraving reduction, the electrode interior changes from a regular block structure to a large number of small octahedral structures, which greatly increases the surface area ( Figure 1 de); from Figure 1 Dense nanoparticles can be observed in fg, which may be related to the deposition of Zr; ZrO2 / Ti 3+ -High-resolution transmission electron microscopy images of the TiO2 electrode showed three typical lattice fringe spacings (0.352nm, 0.292nm, 0.505nm), corresponding to anatase TiO2 (101), Ti3O5 (112), ZrO2 (110) ( Figure 1 h); Figure 1 The selected area electron diffraction pattern shown in Figure 1 shows the coexistence of diffraction spots and diffraction rings, which may come from large polycrystalline particles.

[0052] Figure 2 The X-ray diffraction patterns of different prepared electrodes in the process of preparing the photoelectric electrode of the metal organic framework derivative hybrid semiconductor in Example 1 of the present invention are shown in FIG. Figure 2 As shown, the peak at 25.3° indicates the formation of anatase (101) crystal plane, and the peak is enhanced, indicating higher crystallinity.

[0053] Figure 3 The X-ray photoelectron spectra of different prepared electrodes in the process of preparing the photoelectrode of the metal organic framework derivative hybrid semiconductor in Example 1 of the present invention are shown in FIG. (a) is TiO2-NTs, Ti 3+ -TiO2,Zr-Ti 3+ -TiO2,NH2-UiO-66 / Ti 3+ -TiO2,ZrO2 / Ti 3+ -The full spectrum of TiO2, in which C, Zr, O and Ti elements can be observed, and the presence of F1s and N1s may be related to the hydrothermal acidification process. Figure 3 As shown in b, ZrO2 / Ti 3+ -TiO2 lattice oxygen peak area ratio NH2-UiO-66 / Ti 3+ -TiO2 is large, indicating that ZrO2 / Ti 3+ -TiO2 exposes more oxygen vacancies.

[0054] During the photoelectrocatalytic reaction, 2 mL of sample was taken at intervals (0 min, 3 min, 6 min, 9 min, 12 min, 15 min, and 18 min of catalysis) and filtered through a 0.22 μm filter membrane. The change in peak area at different degradation times was measured by high performance liquid chromatography to determine the concentration of tetracycline hydrochloride after degradation, thereby obtaining the degradation effect of the photoelectrode on tetracycline hydrochloride. The results are shown in Figure 2. Figure 4 shown.

[0055] Figure 4 This is a diagram showing the catalytic degradation effects of different prepared electrodes during the preparation of the photoelectrode of the metal organic framework derivative hybrid semiconductor in Example 1 of the present invention. Figure 4 As shown in a, about 13.51% degradation of tetracycline hydrochloride was observed on TiO2-NTs, which may be due to the presence of trace visible light and the oxidation effect of dissolved oxygen; ZrO2 / Ti 3+ -The degradation effect of TiO2 electrode on tetracycline hydrochloride reaches 100%. Figure 5 As shown in b, the first-order kinetic fitting of the photoelectrode shows that ZrO2 / Ti 3+ -The first-order reaction kinetic constant of the TiO2 electrode increased by 31.1 times, showing good catalytic performance.

[0056] Example 2

[0057] A method for treating antibiotic wastewater using a metal organic framework derivative-semiconductor hybrid photoelectrode, specifically treating tetracycline hydrochloride in the wastewater through a photoelectrocatalytic reaction using a metal organic framework derivative hybrid semiconductor photoelectrode as an anode, comprising the following steps:

[0058] The photoelectrode ZrO2 / Ti hybrid semiconductor of the metal organic framework derivative in Example 1 3+ -TiO2 was used as the anode, platinum sheet as the counter electrode, and Ag / AgCl electrode as the reference electrode. 100 mL of tetracycline hydrochloride wastewater containing sodium sulfate (the concentration of sodium sulfate in the wastewater was 0.5 mol / L, the concentration of antibiotics was 20 mg / L, and the pH was 5.0) was placed in the solution. The catalytic reaction was carried out under different photoelectric conditions to complete the catalytic treatment of tetracycline hydrochloride.

[0059] Condition 1: Apply visible light and 2.0V voltage for 20 minutes;

[0060] Condition 2: Apply visible light for 20 minutes;

[0061] Condition 3: Apply 2.0V voltage and maintain for 20 minutes.

[0062] During the catalytic process under the three conditions, 2 mL of sample was taken at intervals (0 min, 3 min, 6 min, 9 min, 12 min, 15 min, and 18 min of catalysis) and filtered through a 0.22 μm filter membrane. The change in peak area at different degradation times was measured by high performance liquid chromatography to determine the concentration of tetracycline hydrochloride after degradation, thereby obtaining the degradation effect of the metal organic framework derivative hybrid semiconductor photoelectrode on tetracycline hydrochloride. The results are shown in FIG. Figure 5 shown.

[0063] Figure 5 The photoelectrode ZrO2 / Ti of the metal organic framework derivative hybrid semiconductor in Example 2 of the present invention 3+ -TiO2 degradation effect diagram of tetracycline hydrochloride and the corresponding reaction rate diagram, where (a) is the degradation effect diagram and (b) is the reaction rate diagram. Figure 5 In the equation, PEC, PC, and EC represent the photoelectrocatalytic (condition 1), photocatalytic (condition 2), and electrocatalytic (condition 3) processes, respectively. Figure 5 As shown in the figure, tetracycline hydrochloride in wastewater has the best degradation effect and the fastest degradation rate under photoelectrocatalytic conditions. It can be seen that the photoelectrode of metal organic framework derivative hybrid semiconductor has a synergistic effect on the utilization of light and electricity. The synergistic factor can be calculated by equation (1):

[0064]

[0065] Among them, k PEC , k PC and k EC represent the reaction rate constants of tetracycline hydrochloride degradation in the photoelectrocatalytic, photocatalytic and electrocatalytic processes, respectively. Figure 5 b Calculation shows that the synergistic factor in the photoelectrocatalytic process is 0.82.

[0066] Example 3

[0067] A method for treating antibiotic wastewater using a metal organic framework derivative-semiconductor hybrid photoelectrode, specifically treating tetracycline hydrochloride in the wastewater through a photoelectrocatalytic reaction using a metal organic framework derivative hybrid semiconductor photoelectrode as an anode, comprising the following steps:

[0068] The photoelectrode ZrO2 / Ti hybrid semiconductor of the metal organic framework derivative in Example 1 3+-TiO2 was used as the anode, platinum as the counter electrode, and Ag / AgCl electrode as the reference electrode. 100 mL of tetracycline hydrochloride wastewater containing sodium sulfate (the concentration of sodium sulfate in the wastewater was 0.5 mol / L, the concentration of antibiotics was 20 mg / L, and the pH was 5.0) was placed in the solution. Photoelectrocatalysis was carried out at voltages of 1.0 V, 1.5 V, 2.0 V, and 2.5 V for 20 minutes to complete the catalytic treatment of tetracycline hydrochloride.

[0069] During the photoelectrocatalytic process, 2 mL of sample was taken at intervals (0 min, 3 min, 6 min, 9 min, 12 min, 15 min, and 18 min of catalysis) and filtered through a 0.22 μm filter membrane. The change in peak area at different degradation times was measured by high performance liquid chromatography to determine the concentration of tetracycline hydrochloride after degradation, thereby obtaining the degradation effect of the metal organic framework derivative hybrid semiconductor photoelectrode on tetracycline hydrochloride. The results are shown in FIG. Figure 6 shown.

[0070] Figure 6 The photoelectrode ZrO2 / Ti of the metal organic framework derivative hybrid semiconductor in Example 3 of the present invention 3+ -TiO2 degradation effect diagram of tetracycline hydrochloride at different voltages and the corresponding reaction rate diagram, where (a) is the degradation effect diagram and (b) is the reaction rate diagram. Figure 6 As shown in the figure, with the gradual increase of the applied voltage, the degradation efficiency and reaction rate reached the maximum at 2.0 V, and the reaction rate increased from 0.2748 min -1 Increased to 0.6520min -1 , indicating the presence of a potential gradient within the TiO2-NTs. This potential gradient increases carrier transport, significantly enhancing the electrode's photoelectric performance. Considering the charge transfer rate and the potential for additional reactions, such as the oxygen evolution reaction, at excessively high voltages, 2.0 V was ultimately selected as the most suitable applied voltage.

[0071] Example 4

[0072] A method for treating antibiotic wastewater using a metal organic framework derivative-semiconductor hybrid photoelectrode, specifically treating tetracycline hydrochloride in the wastewater through a photoelectrocatalytic reaction using a metal organic framework derivative hybrid semiconductor photoelectrode as an anode, comprising the following steps:

[0073] The photoelectrode ZrO2 / Ti hybrid semiconductor of the metal organic framework derivative in Example 1 3+Using -TiO2 as the anode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode, they were placed in 100 mL of tetracycline hydrochloride wastewater containing sodium sulfate with pH values of 3.0, 5.0, 7.0, and 9.0 respectively (the concentration of sodium sulfate in this wastewater was 0.5 mol / L, and the concentration of the antibiotic was 20 mg / L) for a photoelectrocatalytic reaction for 20 minutes. The photoelectrocatalytic reaction was carried out under visible light irradiation and an applied voltage of 2.0 V to complete the catalytic treatment of tetracycline hydrochloride.

[0074] During the photoelectrocatalytic process, 2 mL of samples were taken at regular intervals (when the catalysis was carried out for 0 min, 3 min, 6 min, 9 min, 12 min, 15 min, and 18 min), and the samples were filtered through a 0.22 μm filter membrane. The change in the peak area at different degradation times was measured by a high - performance liquid chromatograph to determine the concentration of tetracycline hydrochloride after degradation, so as to obtain the degradation effect of the photoelectrode of the metal - organic framework derivative hybrid semiconductor on tetracycline hydrochloride. The results are as Figure 7 shown.

[0075] Figure 7 This is the photoelectrode ZrO2 / Ti of the metal - organic framework derivative hybrid semiconductor in Example 4 of the present invention 3+ -TiO2's degradation effect diagram of tetracycline hydrochloride at different pH values. As Figure 7 shown, as the pH value increases, the degradation rate of tetracycline hydrochloride first increases and then decreases, reaching the maximum at pH = 5.0. That is, the catalytic activity of the photoelectrode shows a trend of first increasing and then decreasing with the increase of the pH value. This phenomenon can be explained as follows:

[0076] (1) The nature of the target pollutant. The dissociation constants (pKa: 3.32, 7.78, 9.58) of TC molecules determine their charged properties (cationic state at pH < 3.32; zwitterionic form: 3.32 < pH < 7.78; anionic species: pH > 7.78). Due to electrostatic interaction, the photoelectrode and TC molecules are effectively combined, which is beneficial to the catalytic effect.

[0077] (2) The presence of amino groups. When exposed to water, tetracycline hydrochloride has amino groups and shows basic characteristics. Therefore, it is more conducive to degrading pollutants under acidic conditions.

[0078] (3) The presence of hydrogen bonds. As Figure 3 shown, the photoelectrode has O - H bonds, and this polar group of O - H bonds is also beneficial to the absorption and catalytic degradation of tetracycline hydrochloride molecules.

[0079] Figure 8 This is the photoelectrode ZrO2 / Ti of the metal - organic framework derivative hybrid semiconductor in Example 1 of the present invention 3+-TiO2 photocurrent decay curve and cycle effect diagram. Figure 8 As shown, the long-term photocurrent decay curve of the metal-organic framework-derived hybrid semiconductor photoelectrode shows no significant downward trend, indicating the electrode's excellent stability. Compared to powdered catalysts, the bulk electrode exhibits significantly improved recyclability, avoiding the problem of low recycling efficiency and demonstrating higher degradation reproducibility. After six cycles of operation, the degradation efficiency remained above 80%.

[0080] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of protection of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that can be made by a person skilled in the art without departing from the principles of the present invention are also considered to be within the scope of protection of the present invention.

Claims

1. A method for treating antibiotic wastewater using a metal organic framework derivative-semiconductor hybrid photoelectrode, characterized in that: The method includes hybridizing a metal organic framework derivative and a semiconductor to generate a photoelectrode, mixing it with antibiotic wastewater, irradiating it with visible light and applying an external bias, thereby completing the efficient treatment of antibiotics in the wastewater; the photoelectrode is based on anatase TiO2-NTs as a conductive substrate; the metal organic framework derivative is ZrO2, which is derived from the metal organic framework NH2-UiO-66 (Zr) calcined in an Ar atmosphere; and the semiconductor is TiO2.

2. The method according to claim 1, characterized in that The method for preparing the hybrid photoelectrode of the metal organic framework derivative and the semiconductor comprises the following steps: S1. Immerse the titanium foil in acetone and anhydrous ethanol for 15 minutes, then immerse it in a mixed solution of hydrofluoric acid, nitric acid and ultrapure water for 30 seconds of polishing and ultrasonication. S2, immersing the titanium foil cleaned in step S1 into an electrolyte containing sodium sulfate and sodium fluoride, stirring, and performing anodization using graphite as a counter electrode to obtain TiO2 nanotubes (TiO2-NTs); S3, calcining the oxidized electrode obtained in step S2 at 450° C. for 3 h to obtain anatase TiO2-NTs; S4, using a three-electrode standard system, the TiO2-NTs obtained in step S3 were electrochemically reduced in sodium sulfate and ammonium sulfate solutions to obtain Ti 3+ -TiO2 electrode, the electrode is immersed in a 45℃ zirconium chloride solution for pulse electrodeposition; S5, immersing the electrode obtained in step S4 in a mixed solution of an organic solvent, 2-aminoterephthalic acid, nitric acid, and hydrofluoric acid for a hydrothermal reaction, maintaining the temperature at 160° C. for 24 hours; S6. The electrode obtained in step S5 is cleaned and dried, and then reduced and engraved in an argon atmosphere at 450° C. for 2 h to obtain a photoelectrode hybridized with a metal organic framework derivative and a semiconductor.

3. The method according to claim 2, characterized in that In step S1, the ratio of hydrofluoric acid to nitric acid to ultrapure water is 1:3:6, and the polished electrode is immersed in ultrapure water for ultrasonic cleaning for 10 to 15 minutes.

4. The method according to claim 2, characterized in that In step S2, the sodium sulfate concentration is 100 mmol / L to 500 mmol / L, the mass fraction of ammonium fluoride is 0.5 wt% to 0.8 wt%, the stirring rate is 200 r / min to 250 r / min, the oxidation time is 5 h to 6 h, and the oxidation DC voltage is 15 V to 20 V.

5. The method according to claim 2, characterized in that In step S3, the calcination heating rate is 5°C to 7°C.

6. The method according to claim 2, characterized in that In step S4, a standard three-electrode system is used, with the electrode obtained in step S2 as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode; the concentration of sodium sulfate is 100 mmol / L to 500 mmol / L, the concentration of ammonium sulfate is 500 mmol / L to 1000 mmol / L, and the concentration of zirconium chloride is 32 mmol / L to 40 mmol / L; the sodium sulfate reduction voltage is -1.3 V to -1.5 V for 20 min; the ammonium sulfate reduction voltage is -1.5 V for 3 s; and pulse electrodeposition is used: the anode voltage is 0.25 mA for 10 ms; Cathode voltage -0.25mA, 3ms; dwell current 0mA, 1s.

7. The method according to claim 2, characterized in that In step S5, the organic solvent is N-N-dimethylformamide, the concentration of 2-aminoterephthalic acid is 66 mmol / L to 70 mmol / L, and the amounts of nitric acid and hydrofluoric acid used are 0.27 ml / 50 mL and 0.35 ml / 50 mL respectively.

8. The method according to claim 2, characterized in that In the step S6, anhydrous ethanol and ultrapure water are used for cleaning, the drying temperature is 60° C. to 80° C., and the drying time is 15 min to 30 min.

9. The method according to claim 1, characterized in that The antibiotic in the wastewater is tetracycline hydrochloride; the antibiotic concentration is 10 mg / L to 30 mg / L; and the pH of the antibiotic wastewater is 5 to 7.

10. The method according to claim 9, characterized in that The antibiotics undergo a catalytic reaction under photoelectric conditions; the antibiotic wastewater contains sodium sulfate at a concentration of 0.5 mol / L to 1.0 mol / L; the pH of the antibiotic wastewater is 5 to 7; the applied external voltage is 2.0 V, and the catalytic time is 18 minutes.

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