Method for removing antibiotics in water body by using composite electrode, composite electrode and preparation method of composite electrode

Abstract

The invention relates to a method for removing antibiotics in a water body by using a composite electrode, the composite electrode and a preparation method of the composite electrode, and the method comprises the following steps: carrying out first wire drawing treatment on a pretreated titanium metal raw material to obtain a first wire drawing treatment product; carrying out dipping treatment on the product subjected to the first wire drawing treatment in a graphite suspension, and sequentially carrying out second wire drawing treatment and annealing treatment on the product subjected to the dipping treatment; wherein the titanium metal raw material comprises a titanium blank. The composite electrode disclosed by the invention has a three-dimensional network structure in which micropores, mesopores and macropores are communicated with one another, so that the electro-catalytic performance of the composite electrode can be effectively improved. The composite electrode disclosed by the invention is simple in preparation process, can be used in the field of wastewater treatment, and can still keep a good removal effect on antibiotics in a solution containing inorganic ions and an environment containing humic acid with a pH value of 4-10.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electrode material preparation, and specifically, to a method for removing antibiotics in water using a composite electrode, the composite electrode, and a preparation method thereof. Background Art

[0002] In today's world, the decline in water quality has attracted wide attention, mainly due to persistent organic pollutants generated by industrial, agricultural, and urban activities. The electrochemical advanced oxidation process (EAOP) performs excellently in removing organic pollutants. EAOP oxidizes organic substances by in-situ generating strong oxidants (such as hydroxyl radicals ·OH, sulfate radicals SO4· - and chlorine radicals Cl· - ), but inorganic ions and natural organic matter (NOM) in water can cause the quenching of free radicals, thereby increasing energy consumption. In addition, the pH value of the solution also affects the generation of oxidants, which limits the application of EAOP in actual wastewater treatment.

[0003] In recent studies, a variety of EAOPs have been developed, involving non-free radical pathways such as high-valent species and electron transfer. For example, Yu et al. proposed an EAOP based on CoFe-LDH / MoS2 in their research, which can effectively remove norfloxacin in a wide pH range. However, the influence of NOM and inorganic ions is still inevitable. Feng et al. enhanced the generation rate of 1 O2 and the degradation efficiency of bisphenol A by regulating the copper-modified carbon interface, but the generation amount is significantly reduced under acidic and neutral conditions, and there are limitations in application. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a method for removing antibiotics in water using a composite electrode, the composite electrode, and a preparation method thereof. The composite electrode has a three-dimensional network structure with interconnected micropores, mesopores, and macropores, which can effectively improve the electrocatalytic performance of the composite electrode and has a good removal effect on antibiotics.

[0005] To achieve the above purpose, the first aspect of the present disclosure provides a method for preparing a composite electrode, the method comprising: performing a first wire drawing treatment on a pretreated titanium metal raw material to obtain a product of the first wire drawing treatment; impregnating the product of the first wire drawing treatment in a graphite suspension, and sequentially performing a second wire drawing treatment and an annealing treatment on the impregnated product; wherein, the titanium metal raw material includes a titanium blank.

[0006] Optionally, the titanium blank includes one or more of titanium plates and titanium rods; the purity of the titanium blank is above 99.999%; The diameter of the titanium bar is 10 to 11 mm; the length of the titanium plate is 0.8 to 1.2 m, the width is 0.4 to 0.6 m, and the thickness is 9 to 13 mm; Optionally, the pretreatment includes: pre-cleaning the titanium metal raw material, the temperature of the pre-cleaning is 45 to 65 °C, the pre-cleaning method is flow cleaning, the solvent is water, and the flow rate is 30 to 40 m³ / h.

[0007] Optionally, the conditions of the first wire drawing treatment include: being carried out under a vacuum condition, the temperature is 900 to 1000 °C, the time is 1 to 2 h, the drawing ratio is (2 to 10):1, and the drawing speed is 0.5 to 10 cm / min; Optionally, the method further includes: skinning the pretreated titanium metal raw material before the first wire drawing treatment, and the skinning thickness is 0.8 to 1.2 mm.

[0008] Optionally, the concentration of the graphite suspension is 10 to 20 g / L, and the solvent of the graphite suspension includes one or more of ethanol, isopropanol, and water; the time of the impregnation treatment is 6 to 12 h; Optionally, the method further includes: performing secondary cleaning on the product of the first wire drawing treatment before the impregnation treatment, the temperature of the secondary cleaning is 20 to 30 °C, and the solvent used for the secondary cleaning includes water, and the flow rate is 1 to 5 m³ / h.

[0009] Optionally, the conditions of the second wire drawing treatment include: being carried out under a vacuum condition, the temperature is 600 to 700 °C, the time is 8 to 12 h, the drawing ratio is (1 to 3):1, and the drawing speed is 0.5 to 10 cm / min; The conditions of the annealing treatment include: being carried out under a vacuum condition, the vacuum degree is 10 -1 ~10 -5 Pa, the temperature is 600 to 650 °C, and the time is 5 to 6 h.

[0010] The second aspect of the present disclosure provides a composite electrode prepared by using the method described in the first aspect of the present disclosure.

[0011] The third aspect of the present disclosure provides a composite electrode, which includes a composite material wire and a graphite layer coated on the surface of the composite material wire, and the composite material wire includes a titanium wire and titanium dioxide coated on the surface of the titanium wire.

[0012] Optionally, the thickness of the graphite layer is 10 to 50 μm; the titanium wire is formed into a wire mesh, and the pore diameter of the wire mesh is 0.3 to 1 mm; and / or, The micropore volume ratio of the composite electrode is 40-60%, the mesopore volume ratio is 20-40%, and the macropore volume ratio is 10-20%; the specific surface area of the composite electrode is 50-200 m 2 / g.

[0013] The fourth aspect of the present disclosure provides a method for removing antibiotics from water by electrochemistry, using the composite electrode described in the second aspect and / or the third aspect of the present disclosure.

[0014] Optionally, the antibiotics include one or more of tetracyclines, sulfonamides, and fluoroquinolones; and / or, The conditions of the electrochemistry reaction include: the electrode voltage is 1.5-3V; and / or, The pH of the water body is 4-10; and / or, The water body contains Cl - , SO4 2- , NO3 - and PO4 3- one or more of the ions; and / or, The water body contains humic acid, and the concentration of the humic acid is 50-300 mg / L.

[0015] Through the above technical solutions, the present disclosure processes the titanium metal raw material by wire drawing to process the titanium metal into slender titanium wires, and titanium dioxide can be in-situ generated on the surface of the titanium wires at high temperature; then through impregnation treatment, a graphite layer with a certain thickness is adsorbed on its surface, and then through annealing treatment, the stress and lattice strengthening of the titanium wires are eliminated, and woven into a titanium mesh electrode to obtain a composite electrode. The composite electrode has a three-dimensional network structure with interconnected micropores, mesopores, and macropores, which can effectively improve the electrocatalytic performance of the composite electrode. The preparation process of the composite electrode of the present disclosure is simple, has good large-scale integration productivity, can be used in the field of wastewater treatment, and can still maintain a good removal effect on antibiotics in an environment with a pH of 4-10, a solution containing inorganic ions, and a solution containing humic acid.

[0016] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification, and are used together with the following specific implementation to explain the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings: Figure 1 is the SEM image of the composite electrode of Example 1 of the present disclosure.

[0018] Figure 2 is the N2 adsorption-desorption curve of the composite electrodes of Examples 1-4 of the present disclosure.

[0019] Figure 3 It is the pore structure distribution diagram of the composite electrodes in Embodiments 1 to 4 of the present disclosure. Detailed implementation manners

[0020] The following will describe in detail the specific implementation manners of the present disclosure with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only for explaining and illustrating the present disclosure, and are not used to limit the present disclosure.

[0021] The first aspect of the present disclosure provides a method for preparing a composite electrode, and the method includes: performing a first wire drawing treatment on a pretreated titanium metal raw material to obtain a product of the first wire drawing treatment; impregnating the product of the first wire drawing treatment in a graphite suspension, and sequentially performing a second wire drawing treatment and an annealing treatment on the impregnated product; Wherein, the titanium metal raw material includes a titanium blank.

[0022] The present disclosure processes the titanium metal raw material by wire drawing to process the titanium metal into slender titanium wires, and titanium dioxide can be in-situ generated on the surface of the titanium wires at high temperature; then through impregnation treatment, a certain thickness of graphite is adsorbed on its surface, and then through annealing treatment, the stress of the titanium wires and lattice strengthening are eliminated, and woven into a titanium mesh electrode to obtain a composite electrode. This composite electrode has a three-dimensional network structure with interconnected micropores, mesopores and macropores, which can effectively improve the electrocatalytic performance of the composite electrode. The preparation process of the composite electrode of the present disclosure is simple, has good large-scale integration productivity, can be used in the field of wastewater treatment, and can still maintain a good removal effect on antibiotics in a solution with a pH of 4 to 10, containing inorganic ions, and in an environment containing humic acid.

[0023] According to an implementation manner of the present disclosure, the titanium blank includes one or more of titanium plates and titanium rods; the purity of the titanium blank is above 99.999%; the length of the titanium plate is 0.8 to 1.2 m, the width is 0.4 to 0.6 m, and the thickness is 9 to 13 mm; the diameter of the titanium rod is 10 to 11 mm, and the present disclosure does not specifically limit the length of the titanium rod, for example, it can be 0.8 to 1.2 m.

[0024] According to an implementation manner of the present disclosure, the pretreatment includes: pre-cleaning the titanium metal raw material, the temperature of the pre-cleaning is 45 to 65 °C, the pre-cleaning method is flowing cleaning, the solvent is water, and the flow rate is 30 to 40 m³ / h. The above implementation manner is beneficial to removing stains such as oil stains on the surface of the titanium metal raw material, and is beneficial to improving the effect of the first wire drawing treatment.

[0025] According to an embodiment of the present disclosure, the conditions for the first wire drawing treatment include: being carried out under vacuum conditions, with a temperature of 900 - 1000 °C, for example, it can be 900 °C, 910 °C, 920 °C, 930 °C, 940 °C, 950 °C, 960 °C, 970 °C, 980 °C, 990 °C, 1000 °C or any value within the range composed of any two of these values; the time is 1 - 2 h, for example, it can be 1 h, 1.1 h, 1.2 h, 1.3 h, 1.4 h, 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h, 2 h or any value within the range composed of any two of these values; the drawing ratio is (2 - 10):1, for example, it can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1 or any value within the range composed of any two of these values; the drawing speed is 0.5 - 10 cm / min, for example, it can be 0.5 cm / min, 1 cm / min, 2 cm / min, 3 cm / min, 4 cm / min, 5 cm / min, 6 cm / min, 7 cm / min, 8 cm / min, 9 cm / min, 10 cm / min or any value within the range composed of any two of these values. The above - mentioned embodiment is beneficial to obtaining titanium wires with a suitable structure, facilitating the formation of titanium wires into wire meshes, and improving the electro - catalytic performance of the composite electrode.

[0026] According to an embodiment of the present disclosure, the method further includes: performing a skin - peeling treatment on the pretreated titanium metal raw material before the first wire drawing treatment, with a skin - peeling thickness of 0.8 - 1.2 mm, for example, it can be 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm or any value within the range composed of any two of these values. The above - mentioned embodiment is beneficial to removing the impurity layer on the surface of the titanium billet, obtaining titanium wires with a suitable structure, facilitating the formation of titanium dioxide on the surface of the titanium wires, and improving the electro - catalytic performance of the composite electrode.

[0027] According to an embodiment of the present disclosure, the concentration of the graphite suspension is 10 - 20 g / L, for example, it can be 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L, 15 g / L, 16 g / L, 17 g / L, 18 g / L, 19 g / L, 20 g / L or any value within the range composed of any two of these values; the solvent of the graphite suspension includes one or more of ethanol, isopropanol, and water; the time for the impregnation treatment is 6 - 12 h, for example, it can be 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h or any value within the range composed of any two of these values. The present disclosure does not make specific limitations on the used graphite. For example, graphite with a particle size of 1 - 5 mm and a specific surface area of 40 - 60 m 2Graphite particles of / g. The above embodiments are conducive to forming the composite electrode into a three-dimensional network pore structure with interconnected micropores, mesopores, and macropores, effectively improving its electrocatalytic performance.

[0028] According to an embodiment of the present disclosure, the method further includes: performing secondary cleaning on the product of the first wire drawing treatment before the impregnation treatment. The temperature of the secondary cleaning is 20~30°C, the solvent used for the secondary cleaning includes water, and the flow rate is 1~5 m³ / h. The above embodiments are conducive to removing oil stains or other impurities on the surface of the product of the first wire drawing treatment, making the surface clean, and facilitating the improvement of the adhesion of graphite.

[0029] According to an embodiment of the present disclosure, the conditions for the second wire drawing treatment include: being carried out under a vacuum condition, the temperature is 600~700°C, for example, it can be 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, 660°C, 670°C, 680°C, 690°C, 700°C or any value within the range composed of any two of these values; the time is 8~12 h, for example, it can be 8 h, 9 h, 10 h, 11 h, 12 h or any value within the range composed of any two of these values; the draw ratio is (1~3):1, for example, it can be 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.1:1, 2.3:1, 2.5:1, 2.7:1, 2.9:1, 3:1 or any value within the range composed of any two of these values; the drawing speed is 0.5~10 cm / min, for example, it can be 0.5 cm / min, 1 cm / min, 2 cm / min, 3 cm / min, 4 cm / min, 5 cm / min, 6 cm / min, 7 cm / min, 8 cm / min, 9 cm / min, 10 cm / min or any value within the range composed of any two of these values. The above embodiments are conducive to obtaining titanium wires with a suitable structure, making it easy for the titanium wires to form a wire mesh, and improving the electrocatalytic performance of the composite electrode.

[0030] According to an embodiment of the present disclosure, the conditions for the annealing treatment include: being carried out under a vacuum condition, the vacuum degree is 10 -1 ~10 -5Pa, the temperature is 600 - 650 °C, for example, it can be 600 °C, 610 °C, 620 °C, 630 °C, 640 °C, 650 °C or any value within the range composed of any two of these values, the time is 5 - 6 h, for example, it can be 5 h, 5.1 h, 5.2 h, 5.3 h, 5.4 h, 5.5 h, 5.6 h, 5.7 h, 5.8 h, 5.9 h, 6 h or any value within the range composed of any two of these values. The above embodiments are beneficial to eliminating the stress of the titanium wire and lattice strengthening, and obtaining a composite electrode with a suitable structure.

[0031] The second aspect of the present disclosure provides a composite electrode prepared by the method described in the first aspect of the present disclosure.

[0032] The third aspect of the present disclosure provides a composite electrode, which includes a composite material wire and a graphite layer coated on the surface of the composite material wire, and the composite material wire includes a titanium wire and titanium dioxide coated on the surface of the titanium wire.

[0033] According to an embodiment of the present disclosure, the thickness of the graphite layer is 10 - 50 μm, for example, it can be 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm or any value within the range composed of any two of these values. The above embodiments are beneficial to making the composite electrode have suitable micropores, mesopores and macropores, making the composite electrode have a suitable specific surface area, and improving the electrocatalytic performance of the composite electrode.

[0034] According to an embodiment of the present disclosure, the titanium wire is formed into a wire mesh, and the pore diameter of the wire mesh is 0.3 - 1 mm, for example, it can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm or any value within the range composed of any two of these values.

[0035] According to an embodiment of the present disclosure, the proportion of the micropore pore volume of the composite electrode is 40 - 60%, for example, it can be 40%, 43%, 45%, 47%, 49%, 50%, 53%, 55%, 57%, 59%, 60% or any value within the range composed of any two of these values, the proportion of the mesopore pore volume is 20 - 40%, for example, it can be 20%, 23%, 25%, 27%, 29%, 30%, 33%, 35%, 37%, 39%, 40% or any value within the range composed of any two of these values, the proportion of the macropore pore volume is 10 - 20%, for example, it can be 10%, 11%, 13%, 15%, 17%, 19%, 20% or any value within the range composed of any two of these values; the specific surface area of the composite electrode is 50 - 200 m 2 / g, for example, it can be 50 m 2 / g, 55 m 2 / g, 60 m 2 / g, 70 m 2 / g, 80 m 2 / g, 90 m 2 / g, 100 m 2 / g, 120 m 2 / g, 140 m 2 / g, 160 m 2 / g, 180 m 2 / g, 200 m 2 / g or any value within the range formed by any two of these values.

[0036] The fourth aspect of the present disclosure provides a method for removing antibiotics from water by electrochemistry, using the composite electrode described in the second aspect and / or the third aspect of the present disclosure.

[0037] According to an embodiment of the present disclosure, the antibiotics include one or more of tetracyclines, sulfonamides, and fluoroquinolones.

[0038] According to an embodiment of the present disclosure, the conditions of the electrochemistry reaction include: the electrode voltage is 1.5 - 3 V, for example, it can be 1.5 V, 1.7 V, 1.9 V, 2 V, 2.1 V, 2.3 V, 2.5 V, 2.7 V, 2.9 V, 3 V or any value within the range formed by any two of these values; and / or, the pH of the solution is 4 - 10, for example, the pH can be 4, 5, 6, 7, 8, 9, 10 or any value within the range formed by any two of these values; and / or, the solution contains one or more ions of Cl - , SO4 2- , NO3 - and PO4 3- ; and / or, the solution contains humic acid, and the concentration of the humic acid is 50 - 300 mg / L, for example, it can be 50 mg / L, 60 mg / L, 70 mg / L, 80 mg / L, 90 mg / L, 100 mg / L, 130 mg / L, 150 mg / L, 170 mg / L, 190 mg / L, 200 mg / L, 220 mg / L, 240 mg / L, 260 mg / L, 280 mg / L, 300 mg / L or any value within the range formed by any two of these values. The above embodiments are beneficial to improving the removal effect of the composite electrode on antibiotics.

[0039] The present disclosure will be further described in detail below in conjunction with embodiments, but it does not limit the present disclosure. Unless otherwise specified, the reagents used in the present disclosure are all commercially available. The graphite used was purchased from Shanghai Reagent Co., Ltd., with the product number 7782-42-5; the tetracycline antibiotic was purchased from Shanghai Reagent Co., Ltd., with the product number 60-54-8, the sulfonamide antibiotic was purchased from Sigma-Aldrich Co., LLC, with the product number 68-35-9, and the fluoroquinolone antibiotic was purchased from Tokyo Chemical Industry Co., Ltd., with the product number 85721-33-1.

[0040] Example 1 Select a titanium rod with a length of 1 m and a diameter Φ of 10 mm, with a purity of 99.999%. Perform a flowing pre-cleaning using deionized water. The temperature of the pre-cleaning is 65 °C, and the flow rate is 40 m³ / h; perform a skiving treatment on the pre-cleaned titanium rod. The skiving thickness is 1.2 mm to remove the oxide layer on the surface of the titanium rod; perform a first wire drawing treatment on the skived titanium rod. Put the skived titanium billet into a first vacuum furnace to evacuate, heat it to 1000 °C in 4 h, and perform stretching along the length direction of the titanium rod. Control the stretching ratio to be 2:1, keep it warm for 2 hours and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ6 mm through wire drawing by a first roller die wire drawing machine. The wire drawing speed is 5 cm / min. Perform a test using XRD. Characteristic peaks appear at 2θ of 27.4°, 36.0°, 39.1°, 41.2°, 44.0°, 54.3° and 56.6°, indicating that titanium dioxide is in-situ generated on the surface of the titanium wire; perform a secondary cleaning on the Φ6 mm composite material wire using water. The temperature is 20 °C, and the flow rate is 5 m³ / h; place the secondary-cleaned composite material wire in a graphite suspension for impregnation treatment. The impregnation time is 12 h. The concentration of the graphite suspension is 20 g / L. The particle size of the used graphite is 3 mm, and the specific surface area is 50 m 2 / g. The solvent is isopropyl alcohol. After the impregnation is completed, the thickness of the graphite layer on the surface of the composite material wire is measured to be 50 μm. Put the impregnated composite material wire into a second vacuum furnace to evacuate, heat it to 700 °C in 30 minutes, keep it warm for 12 h and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ3 mm through wire drawing by a second roller die wire drawing machine. The wire drawing speed is 10 cm / min. Perform stretching along the length direction of the composite material wire, and the stretching ratio is 1:1; place the Φ3 mm composite material wire in an annealing furnace with a vacuum degree of 10 -4 Pa for annealing treatment. The temperature is 650 °C, keep it warm for 6 h, evacuate the air and replace it with argon, cool it to 150 °C, and weave it into a titanium mesh to obtain a composite electrode. This composite electrode includes a composite material wire and a graphite layer coated on the surface of the composite material wire. The composite material wire includes a titanium wire and titanium dioxide on the surface of the titanium wire; through a scanning electron microscope test on the composite electrode, as Figure 1 shown, it can be seen that the titanium wire forms a wire mesh, and the pore diameter of the mesh holes is 0.4 mm.

[0041] Example 2 Select a titanium rod with a length of 1 m and a diameter Φ of 10 mm, with a purity of 99.999%. Conduct a flowing pre-cleaning using deionized water. The temperature of the pre-cleaning is 65 °C and the flow rate is 40 m³ / h; perform a skiving treatment on the pre-cleaned titanium rod, with a skiving thickness of 1.2 mm, to remove the oxide layer on the surface of the titanium rod; conduct a first wire drawing treatment on the skived titanium rod. Put the skived titanium rod into a first vacuum furnace to evacuate, heat it to 1000 °C in 4 h, stretch it along the length direction of the titanium rod, control the draw ratio to be 3:1, keep it warm for 2 hours and then cool it naturally to room temperature. Obtain a composite material wire with a specification of Φ6 mm through wire drawing by a first roller die wire drawing machine, and the wire drawing speed is 4 cm / min; conduct a secondary cleaning on the Φ6 mm composite material wire using water, with a temperature of 25 °C and a flow rate of 3 m³ / h; immerse the secondary-cleaned composite material wire in a graphite suspension. The immersion time is 8 h, the concentration of the graphite suspension is 15 g / L, the solvent is ethanol. After the immersion is completed, the thickness of the graphite layer on the surface of the composite material wire is measured to be 40 μm. Put the immersed composite material wire into a second vacuum furnace to evacuate, heat it to 700 °C in 30 minutes, keep it warm for 12 h and then cool it naturally to room temperature. Obtain a composite material wire with a specification of Φ3 mm through wire drawing by a second roller die wire drawing machine, and the wire drawing speed is 7 cm / min, stretch it along the length direction of the composite material wire, and the draw ratio is 2:1; place the Φ3 mm composite material wire in an annealing furnace with a vacuum degree of 10 -4 Pa for annealing treatment, with a temperature of 650 °C, keep it warm for 6 h, evacuate the air and replace it with argon, cool it to 150 °C, and braid it into a titanium mesh to obtain a composite electrode.

[0042] Example 3 Select a titanium rod with a length of 1 m and a diameter Φ of 10 mm, with a purity of 99.999%. Use deionized water for flowing pre-cleaning. The temperature of the pre-cleaning is 65 °C and the flow rate is 40 m³ / h. Perform skinning treatment on the pre-cleaned titanium rod, with a skinning thickness of 1.2 mm to remove the oxide layer on the surface of the titanium rod. Perform the first wire drawing treatment on the skinned titanium rod. Put the skinned titanium rod into the first vacuum furnace to evacuate, heat it to 1000 °C in 4 h, stretch it along the length direction of the titanium rod, control the drawing ratio to be 5:1, keep it warm for 2 hours and then cool it naturally to room temperature. Obtain a composite material wire with a specification of Φ6 mm by wire drawing with the first roller die wire drawing machine, and the wire drawing speed is 6 cm / min. Use water to perform secondary cleaning on the Φ6 mm composite material wire, with a temperature of 30 °C and a flow rate of 4 m³ / h. Immerse the secondary-cleaned composite material wire in a graphite suspension for impregnation treatment. The impregnation time is 9 h, the concentration of the graphite suspension is 18 g / L, the solvent is water. After the impregnation is completed, the thickness of the graphite layer on the surface of the composite material wire is measured to be 50 μm. Put the impregnated composite material wire into the second vacuum furnace to evacuate, heat it to 700 °C in 30 minutes, keep it warm for 12 h and then cool it naturally to room temperature. Obtain a titanium wire with a specification of Φ3 mm by wire drawing with the second roller die wire drawing machine, stretch it along the length direction of the composite material wire, and the wire drawing speed is 10 cm / min, and the drawing ratio is 2:1. Place the Φ3 mm composite material wire in an annealing furnace with a vacuum degree of 10 -4 Pa for annealing treatment, with a temperature of 650 °C, keep it warm for 6 h, evacuate the air and replace it with argon, cool it to 150 °C, and braid it into a titanium mesh to obtain a composite electrode.

[0043] Example 4 Select a titanium rod with a length of 1 m and a diameter Φ of 10 mm, with a purity of 99.999%. Conduct a flowing pre-cleaning using deionized water. The temperature of the pre-cleaning is 65 °C and the flow rate is 40 m³ / h; perform a peeling treatment on the pre-cleaned titanium rod, with a peeling thickness of 1.2 mm, to remove the oxide layer on the surface of the titanium rod; conduct the first wire drawing treatment on the peeled titanium rod. Put the peeled titanium rod into the first vacuum furnace to evacuate, heat it to 1000 °C in 4 h, perform stretching along the length direction of the titanium rod, control the stretching ratio to be 7:1, keep it warm for 2 hours and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ6 mm through wire drawing by the first roller die wire drawing machine, and the wire drawing speed is 8 cm / min; conduct a secondary cleaning on the Φ6 mm composite material wire using water, with a temperature of 30 °C and a flow rate of 3 m³ / h; place the secondary-cleaned composite material wire in a graphite suspension for impregnation treatment. The impregnation time is 10 h, the concentration of the graphite suspension is 13 g / L, and the solvent is a mixed solution of ethanol and water. After the impregnation is completed, the thickness of the graphite layer on the surface of the composite material wire is measured to be 50 μm. Put the impregnated composite material wire into the second vacuum furnace to evacuate, heat it to 700 °C in 30 minutes, keep it warm for 12 h and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ3 mm through wire drawing by the second roller die wire drawing machine, perform stretching along the length direction of the composite material wire, the wire drawing speed is 10 cm / min, and the stretching ratio is 2:1; place the Φ3 mm composite material wire in an annealing furnace with a vacuum degree of 10 -4 Pa for annealing treatment, with a temperature of 650 °C, keep it warm for 6 h, evacuate the air and replace it with argon, cool it to 150 °C, and weave it into a titanium mesh to obtain a composite electrode.

[0044] Example 5 Select a titanium plate with a length of 1 m, a width of 0.5 m, and a thickness of 11 mm, with a purity of 99.999%. Conduct a flowing pre-cleaning using deionized water. The temperature of the pre-cleaning is 45 °C, and the flow rate is 30 m³ / h. Perform a peeling treatment on the pre-cleaned titanium plate, with a peeling thickness of 0.8 mm, to remove the oxide layer on the surface of the titanium plate. Perform a first wire drawing treatment on the peeled titanium plate. Place the peeled titanium plate in a first vacuum furnace to evacuate, heat to 1000 °C in 4 h, perform stretching along the length direction of the titanium plate, control the stretching ratio to be 10:1, keep it warm for 2 hours, and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ6 mm through wire drawing by a first roller die wire drawing machine, and the wire drawing speed is 5 cm / min. Use water to perform a secondary cleaning on the Φ6 mm composite material wire, with a temperature of 30 °C and a flow rate of 5 m³ / h. Immerse the secondary-cleaned composite material wire in a graphite suspension for impregnation treatment. The impregnation time is 12 h, the concentration of the graphite suspension is 20 g / L, the solvent is ethanol. After the impregnation is completed, the thickness of the graphite layer on the surface of the composite material wire is measured to be 40 μm. Place the impregnated composite material wire in a second vacuum furnace to evacuate, heat to 700 °C in 30 minutes, keep it warm for 12 h, and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ3 mm through wire drawing by a second roller die wire drawing machine, perform stretching along the length direction of the composite material wire, and the stretching ratio is 3:1, and the wire drawing speed is 5 cm / min. Place the Φ3 mm composite material wire in an annealing furnace with a vacuum degree of 10 -4 Pa for annealing treatment, with a temperature of 600 °C, keep it warm for 6 h, evacuate the air and replace it with argon, cool to 150 °C, and weave it into a titanium mesh to obtain a composite electrode.

[0045] Example 6 The method of this example is the same as that of Example 1, except that the stretching ratio during the first wire drawing treatment is 12:1.

[0046] Example 7 The method of this example is the same as that of Example 1, except that the concentration of the graphite suspension is 30 g / L, the impregnation treatment is 15 h, and after the impregnation is completed, the thickness of the graphite powder on the surface of the titanium wire is measured to be 60 μm.

[0047] Example 8 The method of this example is the same as that of Example 1, except that the stretching ratio during the second wire drawing treatment is 12:1.

[0048] Comparative Example 1 This Comparative Example 1 is the same as Example 1, except that the impregnation treatment is not performed in this comparative example; the specific method is as follows: Select a titanium rod with a length of 1 m and a diameter Φ of 10 mm, with a purity of 99.999%. Conduct a flowing pre-cleaning using deionized water. The temperature of the pre-cleaning is 65 °C and the flow rate is 40 m³ / h; perform a peeling treatment on the titanium rod after pre-cleaning, with a peeling thickness of 1.2 mm to remove the oxide layer on the surface of the titanium rod; conduct the first wire drawing treatment on the peeled titanium rod. Put the peeled titanium billet into the first vacuum furnace to evacuate, heat it to 1000 °C in 4 h, perform stretching along the length direction of the titanium rod, control the drawing ratio to be 2:1, keep it warm for 2 hours and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ6 mm through wire drawing by the first roller die wire drawing machine, and the wire drawing speed is 5 cm / min; use water to conduct a secondary cleaning on the Φ6 mm composite material wire, with a temperature of 30 °C and a flow rate of 5 m³ / h; place the composite material wire after secondary cleaning into the second vacuum furnace to evacuate, heat it to 700 °C in 30 minutes, keep it warm for 12 h and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ3 mm through wire drawing by the second roller die wire drawing machine, perform stretching along the length direction of the composite material wire, the wire drawing speed is 10 cm / min, and the drawing ratio is 1:1; place the Φ3 mm composite material wire into an annealing furnace with a vacuum degree of 10 -4 Pa for annealing treatment, with a temperature of 650 °C, keep it warm for 6 h, evacuate the air and replace it with argon, cool it to 150 °C, and weave it into a titanium mesh to obtain a composite electrode.

[0049] Comparative Example 2 This Comparative Example 2 is the same as Example 1, except that the second wire drawing treatment is not carried out in this comparative example. The specific method is as follows: Select a titanium rod with a length of 1 m and a diameter Φ of 10 mm, with a purity of 99.999%. Conduct a flowing pre-cleaning using deionized water. The temperature of the pre-cleaning is 65 °C and the flow rate is 40 m³ / h; perform a peeling treatment on the titanium rod after pre-cleaning, with a peeling thickness of 1.2 mm to remove the oxide layer on the surface of the titanium rod; conduct the first wire drawing treatment on the peeled titanium rod. Put the peeled titanium billet into the first vacuum furnace to evacuate, heat it to 1000 °C in 4 h, perform stretching along the length direction of the titanium rod, control the drawing ratio to be 2:1, keep it warm for 2 hours and then naturally cool to room temperature. Obtain a composite material wire with a specification of Φ6 mm through wire drawing by the first roller die wire drawing machine, and the wire drawing speed is 5 cm / min; use water to conduct a secondary cleaning on the Φ6 mm composite material wire, with a temperature of 25 °C and a flow rate of 5 m³ / h; place the composite material wire after secondary cleaning into a graphite suspension for impregnation treatment, with an impregnation time of 12 h, the concentration of the graphite suspension is 20 g / L, the solvent is ethanol. After the impregnation is completed, the thickness of the graphite layer on the surface of the composite material wire is measured to be 50 μm. Place the impregnated composite material wire into a vacuum degree of 10 -4Annealing treatment was carried out in an annealing furnace at 650 °C for 6 h, the air was excluded and replaced with argon, cooled to 150 °C, and woven into a titanium mesh to obtain a composite electrode.

[0050] Comparative Example 3 This Comparative Example 3 is the same as Example 1, the difference is that the first wire drawing treatment was not carried out in this comparative example; the specific method is as follows: Select a titanium rod with a length of 1 m and a diameter Φ of 10 mm, with a purity of 99.999%. Flow pre-cleaning was carried out using deionized water. The temperature of the pre-cleaning was 65 °C and the flow rate was 40 m³ / h; the titanium rod after pre-cleaning was skived, and the skiving thickness was 1.2 mm to remove the oxide layer on the surface of the titanium rod; the skived titanium rod was placed in a graphite suspension for impregnation treatment, and the impregnation time was 12 h. The concentration of the graphite suspension was 20 g / L, and the solvent was isopropanol. After the impregnation was completed, the thickness of the graphite layer on the surface of the titanium rod was measured to be 40 μm. The impregnated titanium rod was put into a second vacuum furnace to evacuate, heated to 700 °C in 30 minutes, naturally cooled to room temperature after holding for 12 h, and drawn into a composite material wire with a specification of Φ3 mm through a second roller die wire drawing machine, and stretched along the length direction of the composite material wire. The wire drawing speed was 10 cm / min, and the drawing ratio was 3:1; the Φ3 mm composite material wire was placed in a vacuum of 10 -4 Annealing treatment was carried out in an annealing furnace at 650 °C for 6 h, the air was excluded and replaced with argon, cooled to 150 °C, and woven into a titanium mesh to obtain a composite electrode.

[0051] Test Example 1 The graphite layer thickness, mesh hole diameter of the wire mesh, pore volume and specific surface area of the composite electrodes obtained in the above examples and comparative examples were tested; the thickness of the graphite layer was tested by scanning electron microscopy; the mesh hole diameter of the wire mesh was tested by scanning electron microscopy; the pore volume ratio of the composite electrode was tested by nitrogen adsorption and desorption; the specific surface area of the composite electrode was tested by nitrogen adsorption and desorption. The test results are as Figures 2 - 3 shown in Table 1.

[0052] Table 1

[0053] Test Example 2 The composite electrodes of the above examples and comparative examples were used to remove antibiotics in different livestock and poultry breeding wastewaters, and the removal effect of the composite electrodes was tested. The concentration of antibiotics was tested by high performance liquid chromatography. The calculation formula of the removal efficiency = (initial concentration of antibiotics - concentration after removing antibiotics) / initial concentration of antibiotics × 100%. The results are shown in Table 2.

[0054] Table 2

[0055] According to the data in Table 2, it can be seen that the composite electrode of the present disclosure can still maintain excellent antibiotic removal performance under the conditions that the pH of the solution is 4-10, or the solution contains Cl - , SO4 2- , NO3 - and PO4 3- plasma, or the solution contains humic acid. By comparing Example 1 with Example 6, it can be seen that within the range of the conditions of the first wire drawing treatment preferred in the present disclosure, the obtained composite electrode has better antibiotic removal performance. By comparing Example 1 with Example 7, it can be seen that within the range of the thickness of the graphite layer preferred in the present disclosure, the obtained composite electrode has better antibiotic removal performance. By comparing Example 1 with Example 8, it can be seen that within the range of the conditions of the second wire drawing treatment preferred in the present disclosure, the obtained composite electrode has better antibiotic removal performance.

[0056] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0057] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination methods.

[0058] In addition, any combination can be made between various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A method for preparing a composite electrode, characterized in that, The method includes: performing a first wire drawing treatment on the pretreated titanium metal raw material to obtain a product of the first wire drawing treatment; impregnating the product of the first wire drawing treatment in a graphite suspension, and successively performing a second wire drawing treatment and an annealing treatment on the impregnated product; Wherein, the titanium metal raw material includes a titanium blank.

2. The method according to claim 1, wherein The titanium blank includes one or more of titanium plates and titanium rods; the purity of the titanium blank is above 99.999%; The diameter of the titanium rod is 10 - 11 mm; the length of the titanium plate is 0.8 - 1.2 m, the width is 0.4 - 0.6 m, and the thickness is 9 - 13 mm; Optionally, the pretreatment includes: pre - cleaning the titanium metal raw material, the temperature of the pre - cleaning is 45 - 65 °C, the pre - cleaning method is flow cleaning, the solvent is water, and the flow rate is 30 - 40 m³ / h.

3. The method according to claim 1, wherein, The conditions of the first wire drawing treatment include: being carried out under vacuum conditions, the temperature is 900 - 1000 °C, the time is 1 - 2 h, the drawing ratio is (2 - 10):1, and the drawing speed is 0.5 - 10 cm / min; Optionally, the method further includes: performing a skinning treatment on the pretreated titanium metal raw material before the first wire drawing treatment, and the skinning thickness is 0.8 - 1.2 mm.

4. The method according to claim 1, wherein The concentration of the graphite suspension is 10 - 20 g / L, the solvent of the graphite suspension includes one or more of ethanol, isopropanol, and water; the time of the impregnation treatment is 6 - 12 h; Optionally, the method further includes: performing secondary cleaning on the product of the first wire drawing treatment before the impregnation treatment, the temperature of the secondary cleaning is 20 - 30 °C, the solvent used for the secondary cleaning includes water, and the flow rate is 1 - 5 m³ / h.

5. The method according to claim 1, wherein, The conditions of the second wire drawing treatment include: being carried out under vacuum conditions, the temperature is 600 - 700 °C, the time is 8 - 12 h, the drawing ratio is (1 - 3):1, and the drawing speed is 0.5 - 10 cm / min; The conditions of the annealing treatment include: being carried out under vacuum conditions, with a vacuum degree of 10 -1 ~10 -5 Pa, a temperature of 600 - 650 °C, and a time of 5 - 6 h.

6. A composite electrode prepared by the method according to any one of claims 1 - 5.

7. A composite electrode, characterized in that, The composite electrode includes a composite material wire and a graphite layer coated on the surface of the composite material wire, and the composite material wire includes a titanium wire and titanium dioxide coated on the surface of the titanium wire.

8. The composite electrode according to claim 7, wherein, The thickness of the graphite layer is 10 - 50 μm; the titanium wire is formed into a wire mesh, and the pore diameter of the wire mesh is 0.3 - 1 mm; and / or, The micropore volume fraction of the composite electrode is 40-60%, the mesopore volume fraction is 20-40%, and the macropore volume fraction is 10-20%; the specific surface area of the composite electrode is 50-200 m 2 / g.

9. A method for removing antibiotics from water by electrochemical reaction, characterized in that, Using the composite electrode according to any one of claims 6 - 8.

10. The method according to claim 9, wherein, The antibiotic includes one or more of tetracyclines, sulfonamides, and fluoroquinolones; and / or, The conditions of the electrochemical reaction include: the electrode voltage is 1.5 - 3 V; and / or, The pH of the water body is 4 - 10; and / or, The water body contains Cl - , SO4 2- , NO3 - and PO4 3- ; and / or, The water body contains humic acid, and the concentration of the humic acid is 50 - 300 mg / L.

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