Method for removing antibiotics from water using composite electrode, composite electrode and preparation method thereof

Abstract

The present disclosure relates to a method for removing antibiotics from water using a composite electrode, a composite electrode, and a preparation method thereof, the method comprising: subjecting a pretreated titanium metal raw material to a first wire drawing treatment to obtain a first wire drawing product; subjecting the first wire drawing product to an immersion treatment in a graphite suspension, and subjecting the impregnation product to a second wire drawing treatment and an annealing treatment in sequence; wherein the titanium metal raw material comprises a titanium billet. The composite electrode disclosed herein has a three-dimensional network structure in which micropores, mesopores, and macropores are interconnected, which can effectively improve the electrocatalytic performance of the composite electrode. The composite electrode disclosed herein has a simple preparation process and can be used in the field of wastewater treatment. It can still maintain a good removal effect on antibiotics in a solution containing inorganic ions at a pH of 4 to 10 and in an environment containing humic acid.

Description

Technical Field

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

[0002] In today's world, the decline of water quality has caused widespread concern, mainly due to persistent organic pollutants generated by industrial, agricultural and urban activities. Electrochemical advanced oxidation process (EAOP) has performed well in removing organic pollutants. EAOP generates strong oxidants (such as hydroxyl radicals ·OH, sulfate radicals SO4· - and chlorine radical Cl· - ) to oxidize organic matter, but inorganic ions and natural organic matter (NOM) in water can lead to 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-radical pathways such as high-valent species and electron transfer. For example, Yu et al. proposed an EAOP based on CoFe-LDH / MoS2, which can effectively remove norfloxacin in a wide pH range. However, the influence of NOM and inorganic ions is still difficult to avoid. Feng et al. improved the EAOP by regulating the copper-modified carbon interface. 1 The generation rate of O2 enhances the degradation efficiency of bisphenol A, but the generation amount under acidic and neutral conditions is significantly reduced, which has application limitations. Summary of the Invention

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

[0005] To achieve the above-mentioned object, the present disclosure provides a method for preparing a composite electrode in a first aspect, the method comprising: subjecting a pretreated titanium metal raw material to a first wire drawing process to obtain a first wire drawing product; impregnating the first wire drawing product in a graphite suspension, and sequentially subjecting the impregnated product to a second wire drawing process and an annealing process;

[0006] Wherein, the titanium metal raw material includes titanium blank.

[0007] Optionally, the titanium blank includes one or more of a titanium plate and a titanium rod; the purity of the titanium blank is above 99.999%;

[0008] 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;

[0009] Optionally, the pretreatment includes: pre-cleaning the titanium metal raw material, the pre-cleaning temperature is 45-65° C., the pre-cleaning method is flow cleaning, the solvent is water, and the flow rate is 30-40 m³ / h.

[0010] Optionally, the conditions of the first wire drawing process include: being carried out under vacuum conditions, at a temperature of 900-1000° C., for 1-2 hours, with a stretching ratio of (2-10):1 and a stretching speed of 0.5-10 cm / min;

[0011] Optionally, the method further comprises: performing a peeling process on the pretreated titanium metal raw material before the first wire drawing process, wherein the peeling thickness is 0.8-1.2 mm.

[0012] Optionally, 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; and the immersion treatment time is 6-12 h;

[0013] Optionally, the method further comprises: performing a secondary cleaning on the product of the first wire drawing treatment before the immersion treatment, wherein the temperature of the secondary cleaning is 20-30° C., and the solvent used for the secondary cleaning comprises water, and the flow rate is 1-5 m³ / h.

[0014] Optionally, the conditions of the second wire drawing process include: being carried out under vacuum conditions, at a temperature of 600-700°C, for 8-12 hours, with a stretching ratio of (1-3):1, and a stretching speed of 0.5-10 cm / min;

[0015] The annealing treatment conditions include: being carried out under vacuum conditions, with a vacuum degree of 10 -1 ~10 -5 Pa, temperature is 600~650℃, and time is 5~6h.

[0016] A second aspect of the present disclosure provides a composite electrode prepared by the method described in the first aspect of the present disclosure.

[0017] A third aspect of the present disclosure provides a composite electrode, comprising a composite material wire and a graphite layer coated on a surface of the composite material wire, wherein the composite material wire comprises a titanium wire and titanium dioxide coated on a surface of the titanium wire.

[0018] Optionally, the graphite layer has a thickness of 10-50 μm; the titanium wire is formed into a wire mesh, and the mesh size of the wire mesh is 0.3-1 mm; and / or,

[0019] The volume of the composite electrode is 40-60% for micropores, 20-40% for mesopores, and 10-20% for macropores; the specific surface area of ​​the composite electrode is 50-200 m 2 / g.

[0020] A fourth aspect of the present disclosure provides a method for removing antibiotics from water through electrochemical reaction, using the composite electrode described in the second aspect and / or the third aspect of the present disclosure.

[0021] Optionally, the antibiotics include one or more of tetracyclines, sulfonamides and fluoroquinolones; and / or,

[0022] The conditions of the electrochemical reaction include: an electrode voltage of 1.5 to 3 V; and / or,

[0023] The pH of the water body is 4 to 10; and / or,

[0024] The water contains Cl - 、SO4 2- 、NO3 - and PO4 3- One or more ions in; and / or,

[0025] The water body contains humic acid, and the concentration of the humic acid is 50-300 mg / L.

[0026] Through the above technical solution, the present invention processes titanium metal raw material into slender titanium wire by wire drawing, and titanium dioxide can be generated in situ on the surface of the titanium wire at high temperature; then through impregnation treatment, a graphite layer of a certain thickness is adsorbed on the surface of the titanium wire, and then annealing treatment is performed to eliminate the stress of the titanium wire and strengthen the lattice, and the titanium mesh electrode is woven into a composite electrode. The composite electrode has a three-dimensional network structure with micropores, mesopores and macropores interconnected, which can effectively improve the electrocatalytic performance of the composite electrode. The composite electrode disclosed in the present invention has a simple preparation process and good large-scale integrated productivity. It 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.

[0027] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0029] Figure 1is a SEM image of the composite electrode of Example 1 of the present disclosure.

[0030] Figure 2 2 is a graph showing the N2 adsorption and desorption curves of the composite electrodes of Examples 1 to 4 of the present disclosure.

[0031] Figure 3 1 is a pore structure distribution diagram of the composite electrodes of Examples 1 to 4 of the present disclosure. DETAILED DESCRIPTION

[0032] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0033] A first aspect of the present disclosure provides a method for preparing a composite electrode, the method comprising: subjecting a pretreated titanium metal raw material to a first wire drawing process to obtain a first wire drawing product; immersing the first wire drawing product in a graphite suspension, and sequentially subjecting the impregnated product to a second wire drawing process and an annealing process;

[0034] Wherein, the titanium metal raw material includes titanium blank.

[0035] The present invention processes titanium metal raw material into slender titanium wire by drawing it, and titanium dioxide can be generated in situ on the surface of the titanium wire at high temperature; then, through impregnation treatment, graphite of a certain thickness is adsorbed on the surface of the titanium wire, and then annealing treatment is performed to eliminate the stress of the titanium wire and strengthen the lattice, and the titanium mesh electrode is woven into a composite electrode. The composite electrode has a three-dimensional network structure with micropores, mesopores and macropores interconnected, which can effectively improve the electrocatalytic performance of the composite electrode. The composite electrode disclosed in the present invention has a simple preparation process and good large-scale integrated productivity. It 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.

[0036] According to one embodiment of the present disclosure, the titanium billet includes one or more of a titanium plate and a titanium rod; the purity of the titanium billet is above 99.999%; the length of the titanium plate is 0.8~1.2m, the width is 0.4~0.6m, and the thickness is 9~13mm; the diameter of the titanium rod is 10~11mm. The present disclosure does not specifically limit the length of the titanium rod, for example, it can be 0.8~1.2m.

[0037] According to one embodiment of the present disclosure, the pretreatment includes pre-cleaning the titanium metal raw material at a temperature of 45-65°C using a flow-through cleaning method using water as the solvent at a flow rate of 30-40 m³ / h. This embodiment facilitates the removal of oil and other stains from the surface of the titanium metal raw material, thereby improving the effectiveness of the first wire drawing process.

[0038] According to one embodiment of the present disclosure, the conditions of the first wire drawing treatment include: being carried out under vacuum conditions, a temperature of 900-1000°C, for example, 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 in a range consisting of any two of the numerical values ​​therein, and a time of 1-2h, for example, 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h or any value in a range consisting of any two of the numerical values ​​therein. The stretching ratio is (2-10):1, for example, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or any value within a range consisting of any two of these values. The stretching speed is 0.5-10 cm / min, for example, 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 a range consisting of any two of these values. The above embodiment is conducive to obtaining titanium wire with a suitable structure, facilitating the formation of the titanium wire into a wire mesh, and improving the electrocatalytic performance of the composite electrode.

[0039] According to one embodiment of the present disclosure, the method further includes: peeling the pretreated titanium metal raw material before the first wire drawing process, wherein the peeling thickness is 0.8 to 1.2 mm, for example, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, or any value within a range consisting of any two of these values. The above embodiment is conducive to removing the impurity layer on the surface of the titanium blank, facilitating the production of titanium wire with a suitable structure, facilitating the formation of titanium dioxide on the surface of the titanium wire, and improving the electrocatalytic performance of the composite electrode.

[0040] According to one 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 in the range of any two values ​​therein; the solvent of the graphite suspension includes one or more of ethanol, isopropanol and water; the time of the immersion 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 in the range of any two values ​​therein. The present disclosure does not specifically limit the graphite used, for example, particles with a particle size of 1-5 mm and a specific surface area of ​​40-60 m 2 The above embodiment is conducive to forming the composite electrode into a three-dimensional network pore structure with micropores, mesopores and macropores interconnected, effectively improving its electrocatalytic performance.

[0041] According to one embodiment of the present disclosure, the method further includes: performing a secondary wash on the product of the first wire drawing process before the impregnation process, wherein the temperature of the secondary wash is 20-30°C, and the solvent used in the secondary wash includes water at a flow rate of 1-5 m³ / h. This embodiment facilitates the removal of oil and other impurities from the surface of the product of the first wire drawing process, thereby cleaning the surface and improving the adhesion of the graphite.

[0042] According to one embodiment of the present disclosure, the conditions of the second wire drawing process include: being carried out under vacuum conditions, a temperature of 600-700°C, for example, 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 in a range consisting of any two thereof, a time of 8-12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, or any value in a range consisting of any two thereof, and a stretching ratio of (1-3):1, for example, 1:1, 1.1:1, 1.2:1, 1.3:1, 1. The ratio of the titanium wire to the titanium alloy is 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 in the range of any two thereof, and the stretching speed is 0.5-10 cm / min, for example, 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 in the range of any two thereof. The above embodiment is conducive to obtaining a titanium wire with a suitable structure, making it easy for the titanium wire to form a wire mesh, and improving the electrocatalytic performance of the composite electrode.

[0043] According to one embodiment of the present disclosure, the annealing treatment conditions include: performing the annealing treatment under vacuum conditions with a vacuum degree of 10 -1 ~10 -5 Pa, the temperature is 600-650°C, for example, 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, or any value within a range consisting of any two of them, and the time is 5-6 hours, for example, 5 hours, 5.1 hours, 5.2 hours, 5.3 hours, 5.4 hours, 5.5 hours, 5.6 hours, 5.7 hours, 5.8 hours, 5.9 hours, 6 hours, or any value within a range consisting of any two of them. The above embodiment is conducive to eliminating stress in the titanium wire and lattice strengthening, thereby obtaining a composite electrode with a suitable structure.

[0044] A second aspect of the present disclosure provides a composite electrode prepared by the method described in the first aspect of the present disclosure.

[0045] A third aspect of the present disclosure provides a composite electrode, comprising a composite material wire and a graphite layer coated on a surface of the composite material wire, wherein the composite material wire comprises a titanium wire and titanium dioxide coated on a surface of the titanium wire.

[0046] According to one embodiment of the present disclosure, the thickness of the graphite layer is 10 to 50 μm, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or any value within a range consisting of any two of these values. This embodiment is beneficial for providing the composite electrode with suitable micropores, mesopores, and macropores, providing the composite electrode with a suitable specific surface area, and improving the electrocatalytic performance of the composite electrode.

[0047] According to one embodiment of the present disclosure, the titanium wire is formed into a wire mesh, and the mesh diameter of the wire mesh is 0.3~1mm, for example, it can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm or any value in the range consisting of any two of the values.

[0048] According to one embodiment of the present disclosure, the micropore 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 in the range of any two values ​​thereof, the mesopore volume is 20-40%, for example, it can be 20%, 23%, 25%, 27%, 29%, 30%, 33%, 35%, 37%, 39%, 40% or any value in the range of any two values ​​thereof, the macropore volume is 10-20%, for example, it can be 10%, 11%, 13%, 15%, 17%, 19%, 20% or any value in the range of any two values ​​thereof; the specific surface area of ​​the composite electrode is 50-200m 2 / g, for example, 50m 2 / g、55m 2 / g, 60m 2 / g、70m 2 / g、80m 2 / g、90m 2 / g、100m 2 / g, 120m 2 / g, 140m 2 / g, 160m 2 / g, 180m 2 / g, 200m 2 / g or any value in the range consisting of any two values ​​therein.

[0049] A fourth aspect of the present disclosure provides a method for removing antibiotics from water through electrochemical reaction, using the composite electrode described in the second aspect and / or the third aspect of the present disclosure.

[0050] According to one embodiment of the present disclosure, the antibiotics include one or more of tetracyclines, sulfonamides and fluoroquinolones.

[0051] According to one embodiment of the present disclosure, the conditions for the electrochemical reaction include: an electrode voltage of 1.5 to 3 V, for example, 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 in a range consisting of any two of the values ​​thereof; and / or, the pH of the solution is 4 to 10, for example, the pH can be 4, 5, 6, 7, 8, 9, 10, or any value in a range consisting of any two of the values ​​thereof; and / or, the solution contains Cl - 、SO4 2- 、NO3 - and PO4 3- and / or the solution contains humic acid, the concentration of which is 50-300 mg / L, for example, 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 a range consisting of any two of these values. The above embodiment is conducive to improving the removal effect of the composite electrode on antibiotics.

[0052] The present disclosure is further described in detail below with reference to the examples, but is not intended to 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 Test Company with the item number 7782-42-5; the tetracycline antibiotics were purchased from Shanghai Test Company with the item number 60-54-8; the sulfonamide antibiotics were purchased from Sigma with the item number 68-35-9; and the fluoroquinolone antibiotics were purchased from TCI with the item number 85721-33-1.

[0053] Example 1

[0054] A titanium rod with a length of 1m and a diameter of 10mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 65℃ and a flow rate of 40m³ / h. The pre-cleaned titanium rod was peeled with a peeling thickness of 1.2mm to remove the oxide layer on the surface of the titanium rod. The peeled titanium rod was subjected to the first wire drawing process. The peeled titanium billet was placed in a first vacuum furnace and vacuumed. It was heated to 1000℃ for 4 hours and stretched along the length direction of the titanium rod. The stretching ratio was controlled to 2:1. After keeping warm for 2 hours, it was naturally cooled to room temperature and drawn through the first roller die wire drawing machine to obtain a wire with a specification of Φ The Φ6mm composite wire was drawn at a speed of 5cm / min and tested using XRD. Characteristic peaks appeared at 2θ of 27.4°, 36.0°, 39.1°, 41.2°, 44.0°, 54.3° and 56.6°, indicating that titanium dioxide was generated in situ on the surface of the titanium wire. The Φ6mm composite wire was washed twice with water at a temperature of 20°C and a flow rate of 5m³ / h. The composite wire after the second washing was immersed in a graphite suspension for 12h. The concentration of the graphite suspension was 20g / L. The particle size of the graphite used was 3mm and the specific surface area was 50m 2 / g, the solvent is isopropanol, and the thickness of the graphite layer on the surface of the composite material wire is measured to be 50 μm after the impregnation is completed. The composite material wire after impregnation is placed in a second vacuum furnace and evacuated, heated to 700 ° C for 30 minutes, kept warm for 12 hours and then naturally cooled to room temperature. The composite material wire with a specification of Φ3 mm is obtained by drawing through a second roller die drawing machine, the drawing speed is 10 cm / min, and the composite material wire is stretched along the length direction, and the stretching ratio is 1:1; the Φ3 mm composite material wire is placed in a vacuum furnace with a degree of vacuum of 10 -4 The composite electrode is annealed in an annealing furnace at 650°C for 6 hours, the air is removed and replaced with argon, and the electrode is cooled to 150°C and woven into a titanium mesh to obtain a composite electrode. The composite electrode comprises a composite wire and a graphite layer coated on the surface of the composite wire, wherein the composite wire comprises titanium wire and titanium dioxide on the surface of the titanium wire. The composite electrode is tested by scanning electron microscopy. Figure 1 As shown, it can be seen that the titanium wire is formed into a wire mesh with a mesh aperture of 0.4 mm.

[0055] Example 2

[0056] A titanium rod with a length of 1m and a diameter of 10mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 65℃ and a flow rate of 40m³ / h. The pre-cleaned titanium rod was peeled with a peeling thickness of 1.2mm to remove the oxide layer on the surface of the titanium rod. The titanium rod after peeling was subjected to the first wire drawing treatment. The peeled titanium rod was placed in a first vacuum furnace and vacuumed. It was heated to 1000℃ for 4h and stretched along the length direction of the titanium rod. The stretching ratio was controlled to be 3:1. After keeping warm for 2 hours, it was naturally cooled to room temperature and drawn through the first roller die drawing machine to obtain a composite material wire with a specification of Φ6mm. The drawing speed was 4 cm / min; the Φ6mm composite material wire was washed twice with water at a temperature of 25°C and a flow rate of 3m³ / h; the composite material wire after the second washing was placed in a graphite suspension for impregnation treatment, the impregnation time was 8h, the concentration of the graphite suspension was 15g / L, the solvent was ethanol, and after the impregnation was completed, the thickness of the graphite layer on the surface of the composite material wire was measured to be 40μm, the impregnated composite material wire was placed in a second vacuum furnace and vacuumed, heated to 700°C for 30 minutes, kept warm for 12h and then naturally cooled to room temperature, and drawn through a second roller die drawing machine to obtain a composite material wire with a specification of Φ3mm, the drawing speed was 7cm / min, and the composite material wire was stretched along the length direction, and the stretching ratio was 2:1; the Φ3mm composite material wire was placed in a vacuum furnace with a degree of vacuum of 10 -4 The composite electrode was annealed in an annealing furnace at 650°C for 6 hours, the air was removed and replaced with argon, and the electrode was cooled to 150°C and woven into a titanium mesh.

[0057] Example 3

[0058] A titanium rod with a length of 1m and a diameter of Φ10mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 65℃ and a flow rate of 40m³ / h. The pre-cleaned titanium rod was peeled with a peeling thickness of 1.2mm to remove the oxide layer on the surface of the titanium rod. The titanium rod after peeling was subjected to the first wire drawing treatment. The peeled titanium rod was placed in a first vacuum furnace and vacuumed. It was heated to 1000℃ for 4h and stretched along the length direction of the titanium rod. The stretching ratio was controlled to be 5:1. After keeping warm for 2 hours, it was naturally cooled to room temperature and drawn through the first roller die wire drawing machine to obtain a composite material wire with a specification of Φ6mm. The drawing speed was 6:1. cm / min; the Φ6mm composite material wire was washed twice with water at a temperature of 30℃ and a flow rate of 4m³ / h; the composite material wire after the second washing was placed in a graphite suspension for impregnation treatment, the impregnation time was 9h, the concentration of the graphite suspension was 18g / L, the solvent was water, and after the impregnation was completed, the thickness of the graphite layer on the surface of the composite material wire was measured to be 50μm, the impregnated composite material wire was placed in a second vacuum furnace and vacuumed, heated to 700℃ for 30 minutes, kept warm for 12h and then naturally cooled to room temperature, and drawn through a second roller die drawing machine to obtain a titanium wire with a specification of Φ3mm, which was stretched along the length direction of the composite material wire at a drawing speed of 10cm / min and a stretching ratio of 2:1; the Φ3mm composite material wire was placed in a vacuum furnace with a degree of vacuum of 10 -4 The composite electrode was annealed in an annealing furnace at 650°C for 6 hours, the air was removed and replaced with argon, and the electrode was cooled to 150°C and woven into a titanium mesh.

[0059] Example 4

[0060] A titanium rod with a length of 1m and a diameter of Φ10mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 65℃ and a flow rate of 40m³ / h. The pre-cleaned titanium rod was peeled with a peeling thickness of 1.2mm to remove the oxide layer on the surface of the titanium rod. The titanium rod after peeling was subjected to the first wire drawing treatment. The peeled titanium rod was placed in a first vacuum furnace and vacuumed. It was heated to 1000℃ for 4h and stretched along the length direction of the titanium rod. The stretching ratio was controlled to 7:1. After keeping warm for 2 hours, it was naturally cooled to room temperature and drawn through the first roller die wire drawing machine to obtain a composite material wire with a specification of Φ6mm. The drawing speed was 8cm / min. Water was used to draw the Φ6mm composite material. The wire was washed twice at a temperature of 30°C and a flow rate of 3 m³ / h. The composite wire after the second washing was immersed in a graphite suspension for 10 h. The concentration of the graphite suspension was 13 g / L. The solvent was a mixed solution of ethanol and water. After the immersion, the thickness of the graphite layer on the surface of the composite wire was measured to be 50 μm. The impregnated composite wire was placed in a second vacuum furnace and vacuumed. It was heated to 700°C for 30 minutes, kept warm for 12 hours, and then naturally cooled to room temperature. The composite wire with a specification of Φ3 mm was drawn through a second roller die drawing machine. The composite wire was stretched along the length direction at a drawing speed of 10 cm / min and a drawing ratio of 2:1. The Φ3 mm composite wire was placed in a vacuum furnace with a degree of vacuum of 10 -4 The composite electrode was annealed in an annealing furnace at 650°C for 6 hours, the air was removed and replaced with argon, and the electrode was cooled to 150°C and woven into a titanium mesh.

[0061] Example 5

[0062] A titanium plate with a length of 1m, a width of 0.5m and a thickness of 11mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 45°C and a flow rate of 30m³ / h. The pre-cleaned titanium plate was peeled with a thickness of 0.8mm to remove the oxide layer on the surface of the titanium plate. The peeled titanium plate was subjected to the first wire drawing treatment. The peeled titanium plate was placed in a first vacuum furnace and vacuumed. It was heated to 1000°C for 4 hours and stretched along the length direction of the titanium plate with a controllable stretching ratio of 10:1. After keeping warm for 2 hours, it was naturally cooled to room temperature and drawn through a first roller die wire drawing machine to obtain a composite material wire with a specification of Φ6mm. The drawing speed was 5cm / min. Water was used to draw the Φ The 6mm composite material wire was washed twice at a temperature of 30℃ and a flow rate of 5m³ / h. The composite material wire after the second washing was placed in a graphite suspension for impregnation treatment. The impregnation time was 12h, the concentration of the graphite suspension was 20g / L, and the solvent was ethanol. After the impregnation was completed, the thickness of the graphite layer on the surface of the composite material wire was measured to be 40μm. The impregnated composite material wire was placed in a second vacuum furnace and vacuumed. It was heated to 700℃ for 30 minutes, kept warm for 12h, and then naturally cooled to room temperature. It was drawn through a second roller die drawing machine to obtain a composite material wire with a specification of Φ3mm. The composite material wire was stretched along the length direction with a stretching ratio of 3:1 and a drawing speed of 5cm / min. The Φ3mm composite material wire was placed in a vacuum furnace with a degree of vacuum of 10 -4 The electrode was annealed in an annealing furnace at 600 °C for 6 h, the air was removed and replaced with argon, and the electrode was cooled to 150 °C and woven into a titanium mesh to obtain a composite electrode.

[0063] Example 6

[0064] The method of this embodiment is the same as that of Example 1, except that the stretching ratio during the first drawing process is 12:1.

[0065] Example 7

[0066] The method of this embodiment is the same as that of Example 1, except that the concentration of the graphite suspension is 30 g / L, the immersion treatment is 15 hours, and after the immersion is completed, the thickness of the graphite powder on the surface of the titanium wire is measured to be 60 μm.

[0067] Example 8

[0068] The method of this embodiment is the same as that of Example 1, except that the stretching ratio during the second drawing process is 12:1.

[0069] Comparative Example 1

[0070] This comparative example 1 is the same as Example 1, except that the immersion treatment is not performed in this comparative example; the specific method is as follows:

[0071] A titanium rod with a length of 1m and a diameter of 10mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 65℃ and a flow rate of 40m³ / h. The pre-cleaned titanium rod was peeled with a peeling thickness of 1.2mm to remove the oxide layer on the surface of the titanium rod. The peeled titanium rod was subjected to the first wire drawing process. The peeled titanium billet was placed in a first vacuum furnace and vacuumed. It was heated to 1000℃ for 4 hours and stretched along the length direction of the titanium rod. The stretching ratio was controlled to 2:1. After keeping warm for 2 hours, it was naturally cooled to room temperature and drawn through the first roller die. The composite material wire with a specification of Φ6mm was obtained by wire drawing with a wire drawing speed of 5cm / min; the Φ6mm composite material wire was washed twice with water at a temperature of 30℃ and a flow rate of 5m³ / h; the composite material wire after the second washing was placed in a second vacuum furnace to evacuate, heated to 700℃ for 30 minutes, kept warm for 12 hours and then naturally cooled to room temperature, and drawn by a second roller die wire drawing machine to obtain a composite material wire with a specification of Φ3mm, and stretched along the length direction of the composite material wire at a wire drawing speed of 10cm / min and a stretching ratio of 1:1; the Φ3mm composite material wire was placed in a vacuum furnace with a degree of vacuum of 10 -4 The composite electrode was annealed in an annealing furnace at 650°C for 6 hours, the air was removed and replaced with argon, and the electrode was cooled to 150°C and woven into a titanium mesh.

[0072] Comparative Example 2

[0073] Comparative Example 2 is the same as Example 1, except that the second wire drawing process is not performed in this comparative example. The specific method is as follows:

[0074] A titanium rod with a length of 1m and a diameter of 10mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 65℃ and a flow rate of 40m³ / h. The pre-cleaned titanium rod was peeled with a peeling thickness of 1.2mm to remove the oxide layer on the surface of the titanium rod. The peeled titanium rod was subjected to the first wire drawing process. The peeled titanium billet was placed in the first vacuum furnace and vacuumed. It was heated to 1000℃ for 4h and stretched along the length direction of the titanium rod. The stretching ratio was controlled to 2:1 and kept warm for 2 hours. After cooling naturally to room temperature, the composite material wire with a specification of Φ6mm was drawn by the first roller die drawing machine at a drawing speed of 5cm / min; the Φ6mm composite material wire was washed twice with water at a temperature of 25℃ and a flow rate of 5m³ / h; the composite material wire after the secondary washing was immersed in a graphite suspension for 12h, the concentration of the graphite suspension was 20g / L, and the solvent was ethanol. After the immersion, the thickness of the graphite layer on the surface of the composite material wire was measured to be 50μm. The composite material wire after the immersion was placed in a vacuum chamber with a degree of vacuum of 10 -4The composite electrode was annealed in an annealing furnace at 650°C for 6 hours, the air was removed and replaced with argon, and the electrode was cooled to 150°C and woven into a titanium mesh.

[0075] Comparative Example 3

[0076] Comparative Example 3 is the same as Example 1, except that the first wire drawing process is not performed in this comparative example; the specific method is as follows:

[0077] A titanium rod with a length of 1m and a diameter of 10mm was selected with a purity of 99.999%. It was pre-cleaned with deionized water at a temperature of 65℃ and a flow rate of 40m³ / h. The pre-cleaned titanium rod was peeled with a peeling thickness of 1.2mm to remove the oxide layer on the surface of the titanium rod. The peeled titanium rod was immersed in a graphite suspension for 12h. The concentration of the graphite suspension was 20g / L and the solvent was isopropanol. After the immersion, the thickness of the graphite layer on the surface of the titanium rod was measured to be 40μm. The impregnated titanium rod was placed in a second vacuum furnace and vacuumed, heated to 700℃ for 30 minutes, kept warm for 12h and then naturally cooled to room temperature. A composite wire with a specification of Φ3mm was obtained by drawing through a second roller die drawing machine. The composite wire was stretched along the length direction at a drawing speed of 10cm / min and a stretching ratio of 3:1. The Φ3mm composite wire was placed in a vacuum furnace with a degree of vacuum of 10 -4 The composite electrode was annealed in an annealing furnace at 650°C for 6 hours, the air was removed and replaced with argon, and the electrode was cooled to 150°C and woven into a titanium mesh.

[0078] Test Example 1

[0079] The graphite layer thickness, mesh pore size of the composite electrode obtained in the above examples and comparative examples, as well as the pore volume and specific surface area of ​​the composite electrode were tested; the thickness of the graphite layer was tested by scanning electron microscopy; the mesh pore size of the mesh was tested by scanning electron microscopy; the pore volume ratio of the composite electrode was tested by nitrogen adsorption and desorption; and the specific surface area of ​​the composite electrode was tested by nitrogen adsorption and desorption. The test results are as follows: Figures 2 and 3 and as shown in Table 1.

[0080] Table 1

[0081]

[0082] Test Example 2

[0083] The composite electrodes described in the examples and comparative examples were used to remove antibiotics from various livestock and poultry wastewaters. The removal efficiency of the composite electrodes was tested, and the antibiotic concentration was measured using high-performance liquid chromatography. The removal efficiency was calculated as (initial antibiotic concentration - concentration after antibiotic removal) / initial antibiotic concentration × 100%. The results are shown in Table 2.

[0084] Table 2

[0085]

[0086] According to the data in Table 2, the composite electrode disclosed herein has a pH of 4 to 10, or the solution contains Cl - 、SO4 2- 、NO3 - and PO4 3- Under the conditions of plasma or humic acid contained in the solution, it can still maintain excellent antibiotic removal performance. By comparing Example 1 with Example 6, it can be seen that within the preferred conditions of the first wire drawing treatment of 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 preferred thickness range of the graphite layer of 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 preferred conditions of the second wire drawing treatment of the present disclosure, the obtained composite electrode has better antibiotic removal performance.

[0087] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within 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 scope of protection of the present disclosure.

[0088] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0089] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for preparing a composite electrode, characterized in that: The method comprises: subjecting a pretreated titanium metal raw material to a first wire drawing process to obtain a first wire drawing product; immersing the first wire drawing product in a graphite suspension, and sequentially subjecting the impregnated product to a second wire drawing process and an annealing process; Wherein, the titanium metal raw material includes titanium blank.

2. The method according to claim 1, wherein The titanium blank comprises one or more of a titanium plate and a titanium rod; 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 at a temperature of 45-65°C, using a flow cleaning method with water as the solvent and a flow rate of 30-40 m 3 / h.

3. The method according to claim 1, wherein The conditions of the first wire drawing process include: being carried out under vacuum conditions, at a temperature of 900-1000°C, for 1-2 hours, with a stretching ratio of (2-10):1 and a stretching speed of 0.5-10 cm / min; Optionally, the method further comprises: performing a peeling process on the pretreated titanium metal raw material before the first wire drawing process, wherein the peeling 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, and the solvent of the graphite suspension includes one or more of ethanol, isopropanol and water; the immersion treatment time is 6-12 hours; Optionally, the method further comprises: performing a secondary cleaning on the product of the first wire drawing treatment before the immersion treatment, wherein the temperature of the secondary cleaning is 20-30°C, the solvent used for the secondary cleaning comprises water, and the flow rate is 1-5 m 3 / h.

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

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

7. The composite electrode according to claim 6, characterized in that The composite electrode comprises a composite material wire and a graphite layer coated on the surface of the composite material wire. The composite material wire comprises 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 mesh size of the wire mesh is 0.3-1 mm; and / or, The volume of the composite electrode is 40-60% for micropores, 20-40% for mesopores, and 10-20% for macropores; 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: The composite electrode according to any one of claims 6 to 8 is used.

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

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