Titanium mesh-based polypyrrole nanowire electrode and its preparation and electroporation disinfection applications

Abstract

This invention discloses a titanium mesh-based polypyrrole nanowire electrode, its preparation, and its application in electroporation disinfection, belonging to the field of water treatment and disinfection technology. Using a titanium mesh as a substrate, after pretreatment including acid washing, sandblasting, and ultrasonic cleaning, a two-step deposition process is performed in an electrochemical workstation: first, a polypyrrole seed layer is deposited in a solution containing hydrochloric acid and pyrrole using a constant potential; subsequently, a vertically oriented polypyrrole nanowire array is grown in situ in an electrolyte containing phosphate buffer, pyrrole, and β-naphthalenesulfonic acid using a constant current. The hydrophilicity of the polypyrrole surface is regulated by controlling the duration of the applied oxidation potential, resulting in low interfacial resistance, strong cell adhesion, and enhanced local electric field, thereby improving electroporation efficiency. This electrode can rapidly inactivate bacteria, microalgae, and viruses under low voltage conditions, achieving a sterilization rate of over 99.9%. It exhibits excellent mechanical strength and electrochemical stability, avoiding nanowire breakage and heavy metal ion leaching problems.

Description

Technical Field

[0001] This invention relates to the field of water treatment and disinfection technology, and in particular to a titanium mesh-based polypyrrole nanowire electrode, its preparation and electroporation disinfection application. Background Technology

[0002] Nanowire-assisted electroporation (NAPE) disinfection technology is gradually emerging as a new physical disinfection method. Its principle stems from the "lightning rod effect" of conductive nanowires: when nanowires have nanometer-scale diameters and micrometer-scale lengths, even with a low applied voltage, the local electric field strength near their tips can be amplified by several orders of magnitude. Inspired by this phenomenon, researchers have demonstrated that nanowire-assisted electroporation can achieve highly efficient bacterial inactivation at low voltages. Specifically, the strong local electric field formed near the nanowire tip can disrupt cell membranes or viral capsids, thereby inactivating pathogens. This technology shows great promise in point-of-use disinfection and decentralized water supply systems, especially in developing regions, achieving highly efficient disinfection at several volts, and even using portable devices powered by button batteries.

[0003] Existing research has reported various nanowire arrays based on metal compounds, including Cu(OH)₂, Cu₂O, Fe₂O₃, ZnO, and Cu₃P. These nanowire materials can be grown in situ on substrates and combined with flow electroporation disinfection devices for water treatment, offering advantages over ultraviolet radiation in terms of low energy consumption and adaptability. However, metal compound-based nanowires have significant drawbacks:

[0004] 1. Poor mechanical strength: Under the action of hydraulic shear force, nanowires are prone to breakage, producing detectable nanoparticles and shortening electrode life;

[0005] 2. Poor electrochemical stability: Under applied voltage, metal compounds are prone to anodic oxidation, leading to corrosion and dissolution, releasing heavy metal ions or nanoparticles, which poses a risk of secondary pollution.

[0006] 3. Safety is difficult to control: The release of metal ions or nanoparticles limits its application and promotion in the field of drinking water disinfection.

[0007] Based on the above problems, there is an urgent need to develop an alternative nanowire material that combines high conductivity, excellent stability, and structural durability. Summary of the Invention

[0008] The purpose of this invention is to provide a titanium mesh-based polypyrrole nanowire electrode, its preparation, and its electroporation disinfection application, which solves the problem of insufficient mechanical and chemical stability of existing metal compound nanowire electrodes in water disinfection applications. Furthermore, by artificially controlling the hydrophilicity and hydrophobicity of the material surface, the disinfection efficiency can be further improved, making it a more reliable and durable electroporation disinfection material.

[0009] To achieve the above objectives, the present invention provides a method for preparing a titanium mesh-based polypyrrole nanowire electrode, comprising the following steps:

[0010] S1, Titanium-based substrate pretreatment

[0011] The titanium mesh was ultrasonically cleaned in a strong acid solution to remove the surface oxide layer. Then it was ultrasonically cleaned in acetone, methanol and distilled water to remove residual contaminants. Then it was sandblasted, with multiple sprayings on the front, back and four sides to form synthesis points. The ultrasonic cleaning steps were repeated and then dried.

[0012] S2, Synthesis of polypyrrole nanowires on titanium mesh surface

[0013] The pretreated titanium substrate was used as the working electrode and placed in a first electrolyte containing pyrrole monomer for initial electrochemical deposition. A polypyrrole seed layer was formed on the surface of the titanium substrate by electrodeposition using a constant potential method.

[0014] A titanium-based substrate with a polypyrrole seed layer was used as the working electrode. It was placed in a second electrolyte for secondary electrochemical deposition and electropolymerization was carried out. After completion, the product was taken out, cleaned and dried to obtain a vertically oriented polypyrrole nanowire array on the titanium-based substrate, thus obtaining a titanium mesh-based polypyrrole nanowire electrode.

[0015] S3, hydrophilicity modulation of polypyrrole nanowire array

[0016] The surface hydrophilicity of the polypyrrole nanowire array on the titanium substrate was adjusted to a hydrophilic state suitable for flow electroporation sterilization by adjusting the electrochemical oxidation time.

[0017] Preferably, in S1, the titanium-based substrate is a woven titanium mesh substrate with a pore size of 45μm to 80μm and a thickness of 0.5mm to 1.0mm.

[0018] Preferably, in S2, both the primary electrochemical deposition and the secondary electrochemical deposition employ a three-electrode system;

[0019] In the initial electrochemical deposition, the working electrode was a titanium-based substrate, the reference electrode was Ag / AgCl, the counter electrode was a platinum sheet, and the first electrolyte was a compound electrolyte of 0.20~0.30 mol / L hydrochloric acid and 0.20~0.30 mol / L pyrrole.

[0020] In the secondary electrochemical deposition, the working electrode is a titanium-based substrate with a polypyrrole seed layer, the reference electrode is Ag / AgCl, the counter electrode is a titanium-based substrate, and the second electrolyte is a phosphate buffer solution containing 0.20~0.30 mol / L pyrrole and 0.01~0.03 mol / L β-naphthalenesulfonic acid. The concentration of the phosphate buffer solution is 0.5 mol / L, and the pH is 6.8.

[0021] Preferably, in S2, the potential applied by the potentiostatic method is 0.9~1.1 V (vs. Ag / AgCl), and the deposition time is 60~90 seconds.

[0022] Preferably, in S2, during the constant current electropolymerization, the current density is 3.6 mA / cm². 2 The deposition time is 20-40 minutes.

[0023] Preferably, in S3, the electrochemical oxidation potential is +0.5~1.0V, the treatment time is 5~10min, and the surface water contact angle of the polypyrrole nanowire array is <20°.

[0024] The present invention also provides a titanium mesh-based polypyrrole nanowire electrode prepared by the above preparation method, comprising a titanium mesh substrate and a polypyrrole nanowire array vertically oriented on the titanium mesh substrate, wherein the height of the polypyrrole nanowire array is 1~2 μm, the diameter is 200~300 nm, and the aspect ratio is 3~10.

[0025] This titanium mesh-based polypyrrole nanowire electrode is used in electroporation sterilization.

[0026] Application method: The above-mentioned titanium mesh-based polypyrrole nanowire electrode is applied to a flow electroporation disinfection device, with the flow direction of the target disinfection water perpendicular to the titanium mesh-based polypyrrole nanowire electrode, which serves as the anode and cathode respectively. By applying a DC electric field between the cathode and anode, when the water flows through the electrode gap, the bacteria undergo electroporation under the strong local electric field at the electrode tip, thus becoming inactive.

[0027] In this electroporation disinfection system, the electrode near the inlet is designated as the cathode, while the electrode near the outlet serves as the anode. When water flows through the cathode, the inherent negative charge of the bacterial cell membrane further enhances the negative charge effect, promoting cell membrane polarization. Subsequently, when water flows through the anode, bacteria are adsorbed by the positive charge on the anode surface, further improving the efficiency of the electroporation process and thus enhancing the disinfection effect. Furthermore, the titanium mesh-based polypyrrole nanowire electrode is hydrophilic, further reducing interfacial resistance and enhancing cell adhesion, thereby achieving a high sterilization rate with lower energy consumption.

[0028] Therefore, the present invention employs the above-mentioned titanium mesh-based polypyrrole nanowire electrode, its preparation, and its application in electroporation sterilization, with the following specific beneficial effects:

[0029] 1. The titanium mesh-based polypyrrole nanowire electrode provided by this invention exhibits excellent structural stability and a long service life. Due to the excellent flexibility and chemical stability of polypyrrole itself, the polypyrrole nanowire array described in this invention can effectively avoid the breakage and detachment problems that easily occur in rigid materials such as metal oxides or noble metal nanowires under fluid impact or operating stress. Simultaneously, under long-term operation and electrochemical action, no heavy metal ions or nanoparticles dissolve, ensuring not only the integrity of the electrode structure and its long service life but also eliminating the risk of secondary pollution.

[0030] 2. The titanium mesh-based polypyrrole nanowire electrode provided by this invention exhibits excellent interfacial properties and high electroporation disinfection efficiency. The polypyrrole nanowires show significant hydrophilicity in their oxidized state, a characteristic that allows the water to be treated to fully wet and spread on the electrode surface, greatly reducing the retention of air bubbles and thus effectively lowering interfacial resistance and energy consumption. Furthermore, the excellent hydrophilicity promotes close adhesion between bacteria and other microorganisms and the electrode surface. When an external electric field is applied, a more concentrated and efficient voltage drop can be generated locally on the bacterial membrane, greatly improving the efficiency of electroporation in destroying the cell membrane, thereby achieving highly efficient disinfection.

[0031] 3. The electroporation disinfection method provided by this invention is environmentally friendly, safe, and non-toxic. The entire disinfection process requires no chemical additives, relying solely on the electroporation effect of a physical electric field. Therefore, it does not produce any toxic or harmful byproducts. The electrode material, polypyrrole, is safe and non-toxic, and there is no issue of metal ion leaching, ensuring absolute safety of the treatment process and the quality of the effluent. This technology is a purely physical, green disinfection method suitable for various scenarios such as drinking water treatment, medical wastewater disinfection, and portable point-of-use disinfection, and has broad application prospects.

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0033] Figure 1 These are SEM images of the titanium mesh-based polypyrrole nanowire electrode prepared in Example 1 of this invention, wherein a is an SEM image with a scale bar of 200 μm, b is an SEM image with a scale bar of 50 μm, c is an SEM image with a scale bar of 2 μm, and d is an SEM image with a scale bar of 500 nm.

[0034] Figure 2 This is a schematic diagram of the structure of the flow electroporation disinfection device according to an embodiment of the present invention;

[0035] Figure 3This is a graph showing the change in sterilization rate of the titanium mesh-based polypyrrole nanowire electrodes prepared in Examples 1 and 2 of this invention;

[0036] Figure 4 This is a graph showing the sterilization rate and surface water contact angle changes of the titanium mesh-based polypyrrole nanowire electrodes prepared in Examples 1 and 3 of this invention;

[0037] Figure 5 This is a graph showing the change in sterilization rate of four different nanowires under different conditions with working time in an application example of the present invention.

[0038] Figure label:

[0039] 1. Electrode chamber; 2. Cathode module; 3. Anode module; 4. Leak-proof rubber gasket; 5. External power cord; 6. Water inlet; 7. Water outlet. Detailed Implementation

[0040] This invention provides a titanium mesh-based polypyrrole nanowire electrode, comprising a titanium mesh substrate and a vertically oriented array of polypyrrole nanowires on the titanium mesh substrate. The polypyrrole nanowire array has a height of approximately 1-2 μm, a diameter of approximately 200-300 nm, and an aspect ratio of approximately 3-10. It is prepared using the following method:

[0041] The electrode material is prepared using a titanium mesh as a substrate. The titanium mesh is a mat-like woven structure. To increase the probability of contact between bacteria and the material and to facilitate the uniformity of subsequent polypyrrole synthesis on the surface, the pore size of the titanium mesh is 45-80 μm, and the thickness is 0.5 mm-1 mm.

[0042] Pretreatment: The titanium mesh is ultrasonically cleaned in strong acid solutions such as hydrochloric acid, nitric acid or hydrofluoric acid to remove the surface oxide layer; then ultrasonically cleaned in acetone, methanol and distilled water respectively to remove residual contaminants on the surface; then sandblasting is used, with the front and back sides and four sides blasted three times each to increase the surface roughness and form synthesis sites.

[0043] Synthesis of polypyrrole nanowire arrays on titanium mesh surface: The pretreated titanium mesh was placed in a three-electrode system, with the working electrode being the titanium mesh, the reference electrode being Ag / AgCl, and the counter electrode being a platinum sheet; the electrolyte was preferably a composite electrolyte of 0.20~0.30 mol / L hydrochloric acid and 0.20~0.30 mol / L pyrrole, and deposition was carried out at a constant potential of 0.9~1.1 V (vs. Ag / AgCl) for 60~90 s to obtain a uniform polypyrrole seed layer on the surface. In a three-electrode system, further electropolymerization was used to form a polypyrrole nanowire array. The working electrode was a titanium mesh with a polypyrrole seed layer, the reference electrode was Ag / AgCl, and the counter electrode was a titanium mesh. The electrolyte was phosphate buffer solution (PBS, concentration 0.5 mol / L, pH = 6.8), which contained dissolved 0.20–0.30 mol / L pyrrole and 0.01–0.03 mol / L β-naphthalenesulfonic acid (NSA). The power supply preferably adopted constant current mode with a current density of 3.6 mA / cm². 2 The deposition time is 20-40 min; then a vertically oriented polypyrrole nanowire array is obtained, which is taken out, rinsed with pure water, and dried in an oven at 60℃ overnight to obtain a titanium mesh-based polypyrrole nanowire electrode.

[0044] Hydrophilicity adjustment: The surface hydrophilicity of the above-mentioned titanium mesh-based polypyrrole nanowire electrode can be adjusted by electrochemical oxidation time. It is preferred to treat it at a potential of +0.50~1.0 V for 5~10 min to oxidize the electrode surface to a hydrophilic state suitable for flow electroporation sterilization, that is, the surface water contact angle of the polypyrrole nanowire array is <20°.

[0045] Titanium mesh-based polypyrrole nanowire electrodes are used in electroporation sterilization.

[0046] In application, a pair of parallel titanium mesh-based polypyrrole nanowire electrodes are connected to the cathode and anode respectively to form a cathode module and an anode module. A DC electric field is applied between the two titanium mesh-based polypyrrole nanowire electrodes, so that the target disinfected water enters from the cathode module and flows out from the anode module, thereby achieving the purpose of disinfecting the target disinfected water.

[0047] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0048] The present invention will be further described below through specific embodiments. However, it should be understood that these embodiments are only for more detailed description and should not be construed as limiting the present invention in any way, that is, not intended to limit the scope of protection of the present invention.

[0049] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] Example 1

[0051] This embodiment provides a titanium mesh-based polypyrrole nanowire electrode, and the preparation steps are as follows:

[0052] (1) Titanium mesh pretreatment: A 10 cm × 4 cm woven titanium mesh was selected as the substrate. The thickness of the titanium mesh was 600 μm and the pore size was 50 μm. The mesh was then subjected to HF, HNO3, and... Ultrasonic cleaning in a mixed solution (volume ratio 1:1:100) for 30 min, followed by rinsing with pure water; then ultrasonic cleaning in acetone, methanol, and distilled water for 20 min each; then sandblasting the front and back sides and all four sides three times with 100-mesh white alumina steel grit; finally, repeat the ultrasonic cleaning steps and dry.

[0053] (2) Preparation of titanium mesh-based polypyrrole nanowire electrode: In the three-electrode system, the pretreated titanium mesh was cut into 2 cm × 2 cm pieces as working electrodes, Ag / AgCl as reference electrodes, and 1 cm × 1 cm platinum sheets as counter electrodes. The titanium mesh was placed in 80 mL of electrolyte, which was a mixed solution of 0.25 mol / L hydrochloric acid and 0.20 mol / L pyrrole. The solution was deposited at a constant potential of 0.9 V for 60 s to obtain a polypyrrole seed layer on the surface of the titanium mesh.

[0054] Subsequently, in another three-electrode system, the working electrode was the aforementioned titanium mesh with a polypyrrole seed layer, the reference electrode was Ag / AgCl, and the counter electrode was a 2 cm × 2 cm titanium mesh. 0.20 mol / L pyrrole and 0.01 mol / L β-naphthalenesulfonic acid were dissolved in 80 mL of 0.5 mol / L PBS at pH = 6.8 as the electrolyte. The electrolyte was then used at a constant current density of 3.6 mA / cm². 2 A total current of approximately 14.4 mA was applied for deposition over 30 min to obtain a vertically oriented polypyrrole nanowire array. The electrodes were rinsed with pure water and then dried overnight in a 60°C oven.

[0055] (3) Adjustment of hydrophilicity of polypyrrole electrode: The prepared electrode is subjected to a potential of +0.50 V for 12 min to initiate an oxidation reaction, so that the surface is in a hydrophilic state suitable for flow electroporation sterilization.

[0056] The SEM image of the titanium mesh-based polypyrrole nanowire electrode prepared in this embodiment is shown below.Figure 1 As shown, Figure 1 a and Figure 1 Image b is a SEM image of the titanium mesh. This titanium mesh has a mat-like woven structure and a certain degree of surface roughness, showing an uneven structure at the micron level. Figure 1 c and Figure 1 In the middle d, there is a polypyrrole nanowire array, which is densely arranged and covers the entire surface of the titanium mesh. It is uniformly distributed and has high longitudinal alignment. The nanowires have a smooth surface and a compact structure.

[0057] Example 2

[0058] This embodiment provides a titanium mesh-based polypyrrole nanowire electrode. The preparation steps are basically the same as in Example 1, except that in step (2), the constant current density is 3.6 mA / cm². 2 With a total current of approximately 14.4 mA, deposition was carried out for 5 min, 10 min, 50 min, and 80 min, respectively, to obtain vertically oriented polypyrrole nanowire arrays of different lengths.

[0059] Example 3

[0060] This embodiment provides a titanium mesh-based polypyrrole nanowire electrode. The preparation steps are basically the same as those in Example 1. The only difference is that in step (3), the electrode is subjected to a potential of +0.50 V for 2 min, 4 min, 8 min and 16 min to initiate an oxidation reaction, thereby obtaining titanium mesh-based polypyrrole nanowire electrodes with different degrees of hydrophilicity.

[0061] Application examples

[0062] To verify the electroporation sterilization capability of the titanium mesh-based polypyrrole nanowire electrodes prepared in Examples 1-3 above, they were placed in a... Figure 2 The flow electroporation sterilization device shown includes:

[0063] An electrode chamber 1 includes a cathode module 2 and an anode module 3 connected to an external wire 5. Both the cathode module 2 and the anode module 3 contain titanium mesh-based polypyrrole nanowire electrodes. The two titanium mesh-based polypyrrole nanowire electrodes are arranged in parallel and opposite to each other, serving as the cathode and anode respectively. A waterproof gasket 4 is provided around them.

[0064] An inlet 6 is located on the chamber wall near the cathode.

[0065] An outlet 7 is located on the chamber wall near the anode.

[0066] The equivalent flow area of ​​inlet 6, the equivalent flow area of ​​electrode chamber 1 at the titanium mesh-based polypyrrole nanowire electrode, and the equivalent flow area of ​​outlet 7 are equal. Figure 2The direction of the middle arrow indicates the flow direction of the target disinfected water.

[0067] In this application example, *Escherichia coli* was used as a model microorganism for a disinfection experiment. Specifically, *E. coli* was inoculated into liquid culture medium and placed in a 37°C constant temperature air bath shaker for 15 hours to reach the stationary phase. The bacterial suspension was then diluted with deionized water to approximately 1 × 10⁻⁶. 6 The target concentration is CFU / mL.

[0068] In this application example, the conditions for the electroporation disinfection experiment are: an electrode spacing of 2 mm and a flow rate of 1 m³ / min. 3 / h / m 2 Under the condition of an applied voltage of 5V, the system was run continuously for 1 hour. The number of E. coli in the disinfected water was counted using the dilution plate method. .

[0069] After testing the titanium mesh-based polypyrrole nanowire electrodes in Examples 1 and 2-3, the following was found:

[0070] By comparing the sterilization rates of the titanium mesh-based polypyrrole nanowire electrodes prepared in Example 1 and Example 2, it can be seen that the length of the polypyrrole nanowire array on the titanium mesh surface is closely related to the electrochemical polymerization time. The results are as follows: Figure 3 As shown, when the polymerization time is 30 min, the nanowire structure is complete and uniform, achieving a sterilization rate of 99.94 ± 0.03%, which is the best performance. If the polymerization time is too short, the nanowires have not grown sufficiently, making it difficult to produce a significant electroporation effect; while if the polymerization time is too long, the nanowire structure will be damaged, accompanied by the disordered deposition of a large amount of polypyrrole, eventually forming a smooth film layer, thereby weakening the local electric field strength. This result fully demonstrates the key role of the nanowire structure in the low-voltage electroporation sterilization process.

[0071] Further research, by comparing the bactericidal rate and surface water contact angle of the titanium mesh-based polypyrrole nanowire electrodes prepared in Example 1 and Example 3, shows that the hydrophilicity of the polypyrrole nanowires can be enhanced with the extension of electro-oxidation time. Figure 4 As shown, within the oxidation time range of 0–16 min, the surface water contact angle gradually decreased from 92.5° to 14.4°, and the corresponding sterilization rate gradually increased. Considering that the contact angle change tends to stabilize after the oxidation time exceeds 12 min...

[0072] Copper hydroxide nanowires were used as a comparative test for electroporation disinfection. Copper hydroxide nanowires with a pore size of 60 μm and a thickness of 600 μm as the substrate were selected and electroporation disinfection was carried out under the same conditions.

[0073] The preparation process of the copper hydroxide nanowire electrode is as follows: Copper foam was cut into sheets with a size of 2×2 cm. It was first ultrasonically cleaned with anhydrous ethanol for 3 minutes to remove grease and organic contaminants, and then ultrasonically cleaned with 1M hydrochloric acid solution for 5 minutes to remove the surface oxide layer. After cleaning, it was rinsed several times with deionized water and dried in a vacuum drying oven for use. Next, the reaction solution for the copper hydroxide nanowires was prepared by dissolving 2.5M NaOH (15 g) and 0.1 M (NH4)2S2O8 (3.42 g) in 100 mL of deionized water and stirring until the solution was homogeneous. The solution was cooled to 4℃ and maintained at a low temperature using an ice bath. Then, the cleaned copper foam was immersed in the reaction solution, ensuring complete immersion, and reacted in this solution for 20 minutes. After the reaction, the copper foam was removed and thoroughly rinsed with deionized water to remove residual reaction solution. Finally, the sample was placed in a vacuum drying oven and dried at low temperature under vacuum conditions, with the temperature controlled within the range of 40–60℃ to ensure the integrity of the nanowire structure and the stability of its performance.

[0074] Subsequently, four groups of experiments were set up for 1 hour of continuous disinfection and sampling to detect the number of E. coli. The four groups of experiments were the titanium mesh-based polypyrrole nanowire electrode (5V voltage) prepared in Example 1, the copper hydroxide nanowire electrode (5V voltage), the titanium mesh-based polypyrrole nanowire electrode (without power) prepared in Example 1, and the copper hydroxide nanowire electrode (without power). The four groups of experiments were carried out simultaneously, and there were no differences except for the materials and voltage.

[0075] Comparative experimental results as follows Figure 5 As shown, under no external voltage applied, the sterilization rates of polypyrrole nanowires (<3%) and copper hydroxide nanowires (<11%) were both at a low level. When a 5 V DC current was applied, the sterilization rates of both electrodes increased significantly, but their stability differed significantly: the sterilization performance of copper hydroxide nanowires decreased rapidly after about 10 minutes of operation, eventually remaining at about 40%, with its sterilization effect mainly derived from the high concentration of copper ions released by electrode dissolution; in contrast, the instantaneous sterilization rate of polypyrrole nanowires under the same conditions remained above 99.8%, fully demonstrating the high efficiency and excellent structural stability of this material in electroporation sterilization. In summary, compared with the control material, the titanium mesh-based polypyrrole nanowire electrode prepared in this invention exhibits superior structural stability and more durable electroporation sterilization performance. This is because polypyrrole material has excellent mechanical flexibility and electrochemical stability, avoiding the problems of easy damage and dissolution of metal compound nanowires under electric and hydraulic conditions, thus ensuring efficient sterilization and long-term operational stability.

[0076] Therefore, this invention employs the aforementioned titanium mesh-based polypyrrole nanowire electrode, its preparation, and its electroporation disinfection application to solve the problem of insufficient mechanical and chemical stability of existing metal compound nanowire electrodes in water disinfection applications. Furthermore, by artificially controlling the hydrophilicity and hydrophobicity of the material surface, the disinfection efficiency is further improved, making it a more reliable and durable electroporation disinfection material.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An application of a titanium mesh-based polypyrrole nanowire electrode in electroporation sterilization, characterized in that: The titanium mesh-based polypyrrole nanowire electrode includes a titanium mesh substrate and a vertically oriented polypyrrole nanowire array on the titanium mesh substrate. The height of the polypyrrole nanowire array is 1~2 μm, the diameter is 200~300 nm, and the aspect ratio is 3~10. The preparation and application method of the titanium mesh-based polypyrrole nanowire electrode includes the following steps: S1, Titanium-based substrate pretreatment The titanium mesh was ultrasonically cleaned in a strong acid solution to remove the surface oxide layer. Then it was ultrasonically cleaned in acetone, methanol and distilled water to remove residual contaminants. Then it was sandblasted, with multiple sprayings on the front, back and four sides to form synthesis points. The ultrasonic cleaning steps were repeated and then dried. S2, Synthesis of polypyrrole nanowires on titanium mesh surface The pretreated titanium substrate was used as the working electrode and placed in a first electrolyte containing pyrrole monomer for initial electrochemical deposition. A polypyrrole seed layer was formed on the surface of the titanium substrate by electrodeposition using a constant potential method. A titanium-based substrate with a polypyrrole seed layer was used as the working electrode. It was placed in a second electrolyte for secondary electrochemical deposition and electropolymerization was carried out. After completion, the product was taken out, cleaned and dried to obtain a vertically oriented polypyrrole nanowire array on the titanium-based substrate, thus obtaining a titanium mesh-based polypyrrole nanowire electrode. S3, hydrophilicity modulation of polypyrrole nanowire array The surface hydrophilicity of the polypyrrole nanowire array on the titanium substrate was adjusted to a hydrophilic state suitable for flow electroporation sterilization by adjusting the electrochemical oxidation time. S4. Electrode pair assembly and sterilization application A pair of parallel titanium mesh-based polypyrrole nanowire electrodes are connected to the cathode and anode respectively to form a cathode module and an anode module. A DC electric field is applied between the two titanium mesh-based polypyrrole nanowire electrodes, so that the target disinfected water enters from the cathode module and flows out from the anode module.

2. The application of a titanium mesh-based polypyrrole nanowire electrode according to claim 1 in electroporation sterilization, characterized in that: In S1, the titanium-based substrate is a woven titanium mesh substrate with a pore size of 45μm to 80μm and a thickness of 0.5mm to 1.0mm.

3. The application of a titanium mesh-based polypyrrole nanowire electrode according to claim 1 in electroporation sterilization, characterized in that: In S2, both the primary and secondary electrochemical depositions employ a three-electrode system. In the initial electrochemical deposition, the working electrode was a titanium-based substrate, the reference electrode was Ag / AgCl, the counter electrode was a platinum sheet, and the first electrolyte was a compound electrolyte of 0.20~0.30 mol / L hydrochloric acid and 0.20~0.30 mol / L pyrrole. In the secondary electrochemical deposition, the working electrode is a titanium-based substrate with a polypyrrole seed layer, the reference electrode is Ag / AgCl, the counter electrode is a titanium-based substrate, and the second electrolyte is a phosphate buffer solution containing 0.20~0.30 mol / L pyrrole and 0.01~0.03 mol / L β-naphthalenesulfonic acid. The concentration of the phosphate buffer solution is 0.5 mol / L, and the pH is 6.

8.

4. The application of a titanium mesh-based polypyrrole nanowire electrode according to claim 1 in electroporation sterilization, characterized in that: In S2, the potential applied by the potentiostatic method is 0.9~1.1 V, the reference electrode is an Ag / AgCl electrode, and the deposition time is 60~90 seconds.

5. The application of a titanium mesh-based polypyrrole nanowire electrode according to claim 1 in electroporation sterilization, characterized in that: In S2, during constant current electropolymerization, the current density is 3.6 mA / cm². 2 The deposition time is 20-40 minutes.

6. The application of a titanium mesh-based polypyrrole nanowire electrode according to claim 1 in electroporation sterilization, characterized in that: In S3, the electrochemical oxidation potential is +0.5~1.0V, the treatment time is 5~10min, and the surface water contact angle of the polypyrrole nanowire array is <20°.

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