P-type GaN nanowire based on zinc doping and preparation method and application thereof

Abstract

The invention provides a p-type GaN nanowire based on zinc doping and a preparation method and application thereof, and the preparation method comprises the steps: S1, providing carbon fiber cloth, and forming a gold film on each of the front and back surfaces of the carbon fiber cloth; and S2, in CVD method equipment, preparing the p-type GaN nanowire by taking the carbon fiber cloth as a substrate, the gold film on the carbon fiber cloth as a catalyst, gallium acetylacetonate as a gallium source, ammonia gas as a nitrogen source and zinc powder as a doping source through evaporation of the zinc powder in a CVD growth stage. The prepared p-type GaN nanowire can be used for long-term efficient water treatment under low voltage, and is lower in energy consumption, better in material stability, longer in service life and higher in sterilization, algae removal and disinfection efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the field of water treatment, in particular to a zinc-doped p-type GaN nanowire and a preparation method and application thereof. BACKGROUND

[0002] Pathogen infection has become the main cause of human morbidity and mortality in the world, and most of the deaths are caused by water-borne pathogen infection. Therefore, in order to better protect human health, an efficient, reliable, low-energy, easy-to-use water disinfection method is crucial. However, the traditional disinfection method of chlorination inevitably leads to the formation of carcinogenic disinfection by-products (DBPs). Alternative methods such as membrane filtration and ultraviolet disinfection are limited by high cost, low flux and / or high energy consumption. Although electroporation sterilization has the mechanism of not using chemicals, not forming harmful DBPs and having universal disinfection for all pathogens, the high working voltage required by the electroporation sterilization leads to huge energy consumption and causes operation safety problems.

[0003] In recent years, researchers have found that one-dimensional nanostructures, such as nanowires, nanotubes and nanocolumns, can generate a large electric field to kill bacteria and other microorganisms by the lightning rod effect of the tip at a lower voltage. The use of one-dimensional nanostructure electrochemical sterilization as an efficient water treatment technology has made significant progress in the field of microbial inactivation in flowing water in recent years. The team of Professor Yifei Wu at Stanford University developed an electric sterilization filter device that effectively inactivates bacteria, viruses and single-cell organisms by using the local electric field enhancement effect of silver nanowires (Ag NWs). The team of Professor Xing Xie at Georgia Institute of Technology also used Ag NWs electrodes to achieve a 6-log inactivation rate of bacteria in flowing water at a low voltage of 1 V. The team of Professor Hongying Hu at Tsinghua University prepared carbon nanotube (CNT) sponge electrodes, which can reduce the survival rate of microorganisms such as Escherichia coli, Enterococcus faecalis, Bacillus subtilis and MS2 bacteriophages to below 0.00001% in only 5 seconds of contact time at a voltage of 2 V. Copper oxide nanowire (CuO NWs) electrodes also exhibit high sterilization performance. The research of Professor Yifei Wu, Professor Hongying Hu and Professor Xing Xie respectively confirmed that the electrodes can effectively treat flowing water with a flow rate of 50 mL / min at a voltage of about 10 V and 1 V. To improve the durability of the electrodes, Professor Hongying Hu and Professor Xing Xie successfully extended the sterilization life of CuO NWs from 2 hours to 16 hours by coating a dopamine layer on the surface of the CuO NWs electrodes. Further, after converting CuO NWs into Cu3P NWs by high-temperature phosphorization and coating dopamine, the sterilization life of the electrodes at a working voltage of 1 V can reach 15 days. The team of Professor Shougong Chen at Ocean University of China coated carbon on the surface of cuprous oxide nanowire (Cu2O NWs) electrodes and loaded Ag or ZnO nanoparticles, achieving a 99.6% sterilization rate for high-speed flowing water (1200 mL / min) at a voltage of 10 V. The team of Professor Zong-Hong Lin deposited ZnO nanowires on a carbon cloth (CC) substrate and modified Ag nanoparticles, achieving electric perforation sterilization of flowing water by powering a triboelectric nanogenerator. The team of Professor Zong-Hong Lin prepared gold-modified tellurium nanowires (Au-Te NWs) on a carbon cloth, which, driven by a triboelectric nanogenerator, effectively inactivated Escherichia coli and Staphylococcus aureus by combining the nano-electroporation effect and the generated H2O2.

[0004] However, the technology still faces key material challenges in practical applications. CNTs and Ag NWs are prone to agglomeration and difficult to be stably fixed in high-speed water flow. Metal oxide nanowires (such as CuO, Cu2O, Fe2O3, ZnO) and tellurium nanowires grown in situ usually have poor electrical conductivity; and their metal substrates (such as copper mesh, foam copper, cast iron mesh) are prone to corrosion in air and water environment. Even the Cu3P NWs copper electrode modified by dopamine gradually undergoes electrochemical dissolution after 15 days of electrification. In addition, water quality (such as suspended solids and macromolecular organic matter deposition blocking electrode channels) and air quality can also significantly affect the bactericidal efficiency and working life of nanowire electrodes. Therefore, the development of nanowire electrodes with both durability and long life is the key to realizing large-scale practical application of the technology. SUMMARY

[0005] Applicants found in the research process that nanowire materials need to meet the conditions of high electrical conductivity, good mechanical properties, corrosion resistance, low toxicity, and firm connection between nanowires and electrode substrates at the same time, in order to achieve sustained electrical sterilization in high-speed water flow and air. As the third generation of wide bandgap semiconductor materials, gallium nitride (GaN) is insoluble in water and acid-base at room temperature, showing excellent chemical stability, and trace amounts of gallium ions are harmless to the human body. At a lower voltage (<10V), a lightning rod effect can be generated at the tip of the GaN nanowire, forming a local strong electric field (106-107 V m-1) higher than the electric field threshold of cell tissue (~105 V m-1), thereby piercing the cell membrane, causing irreversible electroporation, leading to irreversible death of bacteria and microorganisms, and achieving the purpose of killing bacteria and microorganisms.

[0006] In previous work (see CN 115938679 A, a gallium nitride nanowire / graphene composite material, a preparation method thereof, and a sterilization device; CN 113973839B, a carbon fiber loaded GaN:ZnO nanowire composite material, a preparation method thereof, and a sterilization device), applicants have used CVD method to grow GaN:ZnO nanowires on carbon fiber cloth using gallium acetylacetonate and zinc oxide as precursors, ammonia as reaction gas, and gold as catalyst, obtaining a carbon fiber loaded GaN:ZnO nanowire composite material, in which the maximum molar percentage of ZnO reached 18%. GaN:ZnO nanowires are very stable in aqueous solution, with properties such as acid resistance, alkali resistance, corrosion resistance, and heat resistance. Using the electric field sterilization effect and zinc ion dissolution effect of GaN:ZnO nanowires, a pair of single-layer GaN:ZnO nanowire electrodes can achieve 100% sterilization rate on 10 5 CFU / mL of E. coli in a PBS buffer solution with a flow rate of 10 mL / min at 7V; and a pair of double-layer GaN:ZnO nanowire electrodes can achieve 100% sterilization rate on 10 5CFU / mL Escherichia coli, 0.9% NaCl aqueous solution of 16 mL / min of physiological saline (0.9% NaCl aqueous solution) reached 100%. At the same time, we also in-situ grow graphene film on the surface of gallium nitride nanowire electrode, improve the conductivity, tensile strength of gallium nitride nanowire electrode, and enhance the binding force of gallium nitride nanowire and substrate, improve the ability of electrode to resist water flow and air impact; a pair of two-layer gallium nitride nanowire / graphene composite material electrode can kill 10 5 CFU / mL Escherichia coli, 80 mL / min of PBS buffer solution reached 100%.

[0007] In the research process, the applicant further found that: the lower the electron concentration of gallium nitride nanowire (GaN nanowire), the higher the hole concentration, the better the electric sterilization effect. The applicant analyzes: the oxidation reaction of the positive electrode GaN / solution interface forms gallium oxide, the Fermi level of GaN moves towards the top of the valence band, which can significantly increase the hole carrier concentration, and reduce the potential barrier between GaN and gallium oxide. Holes can migrate from GaN to the surface of gallium oxide at a lower external voltage, directly splitting the surface-adsorbed H2O / OH - , and efficiently generating hydroxyl radicals (·OH). Hydroxyl radicals (·OH) are stronger oxidants than ozone and can oxidize almost all dye organic matter and viruses and bacteria. This process significantly improves the inactivation efficiency of the electrochemical sterilization process by increasing the yield of active oxygen species (ROS) hydroxyl radicals (·OH). At the same time, as the negative electrode of the electric sterilization, the hydrogen evolution reaction is easy to cause the alkalization of the surrounding water and produce deposition, and the electron concentration of the p-type GaN nanowire is low, so the hydrogen evolution overpotential is also high. The p-type GaN nanowire can alleviate the phenomenon of metal hydroxide deposition on the surface of the negative electrode. Research has found that the higher the ZnO concentration in the GaN:ZnO nanowire, the lower the electron concentration. However, the GaN:ZnO nanowire containing 18% (mole percent) ZnO is still an n-type semiconductor with a high Fermi level, so its sterilization effect has an upper limit. The applicant also carbon-doped GaN nanowires by introducing methane in the CVD growth process, realizing the growth of p-type GaN nanowires. A pair of single-layer carbon-doped p-type gallium nitride nanowire composite material electrodes can kill 10 5 CFU / mL Escherichia coli, 80 mL / min of PBS buffer solution reached 100%. However, it is difficult to adjust the gallium nitride to p-type by methane, and only a specific flow rate can effectively dope carbon. The doping concentration is limited, and the surface of the GaN nanowire is easy to deposit carbon when the methane flow is slightly larger, which cannot effectively regulate the Fermi level of the GaN nanowire.

[0008] The present application aims at the above-mentioned defects, and provides a zinc-doped p-type GaN nanowire preparation method, which comprises the following steps: S1, providing a carbon fiber cloth, and forming a gold film on both sides of the carbon fiber cloth; S2, in a CVD method device, taking the carbon fiber cloth as a substrate, taking the gold film on the carbon fiber cloth as a catalyst, taking gallium acetylacetonate as a gallium source, taking ammonia as a nitrogen source, and taking zinc powder as a doping source, and preparing the p-type GaN nanowire material by evaporation of the zinc powder in a CVD growth stage.

[0009] Preferably, the present application further comprises the following steps: Pre-treating the zinc powder before preparation, specifically: weighing the zinc powder; immersing and treating the weighed zinc powder in a dilute hydrochloric acid solution for a predetermined time to remove the oxide layer on the surface of the zinc powder; cleaning the zinc powder after the deoxidation treatment with deionized water, ethanol and isopropanol in sequence to ensure that the residual acid and impurities are removed; the cleaning frequency of each solvent is not less than 3 times; separating and taking out the cleaned zinc powder for drying until completely dry.

[0010] Preferably, the mass ratio of the zinc powder to gallium acetylacetonate is 1-4:20. Preferably, the evaporation amount of the zinc powder and gallium acetylacetonate is adjusted by adjusting the mass ratio, so as to adjust the p-doping concentration of the GaN nanowire.

[0011] Preferably, the CVD device is a double-temperature-zone sliding rail tube furnace with a first temperature zone and a second temperature zone, the carbon fiber cloth is arranged in the center of the second temperature zone, and the gallium acetylacetonate and the zinc powder are arranged in the first temperature zone.

[0012] Preferably, the diameter of the prepared single p-type GaN nanowire is less than 50 nm.

[0013] The present application also provides a zinc-doped p-type GaN nanowire prepared by the above-mentioned preparation method.

[0014] The present application also provides an application of an electrode prepared by the above-mentioned zinc-doped p-type GaN nanowire in water sterilization.

[0015] Preferably, the electrode has a sterilization effect of more than 100% under a voltage of 5V.

[0016] Preferably, under the same voltage, the higher the p-doping concentration of the electrode, the more significant the sterilization effect.

[0017] Compared to existing technologies, this invention utilizes CVD-grown GaN nanowires by introducing zinc powder as a dopant source. Through the evaporation of zinc during the CVD growth stage, p-type GaN nanowire materials were successfully prepared. Zinc, as a p-type dopant source for GaN nanowires, allows for controllable doping, enabling heavy doping and the fabrication of highly conductive p-type GaN degenerate semiconductor nanowires. Furthermore, it achieves the fabrication of a pair of monolayer GaN nanowire electrodes containing 10% zinc powder at relatively low voltages (e.g., 5V). 5 The p-type GaN nanowires prepared in this invention achieve a 100% sterilization rate of CFU / mL E. coli and PBS buffer solution at a flow rate of 100 mL / min. These nanowires can perform long-term, high-efficiency water treatment under low voltage, with lower energy consumption, better material stability, longer lifespan, and higher efficiency in sterilization, algae removal, and disinfection. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the zinc-doped p-type GaN nanowire preparation method in Example 1; Figure 2 This is a schematic diagram of the CVD device; Figure 3 This is a schematic diagram of carbon fiber cloth set on a quartz plate; Figures 4(a)-4(c) These are surface scanning electron microscope (SEM) images of the p-type GaN nanowires in this embodiment at different magnifications; Figure 5 These are the Mott-Schottky (MS) test results of three groups of p-type GaN nanowire samples with different doping levels; Figure 6 This is a comparison of the results of three groups of p-type GaN nanowire carbon cloth electrodes with different doping levels in killing Escherichia coli colonies on coated plates. Figure 7 These are the antibacterial rate curves of three sets of p-type GaN nanowire carbon cloth electrodes with different doping levels as a function of voltage. Figure 8(a) compares the killing effects of Zn-doped GaN nanowires and carbon cloth electrodes (CC) on algal cells in seawater at voltages of 1-5V. Figure 8(b) shows optical micrographs of algal cells before and after treatment. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Referring to Figure 1 The first embodiment of the present application provides a preparation method of zinc-doped p-type GaN nanowire, which comprises: S1, providing a carbon fiber cloth, and forming a layer of gold film on both sides of the carbon fiber cloth.

[0021] In this embodiment, the carbon fiber cloth as the substrate 10 needs to be pretreated first, including: The carbon fiber cloth of a predetermined size is obtained by cutting, such as a carbon fiber cloth with an area of 3 4 cm.

[0022] At present, the size of the carbon fiber cloth can be set according to actual needs, which is not described herein.

[0023] After the carbon fiber cloth is sequentially placed in acetone, deionized water and alcohol, it is ultrasonically treated for 10 min; Put into the oven to dry at 60°.

[0024] Spray gold on both sides for 5 seconds in the SEM room, so that a layer of gold film is formed on both sides of the carbon fiber cloth.

[0025] S2, in the CVD device, taking the carbon fiber cloth as the substrate, taking the gold film on the carbon fiber cloth as the catalyst, taking gallium acetylacetonate as the gallium source, taking ammonia as the nitrogen source, and taking zinc powder as the doping source, by evaporation of the zinc powder in the CVD growth stage, p-type GaN nanowire is prepared.

[0026] Specifically, the pretreatment of the zinc powder before preparation includes: Weighing: accurately weighing the zinc powder of a predetermined mass.

[0027] The weight of the zinc powder is determined according to the doping concentration, and generally the weight ratio of the zinc powder to the gallium acetylacetonate is: Deoxidation layer: the weighed zinc powder is immersed in a dilute hydrochloric acid solution (1 volume of concentrated hydrochloric acid mixed with 5 volumes of water) for a predetermined time (for example, about 30 minutes) to effectively remove the oxide layer on the surface of the zinc powder.

[0028] Cleaning: the deoxidized zinc powder is sequentially cleaned with deionized water, ethanol and isopropanol to ensure that the residual acid and impurities are removed. Each solvent is cleaned for no less than 3 times.

[0029] Drying: the cleaned zinc powder is separated and dried with a wash ball until the zinc powder is completely dried.

[0030] In this embodiment, after the pretreatment of the carbon fiber cloth and the zinc powder is completed, they can be put into the CVD device for material preparation.

[0031] In the present embodiment, as shown in Figure 2 the CVD device is a double-temperature-zone sliding-pipe furnace with a first temperature zone (Zone 1) and a second temperature zone (Zone 2), and includes a first pipe 20, a second pipe 30, and a third pipe 40 for injecting gas; and step S2 specifically includes: S21, weighing a predetermined amount of gallium acetylacetonate and placing it in the second pipe 30 by a boat.

[0032] In the present embodiment, the gallium acetylacetonate is placed in the second pipe 30 by a boat A and a boat B. In one implementation, if the weight of the zinc powder is 0.05 g, the boat A can be configured to contain 0.06 g of gallium acetylacetonate, and the boat B can be configured to contain 0.15 g of gallium acetylacetonate.

[0033] S22, weighing the pretreated zinc powder and placing it at the bottom of a quartz tube C 50, and also placing it in the second pipe 30.

[0034] In the present embodiment, the distance between the bottom of the quartz tube C 50 and the pipe opening is 24.2 cm, and one end is flush with the outlet of the second pipe 30. The gallium acetylacetonate and the zinc powder are both located in the first temperature zone.

[0035] In the present embodiment, the distance between the bottom of the quartz tube C 50 and the pipe opening is 24.2 cm, and one end is flush with the outlet of the second pipe 30. The gallium acetylacetonate and the zinc powder are both located in the first temperature zone.

[0036] S23, inserting the substrate 10 into a quartz sheet 60 and placing it in the second temperature zone, inserting a small furnace plug into the second pipe close to the inlet, and inserting two large furnace plugs into the outlet of the furnace pipe and attaching flanges, and the heating band is 150°C.

[0037] As shown in Figure 3 the substrate 10 is inserted into the quartz sheet 60 and placed in the second temperature zone, and in particular, the quartz sheet 60 is placed about 4 cm from the right end of the outlet of the second pipe 40.

[0038] In the present embodiment, the small furnace plug 70 is inserted into the second pipe 40 close to the inlet, and in particular, about 4 cm from the inlet.

[0039] S24, setting the first temperature zone to 500 degrees, and the second temperature zone to between 800-900 degrees, with a temperature rising speed of 10 degrees / min, and after reaching the corresponding target temperature, maintaining the temperature for 50-65 min, and after the maintaining time, stopping heating and gradually cooling.

[0040] S25, during heating, move the furnace to the downwind side, turn on the furnace, and inject nitrogen into the second pipe 30. After the temperature of the second temperature zone reaches the growth temperature of GaN nanowires, stop injecting nitrogen into the second pipe 30 and introduce ammonia into the third pipe 40 (flow rate of 50 sccm). After the furnace temperature recovers to the growth temperature of GaN nanowires (e.g., 800 degrees), move the furnace to the upwind side, that is, align the leftmost side of the furnace with the leftmost mark line of the slide rail furnace. After the furnace temperature recovers to the set temperature (record recovery time: approximately 15 minutes), introduce nitrogen into the second pipe 30 again (flow rate of 20 sccm) and adjust the vacuum pump baffle valve to make the chamber pressure 2000 Pa.

[0041] Specifically, in this embodiment, the heating furnace is sliding. To precisely control the evaporation time of the precursor and zinc powder, the furnace is placed in the downwind zone (right side) without chemicals and substrate during heating, a process that takes approximately 80 minutes. Once the furnace temperature reaches the set temperature (e.g., 500 degrees Celsius for the first temperature zone and 800 degrees Celsius for the second temperature zone), it slides to the left reaction zone. At this point, the reaction zone only needs about 15 minutes to reach 500-800 degrees Celsius.

[0042] S26, remove the furnace, turn off the heating belt, stop the supply of ammonia to the third pipe 40 and nitrogen to the second pipe 30, and supply nitrogen to the first pipe 20; when the furnace temperature is below 200 degrees, evacuate to a vacuum; open the gas outlet flange, take out the sample, and you will get p-type GaN nanowire material.

[0043] Among them, the surface scanning electron microscope images of p-type GaN nanowires are as follows: Figures 4(a)-4(c) As shown, uniform and dense p-type GaN nanowires were obtained on the upper surface of the carbon cloth. The diameter of a single nanowire is less than 50 nm.

[0044] The electrochemical properties of the p-type GaN nanowires prepared in this embodiment will be further illustrated by some experiments or examples below.

[0045] In the CVD growth process described above, p-type GaN nanowires with gradient doping concentrations can be prepared by controlling the amount of zinc powder added. In this example, three groups of p-type GaN nanowire samples were prepared using 0.1g, 0.05g, and 0.03g of zinc powder.

[0046] To quantitatively characterize the doping properties, this embodiment uses an electrochemical workstation (Ivium V54802) to perform MS measurements on the three groups of samples in a three-electrode system. The standard three-electrode method was used, with a p-type GaN nanowire electrode as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode with potassium chloride solution as the reference electrode. The electrolyte was 0.2M acetic acid solution (CH3COOH). The MS measurement frequencies were 1Hz and 0.1Hz. Linear fitting was performed on the MS curves within the open-circuit potential (Eoc) range, as shown below. Figure 5 As shown.

[0047] The obtained MS test results are processed and fitted. The carrier concentration is calculated from the fitting slope of the data segment containing the open circuit potential (Eoc). The intersection of this fitted data segment with the X-axis is the Eoc value for that sample. FB The values ​​of (flat band potential) and the resulting fitting results are summarized in Table 1: Table 1. MS test fitting results of three groups of p-type GaN nanowire samples with different doping levels.

[0048] according to Figure 5 Analysis of the MS test results and the MS test fitting results in Table 1 for three groups of p-type GaN nanowire samples with different doping levels shows that the fitting slope K of the data segment containing the open-circuit potential (Eoc) of the three groups of p-type GaN nanowire electrodes is negative (k < 0), indicating that the surfaces of the three electrodes are all p-type doped. This confirms that zinc powder, as a doping source, effectively achieves p-type doping during the growth of GaN nanowires. Further comparison of the carrier concentration and Eoc of the three groups of samples... FB As a result, with the increase of Zn powder mass during growth, the hole carrier concentration increased accordingly, and the E of the sample... FB It also shifts towards the valence band. The sample with 0.1g of Zn added during growth achieves heavy doping, resulting in a flat band potential E. FB When the position is below the valence band top VB (approximately 2.5 eV), it becomes a degenerate semiconductor.

[0049] MS's test results not only confirmed that zinc powder can be used as a doping source for p-type doping of GaN nanowires, but also that the doping is controllable, heavy doping can be achieved, and p-type GaN degenerate semiconductor nanowires with high conductivity can be prepared.

[0050] The third embodiment of the present invention also provides an application of the above-mentioned zinc-doped p-type GaN nanowires in water disinfection.

[0051] The following will use the sterilization experiment of the p-type GaNg nanowire-carbon cloth composite electrode in this embodiment to verify the water disinfection effect of the present invention.

[0052] I. Sterilization Experiment Conditions

[0053] II. Results of Colony Counting See Figure 6 , Figure 6 A comparison of E. coli colony kill images using three different doped p-type GaN nanowires (p-GaN NWs) carbon cloth electrodes (PBS buffer, 10 μL). 5 (CFU / ml E. coli, 100 ml / min) Figure 7 The antibacterial rate (obtained by plate counting) of the three different doped p-type GaN nanowire carbon cloth electrodes described above is shown as a function of voltage (PBS buffer solution, 10). 5 CFU / ml E. coli, 100 ml / min).

[0054] like Figure 6 and Figure 7 As shown, increasing the p-type doping level significantly enhances the electro-sterilization efficiency. At an initial E. coli concentration of 1×10⁻⁶, this effect was observed. 5 The performance differences of p-type GaN nanowire carbon cloth electrodes with different doping levels under CFU / ml conditions confirm the promoting effect of p-type doping on electrosterilization. Specifically, p-type GaN nanowire carbon cloth electrodes with doping amounts of 0.05 g and 0.03 g Zn showed no sterilization effect at a working voltage of 3 V; when the voltage was increased to 5 V, their sterilization rates reached approximately 70% and 60%, respectively; further increases to 7 V were required for both samples to achieve 100% sterilization. In contrast, the successfully heavily doped p-type GaN nanowire carbon cloth electrode (Zn=0.1 g) exhibited excellent sterilization performance: 100% sterilization was achieved at 5 V; even at the lower 3 V voltage, its sterilization rate still reached approximately 50%.

[0055] To further investigate the sterilization mechanism, one set of experiments introduced isopropanol (IPA), a hydroxyl radical (·OH) scavenger, into the bacterial solution. Comparison with experiments without IPA showed that the sterilization efficiency of the p-type GaN NWs carbon cloth electrode significantly decreased after the addition of IPA, and residual colonies were observed in the plate count results under 5V conditions. This phenomenon directly confirms that hydroxyl radicals (·OH) are generated in the solution during the electro-sterilization process, and that this active substance makes a crucial contribution to the sterilization efficacy.

[0056] As shown in Figures 8(a) and 8(b), Figure 8(a) compares the killing effects of two electrodes: the Zn-doped p-type GaN nanowire and the carbon cloth electrode (CC) in this embodiment on algal cells in seawater at a voltage of 1-5V. It can be seen that this embodiment has a higher algal inactivation rate than CC at the same voltage.

[0057] Figure 8(b) shows optical micrographs of algal cells before and after treatment. It can be seen that the cell walls of algal cells treated in this embodiment are broken down, and the cells shrink and die.

[0058] In summary, compared to existing technologies, this invention utilizes CVD-grown GaN nanowires by introducing zinc powder as a doping source. Through the evaporation of zinc during the CVD growth stage, p-type GaN nanowire materials were successfully prepared. Zinc, as a p-type doping source for GaN nanowires, allows for controllable doping, enabling heavy doping and the fabrication of highly conductive p-type GaN degenerate semiconductor nanowires. Furthermore, it achieves the production of a pair of monolayer GaN nanowire electrodes containing 10% zinc powder at a relatively low voltage (5V). 5 The p-type GaN nanowires prepared in this invention achieve a 100% sterilization rate of CFU / mL E. coli and PBS buffer solution at a flow rate of 100 mL / min. These nanowires can perform long-term, high-efficiency water treatment under low voltage, with lower energy consumption, better material stability, longer lifespan, and higher efficiency in sterilization, algae removal, and disinfection.

[0059] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing zinc-doped p-type GaN nanowires, characterized in that, The method comprises the following steps: S1, providing a carbon fiber cloth, and forming a layer of gold film on both sides of the carbon fiber cloth; S2, in a CVD device, taking the carbon fiber cloth as a substrate, taking the gold film on the carbon fiber cloth as a catalyst, taking gallium acetylacetonate as a gallium source, taking ammonia as a nitrogen source, and taking zinc powder as a doping source, and preparing a p-type GaN nanowire material by evaporation of the zinc powder in a CVD growth stage.

2. The method for preparing zinc-doped p-type GaN nanowires according to claim 1, wherein The method further comprises the following steps: Before preparation, the zinc powder is pretreated, specifically: weighing the required mass of zinc powder; immersing the weighed zinc powder in a dilute hydrochloric acid solution for a predetermined time to remove the oxide layer on the surface of the zinc powder; cleaning the zinc powder after the deoxidation treatment with deionized water, ethanol and isopropanol in sequence to ensure that the residual acid and impurities are removed; the cleaning time of each solvent is not less than 3 times; separating and taking out the cleaned zinc powder for drying until completely dry.

3. The method for preparing zinc-doped p-type GaN nanowires according to claim 1, characterized in that, The mass ratio of the zinc powder to gallium acetylacetonate is 1-4:

20.

4. The method for preparing zinc-doped p-type GaN nanowires according to claim 1, wherein The p-type GaN nanowire material is adjusted by adjusting the evaporation amount of the zinc powder.

5. The method for preparing zinc-doped p-type GaN nanowires according to claim 1, characterized in that, The CVD device is a double-temperature-zone sliding rail tube furnace with a first temperature zone and a second temperature zone, the carbon fiber cloth is arranged in the center of the second temperature zone, and the gallium acetylacetonate and the zinc powder are arranged in the first temperature zone.

6. The method for preparing zinc-doped p-type GaN nanowires according to claim 1, characterized in that, The prepared single p-type GaN nanowire has a diameter of less than 50 nm.

7. A zinc-dopant-based p-type GaN nanowire, characterized in that, The method is prepared by the preparation method of any one of claims 1-5.

8. The electrode prepared based on the zinc-doped p-type GaN nanowire of claim 7 is applied in water body disinfection.

9. Use according to claim 8, characterized in that, Under a voltage of 5V, the electrode has a sterilization effect of more than 100%.

10. Use according to claim 9, characterized in that, The higher the p-doping concentration of the electrode, the smaller the required voltage, and the more significant the sterilization effect.

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