Preparation method and application of metal micro-nanotube array

Abstract

The invention belongs to the technical field of micro-nano processing, and particularly relates to a preparation method and application of a metal micro-nano tube array. Comprising the following steps: preparing a metal layer on the surface of a substrate; coining glue is sprayed on the surface of the metal layer, then coining is conducted through a template, and a micro glue column array is formed after curing; a plasma etching process is adopted, the micro glue column array is used as a mask, the metal layer exposed out of the gaps in the bottom of the micro glue column array is etched, and a structure with the micro glue columns wrapped by metal is formed; and removing the rubber columns in the structure of the metal-coated micro rubber columns to obtain the metal micro-nano tube array. According to the invention, a residual-layer-free imprinting technology is adopted, the problem of glue layer residue in traditional imprinting is avoided, and the etching uniformity is improved. A plasma dynamic balance process is adopted, the side wall redeposition effect of etching by-products is utilized, and the metal micro-nano tubes are formed in a self-assembly mode. The prepared metal micro-nano tube array has high aspect ratio compatibility, and the nano tube array with the aspect ratio as high as 10: 1 can be realized.

Description

Technical Field

[0001] The present invention belongs to the field of micro-nano processing technology, and in particular relates to a preparation method of a metal micro-nano tube array and application thereof. Background Art

[0002] Metal micro-nanotube arrays have important application value in the fields of photoelectrocatalysis, nanofluidic devices and metamaterials, but their large-scale preparation faces significant bottlenecks in traditional processes. Existing technologies such as photolithography combined with etching processes rely on multiple hard mask patterning, which can easily cause structural damage due to mask peeling, and the aspect ratio is limited to less than 5:1; although template-assisted electrochemical deposition can form hollow structures, it is limited by material selection (only applicable to electrodeposited metals); although nanoimprinting can be patterned with high precision, the hard template causes imprinted glue residue (requires secondary etching to remove), and the process is complex and costly. In addition, the redeposition of volatile metal byproducts in plasma etching has long been regarded as a process interference factor and has not been effectively utilized. In response to the above problems, the present invention proposes an innovative technical route: eliminating glue residue through spraying process and flexible template imprinting, and utilizing plasma etching-redeposition dynamic balance to self-assemble metal micro-nanotubes, breaking through material limitations and process bottlenecks. Summary of the Invention

[0003] The technical problem to be solved by this invention is to address the shortcomings of existing technologies and provide a method that uses a spray coating process to calculate the required amount of glue based on the microstructure of the flexible template surface. The required amount of glue is then evenly sprayed onto the substrate surface using a spray coating process. Imprinting is performed using the flexible template, eliminating the glue residue problem encountered in traditional spin-on and drip-on imprinting. Simultaneously, the plasma etching parameters (gas ratio, ion energy, and temperature gradient) are actively controlled to transform the sidewall redeposition effect of the metal halide into a controllable self-assembly mechanism, resulting in a single-step formation of high-aspect-ratio (up to 10:1) and highly uniform metal micro-nanotube arrays. This method overcomes material limitations (compatible with Al, Ti, Au, etc.) and has a low process complexity, providing a new path for the low-cost manufacturing of high-performance nanotube devices.

[0004] In order to solve the above technical problems, the present invention discloses a method for preparing a metal micro-nanotube array, comprising the following steps:

[0005] S1. Preparing a metal layer on the substrate surface;

[0006] S2. Spraying embossing adhesive on the surface of the metal layer, then embossing it through a template, and curing it to form a micro-column array;

[0007] S3 uses a plasma etching process to obtain the micro-gel column array in S2 as a mask to etch the metal layer exposed at the bottom gap of the micro-gel column array to form a metal-coated micro-gel column structure;

[0008] S4. removing the metal-coated micro-gel columns from the structure to obtain the metal micro-nanotube array.

[0009] Wherein, the substrate includes any one of a rigid substrate, a flexible substrate and a composite substrate;

[0010] Specifically, the rigid substrate includes any one of silicon wafer, glass, ceramic and metal foil;

[0011] Specifically, the flexible substrate includes any one of polyimide (PI), polyethylene terephthalate (PET) and polydimethylsiloxane (PDMS);

[0012] Specifically, the composite substrate includes a temporary carrier with a surface pre-coated with a SiO2 sacrificial layer or a photoresist sacrificial layer;

[0013] In some embodiments of the present invention, the substrate includes a silicon wafer, polyimide (PI) and a composite material SiO2 / ITO.

[0014] Wherein, the metal layer includes any one of an aluminum metal layer, a titanium metal layer and a gold metal layer.

[0015] Wherein, the embossing adhesive is any one of a heat-curing adhesive and / or a UV-curing adhesive;

[0016] In some embodiments of the present invention, the embossing adhesive includes SU-8, CN975 and PMMA.

[0017] Wherein, in S1, the metal layer is prepared by magnetron sputtering and / or electron beam evaporation, and the thickness of the metal layer is 100 nm to 1 μm;

[0018] In some embodiments of the present invention, the specific process parameters of the magnetron sputtering are: Ar gas flow rate 20 sccm, power 150 W, vacuum degree 2×10 -6 Torr;

[0019] In some embodiments of the present invention, the specific process parameters of the electron beam evaporation are: vacuum degree 2×10 -6 ~3×10 -6 Torr, evaporation rate

[0020] Wherein, in S2, the embossed adhesive is prepared by spraying with an ultrasonic spraying device, and the thickness of the embossed adhesive is 100 nm to 70 μm; the embossing time is 3 to 5 minutes; the curing is heat curing and / or UV curing;

[0021] In some embodiments of the present invention, the specific process parameters of the ultrasonic spraying are: nozzle diameter 10-100 μm, air pressure 0.1-0.5 MPa, nozzle movement speed 1-50 mm / s;

[0022] In some embodiments of the present invention, the specific temperature of the heat curing is 50° C.; the wavelength of the UV curing light is 365 nm, and the curing time is 3 minutes.

[0023] Among them, in S2, the template is a PDMS soft template, and the specific preparation method is: first, a mother template is prepared by electron beam lithography, nanoimprinting or self-assembly technology, and then a PDMS prepolymer and a curing agent (10:1) are mixed and degassed and then poured on the surface of the mother template. After curing, it is peeled off to obtain a PDMS soft template complementary to the mother template pattern. The pore diameter of the microcolumns or micropores of the PDMS soft template is 200nm~20μm, the period (the spacing between the center points of the micropores) is 200nm~40μm, the micropore depth is 0.2~200μm, and the array density is 10 3 ~10 9 Tube / cm 2 , the aspect ratio is 1:1 to 10:1, and the arrangement includes any one of a tetragonal arrangement, a hexagonal arrangement, and a gradient arrangement; it should be noted that the PDMS soft template used in the present invention has no specific requirements for the microstructure and can be changed accordingly according to the shape and arrangement of the metal micro-nanotube array to be prepared;

[0024] In some embodiments of the present invention, in S2, the amount of the sprayed embossing adhesive is calculated by the micropore volume of the PDMS soft template, and the specific calculation formula is: V = π (D / 2) 2 ×H×ρ×S, where D is the aperture, H is the depth, ρ is the array density, and S is the area.

[0025] Wherein, in S3, the plasma etching process is reactive ion beam etching;

[0026] Specifically, the process parameters of the reactive ion beam etching are: if IBE is selected for etching, the process parameters are: etching energy of 500 to 1000 eV, beam current of 0.5 to 2 mA, vacuum degree of less than 1×10 -4 Torr, Ar gas flow rate is about 5 to 50 sccm.

[0027] Specifically, for IBE etching, the etching rate can be adjusted by adjusting the ion beam energy, the ion bombardment energy can be adjusted by adjusting the RF bias, the ion beam density can be controlled by adjusting the velocity flow, and the by-product condensation and redeposition can be controlled by adjusting the substrate temperature.

[0028] Wherein, in S4, the removal of the glue pillars in the structure of the metal-coated micro glue pillars comprises any one or more of step-by-step glue removal, wet glue removal and dry etching glue removal;

[0029] In some embodiments of the present invention, the specific steps of the step-by-step debonding are: calcining at 200-600° C. for 1-5 hours in a N 2 / H 2 atmosphere;

[0030] In some embodiments of the present invention, the specific steps of the wet degumming process are: soaking in dichloromethane and ultrasonic-assisted cleaning for 30 to 200 minutes;

[0031] In some embodiments of the present invention, the specific steps of dry etching and desmearing are: using oxygen plasma etching, O2 flow rate 10sccm, power 40W, and time 100s.

[0032] Furthermore, the metal micro-nanotube array prepared by the above preparation method is also within the protection scope of the present invention;

[0033] Specifically, the parameters of the metal micro-nanotube array are: micro-nanotube outer diameter is 200nm-20μm, micro-nanotube wall thickness is 20-500nm, micro-nanotube height is 0.2-200μm, array density is 10 3 ~10 9 Tube / cm 2 , the aspect ratio is 1:1 to 10:1; the cross-sectional shape of the micro-nanotubes of the metal micro-nanotube array includes any one of a circular, polygonal and irregular shape; the arrangement of the micro-nanotube array includes any one of a tetragonal arrangement, a hexagonal arrangement and a gradient arrangement.

[0034] Furthermore, the application of the above-mentioned metal micro-nanotube array in the preparation of any of the following products is also within the scope of protection of the present invention, and the products include: surface-enhanced Raman scattering substrate; electrochemical catalytic electrode and / or battery current collector; nanofluid channel and / or molecular sieve; metamaterial absorber and / or optical resonator.

[0035] Specifically, the metal micro-nanotube array serves as a surface-enhanced Raman scattering (SERS) substrate: the gaps between the sidewalls of the densely arranged metal micro-nanotubes form a large number of "hot spots", and the strong localized electromagnetic field (originating from surface plasmon resonance) can significantly enhance the Raman signal of the adsorbed molecules; at the same time, the high specific surface area is conducive to molecular enrichment, thereby improving detection sensitivity and reproducibility.

[0036] Specifically, the metal micro-nanotube array serves as an electrochemical catalytic electrode / battery current collector: the metal tube wall provides a highly conductive network to ensure efficient electron transmission; the vertical array structure significantly increases the active surface area, exposing abundant catalytic sites; the hollow tubes and the gaps between the tubes promote rapid diffusion of reactants / ions, optimizing mass transfer efficiency; and it can be grown directly on a substrate, reducing interfacial resistance and improving electrode stability.

[0037] Specifically, the metal micro-nanotube array serves as a nanofluid channel / molecular sieve: the nanoscale inner cavity (controllable diameter) can achieve confined mass transfer and has a significant surface charge effect; the tube wall can be functionally modified to achieve ion-selective transport or specific molecular screening; and the ordered array structure facilitates integration and high-throughput operation.

[0038] Specifically, the metal micro-nanotube array acts as a metamaterial absorber / optical resonator: its subwavelength structure and gradient refractive index characteristics (porosity change) effectively suppress light reflection and achieve broadband absorption; the metal tube wall has strong dielectric loss; and the hollow cavity can support local electromagnetic mode resonance. By adjusting the tube diameter / spacing / length, the resonant wavelength can be precisely controlled to achieve customized light field manipulation.

[0039] Beneficial effects:

[0040] The present invention adopts a residual layer-free imprinting technology, which accurately matches the thickness of the PDMS soft template with the sprayed adhesive layer, avoiding the adhesive layer residue problem in traditional imprinting and improving etching uniformity.

[0041] The present invention adopts a plasma dynamic balance process and utilizes the sidewall redeposition effect of etching byproducts to self-assemble and form metal micro-nanotubes without the need for additional masking or deposition steps.

[0042] The metal micro-nanotube array prepared by the present invention has high aspect ratio compatibility. By adjusting the plasma parameters to control the thickness of the sidewall passivation layer, a micro-nanotube array with an aspect ratio of up to 10:1 can be achieved.

[0043] The metal micro-nanotube array prepared by the present invention has a specific surface area increased by 1 to 2 times (compared to solid nanocolumns). When a flexible substrate is used, multiple bending / folding and other processes can be achieved without structural damage. Therefore, the metal micro-nanotube array provided by the present invention is suitable as a substrate for a variety of products, such as surface-enhanced Raman scattering (SERS) substrates, nanoreactors and flexible transparent electrodes, and it can enhance catalytic activity, enhance the plasmon resonance effect or enhance the sensitivity of sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.

[0045] Figure 1 This is a flow chart of the preparation method of the metal micro-nanotube array provided by the present invention, wherein 1 is the substrate, 2 is the metal layer, 3 is the embossing glue, 4 is the PDMS soft template, 5 is the micro-gel column array, 6 is the redeposited metal, and 7 is the metal micro-nanotube array.

[0046] Figure 2 Schematic diagram of the plasma dynamic self-assembly mechanism of the present invention, wherein 2-1 is an etching gas and 2-2 is a metal atom.

[0047] Figure 3 This is a SEM image of the aluminum nanotube array prepared by the present invention, wherein: Figure 3 a in the figure is a cross-sectional view of an aluminum nanotube array. Figure 3 b in the figure is the top view of the aluminum nanotube array.

[0048] Figure 4 This is a SEM image of the titanium microtube array prepared by the present invention, wherein: Figure 4 a in the figure is a cross-sectional view of the titanium microtube array. Figure 4 b is the top view of the titanium microtube array.

[0049] Figure 5 This is the SEM image of the gold nanotube array prepared in the present invention.

[0050] Figure 6 The specific surface area comparison of the gold nanotube array prepared in the present invention and the gold nanocolumn array is shown.

[0051] Figure 7 is the light reflectivity of the aluminum nanotube array prepared in the present invention.

[0052] Figure 8 The linear sweep voltammetry (LSV) curve of the gold nanotube array prepared in the present invention tested during the electrocatalytic water decomposition process. DETAILED DESCRIPTION

[0053] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0054] The sources of the raw materials in the following examples are as follows: silicon wafers were purchased from Suzhou Yancai Micro-Nano Technology Co., Ltd.; SU-8 glue was purchased from Suzhou Wenhao Microfluidic Technology Co., Ltd.; polyimide (PI) was purchased from DuPont China Group Co., Ltd.; CN975 glue was purchased from Purin Technology (Hangzhou) Co., Ltd.; the composite material SiO2 / ITO was purchased from Advanced Institute (Shenzhen) Technology Co., Ltd.; PMMA glue was purchased from Aladdin Biochemical Technology Co., Ltd.

[0055] The present invention provides a method for preparing a metal micro-nanotube array using a dynamic self-assembly mechanism. Figure 1This is a flow chart of the preparation method provided by the present invention. First, a metal layer 2 is prepared on a substrate 1, and an embossing glue 3 is sprayed on the metal layer 2. Then, it is embossed through a PDMS soft template 4, and then cured to obtain a micro-gel column array 5. Through a plasma etching process, metal 6 is deposited on the side walls of the micro-gel column array using a dynamic self-assembly mechanism. After debonding, a metal micro-nanotube array 7 is formed.

[0056] The specific preparation method of the PDMS soft template used in the present invention is as follows: first, a mother template is prepared by electron beam lithography, nanoimprinting or self-assembly technology, and then a PDMS prepolymer and a curing agent (10:1) are mixed and degassed and then poured on the surface of the mother template. After curing, the PDMS soft template is peeled off to obtain a PDMS soft template with a pattern complementary to the mother template. Specifically, the pore diameter of the microcolumns or micropores of the PDMS soft template is 200nm to 20μm, the period (the spacing between the center points of the micropores) is 200nm to 40μm, the micropore depth is 0.2 to 200μm, and the array density is 10 3 ~10 9 Tube / cm 2 The aspect ratio is 1:1 to 10:1, and the arrangement includes any one of a tetragonal arrangement, a hexagonal arrangement and a gradient arrangement.

[0057] It should be noted that the PDMS soft template used in the present invention has no specific requirements on the microstructure and can be changed accordingly according to the shape and arrangement of the metal micro-nanotube array to be prepared.

[0058] Figure 2 Figure 2 is a schematic diagram of the plasma dynamic self-assembly mechanism, where 2-1 represents the etching gas and 2-2 represents metal atoms. High-energy ions generated by anisotropic etching (e.g., reactive ion etching) bombard the metal layer at the bottom gap of the gel column, causing the metal atoms to break free from the lattice through a physical sputtering process. The sputtered metal atoms / particles diffuse and migrate on the sidewall surface of the gel column. Driven by driving forces such as concentration gradients, surface energy differences, or possibly electric field gradients, these migrated particles ultimately redeposit, nucleate, and grow on the sidewall surface of the gel column through a physical vapor deposition (PVD) mechanism, forming a tubular structure wall of metal or (under specific atmospheres) metal oxide.

[0059] Example 1: Preparation of aluminum nanotube arrays

[0060] S1. The silicon wafer used as the substrate was ultrasonically cleaned with ethanol and acetone for 15 minutes each. After cleaning, a 100 nm thick aluminum layer was deposited using a magnetron sputtering high vacuum coater (Leica EMACE600). The sputtering parameters were: Ar flow rate 20 sccm, power 150 W, and vacuum degree 2 × 10 -6 Torr.

[0061] S2. First, according to the PDMS soft template (micropore arrangement is hexagonal arrangement, pore diameter D = 250nm, depth H = 300nm, array density ρ = 10 9 pieces / cm 2 , area S = 5cm 2 ) is used to calculate the amount of glue by the volume of micropores. The specific calculation formula is V = π(D / 2) 2 ×H×ρ×S. An ultrasonic spray coating (FUNSONIC FS620 Intelligent) was then applied to the aluminum layer using the following parameters: nozzle diameter 10 μm, air pressure 0.5 MPa, nozzle travel speed 10 mm / s, and a coating thickness of 150 nm. A PDMS soft template was then bonded to the SU-8 adhesive layer and allowed to stand for 5 minutes to allow the sprayed adhesive layer to fully penetrate the pore array of the PDMS soft template. With the PDMS soft template in place, the template was then UV-cured (wavelength 365 nm) for 3 minutes. The PDMS soft template was then removed, forming a micropillar array with a diameter of 250 nm and a height of 300 nm.

[0062] S3. Using the microgel array obtained in S2 as a mask, a reactive ion beam etcher (IBE) was used (Beijing Edvans IBE-150) to etch the aluminum metal exposed at the bottom gap of the microgel array sample. The specific etching parameters were: Ar gas, etching energy 500 eV, beam current 120 mA, etching time 75 s, and vacuum degree less than 1 × 10 -4 Torr. When the etching gas Ar vertically impacts the aluminum metal surface, the high-energy ions (Ar + ) bombards the aluminum metal surface, causing aluminum metal atoms to escape from the crystal lattice. When the escaped aluminum metal atoms diffuse to the side wall of the gel column, under the action of driving forces such as concentration gradient, surface energy difference or possible electric field gradient, these migrated particles are finally re-deposited, nucleated and grown on the side wall surface of the gel column through the physical vapor deposition (PVD) mechanism, and finally form a metal aluminum coating around the micro-gel column array, thereby forming a metal aluminum-coated micro-gel column structure. At this time, the vertically impacting etching gas Ar can achieve secondary etching of the metal aluminum re-deposited on the top of the micro-gel column array. Therefore, the metal aluminum only coats the four sides of the micro-gel column, forming a hollow tubular structure.

[0063] S4. The sample of the metal aluminum-coated microgel columns formed after the S3 treatment is calcined to remove the gel columns by calcining at 400°C in a N2 / H2 atmosphere for 3 hours to obtain an aluminum nanotube array.

[0064] The aluminum nanotube arrays were characterized using scanning electron microscopy. Figure 3 is the SEM image of the aluminum nanotube array, where Figure 3 a in the figure is a cross-sectional view of an aluminum nanotube array. Figure 3b is the top view of the aluminum nanotube array. Figure 3 The aluminum nanotubes have an inner diameter of 250nm and a wall thickness of 20nm, meaning they have an outer diameter of 290nm and a height of 300nm, with an aspect ratio of 1.03:1. They are arranged in a hexagonal pattern, and the structure of the nanotubes is uniform. Furthermore, the 100nm thick aluminum layer deposited on the silicon wafer surface has been completely etched away. Calculations show that the aluminum etching rate and the sidewall redeposition rate during reactive ion beam etching are 1:0.2.

[0065] Example 2: Preparation of Titanium Microtube Array

[0066] S1. The polyimide (PI) substrate was cleaned with ethanol and acetone for 15 minutes in sequence by ultrasonic cleaning. After cleaning, a titanium layer with a thickness of 1 μm was deposited using a high vacuum electron beam evaporation device (Tycono TEMD600). The specific evaporation parameters were: vacuum degree 2×10 -6 Torr, evaporation rate

[0067] S2. First, according to the PDMS soft template (micropore arrangement is square arrangement, pore diameter D = 20 μm, depth H = 200 μm, array density ρ = 10 3 pieces / cm 2 , area S = 5cm 2 ) is used to calculate the amount of glue by the volume of micropores. The specific calculation formula is V = π(D / 2) 2 ×H×ρ×S. Subsequently, an ultrasonic spray coating device (FUNSONIC FS620 intelligent model) was used to spray a CN975 adhesive layer on the titanium metal layer. The specific spraying parameters were: nozzle diameter 50μm, air pressure 0.3MPa, nozzle movement speed 5mm / s, and spray thickness 62.8μm. The PDMS soft template was then attached to the CN975 adhesive layer and allowed to stand for 5 minutes to allow the sprayed adhesive layer to completely penetrate the PDMS soft template hole array. With the PDMS soft template fixed, it was UV-cured (wavelength 365nm) for 3 minutes. The PDMS soft template was then removed to form a micro-gel column array with a diameter of 20μm and a height of 200μm.

[0068] S3. Using the microgel array obtained in S2 as a mask, reactive ion beam etching (IBE) (Beijing Edvans IBE-150) was used to etch the titanium metal exposed at the bottom gap of the microgel array sample. The specific etching parameters were: etching gas: Ar, etching energy: 500 eV, beam current: 120 mA, etching time: 150 s, vacuum degree: less than 1×10 -4 Torr. When the etching gas Ar vertically impacts the titanium metal surface, the high-energy ions (Ar +) bombards the titanium metal surface, causing titanium metal atoms to escape from the lattice. When the escaped titanium metal atoms diffuse to the side wall of the gel column, under the action of driving forces such as concentration gradient, surface energy difference or possible electric field gradient, these migrated particles are finally re-deposited, nucleated and grown on the side wall surface of the gel column through the physical vapor deposition (PVD) mechanism, and finally form a metal titanium coating around the micro-gel column array, thereby forming a metal titanium-coated micro-gel column structure. At this time, the vertically impacting etching gas Ar can achieve secondary etching of the metal titanium re-deposited on the top of the micro-gel column array. Therefore, the metal titanium only coats the four sides of the micro-gel column, forming a hollow tubular structure.

[0069] S4. The sample with the titanium-coated sidewall gel columns formed after the S3 treatment is subjected to wet degumming. The specific process parameters are: immersing the sample in dichloromethane, ultrasonically removing the gel columns in dichloromethane for 100 minutes, and obtaining a titanium microtube array.

[0070] The titanium microtube arrays were characterized using scanning electron microscopy. Figure 4 is the SEM image of the titanium microtube array, where Figure 4 a in the figure is a cross-sectional view of the titanium microtube array. Figure 4 b is the top view of the titanium microtube array. Figure 4 The titanium microtubes have an inner diameter of 20μm and a wall thickness of 500nm, meaning they have an outer diameter of 21μm and a height of 200μm, with an aspect ratio of 10:1. They are arranged in a square pattern, and the structure of the titanium microtubes is complete and uniform. Furthermore, the 1μm titanium layer deposited on the PI surface has been completely etched away. Calculations indicate that the titanium etching rate and the sidewall redeposition rate during reactive ion beam etching are 1:0.5.

[0071] Example 3: Preparation of gold nanotube arrays

[0072] S1. The SiO2 / ITO composite material (SiO2 deposited on the surface of indium tin oxide (ITO)) was cleaned with ethanol and acetone for 15 minutes by ultrasonic cleaning. After cleaning, a 100 nm thick gold layer was deposited using high vacuum electron beam evaporation (TECONO TEMD600). The specific evaporation parameters were: vacuum degree 3×10 -6 Torr, evaporation rate

[0073] S2. First, according to the PDMS soft template (micropore arrangement is hexagonal arrangement, pore diameter D = 300nm, depth H = 380nm, array density ρ = 10 9 pieces / cm 2 , area S = 5cm 2 ) is used to calculate the amount of glue by the volume of micropores. The specific calculation formula is V = π(D / 2) 2×H×ρ×S. A PMMA adhesive layer was then sprayed onto the gold layer using an ultrasonic spray coating device (FUNSONIC FS620 Intelligent). The specific spraying parameters were: nozzle diameter 10 μm, air pressure 0.5 MPa, nozzle movement speed 3 mm / s, and spray thickness 120 nm. A PDMS soft template was then bonded to the PMMA adhesive layer and allowed to stand for 3 minutes to allow the sprayed adhesive layer to fully penetrate the pore array of the PDMS soft template. While the PDMS soft template was fixed, it was heat-cured (50°C) and the PDMS soft template was removed, forming a micropillar array with a diameter of 300 nm and a height of 380 nm.

[0074] S3. Using the microgel array obtained in S2 as a mask, reactive ion beam etching (IBE) (Beijing Edvans IBE-150) was used to etch the gold metal exposed in the bottom gap of the microgel array sample. The specific etching parameters were: etching gas: Ar, etching energy: 500 eV, beam current: 90 mA, etching time: 75 s, vacuum degree: less than 1×10 -4 Torr. When the etching gas Ar vertically impacts the gold metal surface, the high-energy ions (Ar + ) bombards the gold metal surface, causing the gold metal atoms to escape from the crystal lattice. When the escaped gold metal atoms diffuse to the side wall of the gel column, under the action of driving forces such as concentration gradient, surface energy difference or possible electric field gradient, these migrated particles are finally re-deposited, nucleated and grown on the side wall surface of the gel column through the physical vapor deposition (PVD) mechanism, and finally form a gold metal coating around the micro-gel column array, thereby forming a metal gold-coated micro-gel column structure. At this time, the vertically impacting etching gas Ar can achieve secondary etching of the metal gold re-deposited on the top of the micro-gel column array. Therefore, the metal gold only coats the four sides of the micro-gel column, forming a hollow tubular structure.

[0075] S4. The sample with the sidewalls of the metal gold-coated microgel columns formed after the S3 treatment was subjected to dry etching to remove the glue. The specific process parameters are: O2 flow rate 10sccm, power 40W, time 100s, and the gold nanotube array was obtained.

[0076] The gold nanotube arrays were characterized using scanning electron microscopy. Figure 5 is the SEM image of the gold nanotube array. Figure 5 The resulting gold nanotubes have an inner diameter of 300nm and a wall thickness of 40nm, meaning they have an outer diameter of 380nm and a height of 380nm, with an aspect ratio of 1:1 and uniform height overall. Furthermore, the 100nm gold layer deposited on the composite substrate was completely etched away. Calculations indicate that the ratio of gold etching rate to sidewall redeposition rate during reactive ion beam etching is 1:0.4.

[0077] Performance testing:

[0078] The gold nanotube array prepared in Example 3 was compared with the gold nanopillar array sample prepared by traditional sputtering deposition (height 380nm, column diameter 380nm, micropillar arrangement is hexagonal arrangement), as shown in FIG. Figure 6 As shown, the surface areas of the two structures are: S 管阵列 It's S 柱阵列 about 1.7 times of that of the 管阵列 / S 柱阵列 Increased accordingly.

[0079] The aluminum nanotube array substrate prepared in Example 1 was directly used as a light absorber, and the reflectivity of the incident light of the aluminum nanotube array sample was tested using UV-visible absorption spectroscopy. The results are as follows: Figure 7 As shown, the aluminum nanotube array sample exhibits extremely low light reflectivity. This is because the densely packed nanotubes in the array form a deeply porous, high-surface-area, three-dimensional structure. Upon entering this "nanoforest," incident light undergoes multiple reflections and scattering between the sidewalls of adjacent nanotubes. Each reflection consumes a portion of the light energy (converting it into heat), making it difficult for the light to be reflected directly back in the direction of incidence, significantly reducing the overall reflectivity.

[0080] The gold nanotube array substrate prepared in Example 3 was directly used as a catalytic electrode for electrolysis of water to produce hydrogen. The electrocatalytic performance of the gold nanotube array catalytic electrode was tested by linear sweep voltammetry (LSV) in a three-electrode system. The results are as follows: Figure 8 As shown, the gold nanotube array catalytic electrode exhibited excellent catalytic performance.

[0081] The present invention provides a method for preparing a metal micro-nanotube array and its application. Numerous methods and approaches exist for implementing this technical solution. The foregoing description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also within the scope of protection of the present invention. Any components not specified in this embodiment may be implemented using existing technologies.

Claims

1. A method for preparing a metal micro-nanotube array, characterized in that: The steps include: S1. Preparing a metal layer on the substrate surface; S2. Spraying embossing adhesive on the surface of the metal layer, then embossing it through a template, and curing it to form a micro-column array; S3 uses a plasma etching process to obtain the micro-gel column array in S2 as a mask to etch the metal layer exposed at the bottom gap of the micro-gel column array to form a metal-coated micro-gel column structure; S4. removing the metal-coated micro-gel columns from the structure to obtain the metal micro-nanotube array.

2. The preparation method according to claim 1, characterized in that The substrate includes any one of a rigid substrate, a flexible substrate and a composite substrate; the metal layer includes any one of an aluminum metal layer, a titanium metal layer and a gold metal layer; the embossing adhesive is a thermal curing adhesive and / or an ultraviolet curing adhesive.

3. The preparation method according to claim 1, characterized in that In S1, the metal layer is prepared by magnetron sputtering and / or electron beam evaporation, and the thickness of the metal layer is 100 nm to 1 μm.

4. The preparation method according to claim 1, characterized in that In S2, the embossed adhesive is sprayed by ultrasonic spraying equipment, and the thickness of the embossed adhesive is 100 nm to 70 μm; the embossing time is 3 to 5 minutes; and the curing is heat curing and / or UV curing.

5. The preparation method according to claim 1, characterized in that In S3, the plasma etching process is reactive ion beam etching.

6. The preparation method according to claim 5, characterized in that In S3, the process parameters of the reactive ion beam etching are: etching energy of 500 to 1000 eV, beam current of 0.5 to 2 mA, and vacuum degree of less than 1×10 -4 Torr, Ar gas flow rate is about 5 to 50 sccm.

7. The preparation method according to claim 1, characterized in that In S4, the removal of the glue pillars in the metal-coated micro-glue pillar structure may be performed by any one or more of the following methods: stepwise de-glue, wet de-glue and dry etching de-glue.

8. The metal micro-nanotube array prepared by the preparation method according to any one of claims 1 to 7.

9. The metal micro-nanotube array according to claim 8, characterized in that: The parameters of the metal micro-nanotube array are: the outer diameter of the micro-nanotube is 200nm-20μm, the wall thickness of the micro-nanotube is 20-500nm, and the array density is 10 3 ~10 9 Tube / cm 2 The height of the micro-nanotubes is 0.2 to 200 μm, and the aspect ratio is 1:1 to 10:1; the cross-sectional shape of the micro-nanotubes of the metal micro-nanotube array includes any one of circular, polygonal and irregular shapes; the arrangement of the metal micro-nanotube array includes any one of tetragonal arrangement, hexagonal arrangement and gradient arrangement.

10. Use of the metal micro-nanotube array according to claim 8 in the preparation of any one of the following products, wherein the product comprises: Surface-enhanced Raman scattering substrate; Electrochemical catalytic electrodes and / or battery current collectors; nanofluidic channels and / or molecular sieves; Metamaterial absorbers and / or optical resonators.

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