A double-layer nano-array material and a preparation method thereof

Abstract

The application discloses a kind of double-layer nano array materials and preparation method thereof, it is related to nanometer material technical field, the double-layer nano array material includes conductive glass, and nano rod array material and nanotube array material are sequentially arranged on the conductive glass.Nano rod array material and nanotube array material sequentially arranged on the conductive glass can be double-layer array homojunction material or double-layer array heterojunction material, this design can utilize one-dimensional nano array structure to provide high-speed channel for the transmission of photo-generated carriers on the one hand, on the other hand, compared with single-layer nano rod array, the double-layer array homojunction material also has the advantages of large specific surface area, high light absorption efficiency, etc., can greatly change and enhance the inherent photoelectrochemical activity and performance of material itself.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, and in particular to a bilayer nanoarray material and its preparation method. Background Technology

[0002] Titanium dioxide (TiO2) materials possess superior photoelectrochemical performance and stability, and their low cost makes them a key research material in the field of photoelectrochemistry. One-dimensional TiO2 nanoarray materials can combine the unique structural advantages of nanomaterials with the inherent properties of TiO2, effectively achieving a balance between high-efficiency photoelectrochemical properties and low cost in electrode materials, thus showing great promise for applications.

[0003] Current research on TiO2 one-dimensional nanoarray materials mainly focuses on improvements in preparation processes, doping, surface modification, and the construction of multi-level structures.

[0004] However, current TiO2 one-dimensional nanoarray materials still suffer from defects such as low specific surface area, insufficient nanorod growth, low light absorption efficiency of the array, and insufficient nonradiative recombination during carrier transfer. Summary of the Invention

[0005] The main objective of this invention is to propose a bilayer nanoarray material and its preparation method, aiming to solve the problem of low specific surface area of ​​TiO2 one-dimensional nanoarray materials in the prior art.

[0006] To achieve the above objectives, the present invention proposes a bilayer nanoarray material, which includes conductive glass and nanorod array material and nanotube array material sequentially disposed on the conductive glass.

[0007] In one embodiment, the bilayer nanoarray material further includes a titanium dioxide dense layer disposed between the nanorod array and the nanotube array.

[0008] In one embodiment, the nanorod array material includes at least one of titanium dioxide, tin dioxide, and zinc dioxide; and / or, The diameter of a single nanorod is 30~150 nm; and / or, The length of a single nanorod is 0.5~3 μm; and / or, The nanotube array material includes titanium dioxide; and / or, The inner diameter of a single nanotube is 60~100 nm; and / or, The length of a single nanotube is 300~1000 nm; and / or, The wall thickness of a single nanotube is 0.5~2μm; and / or, The thickness of the dense titanium dioxide layer is 50~100nm.

[0009] In one embodiment, the density of the bilayer nanoarray material is 10 nanoparticles / μm. 2 ~30 roots / μm 2 .

[0010] This invention also provides a method for preparing a bilayer nanoarray material, comprising the following steps: S10. Provide a conductive glass, mix the conductive glass with a titanium dioxide precursor solution, and carry out a hydrothermal reaction to form a titanium dioxide nanorod array material on the surface of the conductive glass, thereby obtaining a first intermediate. S20. Prepare a titanium metal layer on the surface of the first intermediate to obtain a second intermediate; S30. The second intermediate is placed in a solution containing fluoride ions for anodic oxidation, so that at least part of the titanium metal layer is converted into titanium dioxide nanotubes. The anodic-oxidized second intermediate is then sintered to obtain the bilayer nanoarray material.

[0011] In one embodiment, in step S10: The titanium dioxide precursor solution includes a hydrochloric acid solution containing tetrabutyl titanate; and / or, The hydrothermal reaction temperature is 130~180℃; and / or, The hydrothermal reaction takes 5 to 8 hours.

[0012] In one embodiment, step S20 includes: A titanium metal layer is deposited on the surface of the first intermediate by magnetron sputtering to obtain the second intermediate.

[0013] In one embodiment, the magnetron sputtering method is a DC magnetron sputtering method: The background vacuum of the DC magnetron sputtering is ≤5.0×10⁻⁶. -4 Pa; and / or, The gas pressure for the DC magnetron sputtering is 0.5~3 Pa; and / or, The power of the DC magnetron sputtering is 100~300W; and / or, The DC magnetron sputtering time is 2-5 hours; and / or, The substrate rotation speed of the DC magnetron sputtering is 3~6 rpm; and / or, The temperature of the DC magnetron sputtering is 300°C.

[0014] In one embodiment, in step S30: The concentration of fluoride ions in the solution containing fluoride ions is 0.09 mol / L to 0.3 mol / L; and / or, The fluoride-containing solution includes an ethylene glycol solution containing ammonium fluoride, wherein the mass percentage of ammonium fluoride in the ethylene glycol solution is 0.3-1%, and the volume percentage of water in the ethylene glycol solution is 1-5%; and / or, The voltage for the anodizing is 20~50V; and / or, The anodizing time is 10-30 min; and / or, The sintering temperature is 400~500℃; and / or, The sintering time is 0.8~1.2h.

[0015] In the technical solution of the present invention, the nanorod array material and the nanotube array material sequentially disposed on the conductive glass can be a bilayer array homojunction material or a bilayer array heterojunction material. This design can, on the one hand, provide a high-speed channel for the transmission of photogenerated carriers using a one-dimensional nanoarray structure. On the other hand, compared with a single-layer nanorod array, the bilayer array homojunction material also has the advantages of large specific surface area and high light absorption efficiency, which can greatly change and improve the inherent photoelectrochemical activity and performance of the material itself. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the homojunction structure of a double-layer array of titanium dioxide nanotubes and titanium dioxide nanorods provided by the present invention; Figure 2 (a) is a scanning electron microscope (SEM) image of the surface of the titanium dioxide nanorod array prepared in step 2 of Example 1; Figure 2 (b) is a SEM image of the cross-section of the titanium dioxide nanorod array prepared in step 2 of Example 1; Figure 3 (a) is a SEM image of the surface of the material after the titanium metal layer is sputtered in step 3 of Example 1; Figure 3 (b) is a SEM image of the cross-section of the material after sputtering the titanium metal layer in step 3 of Example 1; Figure 4 (a) is a SEM image of the surface of the homogeneous junction of titanium dioxide nanotubes and titanium dioxide nanorods prepared in step 4 of Example 1; Figure 4(b) is a SEM image of the cross-section of the titanium dioxide nanotube and titanium dioxide nanorod bilayer array homojunction prepared in step 4 of Example 1; Figure 5 This is a comparison of the photocurrent test curves of the titanium dioxide nanotube and titanium dioxide nanorod bilayer array sample in Example 1 and the single-layer titanium dioxide nanorod array sample in Comparative Example 1.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, or solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Titanium dioxide (TiO2) materials possess superior photoelectrochemical performance and stability, and their low cost makes them a key research material in the field of photoelectrochemistry. One-dimensional TiO2 nanoarray materials can combine the unique structural advantages of nanomaterials with the inherent properties of TiO2, effectively achieving a balance between high-efficiency photoelectrochemical properties and low cost in electrode materials, thus showing great promise for applications.

[0021] Current research on TiO2 one-dimensional nanoarray materials mainly focuses on improvements in preparation processes, doping, surface modification, and the construction of multi-level structures.

[0022] However, current TiO2 one-dimensional nanoarray materials still suffer from defects such as low specific surface area, insufficient nanorod growth, low light absorption efficiency of the array, and insufficient nonradiative recombination during carrier transfer.

[0023] In view of this, such as Figure 1As shown, the present invention proposes a bilayer nanoarray material, which includes conductive glass and nanorod array material and nanotube array material sequentially disposed on the conductive glass.

[0024] In the technical solution of the present invention, the nanorod array material and the nanotube array material sequentially disposed on the conductive glass can be a bilayer array homojunction material or a bilayer array heterojunction material. This design can, on the one hand, provide a high-speed channel for the transmission of photogenerated carriers using a one-dimensional nanoarray structure. On the other hand, compared with a single-layer nanorod array, the bilayer array homojunction material also has the advantages of large specific surface area and high light absorption efficiency, which can greatly change and improve the inherent photoelectrochemical activity and performance of the material itself.

[0025] In some implementations, the bilayer nanoarray material further includes a dense titanium dioxide layer disposed between the nanorod array and the nanotube array. The dense titanium dioxide layer not only provides a stable connection between the nanorod array and the nanotube array, but also optimizes charge transport and reduces recombination losses, thereby further enhancing the overall performance of the material.

[0026] In some embodiments, the nanorod array material includes at least one of titanium dioxide, tin dioxide, and zinc dioxide; and / or, the diameter of a single nanorod is 30-150 nm; and / or, the length of a single nanorod is 0.5-3 μm. It is understood that the above-mentioned nanorod array material possesses good chemical stability, a suitable band structure, and excellent electron transport performance. The diameter of the nanorods can be 30 nm, 100 nm, or 150 nm. A diameter within this range ensures sufficient specific surface area to enhance light absorption efficiency and surface reactivity, while also mitigating the problem of insufficient mechanical strength due to excessive thinness. The length of the nanorods can be 0.5 μm, 1.5 μm, or 3 μm. A length within this range helps improve the carrier transport path and also increases the optical path length, thereby improving light capture efficiency.

[0027] In some embodiments, the nanotube array material includes titanium dioxide; and / or, the inner diameter of a single nanotube is 60-100 nm; and / or, the length of a single nanotube is 300-1000 nm; and / or, the wall thickness of a single nanotube is 0.5-2 μm. The inner diameter of the nanotube can be 60 nm, 80 nm, or 100 nm, and an inner diameter within this range helps to balance specific surface area and internal space utilization efficiency; the length of the nanotube within this range ensures high light absorption capacity, charge separation, and transport efficiency; the wall thickness of the nanotube can be 0.5 μm, 1.5 μm, or 2 μm, and a wall thickness within this range maintains the stability of the nanotube structure and achieves efficient electron transport.

[0028] In some embodiments, the thickness of the titanium dioxide dense layer is 50-100 nm. A thickness within this range ensures a strong and tight bond between the nanorod array material and the nanotube array material.

[0029] In some embodiments, the density of the bilayer nanoarray material is 10 nanoparticles / μm. 2 ~30 roots / μm 2 Therefore, the material also has advantages such as large specific surface area and high light absorption efficiency, which can greatly change and improve the inherent photoelectrochemical activity and performance of the material itself.

[0030] This invention also provides a method for preparing a bilayer nanoarray material, comprising the following steps: S10. Provide a conductive glass, mix the conductive glass with a titanium dioxide precursor solution, and carry out a hydrothermal reaction to form a titanium dioxide nanorod array material on the surface of the conductive glass, thereby obtaining a first intermediate. S20. Prepare a titanium metal layer on the surface of the first intermediate to obtain a second intermediate; S30. The second intermediate is placed in a solution containing fluoride ions for anodic oxidation, so that at least part of the titanium metal layer is converted into titanium dioxide nanotubes. The anodic-oxidized second intermediate is then sintered to obtain the bilayer nanoarray material.

[0031] In the technical solution of this invention, titanium dioxide nanorods are prepared on the surface of conductive glass to obtain a first intermediate. Subsequently, a titanium metal layer is prepared on the surface of the first intermediate, and then anodizing is performed to convert some of the titanium metal in the titanium metal layer into titanium dioxide nanotubes. After sintering, the remaining titanium metal also converts into titanium dioxide. This invention provides a new approach to preparing bilayer nanoarray homojunction or heterojunction materials, which is low-cost, has good process controllability, and is easy to mass-produce and promote. It should be noted that the nanorod array prepared by the above method is tightly connected to the nanotube array, and the nanorod array also has good orientation.

[0032] In some embodiments, in step S10: the titanium dioxide precursor solution includes a hydrochloric acid solution containing tetrabutyl titanate; and / or, the temperature of the hydrothermal reaction is 130~180℃; and / or, the time of the hydrothermal reaction is 5~8h. Simultaneously controlling the mass ratio, hydrothermal reaction time, and temperature within the above ranges can ensure the formation of nanorods with good orientation and close arrangement.

[0033] In some embodiments, step S20 includes: depositing a titanium metal layer on the surface of the first intermediate by magnetron sputtering to obtain a second intermediate. Magnetron sputtering is a simple process and can produce a relatively uniform titanium metal layer on a nanorod array.

[0034] In some embodiments, the magnetron sputtering method is a DC magnetron sputtering method: the background vacuum of the DC magnetron sputtering is ≤5.0×10⁻⁶. -4 Pa; and / or, the gas pressure of the DC magnetron sputtering is 0.5~3 Pa; and / or, the power of the DC magnetron sputtering is 100~300 W; and / or, the time of the DC magnetron sputtering is 2~5 h; and / or, the substrate rotation speed of the DC magnetron sputtering is 3~6 rpm; and / or, the temperature of the DC magnetron sputtering is 300 °C. Simultaneously controlling the parameters of the DC magnetron sputtering method within the above ranges can ensure the preparation of a relatively uniform titanium metal layer on the nanorod array.

[0035] In some embodiments, in step S30: the concentration of fluoride ions in the fluoride-containing solution is 0.09 mol / L to 0.3 mol / L; and / or, the fluoride-containing solution includes an ethylene glycol solution containing ammonium fluoride, wherein the mass percentage of ammonium fluoride in the ethylene glycol solution is 0.3% to 1%, and the volume percentage of water in the ethylene glycol solution is 1% to 5%; and / or, the anodizing voltage is 20 to 50 V; and / or, the anodizing time is 10 to 30 min; and / or, the sintering temperature is 400 to 500 °C; and / or, the sintering time is 0.8 to 1.2 h. Simultaneously controlling the fluoride ion concentration and anodizing parameters within the above ranges ensures that at least a portion of the titanium metal layer is converted into well-oriented, tightly packed titanium dioxide nanotubes. The sintering time and temperature within the above ranges ensure that the remaining titanium metal is fully converted into titanium dioxide.

[0036] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0037] Example 1 A method for preparing a bilayer nanoarray material includes the following steps: Step 1: Using cleaned conductive glass as a substrate, measure 10 mL of deionized water and 5 mL of concentrated hydrochloric acid, add 0.5 mL of tetrabutyl titanate, and sonicate for 10 min to obtain TiO2 precursor solution. Step 2: Place the TiO2 precursor solution obtained in Step 1 and the cleaned conductive glass into a hydrothermal reactor. React at 130℃ for 8 hours, then cool to room temperature, remove the conductive glass, clean and dry it to obtain a TiO2 nanorod array grown on the conductive glass substrate. The array thickness distribution is 0.5~0.8μm, and the nanorod diameter distribution is 30~50nm. Figure 2 (a) and Figure 2 As shown in (b); Step 3: Deposit a Ti metal layer on the surface of the TiO2 nanorod array obtained in Step 2 using DC magnetron sputtering; the Ti target used is a high-purity Ti (99.995%) target material, and the sputtering background vacuum is ≤5.0×10⁻⁶. -4 The sputtering conditions were: Pa, sputtering pressure 0.5 Pa, sputtering power 100 W, sputtering time 5 h, substrate rotation speed 3 rpm, and deposition temperature 300 °C. After sputtering, a TiO2 nanorod array with a 1 μm Ti layer on the surface was obtained. Figure 3 (a) and Figure 3 As shown in (b).

[0038] Step 4: The TiO2 nanorod array with a Ti layer on its surface obtained in Step 3 is placed in an electrolyte for anodic oxidation. The electrolyte composition is an ethylene glycol solution containing 0.3 wt% NH4F and 1 vol% H2O. The anodic oxidation voltage is 20 V, the oxidation time is 30 min, and the counter electrode is a platinum sheet. After anodizing, the sample is cleaned and dried, and then sintered at 450℃ for 1 h to obtain a homogeneous double-layer array of TiO2 nanotubes and nanorods. The pore size distribution of the upper TiO2 nanotube array is between 60 and 80 nm, and the thickness is 0.5 μm. Figure 4 (a) and Figure 4 As shown in (b).

[0039] Example 2 A method for preparing a bilayer nanoarray material includes the following steps: Step 1: Using cleaned conductive glass as a substrate, measure 25 mL of deionized water and 25 mL of concentrated hydrochloric acid, add 2 mL of tetrabutyl titanate, and sonicate for 30 min to obtain TiO2 precursor solution. Step 2: Place the TiO2 precursor solution obtained in Step 1 and the cleaned conductive glass into a hydrothermal reactor. After reacting at 180℃ for 5 hours, cool to room temperature, remove the conductive glass, clean and dry it to obtain a TiO2 nanorod array grown on the conductive glass substrate. The array thickness is 3 μm and the diameter distribution of the nanorods is 100~150 nm. Step 3: Deposit a Ti metal layer on the surface of the TiO2 nanorod array obtained in Step 2 using DC magnetron sputtering; the Ti target used is a high-purity Ti (99.995%) target material, and the sputtering background vacuum is ≤5.0×10⁻⁶. -4 The sputtering pressure was 3 Pa, the sputtering power was 300 W, the sputtering time was 2 h, the substrate rotation speed was 6 rpm, the deposition temperature was 300 °C, and a TiO2 nanorod array with a 3 μm Ti layer on the surface was obtained after sputtering. Step 4: The TiO2 nanorod array with a Ti layer on its surface obtained in Step 3 was placed in an electrolyte solution for anodic oxidation. The electrolyte solution consisted of an ethylene glycol solution containing 1 wt% NH4F and 5 vol% H2O. The anodic oxidation voltage was 50 V, the oxidation time was 10 min, and the counter electrode was a platinum sheet. After anodizing, the sample was cleaned and dried, and then sintered at 450 °C for 1 h to obtain a homogeneous double-layer array of TiO2 nanotubes and nanorods. The pore size of the upper TiO2 nanotube array was distributed between 80 and 100 nm, and the thickness was 2 μm.

[0040] Example 3 A method for preparing a bilayer nanoarray material includes the following steps: Step 1: Using cleaned conductive glass as a substrate, measure 15 mL of deionized water and 15 mL of concentrated hydrochloric acid, add 1 mL of tetrabutyl titanate, and sonicate for 20 min to obtain TiO2 precursor solution. Step 2: Place the TiO2 precursor solution obtained in Step 1 and the cleaned conductive glass into a hydrothermal reactor. After reacting at 150℃ for 6 h, cool to room temperature, remove the conductive glass, clean and dry it to obtain a TiO2 nanorod array grown on the conductive glass substrate. The array thickness is 1 μm and the diameter distribution of the nanorods is 80~100 nm. Step 3: Deposit a Ti metal layer on the surface of the TiO2 nanorod array obtained in Step 2 using DC magnetron sputtering; the Ti target used is a high-purity Ti (99.995%) target material, and the sputtering background vacuum is ≤5.0×10⁻⁶. -4 The sputtering conditions were: sputtering pressure 1.0 Pa, sputtering power 200 W, sputtering time 3 h, substrate rotation speed 6 rpm, and deposition temperature 300℃. After sputtering, a TiO2 nanorod array with a 2 μm Ti layer on the surface was obtained. Figure 3 As shown.

[0041] Step 4: The TiO2 nanorod array with a Ti layer on its surface obtained in Step 3 was placed in an electrolyte solution for anodic oxidation. The electrolyte solution consisted of an ethylene glycol solution containing 0.5 wt% NH4F and 3 vol% H2O. The anodic oxidation voltage was 30 V, the oxidation time was 20 min, and the counter electrode was a platinum sheet. After anodizing, the sample was cleaned and dried, and then sintered at 450℃ for 1 h to obtain a homogeneous double-layer array of TiO2 nanotubes and nanorods. The pore size of the upper TiO2 nanotube array was distributed between 80 and 100 nm, and the thickness was 1.5 μm.

[0042] Comparative Example 1 Comparative Example 1 is the same as Example 3 except that steps 3 and 4 are not performed.

[0043] Performance testing The TiO2 nanotube and nanorod bilayer array in Example 3 and the monolayer TiO2 nanorod array in Comparative Example 1 were characterized to evaluate the photoelectrochemical properties of the two arrays. The detection method was photocurrent measurement of dye-sensitized electrodes. The specific steps were as follows: the two array materials were used as electrodes, immersed in N719 dye solution, and then assembled into a typical sandwich-type dye-sensitized solar cell. The photocurrent of the two electrodes was measured under simulated sunlight intensity of AM 1.5. The results are as follows. Figure 5 As shown.

[0044] Figure 5 In this context, "single-layer array" refers to the material prepared in Comparative Example 1; "double-layer array" refers to the material prepared in Example 3.

[0045] Depend on Figure 5 It can be seen that the dye-sensitized electrode based on the TiO2 nanotube and nanorod bilayer array exhibits a higher photocurrent density than the electrode prepared using only a single layer of TiO2 nanorod array. The enhanced photoelectrochemical performance of the bilayer array is due to its relatively large surface area, which helps to effectively adsorb dyes and thus improves the photoelectrochemical performance.

[0046] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A bilayer nanoarray material, characterized in that, The bilayer nanoarray material includes conductive glass, and nanorod array material and nanotube array material sequentially disposed on the conductive glass.

2. The bilayer nanoarray material as described in claim 1, characterized in that, The bilayer nanoarray material further includes a titanium dioxide dense layer, which is disposed between the nanorod array and the nanotube array.

3. The bilayer nanoarray material as described in claim 2, characterized in that, The nanorod array material includes at least one of titanium dioxide, tin dioxide, and zinc dioxide; and / or, The diameter of a single nanorod is 30~150 nm; and / or, The length of a single nanorod is 0.5~3 μm; and / or, The nanotube array material includes titanium dioxide; and / or, The inner diameter of a single nanotube is 60~100 nm; and / or, The length of a single nanotube is 300~1000 nm; and / or, The wall thickness of a single nanotube is 0.5~2μm; and / or, The thickness of the dense titanium dioxide layer is 50~100nm.

4. The bilayer nanoarray material as described in claim 1, characterized in that, The density of the bilayer nanoarray material is 10 nanoparticles / μm. 2 ~30 roots / μm 2 .

5. A method for preparing a bilayer nanoarray material as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S10. Provide a conductive glass, mix the conductive glass with a titanium dioxide precursor solution, and carry out a hydrothermal reaction to form a titanium dioxide nanorod array material on the surface of the conductive glass, thereby obtaining a first intermediate. S20. Prepare a titanium metal layer on the surface of the first intermediate to obtain a second intermediate; S30. The second intermediate is placed in a solution containing fluoride ions for anodic oxidation, so that at least part of the titanium metal layer is converted into titanium dioxide nanotubes. The anodic-oxidized second intermediate is then sintered to obtain the bilayer nanoarray material.

6. The method for preparing the bilayer nanoarray material as described in claim 5, characterized in that, In step S10: The precursor solution includes a hydrochloric acid solution containing tetrabutyl titanate; and / or, The hydrothermal reaction temperature is 130~180℃; and / or, The hydrothermal reaction takes 5 to 8 hours.

7. The method for preparing the bilayer nanoarray material as described in claim 5, characterized in that, Step S20 includes: A titanium metal layer is deposited on the surface of the first intermediate by magnetron sputtering to obtain the second intermediate.

8. The method for preparing the bilayer nanoarray material as described in claim 7, characterized in that, The magnetron sputtering method is a DC magnetron sputtering method: The background vacuum of the DC magnetron sputtering is ≤5.0×10⁻⁶. -4 Pa; and / or, The gas pressure for the DC magnetron sputtering is 0.5~3 Pa; and / or, The power of the DC magnetron sputtering is 100~300W; and / or, The DC magnetron sputtering time is 2-5 hours; and / or, The substrate rotation speed of the DC magnetron sputtering is 3~6 rpm; and / or, The temperature of the DC magnetron sputtering is 300°C.

9. The method for preparing the bilayer nanoarray material as described in claim 5, characterized in that, In step S30: The concentration of fluoride ions in the solution containing fluoride ions is 0.09 mol / L to 0.3 mol / L; and / or, The fluoride-containing solution includes an ethylene glycol solution containing ammonium fluoride, wherein the mass percentage of ammonium fluoride in the ethylene glycol solution is 0.3-1%, and the volume percentage of water in the ethylene glycol solution is 1-5%; and / or, The voltage for the anodizing is 20~50V; and / or, The anodizing time is 10-30 min; and / or, The sintering temperature is 400~500℃; and / or, The sintering time is 0.8~1.2h.

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