Three-dimensional ordered hollow cuprous oxide nano array and preparation method and application thereof

Abstract

The invention discloses a three-dimensional ordered hollow cuprous oxide nano array and a preparation method and application thereof, and relates to the technical field of photoelectric detection. The preparation method comprises the following steps: oxidizing impurity aluminum to obtain an aluminum oxide template of which the surface is provided with holes, and broaching to obtain a three-dimensional porous aluminum oxide template with back aluminum; taking the three-dimensional porous aluminum oxide template as a cathode and graphite as an anode, and carrying out constant-current electrodeposition in Cu electrodeposition liquid to obtain a three-dimensional porous aluminum oxide template which is loaded with copper nanowires and is provided with back aluminum; removing the three-dimensional porous aluminum oxide template with back aluminum by using aqueous alkali to obtain a three-dimensional interconnection self-supporting copper nanowire array; and annealing the three-dimensional interconnected self-supporting copper nanowire array in a local oxygen-deficient environment, and cooling to obtain the three-dimensional highly-ordered hollow cuprous oxide nano array. The self-powered photoelectrochemical photoelectric detector prepared by adopting the core cuprous oxide nano array has high light absorptivity, high specific surface area and high ion transmission rate, and is suitable for detection of ultraviolet light.

Description

Technical Field

[0001] The present invention belongs to the field of hollow cuprous oxide nanoarray photoelectric detection technology, and in particular provides a three-dimensional ordered hollow cuprous oxide nanoarray, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous advancement of technology in the field of information and communications, light has become an important medium for acquiring, recording, analyzing, and transmitting information. Photodetectors, as optoelectronic devices that use the photoelectric effect to detect and measure light properties, have been widely used in optical communications, radar monitoring, satellite remote sensing, health monitoring, solar cells, and other fields. As a new type of photodetector, photoelectrochemical photodetectors are based on a semiconductor-liquid contact mechanism and have a unique solid-liquid heterostructure. The contact between the semiconductor material and the electrolyte liquid surface forms an approximate Schottky diode interface. The built-in electric field formed at the interface separates electron-hole pairs. When light is irradiated on the semiconductor material on the photoanode, the semiconductor absorbs light energy to generate electron-hole pairs, which are separated under the action of the built-in electric field. Finally, they are captured by FTO (fluorine-doped tin oxide) conductive glass and transmitted to the counter electrode, showing a high response speed and responsivity. Due to its working mechanism, photoelectrochemical photodetectors can be directly used in ocean underwater communications and detection without packaging. Compared with traditional photodetectors that require external power supplies, photoelectrochemical photodetectors can achieve self-powered independent operation under zero bias or low bias conditions, realizing functions such as optical sensing and long-term operation of photodetectors. They can effectively respond to underwater emergencies, have strong risk resistance, and greatly ensure the safety and efficiency of underwater detection communications.

[0003] To obtain high-performance photoelectrochemical photodetectors, researchers typically select and prepare semiconductor materials with excellent light absorption, high specific surface area, and good chemical stability when designing photoelectrode semiconductor materials. Metal oxide semiconductors, due to their excellent photoelectrochemical properties, high chemical stability, and low cost, have become an important choice for semiconductor materials in underwater photoelectrochemical photodetectors. Cuprous oxide (Cu2O), a metal oxide semiconductor material, is made from copper metal, which is abundant in nature, is easy to prepare, and exhibits excellent photoelectric response performance in specific light bands. However, research on Cu2O-based photodetectors is still in its infancy and primarily focuses on traditional solid-state photodetectors, with relatively little research on Cu2O photoelectrochemical photodetectors.

[0004] Currently, most photoelectrochemical photodetectors designed by researchers are sandwich structures, in which the photoelectrode is mostly powder-coated on conductive glass, and the counter electrode is a platinum sheet or wire. Due to the powder coating of the material, the semiconductor material particles are stacked on top of each other, and the contact area with the electrolyte is small. The electron-hole pairs generated at the interface are limited, and in actual applications, they will gradually fall off due to corrosion from seawater. Due to their planar disordered structure, the specific surface area of ​​contact between the electrolyte and the material surface is very small, and ion transport is severely limited in the complex disordered structure. In addition, due to their planar structure, when light directly shines on the material surface, the semiconductor material does not have time to fully absorb the light energy and reflection occurs, resulting in low light utilization. In actual applications, in the dim seabed, the utilization rate of light is seriously insufficient, and the material response speed and responsiveness are reduced, which seriously restricts its photoelectric sensing performance under complex seabed conditions. Traditional nanomaterial arrays are usually composed of independent nanowires or nanosheets. The wires and sheets are independent of each other and are prone to collapse. This not only blocks the propagation path of light, but also hinders the rapid transmission channel of ions, causing serious carrier recombination. At the same time, the structure and working stability of the material are also greatly affected.

[0005] Based on the problems existing in the prior art, the present invention develops a self-powered photoelectrochemical photodetector based on a three-dimensional highly ordered hollow cuprous oxide nanoarray structure to realize photoelectric sensing function in a low light power environment. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art;

[0007] To this end, the present invention proposes a three-dimensional ordered hollow cuprous oxide nanoarray and a preparation method and application thereof, the method comprising:

[0008] S1. Electrochemically anodizing the impure aluminum to obtain an alumina template having a plurality of vertical holes with a plurality of transverse holes on the inner wall, wherein the vertical holes are not connected to each other. After hole expansion, the plurality of vertical holes are connected to each other by transverse holes to obtain a three-dimensional porous alumina template with back aluminum; the impure aluminum is an aluminum alloy material containing controllable impurities;

[0009] S2, using the three-dimensional porous alumina template as the cathode and graphite as the anode, constant current electrodeposition is performed in a Cu electrodeposition solution to obtain a three-dimensional porous alumina template with back aluminum loaded with copper nanowires;

[0010] S3, removing the three-dimensional porous alumina template with back aluminum using an alkaline solution to obtain a three-dimensional interconnected self-supporting copper nanowire array;

[0011] S4. Annealing the three-dimensional interconnected self-supporting copper nanowire array at 180-220° C. in a local oxygen-deficient environment and then naturally cooling the array to obtain a three-dimensional highly ordered hollow cuprous oxide nanowire array.

[0012] Furthermore, in S1, the conditions for electrochemical anodization of the impure aluminum are as follows: the impure aluminum is placed in a phosphoric acid electrolyte for anodization, the electrolyte is a 0.25-0.35M phosphoric acid solution, and the solvent of the phosphoric acid solution is a mixture of anhydrous ethanol and water; the anodization voltage is 190-200V, the temperature is 4-6°C, and the oxidation time is 18-22h.

[0013] Furthermore, in S1, the impurity in the impurity aluminum is copper, and the impurity content is 1%;

[0014] The conditions for electrochemical anodization of impure aluminum are as follows: the impure aluminum is placed in a phosphoric acid electrolyte for anodization, the electrolyte is a 0.3M phosphoric acid solution, and the solvent of the phosphoric acid solution is anhydrous ethanol: pure water mixed in a volume ratio of 1:9; the anodization voltage is 195V, the temperature is 5°C, and the oxidation time is 20h.

[0015] Furthermore, in S1, the hole expansion processing method is:

[0016] The alumina template obtained after electrochemical anodization is dried and immersed in a 4-6wt% phosphoric acid solution at 38-45°C for 30-50 minutes to expand the pores, and the unconnected vertical pores inside the alumina template are expanded and connected through the transverse holes; after washing with pure water, a three-dimensional porous alumina template with back aluminum is obtained, and the pure water is stored for future use.

[0017] Furthermore, in S2, the Cu electrodeposition solution contains 90-100 g / L of CuSO4 and 40-50 g / L of H2SO4.

[0018] Further, in S3, the alkaline solution is a 3-5 M NaOH solution;

[0019] After multiple pure water rinses and drying, a three-dimensional interconnected self-supporting copper nanowire array was obtained.

[0020] Furthermore, in S4, the three-dimensional interconnected self-supporting copper nanowire array prepared in S3 is placed between two flat pieces of foam copper to obtain a local oxygen-deficient environment. The three-dimensional interconnected self-supporting copper nanowire array and the foam copper are placed in a furnace as a whole, maintained in an air atmosphere of 200°C for 15 hours, and then naturally cooled to obtain a three-dimensional ordered hollow cuprous oxide nanoarray.

[0021] A three-dimensional ordered hollow cuprous oxide nanoarray is prepared by the above-mentioned preparation method.

[0022] A self-powered photoelectrochemical photodetector comprises FTO conductive glass and the aforementioned three-dimensional ordered hollow cuprous oxide nanoarray; the three-dimensional ordered hollow cuprous oxide nanoarray is combined with the surface of the FTO conductive glass.

[0023] Application of the aforementioned three-dimensional ordered hollow cuprous oxide nanoarray in the preparation of photodetectors.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention provides a method for preparing a three-dimensional highly ordered hollow cuprous oxide nanoarray self-powered photoelectrochemical photodetector. The method uses a one-step annealing method to directly anneal three-dimensional highly ordered copper nanowires into three-dimensional highly ordered hollow cuprous oxide nanoarrays. This method is simple, greatly simplifies experimental operations, and is environmentally friendly. The raw materials used are non-precious metals, which are inexpensive and readily available, significantly reducing production costs.

[0026] The present invention utilizes a three-dimensional highly ordered hollow cuprous oxide nanoarray to confine light to the nano-slits of the nanowire array and continuously reflect it, thereby improving the efficiency of light utilization and achieving a high photocurrent density in a weak light environment. In a 0.1 mol / L NaSO4 electrolyte solution, light with a wavelength of 365 nm at a power of 0.7 mW / cm 2 Under weak light and low power irradiation, the photocurrent reached 2.4uA / cm 2 The responsivity is 3.43 mA / W, which makes the invention have higher imaging clarity and sensitivity in underwater detection, and solves the problem of low responsivity caused by low light utilization efficiency of traditional photoelectrochemical photodetectors.

[0027] Due to its own three-dimensional highly ordered hollow cuprous oxide nanoarray structure, the material has an extremely high specific surface area, is in full contact with the electrolyte solution, and has a rich solid-liquid contact interface, which is conducive to the separation of carriers. At the same time, under the highly ordered structure, the ion transmission speed is significantly improved, and the response speed of the photodetector is improved; at a wavelength of 365nm, the power is 0.7 mW / cm 2 Under weak light and low-power irradiation, the photoelectric response speed of the present invention is 46 ms / 0.2 s. It has extremely high sensitivity under weak light conditions and is applicable to a wide range of scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a magnified scanning electron microscope image of the side of the three-dimensional highly ordered hollow cuprous oxide nanoarray material of the present invention;

[0029] Figure 2 This is a magnified scanning electron microscope image of a local side surface of the three-dimensional highly ordered hollow cuprous oxide nanoarray material of the present invention;

[0030] Figure 3 This is a magnified scanning electron microscope image of the front side of the three-dimensional highly ordered hollow cuprous oxide nanoarray material of the present invention;

[0031] Figure 4 This is a magnified scanning electron microscope image of the back side of the three-dimensional highly ordered hollow cuprous oxide nanoarray material of the present invention;

[0032] Figure 5 The X-ray diffraction pattern of the three-dimensional highly ordered hollow cuprous oxide nanoarray of the present invention;

[0033] Figure 6 The X-ray photoelectron spectrum of the Cu2p orbital of the three-dimensional highly ordered hollow cuprous oxide nanoarray of the present invention;

[0034] Figure 7 This is the Auger electron spectrum of Cu of the three-dimensional highly ordered hollow cuprous oxide nanoarray of the present invention;

[0035] Figure 8 The UV-visible absorption spectrum and the corresponding Tacu curve of the three-dimensional highly ordered hollow cuprous oxide nanoarray of the present invention;

[0036] Figure 9 The three-dimensional highly ordered hollow cuprous oxide nanoarray of the present invention is applied to the photodetector at a power intensity of 0.7mW / cm 2 Photocurrent curve under 365nm pulse light;

[0037] Figure 10 The three-dimensional highly ordered hollow cuprous oxide nanoarray of the present invention is applied to the photodetector at a power intensity of 0.7mW / cm 2 The effect of different bias voltages on photocurrent under 365nm pulse light;

[0038] Figure 11 The three-dimensional highly ordered hollow cuprous oxide nanoarray of the present invention is applied to the photodetector at a power intensity of 0.7mW / cm 2 Response time curve under 365nm pulse light irradiation;

[0039] Figure 12 Schematic diagram of an alumina template with disconnected vertical holes before hole expansion according to the present invention;

[0040] Figure 13 Schematic diagram of the alumina template with connected vertical holes after hole expansion according to the present invention. DETAILED DESCRIPTION

[0041] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] See also Figures 1-11 , the present application provides a method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray;

[0043] Example 1

[0044] As embodiment 1 of the present application, the method specifically includes:

[0045] The impurity aluminum is electrochemically oxidized and the pores are expanded to obtain a three-dimensional porous alumina template with back aluminum.

[0046] Using the back aluminum of three-dimensional porous alumina as cathode and graphite as anode, constant current electrodeposition was performed in a Cu electrodeposition solution to obtain copper nanowires with a three-dimensional porous alumina template and back aluminum.

[0047] The aluminum oxide template and back aluminum were removed using NaOH to obtain three-dimensional interconnected copper nanowires;

[0048] The three-dimensional interconnected self-supporting copper nanowires were placed in a tube furnace and maintained at 200°C in air for 15 hours to directly anneal the copper into a hollow cuprous oxide structure, obtaining a three-dimensional highly ordered hollow cuprous oxide nanoarray.

[0049] Example 2

[0050] As a second embodiment of the present application, the method specifically includes:

[0051] Step 1: Anodize the impure aluminum in a phosphoric acid electrolyte to obtain an alumina template with disconnected transverse pores on the surface of the impure aluminum; the alumina template with disconnected transverse pores refers to the alumina template having a plurality of vertical pores, the inner walls of the vertical pores having pits formed by a plurality of transverse pores, and the transverse pores of the vertical pores are not connected to the transverse pores of other vertical pores;

[0052] The reasons for the formation of vertical holes and transverse holes are as follows: first, when pure aluminum is oxidized, smooth vertical holes will be formed. However, when impure aluminum is oxidized, due to the presence of impure copper, the impure aluminum will form several holes on its originally smooth inner wall while forming vertical holes. Figure 12 As shown in the figure; these holes are the transverse holes before expansion. After expansion, the transverse holes will be horizontally connected with the adjacent vertical holes. Figure 13 As shown;

[0053] The purity of the impurity aluminum is 99%, the impurity is copper, the phosphoric acid electrolyte is a 0.3 mol / L phosphoric acid solution, and the phosphoric acid electrolyte solvent ratio is anhydrous ethanol: pure water = 1:9;

[0054] The anodic oxidation conditions were as follows: voltage 195 V, temperature 5 °C, and oxidation time 20 h;

[0055] After taking it out and drying it, it was immersed in a 5wt% phosphoric acid solution at 40°C for 40 minutes to expand the pores and connect the unconnected transverse pores in the alumina template;

[0056] Finally, after multiple washings with pure water, a three-dimensional porous alumina template (3D-AAO) with back aluminum was obtained and stored in pure water for future use.

[0057] Step 2: Electrodeposit copper on the 3D-AAO with aluminum back. The Cu electrodeposition solution contains 95g / L CuSO4 and 45g / L H2SO4. The aluminum back of the 3D-AAO is used as the cathode and the graphite sheet is used as the anode. Constant current electrodeposition is performed for 2.5 hours at a current of 3mA to obtain copper nanowires with 3D-AAO template and aluminum back.

[0058] Step 3: Place the copper nanowires with the 3D-AAO template and aluminum back after electrodeposition in 3 mol / L NaOH to remove the 3D-AAO and aluminum back. After multiple rinses with pure water and drying, a three-dimensional interconnected self-supporting copper nanowire array with a thickness of about 20 µm is obtained.

[0059] Step 4: Place the prepared three-dimensional interconnected self-supporting Cu nanowires between two flat copper foams in a tube furnace to create a local oxygen-deficient environment. The temperature is raised at a rate of 1°C / min and maintained at 200°C in an air atmosphere for 15 hours. The temperature is then naturally cooled to obtain a three-dimensional highly ordered hollow cuprous oxide nanoarray.

[0060] Example 3

[0061] As Example 3 of the present application, the three-dimensional highly ordered hollow cuprous oxide nanoarrays mentioned in Examples 1 and 2 are used in combination with FTO conductive glass to prepare a self-powered photoelectrochemical photodetector. The specific preparation method is as follows:

[0062] The FTO conductive glass was ultrasonically cleaned in the order of acetone-ethanol-water-ethanol for 15 min, and then placed in ethanol for later use;

[0063] The adhesive used is PVDF and DMF in a ratio of 1:9; DMF is N, N-dimethylformamide, PVDF is polyvinylidene fluoride, DMF is used to dissolve PVDF, and after the two are mixed, they are used as an adhesive to bond the material to the FTO conductive glass;

[0064] A three-dimensional interconnected self-supporting copper oxide hollow nanoarray was placed on FTO conductive glass, flattened and adhesive was added to prepare a three-dimensional highly ordered hollow cuprous oxide nanoarray self-powered photoelectrochemical photodetector.

[0065] To address the challenges of existing technologies, we employed a three-dimensional, highly ordered hollow cuprous oxide nanostructure array. When light shines on the highly ordered array, it passes through the slits of the hollow Cu2O nanostructures and enters the interior of the highly ordered array. There, the light is continuously reflected and absorbed, significantly increasing the material's light absorptivity and enhancing its responsiveness in low-light environments.

[0066] Due to its three-dimensional, ordered hollow structure, the three-dimensional ordered hollow cuprous oxide nanorod arrays possess numerous micropores on the surface of the array units, allowing electrolyte to enter the hollow nanorod arrays through the micropores, resulting in an extremely high specific surface area and a rich solid-liquid interface. Furthermore, compared to conventional low-order nanorod arrays, individual hollow nanorods are equidistantly connected by hollow nanochannels, preventing stacking. This highly ordered and structurally stable hollow nanorod array exhibits enhanced ion transport and improved light response.

[0067] In summary, the three-dimensional ordered hollow cuprous oxide nanoarray solves the problems of low light utilization, slow ion transport and low specific surface area of ​​traditional photoelectrochemical photodetectors by constructing highly ordered three-dimensional hollow nanoarrays, thereby improving the light responsivity and response speed of photoelectrochemical photodetectors.

[0068] The three-dimensional ordered hollow cuprous oxide nanoarrays mentioned in this application can be applied to the fields of photoelectric water splitting and photoelectric CO2 reduction due to their excellent material structure and photoelectric properties by being compounded with other metal nanoparticles (such as Pt, Au, Ru, etc.).

[0069] like Figure 1 、 Figure 2 As shown in the magnified image of the scanning electron microscope, the thickness of the three-dimensional highly ordered hollow cuprous oxide nanoarray material is about 20µm. It is a highly ordered hollow porous structure with a micron-level thickness and ordered hollow porous structure. Compared with conventional two-dimensional materials, it can be in more complete contact with the electrolyte. The lateral connection avoids the collapse of the nanowires, ensuring its three-dimensional stable structure and rapid ion transmission channel, so that light is reflected multiple times in the process of entering the three-dimensional highly ordered hollow cuprous oxide nanoarray material, which improves the utilization rate of light by the photodetector, especially under weak light conditions, and improves the photoelectric detection capability of the material under weak light conditions.

[0070] like Figure 3 、 Figure 4As shown, under a scanning electron microscope, the front and back magnified images of the three-dimensional highly ordered hollow cuprous oxide nanoarrays can be seen. The slits between the hollow nanowires can allow light to pass through the material well, and at the same time can serve as channels for rapid ion transmission, thereby improving the material's responsiveness and response speed.

[0071] When X-ray detection is performed on the three-dimensional highly ordered hollow cuprous oxide nanoarray of Example 2, as shown in FIG. Figure 5 As shown, the X-ray diffraction pattern of the three-dimensional highly ordered hollow cuprous oxide nanoarray was obtained, which is consistent with the cuprous oxide standard card (Cu2OPDF#01-077-0199), indicating that the main component of this material is Cu2O, the content of CuO substance is low, and there is no negative impact in photoelectric detection.

[0072] When the three-dimensional highly ordered hollow cuprous oxide nanoarray of Example 2 is measured, Figure 6 and Figure 7 As shown in the figure, they are the X-ray photoelectron spectrum and CuLMM Auger electron spectrum of Cu2p orbital of three-dimensional highly ordered hollow cuprous oxide nanoarrays. From the spectrum, it can be seen that the valence state of Cu in this material is mainly Cu + and a small amount of Cu 2+ .

[0073] When the three-dimensional highly ordered hollow cuprous oxide nanoarray of Example 2 is measured, Figure 8 As shown in the UV-visible absorption spectrum of the three-dimensional highly ordered hollow cuprous oxide nanoarray and the corresponding Tacu curve, within the range of 850-350nm, the absorption of light by this material is mainly concentrated in the near-ultraviolet band, that is, around 365nm. According to the Tacu curve, its band gap is about 2.88eV.

[0074] When the three-dimensional highly ordered hollow cuprous oxide nanoarray of Example 3 is applied to a photodetector for detection, Figure 9 As shown, at a power intensity of 0.7 mW / cm 2 The photocurrent curve of the three-dimensional highly ordered hollow cuprous oxide nanoarray was obtained under 365nm pulsed light. The photoelectrochemical photodetector was immersed in 0.1MNa2SO4 electrolyte, with an Ag / AgCl reference electrode and a platinum wire as the reference electrode. A bias of -0.4V was applied relative to the reference electrode. At the same time, it was irradiated with 365nm wavelength pulsed light at a power of 0.7mW / cm 2 The pulse light is switched on and off every 10 seconds, and the photocurrent is approximately 2.4µA / cm 2 , the response is 3.43mA / W, which proves that the photoelectrochemical photodetector has extremely high response in deep-sea exploration.

[0075] When the three-dimensional highly ordered hollow cuprous oxide nanoarray of Example 3 is used in a photodetector for detection, Figure 9 Under the same test conditions, at a power intensity of 0.7mW / cm 2 The effect of different bias voltages on the photocurrent of three-dimensional highly ordered hollow cuprous oxide nanoarrays under 365nm pulsed light is shown in Figure 2. Figure 10 As shown in Figure 2, the photocurrent density is the highest at -0.4 V.

[0076] When the three-dimensional highly ordered hollow cuprous oxide nanoarray of Example 3 is used in a photodetector for detection, Figure 9 Under the same test conditions, at a power intensity of 0.7mW / cm 2 The response time curve of the three-dimensional highly ordered hollow cuprous oxide nanoarray under 365nm pulse light irradiation is shown in Figure 2. Figure 11 As shown, the power of light at 365nm wavelength is 0.7mW / cm 2 Under weak light and low power irradiation, the photoelectric response speed of the present invention is 46ms / 0.2s, and the response speed reaches the millisecond level, which greatly improves the reaction speed of the photoelectric detector in deep-sea exploration and greatly improves the safety.

[0077] The above embodiments are only used to illustrate the technical method of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray, characterized in that: include: S1. Electrochemically anodic oxidation is performed on the impure aluminum to obtain an alumina template having a plurality of vertical holes with a plurality of transverse holes on the inner wall, and the vertical holes are not connected to each other. After the hole expansion treatment, the plurality of vertical holes are connected to each other by transverse holes to obtain a three-dimensional porous alumina template with back aluminum; S2, using the three-dimensional porous alumina template as the cathode and graphite as the anode, constant current electrodeposition is performed in a Cu electrodeposition solution to obtain a three-dimensional porous alumina template with back aluminum loaded with copper nanowires; S3, removing the three-dimensional porous alumina template with back aluminum using an alkaline solution to obtain a three-dimensional interconnected self-supporting copper nanowire array; S4. Annealing the three-dimensional interconnected self-supporting copper nanowire array at 180-220° C. in a local oxygen-deficient environment and then naturally cooling the array to obtain a three-dimensional highly ordered hollow cuprous oxide nanowire array.

2. The method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray according to claim 1, wherein: In S1, the conditions for electrochemical anodization of the impurity aluminum are as follows: the impurity aluminum is placed in a phosphoric acid electrolyte for anodization, the electrolyte is a 0.25-0.35M phosphoric acid solution, and the solvent of the phosphoric acid solution is a mixture of anhydrous ethanol and water; the anodization voltage is 190-200V, the temperature is 4-6°C, and the oxidation time is 18-22h.

3. The method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray according to claim 2, wherein: In S1, the impurity in the impurity aluminum is copper, and the impurity content is 1%; The conditions for electrochemical anodization of impure aluminum are as follows: the impure aluminum is placed in a phosphoric acid electrolyte for anodization, the electrolyte is a 0.3M phosphoric acid solution, and the solvent of the phosphoric acid solution is anhydrous ethanol: pure water mixed in a volume ratio of 1:9; the anodization voltage is 195V, the temperature is 5°C, and the oxidation time is 20h.

4. The method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray according to claim 1, 2 or 3, wherein: In S1, the hole expansion processing method is: The alumina template obtained after electrochemical anodization is dried and immersed in a 4-6wt% phosphoric acid solution at 38-45°C for 30-50 minutes to expand the pores, and the unconnected vertical pores inside the alumina template are expanded and connected through the transverse holes; after washing with pure water, a three-dimensional porous alumina template with back aluminum is obtained, and the pure water is stored for future use.

5. The method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray according to claim 1, wherein: In S2, the Cu electrodeposition solution contains 90-100 g / L of CuSO4 and 40-50 g / L of H2SO4.

6. The method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray according to claim 1, wherein: In S3, the alkaline solution is a 3-5 M NaOH solution; After multiple pure water rinses and drying, a three-dimensional interconnected self-supporting copper nanowire array was obtained.

7. The method for preparing a three-dimensional ordered hollow cuprous oxide nanoarray according to claim 1, wherein: In S4, the three-dimensional interconnected self-supporting copper nanowire array prepared in S3 is placed between two flat pieces of foam copper to obtain a local oxygen-deficient environment. The three-dimensional interconnected self-supporting copper nanowire array and the foam copper are placed in a furnace as a whole. After being kept in an air atmosphere of 200°C for 15 hours, the temperature is naturally lowered to obtain a three-dimensional ordered hollow cuprous oxide nanoarray.

8. A three-dimensional ordered hollow cuprous oxide nanoarray, characterized in that: The method is prepared according to any one of claims 1 to 7.

9. A self-powered photoelectrochemical photodetector, characterized in that: The invention comprises FTO conductive glass and the three-dimensional ordered hollow cuprous oxide nanoarray according to claim 8; the three-dimensional ordered hollow cuprous oxide nanoarray is combined with the surface of the FTO conductive glass.

10. Use of the three-dimensional ordered hollow cuprous oxide nanoarray according to claim 8 in the preparation of a photodetector.

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