A method for growing V2O5 nanowires based on phase separation

Abstract

This invention discloses a method for growing V2O5 nanowires based on phase separation. The method comprises the following steps: forming a tungsten-vanadium oxide thin film on a substrate using a sputtering coating technique; and annealing the thin film to induce crystallization and phase separation, thereby producing V2O5 nanowires grown on a WO3 substrate. This method, which utilizes only sputtering and annealing techniques to produce V2O5 nanowires, is simple and amenable to large-scale production. The preparation process does not require catalysts or other chemical reagents, making it environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterial preparation, and in particular to a method for growing V2O5 nanowires based on phase separation. Background Art

[0002] In recent years, vanadium pentoxide (V2O5) has shown broad application prospects in electrochromic devices, lithium batteries, gas sensors, and other fields due to its ability to transition to multiple valence states upon ion embedding and its unique layered structure. Compared to bulk V2O5, one-dimensional V2O5 nanowires possess physicochemical properties such as high specific surface area, significant anisotropy, and excellent size effects.

[0003] Existing methods for preparing V2O5 nanowires are mostly based on harsh conditions such as liquid phase, high temperature, and high pressure. The operations are complex and require the use of large amounts of catalysts or other chemical reagents during the synthesis process. This not only increases the complexity of the reaction, but also reduces the purity of the product, increasing the difficulty of subsequent separation and product purification, and to some extent limits its application in optoelectronic devices, energy storage, catalysis and other fields.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for growing V2O5 nanowires based on phase separation, so as to solve the problems of complex operation and harsh conditions in synthesizing V2O5 nanowires using the existing methods.

[0006] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0007] The present invention provides a method for growing V2O5 nanowires based on phase separation, the method comprising the following steps:

[0008] Tungsten-vanadium oxide thin films were prepared on substrates using sputtering coating technology;

[0009] The tungsten-vanadium oxide film is subjected to an annealing treatment, wherein the annealing treatment induces a crystallization and phase separation process of the tungsten-vanadium oxide film, thereby obtaining V2O5 nanowires grown on the WO3 substrate with WO3 as the substrate.

[0010] Preferably, the atomic ratio of tungsten to vanadium in the tungsten-vanadium oxide film is 1:(0.2-4).

[0011] Preferably, the sputtering coating technology is selected from one of magnetron sputtering technology, ion beam sputtering technology, and cathode arc sputtering technology.

[0012] Preferably, the substrate is selected from a glass substrate, a silicon substrate or a metal substrate.

[0013] Preferably, the step of preparing a tungsten-vanadium oxide thin film on a substrate using magnetron sputtering technology specifically includes:

[0014] A tungsten source target, a vanadium source target and a substrate are placed in a vacuum chamber of a magnetron sputtering device, and then a mixed gas of inert gas and oxygen is introduced into the vacuum chamber. The parameters of the magnetron sputtering device are adjusted and magnetron sputtering is performed to prepare a tungsten vanadium oxide film on the substrate.

[0015] Preferably, the vacuum chamber of the magnetron sputtering equipment is evacuated to 10 -3 -10 -5 Pa vacuum state;

[0016] The pressure of the mixed gas in the vacuum chamber is 0.7Pa-5.0Pa;

[0017] The parameters of the magnetron sputtering equipment include: the sputtering power of the tungsten source target is 10-100W, the sputtering power of the vanadium source target is 50-200W, and the sputtering time is more than 0.3h.

[0018] Preferably, the flow ratio of the inert gas to the oxygen is (2-5):1.

[0019] Preferably, the annealing temperature is 300°C-600°C.

[0020] Preferably, the annealing treatment time is 1 hour to 15 hours.

[0021] Beneficial effects:

[0022] The present invention discloses a method for growing V2O5 nanowires based on phase separation. The V2O5 nanowires can be prepared only through sputtering coating technology and annealing process. The process is simple and can be produced on a large scale. No catalysts or other chemical reagents are required during the preparation process, which is green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a cross-sectional SEM image of the sample prepared in Example 1 of the present invention;

[0024] Figure 2 This is a SEM image of the sample surface prepared in Example 1 of the present invention;

[0025] Figure 3 This is the XRD pattern of the sample prepared in Example 1 of the present invention;

[0026] Figure 4 TEM image of the V2O5 nanowire structure prepared in Example 1 of the present invention;

[0027] Figure 5 This is the selected area electron diffraction pattern of V2O5 nanowires prepared in Example 1 of the present invention;

[0028] Figure 6 This is the electron diffraction pattern of the WO3 substrate polycrystalline prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The present invention provides a method for growing V2O5 nanowires based on phase separation. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0030] An embodiment of the present invention provides a method for growing V2O5 nanowires based on phase separation, the method comprising the following steps:

[0031] Tungsten-vanadium oxide thin films were prepared on substrates using sputtering coating technology;

[0032] The tungsten-vanadium oxide film is subjected to an annealing treatment, wherein the annealing treatment induces a crystallization and phase separation process of the tungsten-vanadium oxide film, thereby obtaining V2O5 nanowires grown on the WO3 substrate with WO3 as the substrate.

[0033] Patent CN113658852A discloses a method for preparing silicon-based size-controllable β-Ga2O3 nanowires. The process for preparing silicon-based size-controllable β-Ga2O3 nanowires is as follows: first, a gold (Au) catalyst layer of varying thickness is deposited on a single-crystal Si(100) substrate, and the catalyst layer is subjected to in-situ spheroidization annealing to obtain Au nanoparticles of varying sizes. β-Ga2O3 nanowires are then grown by magnetron sputtering and in-situ annealing to obtain β-Ga2O3 nanowires of varying sizes. Compared to the aforementioned patent, which is a mainstream method for conventional nanowire growth, the present invention successfully prepares V2O5 nanowires without the need for any catalyst.

[0034] Specifically, in the aforementioned patent, gold nanoparticles function more like seed crystals, surrounding which β-Ga2O3 nanowires grow. The size and morphology of the gold nanoparticles affect the growth of the β-Ga2O3 nanowires, effectively manipulating the diameter and other morphological characteristics of the β-Ga2O3 nanowires. However, this embodiment eliminates this requirement. Instead, the process involves atomic diffusion during annealing, influencing the internal structure and organization of the material, thereby inducing crystallization and phase separation. Annealing induces the growth of V2O5 nanowires on the WO3 substrate, directly producing V2O5 nanowires without the need for any catalysts or other chemicals.

[0035] In some embodiments, the atomic ratio of tungsten to vanadium in the tungsten-vanadium oxide film is 1:(0.2-4).

[0036] In some embodiments, the sputtering coating technology is selected from one of magnetron sputtering technology, ion beam sputtering technology, and cathode arc sputtering technology.

[0037] The tungsten-vanadium mixed amorphous oxide in the embodiments of the present invention is obtained by sputtering. Specifically, ions bombard the target surface, dislodging atoms from the target surface. These sputtered particles then deposit on the substrate surface, forming an oxide film. Sputtering coating methods include, but are not limited to, magnetron sputtering, ion beam sputtering, and cathode arc sputtering.

[0038] In some embodiments, the substrate is selected from a glass substrate, a silicon substrate, or a metal substrate, but is not limited thereto.

[0039] The substrate used in the embodiment of the present invention may be a glass substrate, a silicon wafer, an aluminum wafer, or the like.

[0040] In some embodiments, the step of preparing a tungsten vanadium oxide thin film on a substrate using magnetron sputtering technology specifically includes:

[0041] A tungsten source target, a vanadium source target and a substrate are placed in a vacuum chamber of a magnetron sputtering device, and then a mixed gas of inert gas and oxygen is introduced into the vacuum chamber. The parameters of the magnetron sputtering device are adjusted and magnetron sputtering is performed to prepare a tungsten vanadium oxide film on the substrate.

[0042] In some embodiments, the vacuum chamber of the magnetron sputtering apparatus is evacuated to 10 -3 -10 -5 Pa vacuum state;

[0043] The pressure of the mixed gas in the vacuum chamber is 0.7-5.0Pa;

[0044] The parameters of the magnetron sputtering equipment include: the sputtering power of the tungsten source target is 10-100W, the sputtering power of the vanadium source target is 50-200W, and the sputtering time is more than 0.3h.

[0045] In some embodiments, the flow ratio of the inert gas to the oxygen is (2-5):1.

[0046] In some embodiments, the annealing treatment is performed at a temperature of 300°C-600°C.

[0047] In some embodiments, the annealing treatment time is 1 hour to 15 hours.

[0048] In this embodiment, the length and density of the nanowires are controlled by adjusting the tungsten-vanadium atomic ratio and annealing parameters. Under the above-defined parameters, the length of the V2O5 nanowires is 10 nm-4000 nm.

[0049] In some embodiments, the present invention provides a method for growing V2O5 nanowires based on phase separation, the method comprising the following steps:

[0050] Place the W and V targets on the target position in the vacuum chamber of the magnetron sputtering equipment;

[0051] Place the substrate on the sample stage;

[0052] The vacuum chamber is evacuated to make the vacuum degree in the vacuum chamber reach the preset value, which is 10 -5 Pa magnitude;

[0053] Fill the vacuum chamber with argon and oxygen, and adjust the air pressure to a predetermined range of 0.7-5.0 Pa;

[0054] Applying DC / RF current and regulating the sputtering power of the W target and V target to control the atomic ratio of the tungsten-vanadium mixed amorphous oxide so that the tungsten-vanadium atomic ratio is 1:(0.2-4), and the deposition rate can be adjusted by the sputtering power;

[0055] Change the scheduled deposition time to adjust the film thickness;

[0056] The deposited sample is annealed to crystallize and phase separate the sample, forming a monoclinic WO3 substrate, and orthorhombic V2O5 nanowires are grown on the substrate. The length and density of the V2O5 nanowires are controlled by adjusting the annealing time and temperature. The annealing temperature range is 300°C-600°C, and the annealing time is more than 1 hour.

[0057] The embodiment of the present invention adopts W and V targets to co-sputter to prepare tungsten-vanadium mixed amorphous oxide. If tungsten-vanadium alloy target or other vanadium oxide target or tungsten oxide target is used for magnetron sputtering to prepare tungsten-vanadium mixed amorphous oxide, it also falls within the scope of the present invention.

[0058] The embodiment of the present invention uses an argon-oxygen mixed gas for magnetron sputtering. If other suitable gases are used for magnetron sputtering to prepare V2O5 nanowires, it falls within the scope of the present invention.

[0059] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them, and are intended only to illustrate the present invention and in no way limit the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0060] Example 1

[0061] A V2O5 nanowire grown based on phase separation, the preparation method of which comprises the following steps:

[0062] The V target, W target and glass substrate were pre-installed into the vacuum chamber of the magnetron sputtering coating equipment, with a vacuum degree of 4×10 -5 Pa magnitude;

[0063] The V target DC sputtering power was adjusted to 160W, the W target DC sputtering power was adjusted to 40W, and an argon-oxygen mixed gas was introduced, with 15sccm of oxygen and 45sccm of argon. The pressure in the chamber was maintained at 2Pa. Sputtering was performed for 2h to obtain a tungsten-vanadium mixed amorphous oxide with a thickness of about 300nm.

[0064] The obtained tungsten-vanadium mixed amorphous oxide was placed in a muffle furnace and annealed at 400°C for 2 hours in an atmospheric atmosphere to finally obtain a WO3 substrate and a sample on which V2O5 nanowires were grown.

[0065] The length of the prepared V2O5 nanowires is 100-250nm. Figure 1-6 The surface morphology was characterized by SEM and TEM; the crystal structure was determined by TEM and XRD. The V2O5 nanowires were single crystal structures belonging to the orthorhombic phase, and the WO3 substrate was a monoclinic phase structure.

[0066] Example 2

[0067] A V2O5 nanowire grown based on phase separation, the preparation method of which comprises the following steps:

[0068] The V target, W target and glass substrate were pre-installed into the vacuum chamber of the magnetron sputtering coating equipment, with a vacuum degree of 4×10 -4 Pa magnitude;

[0069] The V target DC sputtering power was adjusted to 160W, the W target DC sputtering power was adjusted to 40W, and an argon-oxygen mixed gas was introduced, with 15sccm of oxygen and 45sccm of argon. The pressure in the chamber was maintained at 2Pa. Sputtering was performed for 2h to obtain a tungsten-vanadium mixed amorphous oxide with a thickness of about 300nm.

[0070] The obtained tungsten-vanadium mixed amorphous oxide was placed in a muffle furnace and annealed at 400°C for 4 hours in an atmospheric atmosphere to finally obtain V2O5 nanowires.

[0071] The length of the prepared V2O5 nanowires is 400-1200 nm.

[0072] Example 3

[0073] A V2O5 nanowire grown based on phase separation, the preparation method of which comprises the following steps:

[0074] The V target, W target and glass substrate were pre-installed into the vacuum chamber of the magnetron sputtering coating equipment, with a vacuum degree of 4×10 -4 Pa magnitude;

[0075] The V target DC sputtering power was adjusted to 160W, and the W target DC sputtering power was adjusted to 60W. An argon-oxygen mixed gas was introduced, with 15 sccm of oxygen and 45 sccm of argon. The pressure in the chamber was maintained at 2 Pa. The sputtering was performed for 2 hours to obtain a tungsten-vanadium mixed amorphous oxide with a thickness of about 300 nm.

[0076] The obtained tungsten-vanadium mixed amorphous oxide was placed in a muffle furnace and annealed at 400°C for 2 hours in an atmospheric atmosphere to finally obtain V2O5 nanowires.

[0077] The length of the prepared V2O5 nanowires is 100-300 nm.

[0078] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for growing V2O5 nanowires based on phase separation, characterized in that: The method comprises the following steps: Tungsten-vanadium oxide thin films were prepared on substrates using sputtering coating technology; Annealing the tungsten-vanadium oxide film, wherein the annealing induces crystallization and phase separation of the tungsten-vanadium oxide film to obtain V2O5 nanowires grown on a WO3 substrate; The atomic ratio of tungsten to vanadium in the tungsten-vanadium oxide film is 1:(0.2-4); The annealing temperature is 300°C-600°C; The annealing treatment time is 1 h to 15 h.

2. The method for growing V2O5 nanowires based on phase separation according to claim 1, characterized in that: The sputtering coating technology is selected from one of magnetron sputtering technology, ion beam sputtering technology, and cathode arc sputtering technology.

3. The method for growing V2O5 nanowires based on phase separation according to claim 1, characterized in that: The substrate is selected from a glass substrate, a silicon substrate or a metal substrate.

4. The method for growing V2O5 nanowires based on phase separation according to claim 2, characterized in that: The steps of preparing a tungsten-vanadium oxide thin film on a substrate using magnetron sputtering technology specifically include: A tungsten source target, a vanadium source target and a substrate are placed in a vacuum chamber of a magnetron sputtering device, and then a mixed gas of inert gas and oxygen is introduced into the vacuum chamber. The parameters of the magnetron sputtering device are adjusted and magnetron sputtering is performed to prepare a tungsten vanadium oxide film on the substrate.

5. The method for growing V2O5 nanowires based on phase separation according to claim 4, characterized in that: The vacuum chamber of the magnetron sputtering equipment is pumped down to 10 -3 -10 -5 Pa vacuum state; The pressure of the mixed gas in the vacuum chamber is 0.7-5.0Pa; The parameters of the magnetron sputtering equipment include: the sputtering power of the tungsten source target is 10-100 W, the sputtering power of the vanadium source target is 50-200 W, and the sputtering time is more than 0.3 h.

6. The method for growing V2O5 nanowires based on phase separation according to claim 4, characterized in that: The flow ratio of the inert gas and oxygen is (2-5):1.

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