AU2021102207A4

AU2021102207A4 - Magnesium nanowire film, and preparation method and use thereof

Info

Publication number: AU2021102207A4
Application number: AU2021102207A
Authority: AU
Inventors: Hui Liang
Original assignee: Xuzhou University of Technology
Current assignee: Xuzhou University of Technology
Priority date: 2021-04-27
Filing date: 2021-04-27
Publication date: 2021-07-22
Anticipated expiration: 2029-04-27

Abstract

The present disclosure relates to the technical field of metal thin films and provides a method for preparing a magnesium nanowire film. In the present disclosure, the morphology of the magnesium nanowire film is controlled by controlling an inclination angle and a temperature of a substrate. When the magnetron sputtering is conducted at an inclination angle of 600 < a < 890 relative to the substrate, namely, oblique incidence, during the deposition process, the diffusion of magnesium atoms occurs in the direction of the projection of the magnetron sputtering beam on the surface of a film, and the diffusion in the direction parallel to the surface of the film is only determined by the incidence angle, which allows growing magnesium nanowires to have a uniform diameter and a uniform distribution. When the substrate has a temperature of 250 C to 1000 C, well-separated magnesium nanowires can be obtained. Experimental results show that, when the substrate has a temperature of 250 C and an inclination angle of 850, magnesium nanowires in an obtained magnesium nanowire film are well dispersed and have a diameter of 25 nm to 50 nm, which can be used as a solid material for hydrogen storage. 1/5 FIG. 1 FIG. 2 FIG. 3

Description

1/5

FIG. 1

FIG. 2

FIG. 3

MAGNESIUM NANOWIRE FILM, AND PREPARATION METHOD AND USE THEREOF TECHNICAL FIELD

The present disclosure relates to the technical field of metal thin films, and in

particular to a magnesium nanowire film, and a preparation method and use

thereof.

BACKGROUND

With the aggravation of global warming and the increase of fossil fuel

consumption, traditional fuels are gradually replaced by renewable energy sources

such as hydropower, solar power, and wind power. Compared with fossil fuels,

hydrogen has higher chemical energy, which leads to an exhaust gas of water

vapor in a fuel cell, without any other greenhouse gases or harmful emissions.

Therefore, compared with traditional fuels, hydrogen has huge application

potential. However, before hydrogen can be used as an economical and feasible

fuel, it is necessary to solve the problems of hydrogen production, distribution and

storage, especially the problem of hydrogen storage. Since solid materials have a

higher bulk density and are safer than gases or liquids, solid materials are often

used to store hydrogen, thus solving the problem of hydrogen storage.

Among the solid materials for hydrogen storage, magnesium has the

characteristics of abundance, low cost, low density, low toxicity, high hydrogen

storage capacity, and reversibility, which allows magnesium to be a

commonly-used solid material for hydrogen storage. However, this material has

the defects of high desorption temperature, low hydrogen absorption power, and

easy oxidization of magnesium by oxygen, making it difficult for hydrogen to

diffuse in the material. Over the years, various studies have been devoted to

solving the above-mentioned problems. For example, in Energy Rev. 2017, 72,

523-534, the size of Mg/MgH 2 (less than 1 pm) particles was reduced by

mechanical ball milling in the presence (or absence) of a catalyst material, thereby

significantly improving the adsorption kinetics of the solid material. However, the

Mg/MgH 2 particles obtained by this method still have a relatively-large size, which

can only improve the adsorption kinetics of the solid material, but not the

thermodynamic parameters. Therefore, it is necessary to obtain Mg/MgH 2 particles

with a smaller size to simultaneously solve the problems of high desorption

temperature, low hydrogen absorption power, and easy oxidation of magnesium by

oxygen existing in a magnesium material for hydrogen storage.

SUMMARY

The present disclosure is intended to provide a magnesium nanowire film, and

a preparation method and use thereof. In the magnesium nanowire film prepared

by the present disclosure, magnesium nanowires have a small size, with a

diameter of 25 nm to 50 nm.

To achieve the objective of the present disclosure, the present disclosure

provides the following technical solutions.

The present disclosure provides a method for preparing a magnesium nanowire

film, including: using magnetron sputtering to deposit the magnesium nanowire

film on a substrate, where,

a target material for the magnetron sputtering is an Mg target;

there is a distance of 60 mm to 80 mm between the Mg target and the

substrate;

the magnetron sputtering is conducted under the protection of argon;

during the magnetron sputtering, the substrate has a temperature of 250 C to

100°C; and

during the magnetron sputtering, the substrate has an inclination angle of

600< a < 890.

Preferably, the substrate may include a conductive silicon wafer, aSiO 2 wafer, or an A 20 3 wafer.

Preferably, the Mg target may have a purity of 99.99 wt% or more.

Preferably, during the magnetron sputtering, the substrate may have a

temperature of 250 C to 800 C.

Preferably, the magnetron sputtering may be conducted at power of 20 W

tolo W.

Preferably, the magnetron sputtering may be conducted at a working voltage of

0.13 Pa to 1.3 Pa.

Preferably, the magnetron sputtering may be conducted for 10 min to 60 min.

The present disclosure also provides a magnesium nanowire film prepared by

the preparation method according to the above technical solution, and magnesium

nanowires in the magnesium nanowire film have a diameter of 20 nm to 100 nm.

The present disclosure also provides use of the magnesium nanowire film

according to the above technical solution as a solid material for hydrogen storage.

The present disclosure provides a method for preparing a magnesium nanowire

film. In the present disclosure, magnetron sputtering is used to deposit the

magnesium nanowire film on a substrate, where, a target material for the

magnetron sputtering is defined as a Mg target; there is a distance of 60 mm to 80

mm between the Mg target and the substrate; the magnetron sputtering is

conducted under the protection of argon; during the magnetron sputtering, the

substrate has a temperature of 250 C to 100°C; and during the magnetron

sputtering, the substrate has an inclination angle of 600< a < 890. In the present

disclosure, during the magnetron sputtering, the morphology of the magnesium

nanowire film is controlled by controlling an inclination angle and a temperature of

a substrate. When the magnetron sputtering is conducted at an inclination angle of

600 < a < 890 relative to the substrate, namely, oblique incidence, during the deposition process, the diffusion of magnesium atoms occurs in the direction of the projection of the magnetron sputtering beam on the surface of a film, and the diffusion in the direction parallel to the surface of the film is only determined by the incidence angle, which allows growing magnesium nanowires to have a uniform diameter and a uniform distribution. When the substrate has a temperature of

0 C to 100 0 C, well-separated magnesium nanowires can be obtained.

Experimental results show that, when the substrate has a temperature of 250 C and

an inclination angle of 850, magnesium nanowires in an obtained magnesium

nanowire film are well dispersed and have a diameter of 25 nm, which can be used

as a solid material for hydrogen storage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a scanning electron microscopy (SEM) image of the magnesium

nanowire film prepared in Example 1 of the present disclosure;

FIG. 2 is an SEM image of the magnesium nanowire film prepared in Example

2 of the present disclosure;

FIG. 3 is an SEM image of the magnesium nanowire film prepared in Example

3 of the present disclosure;

FIG. 4 is an SEM image of the magnesium nanowire film prepared in Example

4 of the present disclosure;

FIG. 5 is an SEM image of the magnesium nanowire film prepared in Example

of the present disclosure;

FIG. 6 is an SEM image of the magnesium nanowire film prepared in

Comparative Example 1 of the present disclosure;

FIG. 7 illustrates the growth simulation of the magnesium nanowire film

prepared in Example 6 of the present disclosure;

FIG. 8 is an X-ray photoelectron spectroscopy (XPS) spectrum of the

magnesium nanowire film prepared in Example 6 of the present disclosure;

FIG. 9 shows SEM images of the magnesium nanowire films prepared in

Examples 7 to 13 of the present disclosure;

FIG. 10 shows kMC simulation results for the influence of the deposition angle

a of the magnesium nanowire films prepared in Examples 7 to 13 of the present

disclosure on the inclination angle P of the magnesium nanowires;

FIG. 11 shows SEM images of the magnesium nanowire films prepared in

Examples 14 to 17 of the present disclosure; and

FIG. 12 shows the Monte Carlo kinetic simulation for the magnesium nanowire

films prepared in Examples 14 to 17 of the present disclosure.

DETAILED DESCRIPTION

The present disclosure provides a method for preparing a magnesium nanowire

film, including: using magnetron sputtering to deposit the magnesium nanowire

film on a substrate, where,

a target material for the magnetron sputtering is an Mg target;

there is a distance of 60 mm to 80 mm between the Mg target and the

substrate;

the magnetron sputtering is conducted under the protection of argon;

during the magnetron sputtering, the substrate has a temperature of 250 C to

100 °C; and

during the magnetron sputtering, the substrate has an inclination angle of

600< a < 890.

The present disclosure adopts magnetron sputtering to deposit a magnesium

nanowire film on a substrate. The present disclosure has no specific limitations on

a device for the magnetron sputtering, and a magnetron sputtering device well

known to those skilled in the art may be adopted. In the present disclosure, a

device for the magnetron sputtering may preferably be a cylindrical stainless steel

reaction chamber.

In the present disclosure, a target material for the magnetron sputtering is an

Mg target. In the present disclosure, the Mg target may have a purity preferably of

99.99 wt% or more and more preferably of 99.999 wt% or more. In the present

disclosure, when the Mg target has a purity in the above range, it is more conducive

to obtaining a magnesium nanowire film with high purity.

The present disclosure has no specific limitations on a size of the Mg target, and

the size can be adjusted according to an actual situation. In the present disclosure,

the Mg target may have a size preferably of 2 inches in diameter and 0.25 inch in

thickness.

In the present disclosure, there is a distance preferably of 60 mm to 80 mm,

more preferably of 75 mm to 80 mm, and most preferably of 80 mm between the

Mg target and the substrate. In the present disclosure, a distance between the Mg

target and the substrate affects a carrier concentration and mobility. When a

distance between the Mg target and the substrate is in the above range, it is more

conducive to obtaining a magnesium nanowire film with high quality.

In the present disclosure, the substrate may preferably include a

single-side-polished conductive silicon wafer (100), an A 20 3 wafer, or aSiO 2 wafer.

The present disclosure has no specific limitations on a source of the substrate, and

a commercially available product well known to those skilled in the art may be

adopted.

In the present disclosure, the substrate may preferably be cleaned before

magnetron sputtering. The present disclosure has no specific limitations on a

method for the cleaning, and a cleaning method well known to those skilled in the

art may be adopted. In the present disclosure, an agent reagent for the cleaning

may preferably be ultrapure water (UPW). In the present disclosure, the cleaning is

conducted to remove impurities on the surface of the substrate.

In the present disclosure, before magnetron sputtering, a vacuum degree in the reaction chamber may be adjusted preferably to 1.6 x 10-4 to 1.6 x 10-6 Pa, and more preferably to 1.6 x 10-5 to 1.6 x 10-6 Pa. In the present disclosure, when the vacuum degree during the magnetron sputtering is in the above range, air in the reaction chamber can be removed.

The present disclosure has no specific limitations on a device for adjusting the

vacuum degree during magnetron sputtering, and a device for adjusting the

vacuum degree well known to those skilled in the art may be adopted. In the

present disclosure, the device for adjusting the vacuum degree may preferably be

a turbomolecular pump (TMP).

In the present disclosure, the magnetron sputtering is conducted under the

protection of argon. The present disclosure adopts argon as a working gas, which

can prevent the oxidation of magnesium during magnetron sputtering. The present

disclosure has no specific limitations on a flow rate of the argon, and the flow rate

can be adjusted according to an actual experimental process.

In the present disclosure, during the magnetron sputtering, the substrate has

a temperature of 25 0 C to 100 0 C and preferably of 25 0C to 80 0 C. In the present

disclosure, during the magnetron sputtering, the temperature of the substrate

determines a diameter of magnesium nanowires in the magnesium nanowire film.

When the temperature of the substrate is in the above range during the magnetron

sputtering, it can ensure that the magnesium nanowires in the magnesium

nanowire film have a diameter of 25 nm to 100 nm.

In the present disclosure, during the magnetron sputtering, the substrate may

have an inclination angle of 600< a < 890 and preferably of 650 < a < 850. In the

present disclosure, during the sputtering process, a glancing angle deposition

(GLAD) system is used to control the inclination angle of the substrate. When the

inclination angle of the substrate is in the above range, it can ensure that the

magnesium nanowires in the magnesium nanowire film have a diameter of 25 nm to 100 nm.

In the present disclosure, the magnetron sputtering may be conducted at a

working voltage preferably of 0.13 Pa to 1.3 Pa and more preferably of 0.2 Pa to

0.26 Pa. In the present disclosure, when the magnetron sputtering is conducted at

a working voltage in the above range, the morphology of magnesium nanowires in

the magnesium nanowire film can be further controlled.

In the present disclosure, the magnetron sputtering may be conducted at

power preferably of 20 W to 100 W, more preferably of 30 W to 50 W, and most

preferably of 50 W. In the present disclosure, when the magnetron sputtering is

conducted at power in the above range, the morphology of magnesium nanowires

in the magnesium nanowire film can be further controlled.

In the present disclosure, the magnetron sputtering may be conducted

preferably for 10 min to 60 min and more preferably for 15 min to 30 min. In the

present disclosure, when the magnetron sputtering is conducted for a time period

in the above range, the morphology of magnesium nanowires in the magnesium

nanowire film can be further controlled.

The present disclosure uses magnetron sputtering to deposit a nanostructured

magnesium thin film on a substrate and controls the morphology of the magnesium

nanowire film by controlling an inclination angle and a temperature of the substrate

during magnetron sputtering, so that magnesium nanowires are well dispersed in

the magnesium nanowire film and can have a size much lower than that of

magnesium nanowires in the prior art.

The present disclosure also provides a magnesium nanowire film prepared by

the preparation method according to the above technical solution, and magnesium

nanowires in the magnesium nanowire film have a diameter of 25 nm to 100 nm.

The magnesium nanowires in the magnesium nanowire film provided by the

present disclosure may have a diameter of 25 nm to 100 nm and are well dispersed in the magnesium nanowire film.

The present disclosure also provides use of the magnesium nanowire film

The present disclosure has no specific limitations on a method for the use of the

magnesium nanowire film as a solid material for hydrogen storage, and a use

method as a solid material for hydrogen storage well known to those skilled in the

art may be adopted.

The technical solutions of the present disclosure will be clearly and completely

described below with reference to examples of the present disclosure. Apparently,

the described examples are merely some rather than all of the examples of the

present disclosure. All other examples obtained by a person of ordinary skill in the

art based on the examples of the present disclosure without creative efforts shall

fall within the protection scope of the present disclosure.

Example 1

This experiment was conducted in a cylindrical stainless steel reaction chamber

(height: 60 cm and diameter: 42 cm). The reaction chamber was evacuated by a

TMP, and a magnetron cathode was installed on the top of the reaction chamber. An

Mg target (purity: 99.99 wt%) with a diameter of 2 inches and a thickness of 0.25

inches was used. A conductive silicon wafer (100) was used as a substrate, and the

substrate was located at 80 mm below the Mg target. A GLAD system was used to

control an inclination angle of the substrate, and the inclination angle a was

controlled at 85 0 C. The substrate was cleaned with UPW before deposition.

The magnesium target was sputtered in a direct current mode at an argon

atmosphere. During the sputtering process, magnetron sputtering was conducted

under the following conditions to obtain a magnesium nanowire film: power: 50 W;

voltage: 0.26 Pa; time: 20 min; vacuum degree: 1.6 x 10-5 Pa; and substrate

temperature: 250 C.

The magnesium nanowire film prepared in Example 1 was scanned with SEM to

obtain an SEM image shown in FIG. 1. It can be seen from FIG. 1 that, when the

substrate has a temperature of 250 C and an inclination angle a of 850, magnesium

nanowires in an obtained magnesium nanowire film have an inclination angle of

220 and a diameter of 25 nm to 50 nm, and the magnesium nanowires are well

separated.

Example 2

The operations in this example were the same as example 1 except that the

substrate had a temperature of 400C.

The magnesium nanowire film prepared in Example 2 was scanned with SEM to

obtain an SEM image shown in FIG. 2. It can be seen from FIG. 2 that, when the

substrate has a temperature of 400 C and an inclination angle a of 850, magnesium

nanowires in an obtained magnesium nanowire film have an inclination angle of

220 and a diameter of 45 nm to 65 nm, and the magnesium nanowires are well

separated. Compared with nanowires prepared at 25 0 C, the nanowires have a

reduced inclination angle due to the increase in the substrate temperature and the

enhancement in atomic diffusion.

Example 3

The operations in this example were the same as example 1 except that the

substrate had a temperature of 600 C.

The magnesium nanowire film prepared in Example 3 was scanned with SEM to

obtain an SEM image shown in FIG. 3. It can be seen from FIG. 3 that, when the

substrate has a temperature of 600 C and an inclination angle a of 850, magnesium

nanowires in an obtained magnesium nanowire film have an inclination angle of

210 and a diameter of 60 nm to 75 nm, and the magnesium nanowires are well

separated. It can be known that the width of the nanowires is slightly increased,

and as the substrate temperature increases, the atomic diffusion continues to increase. Example 4 The operations in this example were the same as example 1 except that the substrate had a temperature of 800 C. The magnesium nanowire film prepared in Example 4 was scanned with SEM to obtain an SEM image shown in FIG. 4. It can be seen from FIG. 4 that, when the substrate has a temperature of 800 C and an inclination angle a of 850, magnesium nanowires in an obtained magnesium nanowire film have an inclination angle of 210 and a diameter of 65 nm to 100 nm, and the magnesium nanowires are well separated. The diameter of the nanowires continues to increase. Example 5 The operations in this example were the same as example 1 except that the substrate had a temperature of 1000 C. The magnesium nanowire film prepared in Example 5 was scanned with SEM to obtain an SEM image shown in FIG. 5. It can be seen from FIG. 5 that, when the substrate has a temperature of 1000 C and an inclination angle a of 850, obtained magnesium nanowires have an inclination angle of 00 and are not clearly separated, and magnesium of a block structure appears on the top. This is because the atomic diffusion overcomes the shadowing effect, and the temperature effect is dominant. Comparative Example 1 The operations in this example were the same as example 1 except that the substrate had a temperature of 2000 C. The magnesium nanowire film prepared in Comparative Example 1 was scanned with SEM to obtain an SEM image shown in FIG. 6. It can be seen from FIG. 6 that, when the substrate has a temperature of 2000 C and an inclination angle a of 850, obtained nanowires have an inclination angle of 00, and the nanowire structure disappears completely. The cross-sectional morphology of the magnesium thin film characterized by the SEM totally shows magnesium of a block structure.

It can be proved from Examples 1 to 5 and Comparative Example 1 that the

morphology of the magnesium thin film is completely controlled by a temperature,

and when the temperature is not in the range of 250 C to 1000 C, a magnesium

nanowire film cannot be obtained.

Example 6

The magnesium nanowire film in this example was prepared by the same

method as in Example 1 except that the following conditions were adopted:

sputtering power: 50 W; a = 00; and Pot = 0.26 Pa.

The Monte Carlo software was used to simulate the growth of the magnesium

thin film prepared in Example 6, as shown in FIG. 7. It can be seen from FIG. 7 that,

as the energy of the right or left diffusion of magnesium atoms increases, the pore

in the magnesium thin film decreases in size and the width of the magnesium

nanowires increases. However, as the energy of the upward movement of

magnesium atoms increases, both the pore in the magnesium thin film and the

width of the magnesium nanowires remain unchanged. Therefore, the morphology

of the magnesium thin film is mainly determined by the left and right parallel

diffusion of magnesium atoms.

An X-ray photoelectron spectrometer was used to detect the magnesium

nanowire film prepared in Example 6, and an obtained XPS spectrum was shown in

FIG. 8. It can be seen from FIG. 8 that the electronic transitions of Mg, 0, and C in

the thin film are at 49.5 eV (Mg2p), 285 eV (Cs), and 530 eV (01s), respectively.

Further quantitative analysis for these signals reveals that the thin film includes

about 50% of oxygen atoms and 10% of carbon atoms. The presence of carbon

atoms may be related to surface contamination occurring during the transport of

the sample from the reaction chamber to an XPS instrument.

Example 7

The magnesium nanowire film in this example was prepared by the same

operations as Example 1 except that the substrate had an inclination angle of 60

during GLAD.

Example 8

The magnesium nanowire film in this example was prepared by the same

operations as Example 1 except that the substrate had an inclination angle of 700

during GLAD.

Example 9

The magnesium nanowire film in this example was prepared by the same

operations as Example 1 except that the substrate had an inclination angle of 800

during GLAD.

Example 10

The magnesium nanowire film in this example was prepared by the same

operations as Example 1 except that the substrate had an inclination angle of 82.50

during GLAD.

Example 11

The magnesium nanowire film in this example was prepared by the same

operations as Example 1 except that the substrate had an inclination angle of 850

during GLAD.

Example 12

The magnesium nanowire film in this example was prepared by the same

operations as Example 1 except that the substrate had an inclination angle of 870

during GLAD.

Example 13

The magnesium nanowire film in this example was prepared by the same

operations as Example 1 except that the substrate had an inclination angle of 890 during GLAD.

The magnesium nanowire films prepared in Examples 7 to 13 were scanned

with SEM to obtain SEM images shown in FIG. 9. It can be seen from FIG. 9 that,

when an incident angle is of 600 < a < 890, the inclination angle P of nanowires in

the magnesium nanowire film strongly depends on a. At a large incident angle

(greater than 600), the shadowing mechanism is enhanced, thus forming a column

inclined toward the magnesium target. As a increases, P increases significantly,

and when a > 850, P remains stable. This is because when an incident direction of

sputtered atoms is perpendicular to the surface of a deposited film, a diffusion

distance of the atoms is only equivalent to a few atoms in each direction, and a

magnesium thin film with nanotopography will not be obtained. However, when

atoms are sputtered obliquely at a given angle to the substrate, during the

deposition process, the diffusion of atoms occurs in the direction of the projection

of a sputtering beam on the surface of a film, and the diffusion in the direction

parallel to the surface of the film is only determined by the incidence angle.

Therefore, when the incident angle is 600 < a < 890, a magnesium nanowire film

with well-separated nanowires of a diameter of 20 nm to 50 nm may be obtained.

The magnesium nanowire films prepared in Examples 7 to 13 were analyzed to

obtain kMC simulation results illustrating the influence of the deposition angle a on

the inclination angle P of the magnesium nanowires, as shown in FIG. 10. It can be

seen from FIG. 10 that the inclination angle P of nanowires in the magnesium

nanowire film strongly depends on a.

Example 14

The operations in this example were the same as Example 1 except that the

sputtering power was fixed at 50 W, the inclination angle a was fixed at 850, and

the Pot was 0.13 Pa.

Example 15

This example differs from Example 14 in that that the Pot was 0.26 Pa, and the

operations in this example were the same as example 14.

Example 16

This example differs from Example 14 in that that the Pot was 0.65 Pa, and the

operations in this example were the same as example 14.

Example 17

This example differs from Example 14 in that that the Pot was 1.3 Pa, and the

operations in this example were the same as example 14.

The magnesium nanowire films prepared in Examples 14 to 17 were detected

with SEM to obtain SEM images shown in FIG. 11. According to FIG. 11, when Pot

is 0.13 Pa, 0.26 Pa, 0.65 Pa, and 1.3 Pa, magnesium nanowires in obtained

magnesium nanowire films have inclination angles of 51 ±1.00, 44 ±1.00, 24

1.00, and 5 ±0.50, respectively.

The Monte Carlo kinetic simulation was conducted for the magnesium nanowire

films prepared in Examples 14 to 17, as shown in FIG. 12. It can be seen from FIG.

12 that the inclination angle P of magnesium nanowires is used as a variable of the

PTot function, where, 0.13 Pa is the minimum value required to maintain the

discharge of the magnetron. FIG. 12 shows that, with the increase of Pot, @

decreases rapidly, from P = 51 ±1.00 at 0.13 Pa to @ = 5 ±0.50 at 1.3 Pa. This

indicates that the change of the inclination angle of the magnesium nanowires can

be attributed to the increase of Pot, and this may be because the decrease of

incident particle flux leads to the increase of collision probability.

It can be seen from the test results of the foregoing examples that the

preparation method provided by the present disclosure can be used to prepare a

magnesium nanowire film with well-separated magnesium nanowires of a diameter

of 25 nm to 100 nm, which can be used as a solid material for hydrogen storage.

The above descriptions are merely preferred implementations of the present disclosure. It should be noted that a person of ordinary skill in the art may further make several improvements and modifications without departing from the principle of the present disclosure, but such improvements and modifications should be deemed as falling within the protection scope of the present disclosure.

Claims

What is claimed is:

1. A method for preparing a magnesium (Mg) nanowire film, comprising: using

magnetron sputtering to deposit the magnesium nanowire film on a substrate,

wherein,

a target material for the magnetron sputtering is an Mg target;

there is a distance of 60 mm to 80 mm between the Mg target and the

substrate;

the magnetron sputtering is conducted under the protection of argon;

during the magnetron sputtering, the substrate has a temperature of 250 C to

100°C; and

during the magnetron sputtering, the substrate has an inclination angle of

600< a < 890.

2. The preparation method according to claim 1, wherein, the substrate

comprises a conductive silicon wafer, a SiO 2 wafer, or an A1 2 0 3 wafer;

wherein, the Mg target has a purity of 99.99 wt% or more.

3. The preparation method according to claim 1, wherein, during the

magnetron sputtering, the substrate has a temperature of 250 C to 80°C;

wherein, the magnetron sputtering is conducted at power of 20 W tolOO W;

wherein, the magnetron sputtering is conducted at a working voltage of 0.13

Pa to 1.3 Pa;

wherein, the magnetron sputtering is conducted for 10 min to 60 min.

4. A magnesium nanowire film prepared by the preparation method according

to any one of claims 1 to 3, wherein, magnesium nanowires in the magnesium

nanowire film have a diameter of 20 nm to 100 nm.

5. Use of the magnesium nanowire film according to claim 4 as a solid material

for hydrogen storage.