Amorphous copper-tungsten alloy for electrolysis of water to produce hydrogen and preparation method thereof

Abstract

The present invention discloses an amorphous copper-tungsten alloy for electrolysis of water to produce hydrogen and a preparation method thereof. By magnetron co-sputtering of a copper target and a tungsten target, an amorphous copper-tungsten alloy film with a thickness of about 1 μm to 50 μm can be obtained. Compared with conventional methods, the preparation method of the present invention has a simple process and is suitable for large-scale preparation of binary and multi-component copper-tungsten alloys. The amorphous copper-tungsten alloy prepared by the present invention has excellent electrocatalytic hydrogen evolution performance and can be used at 10 mA cm ‑2 The overpotential is only 65mV at a current density of 1.38kV, which has good application prospects in the fields of fuel cells and water electrolysis for hydrogen production.

Description

Technical Field

[0001] The invention belongs to the field of non-precious metal electrocatalytic hydrogen evolution materials, and in particular relates to an amorphous copper-tungsten alloy for electrolyzing water to produce hydrogen and a preparation method thereof. Background Art

[0002] The large-scale application of hydrogen energy faces many challenges, among which the preparation of hydrogen is a crucial link. Hydrogen production by water electrolysis has its unique advantages. On the one hand, the raw material for hydrogen production by water electrolysis is water, which is abundant on the earth; on the other hand, the products of hydrogen production by water electrolysis are oxygen and hydrogen, which does not cause carbon emissions or other environmental pollution. Copper-based materials, as a non-precious metal material, are a promising alternative to precious metal catalysts due to their abundant resources, low cost, and environmental friendliness. However, the electrochemical hydrogen evolution overpotential of metallic copper itself is relatively large, which greatly limits its practical application.

[0003] Amorphous alloys have the characteristics of short-range order and long-range disorder in their microstructure. This disordered structure determines that amorphous alloys have very excellent physical, chemical and mechanical properties and have broad application prospects. They also show excellent performance in the field of electrochemical catalytic hydrogen evolution, such as high corrosion resistance and low hydrogen evolution overpotential.

[0004] The amorphous copper-tungsten alloy obtained after the introduction of tungsten element can effectively change the electronic configuration of copper-based materials, and the synergistic effect produced can improve the activity of copper-based catalysts in electrolysis of water to produce hydrogen. However, there are currently very few methods for preparing copper-tungsten binary amorphous alloys, and it is difficult to prepare them on a large scale. Magnetron sputtering controls the scattering of moving particles and various energy transfer processes during the sputtering process, so that the sputtered atoms are splashed out after exchanging kinetic energy with positive ions with an energy of tens of electron volts. Therefore, the sputtered atoms have high energy, which is beneficial to improve the diffusion ability of atoms during deposition, improve the density of the deposited structure, and make the produced film have strong adhesion to the substrate. At the same time, due to its strong nucleation energy, it is conducive to the formation of an amorphous structure. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing an amorphous copper-tungsten alloy for hydrogen production by electrolysis of water in view of the deficiencies in the prior art. The technical solution of the present invention prepares an amorphous copper-tungsten alloy by magnetron sputtering. The prepared amorphous copper-tungsten alloy has excellent catalytic performance for hydrogen evolution by electrolysis of water and has good application prospects in the fields of fuel cells and hydrogen production by electrolysis of water.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for preparing an amorphous copper-tungsten alloy comprises the following steps:

[0008] S1 polishes, cleans and dries the sputtered substrate, places it on a rotatable substrate holder in a vacuum chamber, and fixes it in a magnetron sputtering device;

[0009] S2 installs copper target and tungsten target in magnetron sputtering instrument;

[0010] S3 uses a direct current sputtering method, adjusts the sputtering power and sputtering time of the target material, and performs magnetron sputtering on the substrate in step S1 for a certain period of time to obtain an amorphous copper-tungsten alloy.

[0011] Preferably, as a preferred embodiment, the sputtering substrate in step S1 is selected from one or more of single crystal silicon, carbon cloth, foamed nickel, foamed copper, nickel foil, and copper foil.

[0012] Preferably, as a preferred embodiment, the distance between the sputtering substrate and the target material in step S2 is 5-10 cm.

[0013] Preferably, as a preferred embodiment, step S3 comprises the following steps: using a DC sputtering method, wait until the vacuum is better than 5*10 -3 After reaching 2 Pa, the sputtering power of the target material is adjusted, 2Pa of argon gas is passed, and magnetron sputtering is performed on the substrate in step S1 for a certain period of time to control the film thickness and ensure that its nucleation energy is large without crystallization. According to the demand, the substrate is simultaneously deposited with copper target and tungsten target, and the amorphous copper-tungsten alloy with a certain distribution of components is obtained by adjusting the sputtering time.

[0014] Preferably, as a preferred embodiment, the sputtering power in step S3 is 10 watts to 500 watts, and the sputtering time is 10 minutes to 120 minutes, more preferably 15 minutes to 90 minutes.

[0015] Another object of the present invention is to provide an amorphous copper-tungsten alloy prepared according to the above preparation method. The electrocatalytic hydrogen evolution activity of the amorphous copper-tungsten alloy material prepared by the preparation method of the present invention in an alkaline solution is greatly improved. The amorphous copper-tungsten alloy sample has a hydrogen evolution activity of 10 mA cm -2 The overpotential is only 65mV at a current density of 1.38kV, which is significantly lower than that of crystalline copper, tungsten metal or alloy.

[0016] Preferably, as a preferred embodiment, the molar content of copper in the amorphous copper-tungsten alloy of the present invention is 10-90%, and the molar content of tungsten is 10-90%.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The preparation method of the present invention utilizes magnetron sputtering technology, and the copper-based amorphous alloy prepared can form an amorphous structure within a wide composition range;

[0019] (2) The preparation method of the present invention utilizes magnetron sputtering technology, and the prepared copper-based amorphous alloy is formed in situ on the substrate, without the need for an additional rapid cooling method;

[0020] (3) The copper-based amorphous film prepared by the preparation method of the present invention has high hydrogen evolution activity in water electrolysis. -2 The overpotential is only 65mV at a current density of 1.38kV; the preparation process is simple, the yield and stability are high, and it is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The amorphous Cu prepared by magnetron sputtering 70 W 30 Surface SEM image of;

[0022] Figure 2 The amorphous Cu prepared by magnetron sputtering 70 W 30 Energy spectrum of

[0023] Figure 3 The amorphous Cu prepared by magnetron sputtering 50 W 50 Surface SEM image of;

[0024] Figure 4 The amorphous Cu prepared by magnetron sputtering 50 W 50 Energy spectrum of

[0025] Figure 5 The amorphous Cu prepared by magnetron sputtering 70 W 30 HER stability test diagram;

[0026] Figure 6 The amorphous Cu prepared by magnetron sputtering 70 W 30 LSV plot of

[0027] Figure 7 The amorphous Cu prepared by magnetron sputtering 50 W 50 HER stability test diagram;

[0028] Figure 8 The amorphous Cu prepared by magnetron sputtering 50 W 50 LSV plot of

[0029] Fig. 9 The amorphous Cu prepared by magnetron sputtering 30 W 70HER stability test diagram;

[0030] Fig.10 The Cu prepared by magnetron sputtering is shown in Fig. 30 W 70 LSV diagram of amorphous film;

[0031] Fig.11 The amorphous Cu prepared by magnetron sputtering 70 W 30 , Cu 50 W 50 , Cu 30 W 70 XRD pattern of . DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited to the described contents.

[0033] 1. Embodiment 1

[0034] The copper target and tungsten target were installed in a magnetron sputtering instrument, and the sputtering power of the copper target was adjusted to 100W and the sputtering power of the tungsten target was adjusted to 190W. Magnetron sputtering was performed on the foamed nickel substrate for 30 minutes to obtain amorphous Cu 70 W 30 Sample. The sample morphology is shown in Figure 1 As shown; Figure 2 This is its energy spectrum, which shows that the elements of the prepared sample are very evenly distributed; Fig.11 There is an XRD pattern, which shows a broad peak near 42°, indicating that the prepared sample has an amorphous structure.

[0035] Figure 5 It is the HER stability test diagram of the sample; Figure 6 The LSV diagram of the sample shows that the sample is -2 The overpotential at a current density of 1.38kV is 65mV.

[0036] 2. Embodiment 2

[0037] The copper target and tungsten target were installed in a magnetron sputtering instrument, and the sputtering power of the copper target was adjusted to 50W and the sputtering power of the tungsten target was adjusted to 250W. Magnetron sputtering was performed on the foamed nickel substrate for 30 minutes to obtain amorphous Cu 50 W 50 Sample. The sample morphology is shown in Figure 3 As shown; Figure 4 This is its energy spectrum, which shows that the elements of the prepared sample are very evenly distributed; Fig.11There is an XRD pattern, which shows a broad peak near 42°, indicating that the prepared sample has an amorphous structure.

[0038] Figure 7 It is the HER stability test diagram of the sample; Figure 8 The LSV diagram of the sample shows that the sample is -2 The overpotential at a current density of is 79 mV.

[0039] 3. Embodiment 3

[0040] The copper target and tungsten target were installed in a magnetron sputtering instrument, and the sputtering power of the copper target was adjusted to 20w and the sputtering power of the tungsten target was adjusted to 260w. Magnetron sputtering was performed on the foamed nickel substrate for 30 minutes to obtain amorphous Cu 30 W 70 sample. Fig.11 There is an XRD pattern, which shows a broad peak near 42°, indicating that the prepared sample has an amorphous structure.

[0041] Fig. 9 It is the HER stability test diagram of the sample; Fig.10 The LSV diagram of the sample shows that the sample is -2 The overpotential at a current density of 181 mV.

[0042] The above-mentioned specific implementation modes are preferred embodiments of the present invention and cannot limit the claims of the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. An application of an amorphous copper-tungsten alloy for electrolysis of water to produce hydrogen, characterized in that: The preparation method of the amorphous copper-tungsten alloy comprises the following steps: S1 polishes, cleans and dries the sputtered substrate, places it on a rotatable substrate holder in a vacuum chamber, and fixes it in a magnetron sputtering device; S2 installs copper target and tungsten target in magnetron sputtering instrument; S3 uses a DC sputtering method, adjusts the sputtering power and sputtering time of the target material, and performs magnetron sputtering on the substrate in step S1 for a certain period of time to obtain an amorphous copper-tungsten alloy; S3 comprises the following steps: using a DC sputtering method, wait until the vacuum is better than 5*10 -3 After reaching 2 Pa, the sputtering power of the target material is adjusted, 2Pa of argon gas is passed, and magnetron sputtering is performed on the substrate in step S1 for a certain period of time to control the film thickness and ensure that its nucleation energy is large without crystallization. According to the demand, the substrate is simultaneously deposited with copper target and tungsten target, and the amorphous copper-tungsten alloy with a certain distribution of components is obtained by adjusting the sputtering time.

2. The use of an amorphous copper-tungsten alloy for producing hydrogen by electrolysis of water according to claim 1, characterized in that: In the step S1, the sputtering substrate is selected from one or more of single crystal silicon, carbon cloth, foamed nickel, foamed copper, nickel foil, and copper foil.

3. The use of an amorphous copper-tungsten alloy for producing hydrogen by electrolysis of water according to claim 1, characterized in that: In step S2, the distance between the sputtering substrate and the target material is 5-10 cm.

4. The use of an amorphous copper-tungsten alloy for producing hydrogen by electrolysis of water according to claim 1, characterized in that: In step S3, the sputtering power is 10 watts to 500 watts, and the sputtering time is 10 minutes to 120 minutes.

5. The use of an amorphous copper-tungsten alloy for producing hydrogen by electrolysis of water according to claim 1, characterized in that: The amorphous copper-tungsten alloy is subjected to 1M KOH solution and 10 mA·cm -2 The overpotential is 65mV at a current density of .

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