A method for preparing tungsten oxide nanowires by plasma immersion metal injection

Abstract

The present invention belongs to the field of engineering material preparation, and discloses a method for preparing plasma immersion metal-implanted tungsten oxide nanowires. The main technical solution includes two parts: the injection time and injection depth of plasma immersion metal-implanted tungsten oxide nanowires. The advantage of this invention is that the metal-doped tungsten oxide nanowires prepared use a plasma metal immersion injection method to make the metal atoms more evenly distributed. The content of the injected metal element and the injection depth of the tungsten oxide nanowires can be controlled by the processing time and injection voltage. No additional impurities will be introduced during the process, and there is no pollution to the environment. The prepared material was tested for electrocatalytic urea oxidation, and the results showed that the M‑W prepared by the present invention 18 O 49 / CC composite catalyst has high efficient electrocatalytic urea oxidation performance.

Description

Technical Field

[0001] The invention belongs to the field of engineering material preparation and relates to a method for preparing plasma immersion metal-injected tungsten oxide nanowires. Background Art

[0002] WO 3-x (x=0~1) compounds are not only abundant in resources but also have a variety of crystals and forms. Non-stoichiometric tungsten oxide presents different colors as the oxygen content changes. These special properties make tungsten oxide have catalytic, optical and electrical properties, and can be widely used in many fields such as flat panel displays, secondary lithium batteries, gas sensors, etc. 18 O 49 Nanomaterials have a larger specific surface area, more catalytically active sites, a smaller electron transport length, and a direct charge transport channel. The present invention uses plasma-immersed metal implantation of tungsten oxide nanowires to regulate the material's electronic conductivity and electron transfer capabilities.

[0003] Ion implantation is rapidly developing in the research of many materials, including metals and semiconductors. The element implanted in the plasma can be any element from the periodic table; ion implantation causes changes in the composition and structure of the material's surface, as well as disturbances in microscopic states such as the atomic environment and electronic configuration. This leads to changes in various physical and chemical properties of the treated material, ultimately resulting in the formation of ideally doped materials. Plasma metal immersion implantation achieves a more uniform distribution of metal atoms. The metal content and implantation depth of tungsten oxide nanowires can be controlled by processing time and injection voltage. Summary of the Invention

[0004] The present invention discloses a method for preparing metal-doped tungsten oxide nanowires by plasma. The method uses carbon cloth as a carrier and synthesizes W through a high-temperature hydrothermal reactor. 18 O 49 Nano-targets are used to modify carbon cloth to prepare W 18 O 49 / CC, and then plasma technology was used to treat W 18 O 49 / CC is metal doped to obtain MW 18 O 49 / CC to improve the electrocatalytic performance. The injection content and injection depth of metal elements into tungsten oxide nanowire materials are controlled by plasma treatment time and injection voltage. No additional impurities are introduced during the process, and there is no pollution to the environment. The electrocatalytic urea oxidation test results show that the MW prepared by the present invention 18 O 49 / CC composite catalyst has high efficient electrocatalytic performance.

[0005] The specific inventive techniques of the present invention are as follows:

[0006] A method for preparing tungsten oxide nanowires by plasma immersion metal implantation, comprising the following steps:

[0007] (1) Wash a carbon cloth of a certain size in deionized water and anhydrous ethanol several times, and dry it in a vacuum drying oven to obtain a carbon cloth free of impurities;

[0008] (2) WCl6 was added to the ethanol solution and ultrasonically stirred for several minutes, then transferred to a reactor. The carbon cloth cleaned in step (1) was added to the solution, transferred to a reactor, and placed in an oven at a certain temperature for high temperature and high pressure reaction to finally obtain uniform needle-shaped W 18 O 49 Grown on the surface of carbon cloth, washed with distilled water until neutral, and then vacuum dried, denoted as W 18 O 49 / CC;

[0009] (3) Set up the plasma equipment in advance, determine the M metal target, and then replace the W 18 O 49 The / CC carbon cloth was fixed on the surface of the sample plate and placed in the vacuum chamber of the plasma equipment to evacuate the chamber and reduce the base pressure to remove gas impurities. Then, argon was introduced to reach the working pressure and the power button of the equipment was turned on. The injection voltage was set and immersion metal injection was performed for different lengths to obtain W doped with M metal. 18 O 49 / CC, recorded as MW 18 O 49 / CC.

[0010] In step (1), the size of the carbon cloth is 1 cm 2 -4 cm 2 , wash with distilled water 2-3 times, and then with ethanol 2-3 times.

[0011] In step (2), the usage ratio of WCl6 and ethanol solution is 0.1-0.4g:40-80mL, the ultrasonic time is 10-30min, the stirring time is 10-60min, the temperature of the high temperature and high pressure reaction is 140-200℃, and the reaction time is 10-24h.

[0012] In step (2), the needle-shaped W 18 O 49 The diameter is 10-30nm and the length is 50-300nm.

[0013] In step (3), the metal target is cylindrical with a diameter of 5-10 mm and a height of 10-35 mm;

[0014] In step (3), the working pressure in the vacuum chamber is 0.05-0.1 Pa, the injection voltage is set to 15-35 kV, and the immersion metal injection time is 0.5-5 h;

[0015] In step (3), the M metal target is: iron target, cobalt target or nickel target.

[0016] The MW obtained by the present invention 18 O 49 / CC is used for electrocatalytic urea oxidation reaction.

[0017] The advantages of the present invention are:

[0018] 1. This invention uses carbon cloth as a carrier and grows tungsten oxide material on its surface, so that the tungsten oxide material is stably loaded on the surface of the carbon cloth material to form a close contact, and then metal doping is performed through plasma technology. The metal is evenly distributed on the tungsten oxide material, improving the material performance and efficiency.

[0019] 2. The injection content and injection depth of metal elements into tungsten oxide nanowire materials are controlled by plasma technology processing time and injection voltage. No additional impurities will be introduced during the process, and there is no pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 :(a) carbon cloth; (b) and (c) W 18 O 49 / CC;(d)Ni-W 18 O 49 SEM image of / CC;

[0021] Figure 2 :Carbon cloth, W 18 O 49 / CC and different metal doping amounts of Ni-W 18 O 49 / XRD of CC;

[0022] Figure 3 :Carbon cloth, W 18 O 49 / CC and different metal doping amounts of Ni-W 18 O 49 / CC electrocatalytic urea oxidation reaction. DETAILED DESCRIPTION

[0023] Example 1:

[0024] (1) 4cm 2 The carbon cloth was washed several times in deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven for a period of time to obtain an impurity-free carbon cloth.

[0025] (2) 0.4 g WCl6 was added to the ethanol solution and ultrasonically stirred for several minutes, then transferred to the reactor. The washed carbon cloth was added to the solution, transferred to the reactor, and placed in an oven at 180 ° C for high temperature and high pressure reaction to finally obtain uniform needle-shaped W 18 O 49 Grown on the surface of carbon cloth (abbreviated as W 18 O 49 / CC), washed with distilled water until neutral, and then dried in vacuum.

[0026] (3)W 18 O 49 The / CC sample is placed in the plasma equipment, and the plasma equipment needs to be set up in advance, mainly by selecting the metal target material Ni with the appropriate size and setting the mechanical parameters. 18 O 49 The / CC carbon cloth was fixed on the surface of the sample plate and placed in a vacuum chamber to evacuate the chamber and reduce the base pressure to remove gas impurities. Then, argon was introduced to reach the working pressure and the power button of the device was turned on. The injection voltage was set and 1 hour of immersion metal injection was performed to obtain nickel-doped W. 18 O 49 / CC (abbreviated as Ni-W 18 O 49 / CC-1).

[0027] The final Ni-W 18 O 49 / CC for electrocatalytic urea oxidation reaction.

[0028] Example 2:

[0029] (1) 4cm 2 The carbon cloth was washed several times in deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven for a period of time to obtain an impurity-free carbon cloth.

[0030] (2) 0.4 g WCl6 was added to the ethanol solution and ultrasonically stirred for several minutes, then transferred to the reactor. The washed carbon cloth was added to the solution, transferred to the reactor, and placed in an oven at 180 ° C for high temperature and high pressure reaction to finally obtain uniform needle-shaped W 18 O 49 Grown on the surface of carbon cloth (abbreviated as W 18 O 49 / CC), washed with distilled water until neutral, and then dried in vacuum.

[0031] (3)W 18 O 49The / CC sample is placed in the plasma equipment, and the plasma equipment needs to be set up in advance, mainly by selecting the metal target material Ni with the appropriate size and setting the mechanical parameters. 18 O 49 The / CC carbon cloth was fixed on the surface of the sample plate and placed in a vacuum chamber to evacuate the chamber and reduce the base pressure to remove gas impurities. Argon was then introduced to reach the working pressure and the power button of the device was turned on. The injection voltage was set and immersion metal injection was performed for 2 hours to obtain nickel-doped W. 18 O 49 / CC (abbreviated as Ni-W 18 O 49 / CC-2).

[0032] The final Ni-W 18 O 49 / CC-2 for electrocatalytic urea oxidation reaction.

[0033] Example 3:

[0034] (1) 4cm 2 The carbon cloth was washed several times in deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven for a period of time to obtain an impurity-free carbon cloth.

[0035] (2) 0.4 g WCl6 was added to the ethanol solution and ultrasonically stirred for several minutes, then transferred to the reactor. The washed carbon cloth was added to the solution, transferred to the reactor, and placed in an oven at 180 ° C for high temperature and high pressure reaction to finally obtain uniform needle-shaped W 18 O 49 Grown on the surface of carbon cloth (abbreviated as W 18 O 49 / CC), washed with distilled water until neutral, and then dried in vacuum.

[0036] (3)W 18 O 49 The / CC sample is placed in the plasma equipment, and the plasma equipment needs to be set up in advance, mainly by selecting the metal target material Ni with the appropriate size and setting the mechanical parameters. 18 O 49 The / CC carbon cloth was fixed on the surface of the sample plate and placed in a vacuum chamber to evacuate the chamber and reduce the base pressure to remove gas impurities. Argon was then introduced to reach the working pressure and the power button of the device was turned on. The injection voltage was set and 4 hours of immersion metal injection was performed to obtain nickel-doped W. 18 O 49 / CC (abbreviated as Ni-W 18 O 49 / CC-4).

[0037] The final Ni-W18 O 49 / CC-4 for electrocatalytic urea oxidation reaction.

[0038] Example 4:

[0039] (1) 4cm 2 The carbon cloth was washed several times in deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven for a period of time to obtain an impurity-free carbon cloth.

[0040] (2) 0.4 g WCl6 was added to the ethanol solution and ultrasonically stirred for several minutes, then transferred to the reactor. The washed carbon cloth was added to the solution, transferred to the reactor, and placed in an oven at 180 ° C for high temperature and high pressure reaction to finally obtain uniform needle-shaped W 18 O 49 Grown on the surface of carbon cloth (abbreviated as W 18 O 49 / CC), washed with distilled water until neutral, and then dried in vacuum.

[0041] (3)W 18 O 49 The / CC sample is placed in the plasma equipment, and the plasma equipment needs to be set up in advance, mainly by selecting the metal target material Ni with the appropriate size and setting the mechanical parameters. 18 O 49 The / CC carbon cloth was fixed on the surface of the sample plate and placed in a vacuum chamber to evacuate the chamber and reduce the base pressure to remove gas impurities. Argon was then introduced to reach the working pressure and the power button of the device was turned on. The injection voltage was set and 6 hours of immersion metal injection was performed to obtain nickel-doped W. 18 O 49 / CC (abbreviated as Ni-W 18 O 49 / CC-6).

[0042] The final Ni-W 18 O 49 / CC-6 for electrocatalytic urea oxidation reaction.

[0043] Comparative Example 1:

[0044] 4cm 2 The carbon cloth was washed several times in deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven for a period of time to obtain an impurity-free carbon cloth.

[0045] The carbon without WCl₂ was placed in a plasma device. The plasma device must be set up in advance, primarily by selecting a metal target of appropriate size and adjusting the mechanical parameters. The carbon cloth was fixed to the surface of a sample tray and placed in a vacuum chamber. The chamber was evacuated and the base pressure was reduced to remove gas impurities. Argon was then introduced to reach the operating pressure, the device was powered on, the injection voltage was set, and immersion metal injection was performed for 4 hours to produce nickel-doped carbon cloth (CC) (referred to as Ni-CC).

[0046] The final Ni-CC was subjected to electrocatalytic urea oxidation reaction.

[0047] Comparative Example 2:

[0048] 4cm 2 The carbon cloth was washed several times in deionized water and anhydrous ethanol respectively, and dried in a vacuum drying oven for a period of time to obtain an impurity-free carbon cloth.

[0049] 0.4 g WCl6 was added to the ethanol solution and ultrasonically stirred for several minutes, then transferred to the reactor. The washed carbon cloth was added to the solution, transferred to the reactor, and placed in an oven at 180 ° C for high temperature and high pressure reaction to obtain uniform needle-shaped W 18 O 49 Grown on the surface of carbon cloth (abbreviated as W 18 O 49 / CC), washed with distilled water until neutral, and then dried in vacuum.

[0050] The final W 18 O 49 / CC for electrocatalytic urea oxidation reaction.

[0051] Figure 1 (a) is the SEM image of the carbon cloth, the surface of the carbon cloth is relatively smooth; (b) and (c) are the W 18 O 49 SEM image of / CC, the surface of the carbon cloth is uniformly and densely grown with needle-like W 18 O 49 (d) is the Ni-W nanowire prepared in Example 3 after 4 hours of plasma nickel injection treatment 18 O 49 SEM image of / CC-4.

[0052] Figure 2 The XRD diagram of the sample shows that the carbon cloth (CC) has a carbon peak at about 26°. After the plasma nickel is injected into nickel, the carbon peak does not change significantly, indicating that the nickel metal is injected more evenly and no metal particles are formed. 18 O 49After / CC, the XRD pattern changes significantly, and a nickel peak appears at around 23°. The possible reason is that the sharp peak appears due to the bonding between nickel and tungsten oxide, but the carbon peak is too broad and overlaps with the nickel-doped peak.

[0053] Figure 3 The electrocatalytic urea oxidation performance of the prepared materials was tested. Figure 1 As shown, Ni-W 18 O 49 / CC-4 exhibited the best electrocatalytic urea oxidation performance at current densities of 10, 40, and 60 mA cm -2 When, Ni-W 18 O 49 The voltages of / CC-4 are 1.32, 1.37, and 1.40 V, respectively, indicating its low urea oxidation potential.

Claims

1. A method for preparing tungsten oxide nanowires by plasma immersion metal implantation, characterized in that: The steps include: (1) Wash a carbon cloth of a certain size in deionized water and anhydrous ethanol several times, and dry it in a vacuum drying oven to obtain a carbon cloth free of impurities; (2) WCl6 was added to the ethanol solution and ultrasonically stirred for several minutes, then transferred to a reactor. The carbon cloth cleaned in step (1) was added to the solution, transferred to a reactor, and placed in an oven at a certain temperature for high temperature and high pressure reaction to finally obtain uniform needle-shaped W 18 O 49 Grown on the surface of carbon cloth, washed with distilled water until neutral, and then vacuum dried, denoted as W 18 O 49 / CC; (3) Set up the plasma equipment in advance, determine the M metal target, and then replace the W 18 O 49 The / CC carbon cloth was fixed on the surface of the sample plate and placed in the vacuum chamber of the plasma equipment to evacuate the chamber and reduce the base pressure to remove gas impurities. Then, argon was introduced to reach the working pressure and the power button of the equipment was turned on. The injection voltage was set and immersion metal injection was performed for different lengths to obtain W doped with M metal. 18 O 49 / CC, recorded as MW 18 O 49 / CC; In step (3), the M metal target is: iron target, cobalt target or nickel target; the working pressure in the vacuum chamber is 0.05-0.1 Pa, the injection voltage is set to 15-35 kV, and the immersion metal injection time is 0.5-5 h.

2. The preparation method according to claim 1, wherein In step (1), the size of the carbon cloth is 1 cm 2 -4 cm 2 , wash with distilled water 2-3 times, and then with ethanol 2-3 times.

3. The preparation method according to claim 1, wherein In step (2), the usage ratio of WCl6 and ethanol solution is 0.1-0.4g:40-80mL, the ultrasonic time is 10-30min, the stirring time is 10-60min, the temperature of the high temperature and high pressure reaction is 140-200℃, and the reaction time is 10-24h.

4. The preparation method according to claim 1, wherein In step (2), the needle-shaped W 18 O 49 The diameter is 10-30nm and the length is 50-300nm.

5. The preparation method according to claim 1, wherein In step (3), the metal target is cylindrical with a diameter of 5-10 mm and a height of 10-35 mm.

6. The MW obtained by the preparation method according to any one of claims 1 to 5 18 O 49 / CC is used for electrocatalytic urea oxidation reaction.

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