CN103762356B - Ni nano wire, NiO/Ni self-supported membrane and its preparation method and application - Google Patents

Abstract

The invention discloses a Ni nanowire, a NiO/Ni self-supporting film, a preparation method and an application thereof. The Ni nanowires are ultra-long nanowires with an average length of 50,000 to 200,000nm; the preparation method is as follows: first, a Ni nanowire liquid-phase growth solution is prepared; then the Ni nanowire element is prepared under an external magnetic field; finally, the Ni nanowire is separated and purified . The NiO/Ni self-supporting film comprises the Ni nanowire and the Ni nanowire whose surface is NiO obtained by calcination; the preparation method is as follows: firstly, the Ni nanowire is dispersed in a surfactant solution; The Ni nanowires are transferred to the microporous filter membrane by filtration to prepare a Ni self-supporting membrane; finally, the Ni self-supporting membrane is calcined in an oxygen-containing atmosphere to obtain a NiO/Ni self-supporting membrane. The NiO/Ni self-supporting film provided by the invention has good flexibility and electrochemical performance, can be used as a supercapacitor active material, and has low cost and simple process.

Description

Ni nanowire, NiO/Ni self-supporting film and its preparation method and application

technical field

The invention belongs to the field of nanometer materials, and more specifically relates to a Ni nanowire, a NiO/Ni self-supporting film and a preparation method and application thereof.

Background technique

With the gradual depletion of traditional fossil energy sources, new energy sources such as solar energy, wind energy, nuclear energy, and geothermal energy, which have the advantages of environmental protection and renewability, have received more and more attention, development, and application. There is often a problem of electric energy storage in the process of grid-connected power generation, and the advantages of supercapacitors in energy storage may be a good solution to these problems.

Yuan et al. published a paper in nature nanotechnology in 2008 based on MnO ₂ self-supporting membrane, and then achieved hydrophobic/hydrophilic properties by adsorption at 234°C and desorption of polydimethylsiloxane (PDMS) at 390°C. It has great application potential in the adsorption of oil pollution. In 2012, Luo et al. obtained a self-supporting film composed of CNT/LiCoO ₂ composites by simply ultrasonically co-depositing ultra-long, ultra-ordered carbon nanotubes and lithium cobalt oxygen microparticles, which is different from conventional lithium The positive electrode of the ion battery needs to add additional conductive agent (such as conductive carbon black, acetylene black, etc.), this preparation method not only saves the cost, but also facilitates the simplification of the preparation process. At 0.1C, the specific capacity of the self-supporting film reaches 151.4 mAhg ^-1 , showing better performance of lithium-ion batteries. In 2012, Yuan et al. used graphene oxide/carbon nanotube film as the substrate, and then directly grew supercapacitor active material Co ₃ O ₄ on the composite material through ^hydrothermal reaction at 90°C for 14 hours. The specific capacitance of 378Fg ^-1 was obtained under the charge and discharge current density, and it has excellent flexibility.

The most successful electrode material for metal oxide-based capacitors is mainly ruthenium oxide. However, due to the limited resources of precious metals, the high price limits its use. The research on metal oxide capacitors is mainly to reduce the cost of materials, and to find more cheap material.

Contents of the invention

Aiming at the above defects or improvement needs of the prior art, the present invention provides a Ni nanowire, a NiO/Ni self-supporting film and its preparation method and application. Low supercapacitor electrode active materials, thereby solving the current technical problems of high cost and complicated manufacturing process of supercapacitors.

To achieve the above object, according to one aspect of the present invention, a Ni nanowire is provided, the average diameter of the Ni nanowire is between 200nm and 300nm, and the average length is between 50,000nm and 200,000nm.

According to another aspect of the present invention, a method for preparing Ni nanowires is provided, comprising the following steps:

(1) Configure Ni nanowire liquid phase growth solution: dissolving Ni salt as a precursor in an organic solvent to obtain a Ni precursor solution; dissolving an organic reducing agent in the organic solvent to obtain a reducing agent solution; Slowly dispersing the Ni precursor solution in a strong alkaline organic solvent, then adding a reducing agent solution, and finally adding a surfactant organic solution to prepare a Ni nanowire liquid phase growth solution;

(2) Under an external magnetic field, the Ni nanowire liquid phase growth solution undergoes a redox reaction to prepare a Ni nanowire element;

(3) magnetically separate and clean the Ni nanowires, and dry them to obtain the Ni nanowires as claimed in claim 1 .

Preferably, in the preparation method, the Ni salt described in step (1) is nickel chloride hexahydrate, the organic solvent is ethylene glycol, and the concentration of the Ni precursor solution is 24 mg/ml; the organic reduction Agent is hydrazine hydrate, and described organic reducing agent solution concentration is 85wt%; Described strongly alkaline organic solvent is the sodium hydroxide ethylene glycol solution of 1.5mol/L; Described surfactant organic solution is the polyethylene of 2wt%. Pyrrolidone; the mixing ratio of the Ni precursor solution, strong basic organic solution, and reducing agent organic solution is 1:4:2 by volume.

Preferably, in the preparation method, the oxidation-reduction reaction condition in step (2) is a constant temperature of 70 degrees Celsius, the reaction time is 1 hour, and the applied magnetic field strength is 0.4 Tesla.

According to another aspect of the present invention, a kind of NiO/Ni self-supporting film is provided, comprising the Ni nanowire and the Ni nanowire with NiO on the surface made by calcination thereof, wherein the molar ratio of Ni and NiO is 2.5: 1 to 20:1.

According to another aspect of the present invention, a kind of preparation method of NiO/Ni self-supporting membrane is provided, comprising the following steps:

(a) uniformly dispersing the Ni nanowires as claimed in claim 1 in an organic surfactant solution to form a Ni nanowire dispersion;

(b) Transfer the Ni nanowire dispersion prepared in step (a) to a microporous filter membrane by suction filtration, wash and dry, and peel off to obtain a Ni self-supporting membrane;

(c) Calcining the Ni self-supporting film prepared in step (b) in an oxygen-containing atmosphere to obtain a NiO/Ni self-supporting film.

Preferably, in the preparation method of the NiO/Ni self-supporting film, the surfactant organic solution described in step (a) is 1 wt% polyvinylpyrrolidone in ethylene glycol solution, and the mass ratio of the Ni nanowires to the organic solution is Between 1:1000 and 1:2500, the dispersion method uses 100 watts of ultrasonic dispersion for 10 minutes.

Preferably, in the preparation method of the NiO/Ni self-supporting film, the oxygen-containing atmosphere in step (c) is an air atmosphere, the calcination temperature is 350°C to 450°C, and the calcination and annealing time is 3 minutes to 10 minutes.

The NiO/Ni self-supporting film provided by the invention can be used as an active material of a supercapacitor.

Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can prepare NiO/Ni self-supporting films with good flexibility due to the ultra-long Ni nanowires provided by the present invention, which can be applied to supercapacitor electrode active materials , the following beneficial effects can be obtained:

(1) The Ni nanowires provided by the present invention have a length between 50,000nm and 200,000nm, which is much longer than ordinary Ni nanowires. As a raw material for a self-supporting film, the flexibility of the self-supporting film can be increased, and it can be used as a capacitive electrode active material , with excellent electrochemical performance.

(2) The ultra-long Ni nanowire manufacturing method provided by the present invention adopts an external magnetic field, which does not affect the chemical reaction of Ni simple substance generation. Under the action of paramagnetic force, ultra-long Ni nanowires can be obtained by liquid phase growth method. At the same time, the production device is simple and can be conveniently obtained by improving the current Ni nanowire production device.

(3) The NiO/Ni self-supporting film provided by the present invention, in which the molar ratio of Ni and NiO is controllable, can meet the requirements of different supercapacitors for electrode materials. It has strong toughness, and the supercapacitor made by using the NiO/Ni self-supporting film provided by the invention can be applied to wearable electronic devices, and is an ideal electrode material for supercapacitors in the future. The NiO/Ni self-supporting film provided by the invention has good transferability, is convenient for processing, and is suitable for large-scale industrial production.

(4) The preparation method of the NiO/Ni self-supporting film provided by the present invention can control the composition ratio of Ni and NiO through different calcination temperatures and annealing times, thereby adjusting its electrochemical performance and other physical and chemical properties. The preparation method of the NiO/Ni self-supporting film provided by the invention uses non-toxic raw materials and simple processes, is applicable to large-scale industrial production, and can produce low-cost supercapacitor electrode active materials.

Description of drawings

Fig. 1 is the transmission electron microscope figure of Ni nanowire sample provided by the present invention;

Fig. 2 is the XRD figure of the Ni nanowire sample provided by the present invention;

Fig. 3 is the scanning electron micrograph of the Ni nanowire self-supporting membrane section provided by the present invention;

Fig. 4 is the NiO/Ni self-supporting film sample figure provided by the present invention;

Fig. 5 is the scanning electron micrograph of Ni nanowire provided by the present invention;

Fig. 6 is the photograph of NiO/Ni self-supporting film provided by the present invention;

Fig. 7 is the NiO/Ni self-supporting membrane provided by the present invention as working electrode photo;

Figure 8 is the NiO/Ni self-supporting film provided by the present invention as the charge and discharge curves of the working electrode at different current densities;

Fig. 9 is the NiO/Ni self-supporting membrane provided by the present invention as the electrochemical impedance spectrum of working electrode;

Fig. 10 is the XRD picture of embodiment sample;

Fig. 11 is a cyclic voltammetry curve at a scan rate of 50 mVs ^-1 of the NiO/Ni self-supporting film provided in each embodiment as a working electrode.

Throughout the drawings, the same reference numerals are used to designate the same elements or structures, wherein:

Figure 4(a) shows that Ni nanowires are evenly distributed on the microporous filter membrane after suction filtration; Figure 4(b) is a Ni nanowire self-supporting film; Figure 4(c) is a Ni self-supporting film cut into 1x1cm;

Figure 5(a) is the scanning electron micrograph of the NiO/Ni self-supporting film sample of Example 2; Figure 5(b) is the scanning electron micrograph of the NiO/Ni self-supporting film sample of Example 3; Figure 5(c) is the example 1 SEM image of NiO/Ni self-supporting film sample;

Figure 10 (a) curve is the XRD pattern of the NiO/Ni self-supporting film provided in Example 2; Figure 10 (b) curve is the XRD pattern of the NiO/Ni self-supporting film provided in Example 3; Figure 10 (c) curve is the implementation The XRD pattern of the NiO/Ni self-supporting film provided in Example 1.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not constitute a conflict with each other.

The Ni nanowire provided by the invention has an average diameter of 200nm to 300nm and an average length of 50,000nm to 200,000nm. Its transmission electron microscope picture is shown in Fig. 1. Its XRD (X-ray diffraction analysis) picture, as shown in Figure 2, shows that the synthesized material is pure Ni.

Ni nanowire provided by the invention, its preparation method comprises the following steps:

(1) Configure Ni nanowire liquid phase growth solution.

Use Ni salt as a precursor, such as nickel chloride hexahydrate (NiCl ₂ 6H ₂ O), and dissolve it in the organic solvent ethylene glycol to prepare a Ni precursor solution. When using nickel chloride hexahydrate to make a Ni precursor solution The concentration is 24mg/ml.

An organic reducing agent such as hydrazine hydrate is dissolved in the organic solvent ethylene glycol to prepare a reducing agent solution, and the concentration of the hydrazine hydrate in ethylene glycol solution is 85 wt%.

The Ni precursor solution is slowly dispersed in a strong basic organic solvent, preferably 1.5 mol/L sodium hydroxide ethylene glycol solution, and the Ni precursor solution is added drop by drop into the strong basic organic solvent and mixed uniformly. Then add a reducing agent solution, and finally add a surfactant solution, such as a solution of polyvinylpyrrolidone with a concentration of 2 wt%, to obtain a Ni nanowire liquid phase growth solution. The mixing ratio of the Ni precursor solution, strong basic organic solution, and reducing agent organic solution is 1:4:2 by volume.

(2) Preparation of Ni nanowires by oxidation-reduction reaction.

Under the external magnetic field, the condition of constant temperature is controlled to make the Ni nanowire liquid phase growth liquid undergo oxidation-reduction reaction, and the Ni nanowire simple substance is prepared. Preferably, the reaction temperature is a constant temperature of 70 degrees Celsius, the reaction time is 1 hour, and the external magnetic field strength is 0.4 Tesla.

(3) Separation of Ni nanowires.

First, magnetically separate Ni nanowires: use a magnet to transfer the generated Ni nanowires to a clean container; then clean Ni nanowires: wash 3 times with deionized water and absolute ethanol; finally dry Ni nanowires: dry in a vacuum In the oven, dry at 60 degrees Celsius for 12 hours to obtain pure Ni nanowire element.

The NiO/Ni self-supporting film provided by the present invention includes the Ni nanowire and the NiO/Ni nanowire obtained by calcining the Ni nanowire, and the molar ratio of Ni and NiO in the NiO/Ni nanowire composite material 2.5:1 to 20:1. The thickness of the NiO/Ni self-supporting film affects its performance, if it is too thin, its strength will be low, and if it is too thick, its conductivity will be affected. Preferably, the thickness of the NiO/Ni self-supporting film is between 25 μm and 30 μm, as shown in FIG. 3 .

NiO/Ni self-supporting film provided by the invention, its preparation method, comprises the following steps:

(a) The Ni nanowires were uniformly dispersed in the surfactant organic solution.

The Ni nanowires are uniformly dispersed in an organic surfactant solution to obtain a Ni nanowire dispersion. The preferred organic surfactant solution is an ethylene glycol solution of polyvinylpyrrolidone with a concentration of 1 wt%. The mass ratio of the Ni nanowires to the organic solvent is between 1:1000 and 1:2500. In order to uniformly disperse the Ni nanowires, a 100-watt ultrasonic cleaning machine was used to ultrasonically disperse the Ni nanowire dispersion for 10 minutes.

(b) Suction filtration of Ni nanowire dispersion to prepare Ni self-supporting membrane.

The Ni nanowire dispersion prepared in step (a) is transferred to a microporous membrane by means of suction filtration. The Ni self-supporting membrane on the microporous filter membrane was washed repeatedly with deionized water, and then vacuum-dried in a vacuum oven at 60 degrees Celsius for 5 hours. After peeling off, the Ni self-supporting membrane was obtained. The morphology of the Ni self-supporting film is shown in Figure 4, where Figure 4(a) shows that the Ni nanowires are evenly distributed on the microporous filter membrane after suction filtration; Figure 4(b) shows the Ni nanowire self-supporting film Photo; Figure 4(c) is a self-supporting Ni film cut into 1x1 cm.

(c) NiO/Ni self-supporting films were prepared by calcining Ni self-supporting films in an oxygen-containing atmosphere.

The Ni self-supporting film prepared in step (b) is calcined in an oxygen-containing atmosphere, usually in an air atmosphere, at a calcination temperature of 350°C to 450°C, and a calcination and annealing time of 3 minutes to 10 minutes. As shown in Figure 5, the higher the calcination temperature, the better the crystal form of NiO, and NiO/Ni self-supporting films with different composition ratios were obtained at different calcination temperatures.

The NiO/Ni self-supporting film provided by the present invention has good flexibility, as shown in FIG. 6 . Described NiO/Ni self-supporting film, as working electrode, as shown in Figure 7, its charge-discharge curve under different current densities is shown in Figure 8, and its impedance spectrum is shown in Figure 9, has been proved to have very good through experiment. Capacitive properties, can be used as the active material of supercapacitors.

The following are examples:

Example 1

A Ni nanowire with an average diameter of 250nm and an average length of 100,000nm.

The preparation method of described Ni nanowire, comprises the following steps:

(1) Configure Ni nanowire liquid phase growth solution.

Nickel chloride hexahydrate (NiCl ₂ ·6H ₂ O) was dissolved in ethylene glycol to prepare a Ni precursor solution with a concentration of 24 mg/ml.

Hydrazine hydrate was dissolved in ethylene glycol to prepare a reducing agent solution with a concentration of 85wt%.

Add the Ni precursor solution drop by drop into 1.5 mol/L sodium hydroxide ethylene glycol, and mix evenly. Add reducing agent solution then, finally add concentration and be the polyvinylpyrrolidone solution solution of 2wt%, promptly make Ni nanowire liquid growth solution. The mixing ratio of the Ni precursor solution, strong basic organic solution, and reducing agent organic solution is 1:4:2 by volume.

(2) Preparation of Ni nanowires by oxidation-reduction reaction.

Transfer the Ni nanowire liquid-phase growth solution prepared in step (1) to a clean beaker, then seal it with a plastic wrap, and leave some small holes on the sealing film. Put the beaker into a constant temperature water bath, and react at 70°C for 1 hour under an external magnetic field of 0.4 Tesla.

(3) Separation of Ni nanowires.

First, magnetically separate Ni nanowires: use a magnet to transfer the generated Ni nanowires to a clean container; then clean Ni nanowires: wash 3 times with deionized water and absolute ethanol; finally dry Ni nanowires: dry in a vacuum In the oven, dry at 60 degrees Celsius for 12 hours to obtain pure Ni nanowire element.

A NiO/Ni self-supporting film, comprising the Ni nanowire and the NiO/Ni composite material obtained by calcining the Ni nanowire, the molar ratio of Ni and NiO in the NiO/Ni composite material is: 2.5:1 , the thickness of the NiO/Ni self-supporting film is 25 μm. Its XRD characterization diagram is shown in FIG. 10 , where the curve c is the XRD diffraction curve of the NiO/Ni self-supporting film provided in this example. Its SEM image is shown in Fig. 5(c).

Described NiO/Ni self-supporting film, its preparation method, comprises the following steps:

(a) The Ni nanowires were uniformly dispersed in the surfactant organic solution.

The Ni nanowires were uniformly dispersed in an ethylene glycol solution of polyvinylpyrrolidone with a concentration of 1 wt%, to prepare a Ni nanowire dispersion. The mass ratio of the Ni nanowires to the organic solvent is 1:1500. In order to uniformly disperse the Ni nanowires, a 100-watt ultrasonic cleaning machine was used to ultrasonically disperse the Ni nanowire dispersion for 10 minutes.

(b) Suction filtration of Ni nanowire dispersion to prepare Ni self-supporting membrane.

The Ni nanowire dispersion prepared in step (a) is transferred to a microporous membrane by means of suction filtration. The Ni self-supporting membrane on the microporous filter membrane was washed repeatedly with deionized water, and then vacuum-dried in a vacuum oven at 60 degrees Celsius for 5 hours. After peeling off, the Ni self-supporting membrane was obtained.

(c) NiO/Ni self-supporting films were prepared by calcining Ni self-supporting films in an oxygen-containing atmosphere.

The Ni self-supporting film prepared in the step (b) is calcined in an air atmosphere at a calcination temperature of 450 degrees Celsius and a calcination and annealing time of 5 minutes to obtain a NiO/Ni self-supporting film.

The NiO/Ni self-supporting film has good flexibility. Experiments have confirmed that the NiO/Ni self-supporting film has good capacitance performance, as shown in FIG. 11 , and can be used as an active material for a supercapacitor.

Example 2

A Ni nanowire with an average diameter of 200nm and an average length of 50,000nm.

The preparation method of described Ni nanowire, comprises the following steps:

(1) Configure Ni nanowire liquid phase growth solution.

Nickel chloride hexahydrate (NiCl ₂ ·6H ₂ O) was dissolved in ethylene glycol to prepare a Ni precursor solution with a concentration of 24 mg/ml.

Hydrazine hydrate was dissolved in ethylene glycol to prepare a reducing agent solution with a concentration of 85wt%.

Add the Ni precursor solution drop by drop into 1.5 mol/L sodium hydroxide ethylene glycol, and mix evenly. Then add a reducing agent solution, and finally add a solution of polyvinylpyrrolidone with a concentration of 2 wt%, to obtain a Ni nanowire liquid phase growth solution. The mixing ratio of the Ni precursor solution, the strongly basic organic solution, and the reducing agent organic solution is 1:4:2 by volume.

(2) Preparation of Ni nanowires by oxidation-reduction reaction.

Transfer the Ni nanowire liquid-phase growth solution prepared in step (1) to a clean beaker, then seal it with a plastic wrap, and leave some small holes on the sealing film. Put the beaker into a constant temperature water bath, and react at 70°C for 1 hour under an external magnetic field of 0.4 Tesla.

(3) Separation of Ni nanowires.

First, magnetically separate Ni nanowires: use a magnet to transfer the generated Ni nanowires to a clean container; then clean Ni nanowires: wash 3 times with deionized water and absolute ethanol; finally dry Ni nanowires: dry in a vacuum In the oven, dry at 60 degrees Celsius for 12 hours to obtain pure Ni nanowire element.

A NiO/Ni self-supporting film comprising the Ni nanowires and calcined with the Ni nanowires The prepared NiO/Ni composite material, the molar ratio of Ni and NiO in the NiO/Ni composite material is: 20:1, and the thickness of the NiO/Ni self-supporting film is 28 μm. Its XRD characterization diagram is shown in FIG. 10 , where curve a is the XRD diffraction curve of the NiO/Ni self-supporting film provided in this example. Its SEM image is shown in Figure 5(a).

Described NiO/Ni self-supporting film, its preparation method, comprises the following steps:

(a) The Ni nanowires were uniformly dispersed in the surfactant organic solution.

The Ni nanowires were uniformly dispersed in an ethylene glycol solution of polyvinylpyrrolidone with a concentration of 1 wt%, to prepare a Ni nanowire dispersion. The mass ratio of the Ni nanowires to the organic solvent is 1:1000. In order to uniformly disperse the Ni nanowires, a 100-watt ultrasonic cleaning machine was used to ultrasonically disperse the Ni nanowire dispersion for 10 minutes.

(b) Suction filtration of Ni nanowire dispersion to prepare Ni self-supporting membrane.

The Ni nanowire dispersion prepared in step (a) is transferred to a microporous membrane by means of suction filtration. The Ni self-supporting membrane on the microporous filter membrane was washed repeatedly with deionized water, and then vacuum-dried in a vacuum oven at 60 degrees Celsius for 5 hours. After peeling off, the Ni self-supporting membrane was obtained.

(c) NiO/Ni self-supporting films were prepared by calcining Ni self-supporting films in an oxygen-containing atmosphere.

The Ni self-supporting film prepared in the step (b) is calcined in an air atmosphere, the calcination temperature is 350 degrees Celsius, and the calcination and annealing time is 3 minutes, and the NiO/Ni self-supporting film is obtained.

The NiO/Ni self-supporting film has good flexibility. Experiments have confirmed that the NiO/Ni self-supporting film has good capacitance performance, as shown in FIG. 11 , and can be used as an active material for a supercapacitor.

Example 3

A Ni nanowire with an average diameter of 300nm and an average length of 200,000nm.

The preparation method of described Ni nanowire, comprises the following steps:

(1) Configure Ni nanowire liquid phase growth solution.

Nickel chloride hexahydrate (NiCl ₂ ·6H ₂ O) was dissolved in ethylene glycol to prepare a Ni precursor solution with a concentration of 24 mg/ml.

Hydrazine hydrate was dissolved in ethylene glycol to prepare a reducing agent solution with a concentration of 85wt%.

Add the Ni precursor solution drop by drop into 1.5 mol/L sodium hydroxide ethylene glycol, and mix evenly. Then add a reducing agent solution, and finally add a solution of polyvinylpyrrolidone with a concentration of 2 wt%, to obtain a Ni nanowire liquid growth solution. The mixing ratio of the Ni precursor solution, the strongly basic organic solution, and the reducing agent organic solution is 1:4:2 by volume.

(2) Preparation of Ni nanowires by oxidation-reduction reaction.

Transfer the Ni nanowire liquid-phase growth solution prepared in step (1) to a clean beaker, then seal it with a plastic wrap, and leave some small holes on the sealing film. Put the beaker into a constant temperature water bath, and react at 70°C for 1 hour under an external magnetic field of 0.4 Tesla.

(3) Separation of Ni nanowires.

First, magnetically separate Ni nanowires: use a magnet to transfer the generated Ni nanowires to a clean container; then clean Ni nanowires: wash 3 times with deionized water and absolute ethanol; finally dry Ni nanowires: dry in a vacuum In the oven, dry at 60 degrees Celsius for 12 hours to obtain pure Ni nanowire element.

A NiO/Ni self-supporting film, comprising the Ni nanowire and the NiO/Ni composite material obtained by calcining the Ni nanowire, the molar ratio of Ni and NiO in the NiO/Ni composite material is 10:1 , the thickness of the NiO/Ni self-supporting film is 30 μm. Its XRD characterization chart is shown in FIG. 10 , where curve b is the XRD diffraction curve of the NiO/Ni self-supporting film provided in this example. Its SEM image is shown in Fig. 5(b).

Described NiO/Ni self-supporting film, its preparation method, comprises the following steps:

(a) The Ni nanowires were uniformly dispersed in the surfactant organic solution.

The Ni nanowires were uniformly dispersed in an ethylene glycol solution of polyvinylpyrrolidone with a concentration of 1 wt%, to prepare a Ni nanowire dispersion. The mass ratio of the Ni nanowires to the organic solvent is 1:2500. In order to uniformly disperse the Ni nanowires, a 100-watt ultrasonic cleaning machine was used to ultrasonically disperse the Ni nanowire dispersion for 10 minutes.

(b) Suction filtration of Ni nanowire dispersion to prepare Ni self-supporting membrane.

The Ni nanowire dispersion prepared in step (a) is transferred to a microporous membrane by means of suction filtration. The Ni self-supporting membrane on the microporous filter membrane was washed repeatedly with deionized water, and then vacuum-dried in a vacuum oven at 60 degrees Celsius for 5 hours. After peeling off, the Ni self-supporting membrane was obtained.

(c) NiO/Ni self-supporting films were prepared by calcining Ni self-supporting films in an oxygen-containing atmosphere.

Calcining the Ni self-supporting film prepared in the step (b) under an air atmosphere at a calcination temperature of 400 degrees Celsius and a calcination and annealing time of 10 minutes to obtain a NiO/Ni self-supporting film.

The NiO/Ni self-supporting film has good flexibility. Experiments have confirmed that the NiO/Ni self-supporting film has good capacitance properties, as shown in Figure 11, and can be used as an active material for supercapacitors

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (8)

1. the preparation method of a NiO/Ni self-supported membrane, it is characterised in that comprise the following steps:

A Ni nano wire is dispersed in surfactant organic solution by (), form Ni nano wire Dispersion liquid；

Described Ni nano wire average diameter is between 200nm to 300nm, and average length is 50,000nm Between 200,000nm；

B Ni nanowire dispersion that () will prepare in step (a), the method using sucking filtration, transfer On microporous filter membrane, peel off after cleaning, drying and obtain Ni self-supported membrane；

C the Ni self-supported membrane prepared in step (b) is calcined in oxygenous atmosphere and is obtained NiO/Ni by () Self-supported membrane.

2. preparation method as claimed in claim 1, it is characterised in that the table described in step (a) Face activating agent organic solution is the ethylene glycol solution of the polyvinylpyrrolidone of 1wt%, described Ni nano wire With organic solution mass ratio is between 1:1000 to 1:2500, described process for dispersing uses 100 watts Ultrasonic disperse 10 minutes.

3. preparation method as claimed in claim 1, it is characterised in that containing described in step (c) Oxygen atmosphere is air atmosphere, calcining heat 350 degrees Celsius to 450 degrees Celsius, calcines annealing time 3 Minute to 10 minutes.

4. preparation method as claimed in claim 1, it is characterised in that

The preparation method of described Ni nano wire comprises the following steps:

(1) configuration Ni nano wire liquid growth liquid: using Ni salt as presoma, be dissolved in organic molten In agent, prepare Ni precursor solution；Organic reducing agent is dissolved in described organic solvent, prepares also Former agent solution；Ni precursor solution is slowly scattered in strong basicity organic solvent, adds reducing agent Solution, is eventually adding surfactant organic solution, prepares Ni nano wire liquid growth liquid；

(2) under externally-applied magnetic field, Ni nano wire liquid growth liquid generation redox reaction is made, system Standby Ni nano wire simple substance；

(3) Magnetic Isolation clean Ni nano wire simple substance, dried prepares as claimed in claim 1 Ni nano wire.

5. preparation method as claimed in claim 4, it is characterised in that the Ni described in step (1) Salt is Nickel dichloride hexahydrate, and described organic solvent is ethylene glycol, and described Ni precursor solution concentration is 24mg/ml；Described organic reducing agent is hydrazine hydrate, and described organic reducing agent solution concentration is 85wt%； Described strong basicity organic solvent is the sodium hydroxide ethylene glycol solution of 1.5mol/L；Described surfactant Organic solution is the polyvinylpyrrolidone of 2wt%；Described Ni precursor solution, strong basicity organic solution, The mixed proportion of reducing agent organic solution is volume ratio 1:4:2.

6. preparation method as claimed in claim 4, it is characterised in that the oxygen described in step (2) Changing reduction reaction conditions is 70 degrees Celsius of constant temperature, and the response time is 1 hour, described applied field strengths It it is 0.4 tesla.

7. a NiO/Ni self-supported membrane, it is characterised in that according to as any in claim 1 to 6 One described method prepares.

8. the application of a NiO/Ni self-supported membrane as claimed in claim 7, it is characterised in that It is used as the active substance of super capacitor.