CN107099822A - Bipolar metal nanometer line and preparation method thereof - Google Patents

Abstract

The invention discloses a bipolar metal nanowire and a preparation method thereof. The track-etched polymer porous film is used as a template, and the electrochemical deposition method is used to deposit on the template, and the change of the current during the deposition process can be adjusted. Growth of different metal moieties in nanowires. The track etching template can adjust the pore type by changing the etching conditions, and prepare more nanowires with special shapes, and the pore size of the obtained metal nanowires can be precisely adjusted and has good uniformity. The template is very easy to dissolve these with organic solvents. The nanowires are released into the solution, and the dissolution is relatively thorough. The electrochemical deposition technology is simple to operate and easy to control, and the growth of different metal parts in the nanowire can be controlled according to the change of the current during the deposition process. This method is very simple and low-cost, which is very suitable for preparing bipolar nanowires.

Description

Bipolar metal nanowire and preparation method thereof

technical field

The invention relates to a bipolar metal nanowire and a preparation method thereof.

Background technique

In recent years, the design and application of self-propelled micro- and nano-devices have aroused great interest in the scientific community. Among them, the most attractive is the self-propelled bipolar metal nanowire (such as gold/platinum or Au/Ni) motor based on the catalytic decomposition of hydrogen peroxide fuel into oxygen and water. Regulating the transport and conduction of these nanowires within microfluidic channels through autonomous transport rather than pressure- or electrically-driven liquid flow is a critical step in designing integrated micro-nanodevices. Some excellent properties of bipolar nanowires, such as fast transmission speed and easy functionalization, make them widely used in nanomotors. Sen's research found that when the hydrogen peroxide fuel in the environment is catalytically decomposed into oxygen and water, the Au/Pt and Au/Ni bipolar nanowires have a self-driving function, and the autonomous movement speed in the axial direction can be greatly increased to 10 μm/ s. Wang's research group at Arizona State University fixed the Pt end of the bipolar nanowire Au/Pt on carbon nanotubes (CNTs), and the speed of the Au/Pt-CNT nanomotor reached 42.8 μm/s, and they found that these Nanomotors can carry certain molecules along a predetermined path within a microchannel network. This property plays a crucial role in the integration of nanomotors into microfluidic networks, and provides the possibility for the preparation of devices such as targeted drug delivery and flow sensors. Bipolar nanowires make it possible to realize the controllability of the transport and conduction of substances at the microscopic scale. The preparation methods of nanowires include electron beam lithography, laser ablation, chemical vapor deposition (CVD), thermal vapor deposition, template method and so on. However, these methods are generally more complicated and costly.

Contents of the invention

In order to overcome the above defects, the present invention provides a bipolar metal nanowire and a preparation method thereof, which are simple and very low in cost.

The technical scheme that the present invention adopts in order to solve its technical problem is:

A method for preparing bipolar metal nanowires, comprising the following steps:

Step 1, preparing nanopores on the nuclear track polymer film material to form a polymer film with nanopores;

Step 2, plating a layer of gold on one side of the polymer film to form a gold-plated template;

Step 3, put the gold-plated template into the electrolytic cell, and use two different metal electrochemical deposition solutions to electrochemically deposit the polymer film, so as to fill the polymer film of the gold-plated template with two metals Nanowires are formed in the nanopores on the

Step 4, dissolving the polymer film material on the gold-plated template to obtain bipolar metal nanowires.

As a further improvement of the present invention, in the step 1, the nuclear track polymer film material is at least polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI ) at least one of the

As a further improvement of the present invention, in the step 1, nanopores are prepared on the nuclear track polymer film material by using the heavy ion track etching method.

As a further improvement of the present invention, in the step 2, the thickness of the gold-plated layer on one side of the polymer film is 50 nm.

As a further improvement of the present invention, in the step 3, the gold-plated template is placed in an electrolytic cell, and the polymer film is electrochemically deposited with metal Ag and Cu to fill the two metals of Ag and Cu into the Ag/Cu bipolar metal nanowires are formed in the nanopores on the polymer film of the gold-plated template;

As a further improvement of the present invention, in step 3, the gold-plated template is placed in an electrolytic cell, and the gold-plated side of the polymer film is a cathode.

As a further improvement of the present invention, in the step 3, silver is first deposited, and during the deposition process, the cathode of the electrolytic cell has a resistance value of 18.2 MΩ. cm of deionized water, the anode is 18 g/l AgNO ₃ , 120 g/l C6H5Na ₃ O ₇ • 2H ₂ O, 40 g/l C4H ₄ O ₆ KNa • 4H ₂ O, 60 g/l Na ₂ SO ₃ solution, The silver electrode is the anode, the voltage is in the range of 0.1-0.3V, and the deposition current density is less than 0.5mA/cm ² ; then during the copper electrode deposition process, the cathode of the electrolytic cell has a resistance value of 18.2 MΩ. cm of deionized water, the anode is 0.25 mol/L CuSO ₄ , 2 mol/L H ₂ SO ₄ , the copper electrode is used as the anode, the deposition voltage is in the range of 0.1-0.3 V, and the deposition current density is less than 0.5 mA/cm ² .

As a further improvement of the present invention, in the step 3, the polymer film material on the gold-plated template is dissolved, and the dissolution method includes any one of an organic solvent and a reactive ion etching method.

The present invention also provides a metal bipolar nanowire obtained by the above-mentioned preparation method of the polar metal nanowire.

The beneficial effects of the present invention are: the present invention utilizes the method of electrochemical deposition to prepare bipolar metal nanowires on the high molecular polymer template. In this method, a porous material with a nanopore diameter is used as a cathode, and the electrochemical reduction reaction of the substance at the cathode is used to make the material move in a direction in the solution, so as to enter the nanopore, and through the control of the shape and size of the hole wall of the template, and can be very The current changes during the deposition process to control the growth of different metals in the nanowires at the corresponding deposition stage, and to regulate the length of the bipolar part of the nanowires. The polymer template is dissolved by organic solvent or reactive ion etching method, and the nanowires are released. The bipolar metal nanowires obtained by this method were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). In this invention, the pore size prepared by the heavy ion track etching method is uniform and continuously controllable, so the pore size of the prepared nanowires can be precisely adjusted and has good uniformity; and the template is very easy to dissolve these nanowires with organic solvents. To the solution, and the dissolution is relatively thorough, easy to make nanowire suspension, and the organic solvent will not interact with the nanowire to cause damage to the nanowire; this track etching template can be modulated by changing the etching conditions Hole type, to obtain nanopores of different shapes (such as cones), so that more nanowires of special shapes can be prepared. The electrochemical deposition technology is simple to operate and easy to control, and the growth of different metal parts in the nanowire can be controlled according to the change of the current during the deposition process. Compared with the prior art, the preparation method provided by the invention is very simple and low in cost, and is very suitable for preparing metal nanowires.

Description of drawings

Fig. 1 is a scanning electron microscope image of nanopillar holes in Example 1, A is a top view, and B is a cross-sectional view.

FIG. 2 is a scanning electron microscope image of Ag/Cu bipolar metal nanowires in Example 1. FIG.

FIG. 3 is an EDX elemental analysis spectrum of Ag/Cu bipolar metal nanowires in Example 1. FIG.

FIG. 4 is a scanning electron microscope image of nanopillar holes in Example 2.

FIG. 5 is a scanning electron microscope image of Ag/Cu bipolar metal nanowires in Example 2. FIG.

detailed description

The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to the following examples. The methods are conventional methods unless otherwise specified. The raw materials can be obtained from open commercial channels unless otherwise specified.

Example 1:

The columnar nano-nuclear pores were prepared on the self-irradiated PC material by chemical etching, forming a polymer film with nanopores. Figure 1 is a scanning electron microscope picture of the nano-pillar pores. Then a layer of gold is plated on one side of the polymer film (the thickness of the gold-plated layer is 50nm) to form a gold-plated template.

Then use electrochemical deposition to prepare Ag and Cu bipolar metal nanowires: put the gold-plated template in the electrolytic cell, and use two different metal Ag and Cu electrochemical deposition solutions to electrochemically deposit the polymer film to Two metals are filled into the nanopores on the polymer film of the gold-plated template to form nanowires. Among them, the gold-plated side of the polymer film is the cathode, and the silver is deposited first. During the deposition process, the cathode of the electrolytic cell has a resistance value of 18.2 MΩ. cm of deionized water, the anode is 18 g/l AgNO3, 120g/l C6H5Na3O7 2H2O, 40g/l C4H4O6KNa 4H2O, 60 g/l Na2SO3 solution, the silver electrode is the anode, the voltage is in the range of 0.1-0.3V, the deposition The current density is less than 0.5mA/cm2; then during the copper electrode deposition process, the cathode of the electrolytic cell has a resistance value of 18.2 MΩ. cm of deionized water, the anode is 0.25 mol/L CuSO ₄ , 2 mol/L H ₂ SO ₄ , the copper electrode is used as the anode, the deposition voltage is in the range of 0.1-0.3 V, and the deposition current density is less than 0.5 mA/cm ² . According to the change of current during the deposition process, the growth of Ag and Cu in the nanowires can be controlled in the corresponding deposition stage, and the length of the silver and copper nanowires in the nanowires can be adjusted.

After the preparation of the bipolar nanowires is completed, the PC template containing the nanowires is dissolved with dichloromethane reagent to prepare the bipolar metal nanowires provided by the present invention.

The morphology of the prepared Ag/Cu bipolar metal nanowires was characterized by scanning electron microscopy (SEM). As shown in FIG. 2 , the diameter and length of the obtained nanowires are relatively uniform, and each nanowire is composed of two sections of different components, and the Ag nanowire part can be clearly observed.

The components of the nanowires are detected by energy dispersive analysis (EDX), and Fig. 4 is the EDX elemental analysis spectrum of the nanowires. In the figure, only the absorption peaks corresponding to the two elements of Ag and Cu are observed, and the elemental analysis results also show that the preparation of Ag/Cu bipolar nanowires is successful.

Example 2:

Columnar nano-core pores were prepared on commercial PC materials by chemical etching. Figure 4 is a scanning electron microscope picture of nano-pillar pores. It can be seen from the figure that the channels are not perpendicular to the surface of the template, and the arrangement is not very neat. Then use the electrochemical deposition method to prepare Ag and Cu bipolar metal nanowires. During the deposition process, according to the current change, the growth of Ag and Cu in the nanowires can be controlled in the corresponding deposition stage, and the silver and copper nanowires in the nanowires can be adjusted. length. After the preparation of the bipolar nanowires is completed, the PC template containing the nanowires is dissolved with dichloromethane reagent to prepare the bipolar metal nanowires provided by the present invention.

The morphology of the prepared Ag/Cu bipolar metal nanowires was characterized by a scanning electron microscope (SEM), and the results are shown in FIG. 5 . The length and aperture of the obtained nanowires are relatively uniform, and the surface is relatively smooth, and each nanowire is composed of two sections of different components, and the Ag nanowire part can be clearly observed.

Claims (9)

1. A method for preparing bipolar metal nanowires, comprising the following steps: Step 1, preparing nanopores on the nuclear track polymer film material to form a polymer film with nanopores; Step 2, plating a layer of gold on one side of the polymer film to form a gold-plated template; Step 3, put the gold-plated template into the electrolytic cell, and use two different metal electrochemical deposition solutions to electrochemically deposit the polymer film, so as to fill the polymer film of the gold-plated template with two metals Nanowires are formed in the nanopores on the Step 4, dissolving the polymer film material on the gold-plated template to obtain bipolar metal nanowires. 2. The preparation method of bipolar metal nanowires according to claim 1, characterized in that: in the step 1, the nuclear track polymer film material is at least polyethylene terephthalate, polyethylene At least one of carbonate and polyimide. 3 . The method for preparing bipolar metal nanowires according to claim 1 , characterized in that: in the step 1, nanopores are prepared on the nuclear track polymer film material by heavy ion track etching. 4 . 4. The method for preparing bipolar metal nanowires according to claim 1, characterized in that: in the step 2, the thickness of the gold-plated layer on one side of the polymer film is 50 nm. 5. the preparation method of bipolar metal nanowire according to claim 1 is characterized in that: in described step 3, described gold-plated template is put into electrolyzer, with metal Ag and Cu to described polymer film Electrochemical deposition is performed to fill Ag and Cu into the nanopores on the polymer film of the gold-plated template to form Ag/Cu bipolar metal nanowires. 6 . The method for preparing bipolar metal nanowires according to claim 5 , wherein in step 3, the gold-plated template is placed in an electrolytic cell, and the gold-plated side of the polymer film is a cathode. 7. The method for preparing bipolar metal nanowires according to claim 5, characterized in that: in step 3, silver is first deposited, and during the deposition process, the cathode of the electrolytic cell has a resistance value of 18.2 MΩ. cm of deionized water, the anode is 18 g/l AgNO ₃ , 120 g/l C6H5Na ₃ O ₇ • 2H ₂ O, 40 g/l C4H ₄ O ₆ KNa • 4H ₂ O, 60 g/l Na ₂ SO ₃ solution, silver The electrode is an anode, the voltage is in the range of 0.1-0.3V, and the deposition current density is less than 0.5mA/cm ² ; then during the copper electrode deposition process, the cathode of the electrolytic cell has a resistance value of 18.2 MΩ. cm of deionized water, the anode is 0.25 mol/L CuSO ₄ , 2 mol/L H ₂ SO ₄ , the copper electrode is used as the anode, the deposition voltage is in the range of 0.1-0.3 V, and the deposition current density is less than 0.5 mA/cm ² . 8. The preparation method of bipolar metal nanowires according to claim 1, characterized in that: in the step 3, the polymer film material on the gold-plated template is dissolved, and the dissolution method includes organic solvent and reactive ion etching Either of the eclipses. 9. A metal bipolar nanowire obtained by the method for preparing a polar metal nanowire according to any one of claims 1 to 8.