CN111646426B

CN111646426B - Method for preparing carbon nanochain @ gold network film

Info

Publication number: CN111646426B
Application number: CN202010410223.0A
Authority: CN
Inventors: 何辉; 范璐瑶; 程建祥; 杨金彭; 曾祥华
Original assignee: Yangzhou University
Current assignee: Yangzhou University
Priority date: 2020-05-15
Filing date: 2020-05-15
Publication date: 2023-03-31
Anticipated expiration: 2040-05-15
Also published as: CN111646426A

Abstract

The invention discloses a method for preparing a carbon nanochain @ gold network film, which combines a chemical method and a physical method and synthesizes the carbon nanochain @ gold network film by a two-step process, wherein the carbon nanochain (the diameter and the length) and the gold film (the thickness and the particle size) can be regulated and controlled by corresponding process parameters. The synthesis method has the advantages of universality, greenness, low cost, easiness in mass synthesis and the like, and due to the unique structure, the network film shows excellent surface enhanced Raman scattering performance.

Description

Method for preparing carbon nanochain @ gold network film

Technical Field

The invention discloses a method for preparing a carbon nanochain @ gold network film with low cost and large quantity, and belongs to the field of preparation of noble metal micro-nano structures.

Background

Gold porous films are of great interest for research due to their excellent performance and potential applications in catalysis, sensing, fuel cells, etc. In terms of Surface Enhanced Raman Scattering (SERS), such films are also excellent SERS substrates because they possess a high density of SERS hot spots and large specific surfaces available for adsorption of probe molecules. The preparation of the gold porous film mainly adopts a chemical method, including chemical reduction, electrodeposition, selective etching and the like. However, these methods have problems of high energy consumption, high pollution, high cost, etc. to various degrees, and the obtained film is also polluted, thereby reducing the performance or affecting the use.

Disclosure of Invention

The invention aims to overcome the defects and develop a method for preparing a gold network film.

The technical scheme for realizing the purpose of the invention is as follows: a method for preparing a carbon nanochain @ gold network film with low cost and large quantity mainly comprises the following steps:

(1) Hydrothermally synthesizing a carbon nano-chain colloidal solution by glucose;

(2) Spin-coating a carbon nano-chain colloidal solution on the surface of the conductive glass and naturally drying to obtain a carbon nano-chain network film;

(3) And gold is plated on the carbon nano-chain network film/conductive glass substrate by an ion beam sputtering method.

Preferably, glucose is dissolved in a mixed solution of water and ethanol at a volume ratio of 10:1, and the concentration of glucose is 0.4M, and the glucose mixed solution is used to hydrothermally synthesize the carbon nanochain colloidal solution.

Preferably, the hydrothermal reaction temperature is 180 ℃ and the reaction time is 6 h.

Preferably, the concentration of the carbon nano-chain colloid solution is 2.8M.

Preferably, 5 mL of carbon nanochain colloidal solution is spin-coated on the surface of the conductive glass of 1cm × 1cm.

Preferably, the rotation speed is 200 rpm when the carbon nano-chain colloidal solution is spin-coated.

Preferably, the ion beam sputtering gold plating time is 30 s, and the deposition rate is 1 nm/s.

Compared with the prior art, the invention has the innovation points that: the carbon nanochain @ gold network film prepared by the method is unique in structure, and the microstructure of the carbon nanochain and the gold film can be regulated and controlled by controlling process parameters (a hydrothermal method and ion beam sputtering), so that the carbon nanochain @ gold network film is easier to control than a single chemical reaction.

The advantages of the present invention will be further illustrated in the following figures and detailed description.

Drawings

FIG. 1 is a schematic view of a process flow for preparing a carbon nanochain @ gold network film according to the present invention.

FIG. 2 is a TEM image of carbon nanochain colloid of example 1 of the present invention.

FIG. 3 is SEM images of the carbon nanochain network film and the carbon nanochain @ gold network film in example 1.

FIG. 4 is a SERS spectrum of the carbon nanochain @ gold network film on an R6G molecule in example 1 of the present invention.

Fig. 5 is SEM images of carbon nanochain @ gold network films according to examples 2 and 3 of the present invention.

Detailed Description

In the invention, the inventor combines a chemical method and a physical method, and adopts a three-step process to controllably prepare the carbon nanochain @ gold network film. The process route is shown in figure 1: firstly, carrying out hydrothermal decomposition on glucose to obtain a carbon nano-chain colloidal solution; secondly, spin-coating a carbon nano-chain colloidal solution on the surface of the clean conductive glass and drying; finally, the conductive glass for obtaining the carbon nano-chain network film is taken as a substrate, and gold is deposited by ion beam sputtering.

The carbon nanochain @ gold film prepared in the way is in a three-dimensional network shape, is uniform in macroscopical aspect, and is rough and porous in microcosmic aspect. Wherein, the carbon nano-chain (diameter and length) and the gold film (thickness and particle size) can be regulated and controlled by corresponding process parameters. Due to the unique structure, the film shows excellent SERS performance.

Example 1

(1) Dissolving 8 g of glucose powder in 100 mL of deionized water, adding 10 mL of ethanol, uniformly mixing, stirring for 10 min to form 0.4M glucose mixed solution, then pouring 30 mL of the mixed solution into a 50 mL stainless steel hydrothermal reaction kettle with a polytetrafluoroethylene lining, sealing, reacting at 180 ℃ for 6 h, naturally cooling to room temperature to obtain brown colloidal solution, and repeatedly cleaning by using a centrifuge, deionized water and ethanol to finally obtain 2.8M high-concentration carbon nano-chain colloidal aqueous solution. (2) And (3) placing conductive glass (1cm x 1cm) on a spin coater, adjusting the rotating speed to 200 rpm, dropwise adding 5 mL of carbon nano-chain colloidal aqueous solution on the surface of the conductive glass until the conductive glass is naturally dried, and obtaining a layer of carbon nano-chain network film on the surface of the conductive glass. (3) Using carbon nanochain network film as substrate, sputtering gold by ion beam at deposition rate of 1 nm/s for 30 s, and using SCD-500 ion sputtering apparatus of Leica, germany, which maintains vacuum degree at 10 during sputtering ^-2 pa~10 ^-3 pa, the current is kept at 40 mA.

The morphology of the sample was observed by a transmission electron microscope (TEM, JEM-200 CX) and a Japanese Hitachi S-4800 Field Emission Scanning Electron Microscope (FESEM). The SERS performance of the samples was analyzed using an In Via laser confocal raman spectrometer from Renishwa, england.

Fig. 2 is a TEM image of the carbon nanochain colloid of example 1. It can be seen that the carbon nanochain is an irregularly shaped, multi-branched chain structure, and the chain is formed by connecting a plurality of nanoparticles end to end. Statistically, the chain length is about 500-2000 nm and the diameter is about 60-130 nm. The formation of the chain-like carbon colloid is divided into two steps: during a period of time after the reaction starts, the concentration of the generated carbon nano-particles is very thin, and the particles can be uniformly dispersed due to the electrostatic repulsion effect of the surface charges of the colloid particles; the colloid concentration increases along with the prolonging of the reaction time, and after the colloid concentration reaches a certain concentration, the collision and agglomeration occur among the particles, and finally a multi-branch chain structure is formed.

FIG. 3 is SEM images of the carbon nanochain network film and the carbon nanochain @ gold network film of example 1. Fig. 3a is a SEM image of a carbon nanochain network film, as shown in the figure, the carbon nanochain film obtained by spin coating is microscopically in a porous network structure, the pore size is from several nanometers to several hundred nanometers, and the distribution range is wide. The film is formed by stacking carbon nano chains, the nano chains are mutually connected and superposed, and the thickness of the film can be regulated and controlled by the spin coating amount of the carbon chain colloid. Figure 3b is a SEM image of a carbon nanochain @ gold network film. After 30 s of gold plating, the gold film is deposited on the surface of the carbon chain, the gold particles are dispersed and uniformly distributed, the particle shapes are irregular, and the size is about 20 nm.

FIG. 4 is a SERS spectrum of the carbon nanochain @ gold network film versus the R6G molecule in example 1. Curves 1 and 2 correspond to SERS spectra of the carbon nanochain @ gold network film and the gold particle film on the flat silicon wafer, respectively (the two have the same process parameters). It can be seen that the carbon nanochain @ gold network film has greater reinforcing capability, which indicates that the nanoscale gaps between carbon chains play a main reinforcing role. Furthermore, the carbon nanochain @ gold network film substrate has good signal uniformity, because statistically, the sample is uniform within 10 μm of the raman laser spot.

Example 2

Other steps and process conditions were the same as in example 1. Except that the sputter gold plating time in step 3 was 2 minutes.

FIG. 5a is a SEM image of a carbon nanochain @ gold network film plated with gold for 2 minutes, showing that the gold particles of comparative example 1 are increased in size, about 70-140 nm. It can be seen that the gold particle size or gold film thickness in the network film can be controlled by varying the gold plating time.

Example 3

The other steps and process conditions were the same as in example 1. Except that the hydrothermal synthesis time of the carbon chain in the step 1 was 4 hours.

FIG. 5b is SEM image of the gold network film corresponding to the carbon chain, and it can be observed that the carbon chain size obtained by the hydrothermal reaction time is small, about 30-70 nm, and the gold particle size is not changed significantly in comparative example 1. It can be seen that the diameter of carbon chains in the network film can be controlled by changing the hydrothermal reaction time.

From the above results, it can be seen that: the method combines chemical and physical methods, namely simple and common hydrothermal reaction and sputtering coating, can use a carbon chain as a template, and can controllably prepare the carbon nanochain @ gold network film, and the process flow has the advantages of low cost, capability of macroscopic preparation and the like, and is expected to be practically applied.

Claims

1. A method for preparing a carbon nanochain @ gold network film is characterized by mainly comprising the following steps:

(3) Taking the carbon nano-chain network film/conductive glass as a substrate, and plating gold by an ion beam sputtering method;

wherein the hydrothermal reaction temperature is 180 ℃, and the reaction time is 6 h;

the ion beam sputtering gold plating time is 30 s, and the deposition rate is 1 nm/s;

glucose was dissolved in a mixed solution of water and ethanol at a volume ratio of 10.

2. The method of claim 1, wherein the concentration of the carbon nanochain colloid solution is 2.8M.

3. The method of claim 1, wherein 5 mL of the carbon nanochain colloidal solution is spin coated on a 1cm x 1cm surface of the conductive glass.

4. The method of claim 1, wherein the carbon nanochain colloid solution is spin-coated at a rotation speed of 200 rpm.