阅读说明：本技术 一种高效筛选高质量碳纳米管生长条件的高通量方法 (High-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes ) 是由 刘畅 吉忠海 张莉莉 汤代明 成会明 于 2019-09-27 设计创作，主要内容包括：本发明涉及碳纳米管制备与结构控制领域,具体为一种高效筛选高质量碳纳米管生长条件的高通量方法。将离子束沉积方法与四元模板法相结合,在同一标记硅片基底上制备出不同厚度或成分组合的催化剂薄膜,并采用化学气相沉积法催化生长获得碳纳米管水平网络。此后对样品进行拉曼光谱面扫分析,将获得的碳纳米管G、D模强度比值作为判断碳纳米管质量的依据,并利用标记硅片定位关联催化剂薄膜厚度或成分等与碳纳米管质量的关系。进一步建立Excel模板对多组G、D模强度比进行自动分析,筛选出生长高质量碳纳米管的最佳催化剂薄膜厚度和最佳生长条件。从而,适于高效筛选出催化剂厚度或成分、温度、气氛等反应参数,生长高质量碳纳米管。(The invention relates to the field of carbon nanotube preparation and structure control, in particular to a high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes. Combining an ion beam deposition method with a quaternary template method, preparing catalyst films with different thicknesses or component combinations on the same marked silicon wafer substrate, and obtaining the carbon nano tube horizontal network by adopting a chemical vapor deposition method for catalytic growth. And then performing Raman spectrum surface scanning analysis on the sample, taking the obtained G, D mode intensity ratio of the carbon nanotube as a basis for judging the quality of the carbon nanotube, and positioning the relation between the thickness or the components of the associated catalyst film and the quality of the carbon nanotube by using a marking silicon wafer. And further establishing an Excel template to automatically analyze the strength ratio of a plurality of groups of G, D templates, and screening the optimal catalyst film thickness and the optimal growth conditions for growing the high-quality carbon nano tubes. Therefore, the method is suitable for efficiently screening out the thickness or components of the catalyst, the temperature, the atmosphere and other reaction parameters to grow the high-quality carbon nano tube.)

1. A high-throughput method for efficiently screening the growth conditions of high-quality carbon nanotubes is characterized in that an ion beam deposition method and a quaternary template method are combined, and catalyst films with different thicknesses or component combinations are prepared on the same marked silicon wafer substrate by rotating a mask plate for more than two times in the process of preparing the catalyst film by physical deposition, wherein the thickness of the catalyst film generally determines the particle size of the catalyst; pretreating a catalyst at a series of temperatures and in a reaction atmosphere, and catalytically growing by adopting a chemical vapor deposition method to obtain a carbon nano tube horizontal network; then, performing Raman spectrum surface scanning analysis on the sample, and taking the obtained G, D mode intensity ratio of the carbon nanotube as a basis for judging the quality of the carbon nanotube; further establish G, D mode strength ratio (I) of Excel template to carbon nanotubes grown with multiple catalyst thicknesses_G/I_D) Carrying out automatic analysis; positioning the relation between the thickness or the component of the associated catalyst film and the quality of the carbon nano tube by using a marked silicon wafer; the quality of the carbon nano tube is regulated and controlled through the optimized thickness or components, the growth temperature of the carbon nano tube and the pretreatment condition of the catalyst; screening the optimal catalyst film thickness or components for growing the high-quality carbon nano-tube, and the optimal growth conditions of temperature and atmosphere.

2. The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nanotubes according to claim 1, which comprises the following specific steps:

(1) designing a 'quaternary mask plate' and a marking silicon wafer which are matched with an ion beam coating instrument;

(2) combining the ion beam deposition method with the quaternary template methodPreparation on a marked silicon wafer 4^N(N is more than or equal to 1) catalyst film with more than one thickness or component, the thickness range of the film is 0-20 nm, and the component range of the film is 1-20 (such as iron, cobalt, nickel, molybdenum, tungsten, platinum, gold, copper, rhodium and binary and ternary … N-element alloy thereof);

(3) carrying out oxidation treatment on the sample in air atmosphere at 300-700 ℃; introducing argon gas into the reaction furnace for protection, and raising the temperature of the furnace to the growth temperature of the carbon nano tube; carrying out reduction treatment in a hydrogen atmosphere to form catalyst nanoparticles on the surface of the marked silicon wafer substrate; then introducing a carbon source and a carrier gas, wherein the carbon source is subjected to catalytic cracking, nucleation and growth of the carbon nano tube on the catalyst particles;

(4) performing Raman spectrum surface scanning analysis on the sample; normalizing the surface scanning data by using Raman spectrum software, removing cosmic rays and removing background; then, the data are imported into an established Excel template for analysis, and I of the carbon nano tube with different thicknesses or component catalyst growth is obtained_G/I_D；

(5) Optimizing the growth temperature and catalyst pre-treatment condition of carbon nanotube and making two or more groups of carbon nanotube I grow_G/I_DThe results are summarized and compared, and the optimal catalyst film thickness or component, and the optimal growth conditions of temperature and atmosphere for growing the high-quality carbon nano-tube are screened.

3. A high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes according to claim 2, wherein the quaternary template method comprises N masks (N.gtoreq.1), each mask is used for four sequential depositions at most, after each deposition, the mask is rotated by 90 degrees, only N masks are needed, 4N deposition steps are needed, and 4 are generated^NDifferent components of catalyst.

4. The high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes according to claim 2, wherein the quaternary mask design method is as follows: the quaternary mask plate comprises 3 parts, namely a sample placing chamber, a bolt and a mask plate; the sample placing chamber and the bolt are respectively used for assisting in fixing and marking the silicon chip and the maskThe template device has a lofting chamber with the size of 10.1mm multiplied by 0.3mm, and each mask plate has 4^N-1(N is more than or equal to 1) gaps.

5. The high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes according to claim 4, wherein N (N is not less than 1) masks are adopted, the marked silicon wafer is placed in a sample placing chamber, an A mask is covered and sent into a coating instrument, after the sample is deposited by the ion beam, the A mask is rotated clockwise by 90 degrees and sequentially deposited for 4 times, then B, C, D … N masks are sequentially replaced, and the A mask operation is repeated to prepare 4 masks^NA catalyst of a certain thickness or composition.

6. The high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes according to claim 2, wherein the design method of the labeled silicon wafer is as follows: the size of the marked silicon chip is 10mm multiplied by 10mm, and the marked silicon chip is internally provided with a T-shaped mark and 1-4^NRoman numerals (N is more than or equal to 1), T-shaped mark as the starting point of Raman spectrum surface scanning, 4^NRoman numerals are 4^NThe location of the catalyst sample.

7. A high throughput method for efficiently screening high quality carbon nanotube growth conditions according to claim 2, wherein the carbon nanotube growth method is as follows: the growth temperature is 800-950 ℃, the carbon source is argon-loaded ethanol steam, and the carrier gas is argon or hydrogen.

8. A high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes according to claim 2, wherein the raman spectroscopy surface scan method is as follows: the T-shaped mark of the marked silicon chip is used as the starting point of Raman spectrum surface scanning, the surface scanning range is 10mm multiplied by 10mm, and the step length range is 0.005 mm-0.2 mm.

9. The high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes according to claim 2, wherein the method for establishing the Excel template is as follows: importing data into Excel; summary 4^N(N.gtoreq.1) number of samplesAccording to the data; respectively selecting the wavelength ranges from 1310 cm to 1370cm^-1And 1570-1610 cm^-1The maximum value of the data is used as the intensity value of a D mode and a G mode, and the I of each data point is calculated_G/I_D(ii) a Claim 4^NSample I_G/I_DMaximum, mean and variance.

10. The high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes according to claim 2, wherein the optimal catalyst film thickness or composition for growing the high-quality carbon nanotubes and the optimal growth conditions of temperature and atmosphere are selected, in order to obtain the high-quality carbon nanotubes, the optimal thickness range of the cobalt catalyst is 0.1-0.6 nm, the growth temperature is 850-900 ℃, and the optimal carbon source/hydrogen ratio is 30-50 sccm: 100 sccm.

Technical Field

The invention relates to the field of carbon nanotube preparation and structure control, in particular to a high-throughput method for efficiently screening the growth conditions of a high-quality carbon nanotube, which is suitable for efficiently screening the reaction parameters such as the thickness or the components, the temperature, the atmosphere and the like of a catalyst to grow the high-quality carbon nanotube.

Background

Carbon nanotubes have received much attention because of their quasi-one-dimensional tubular structure and excellent electrical, optical, thermal and mechanical properties. The preparation of high-quality carbon nanotube samples is the basis of the performance characterization and practical application of the carbon nanotubes. The chemical vapor deposition method has the advantages of high yield, low cost, good controllability and the like, and is the most widely used method for preparing the carbon nano tube at present. In the process of growing carbon nanotubes by chemical vapor deposition, a plurality of factors can influence the structure of the carbon nanotubes, such as a catalyst, a carbon source, an etching atmosphere, oxidation/reduction treatment time, a growth substrate and the like, and different parameters influence each other, so that the control and preparation of the carbon nanotubes become a challenge. The catalyst is the key for growing the high-quality carbon nanotube, the diameter and the number of the walls of the carbon nanotube are determined by the size of catalyst particles, and the components of the catalyst influence the catalytic activity, the high-temperature thermal stability, the carbon solubility and the carbon diffusivity of the catalyst, so as to influence the quality of the carbon nanotube (document 1, giemhai, zhuli, tomaying, liug, cheng. However, the exploration of the catalyst and the selection of the growth conditions usually adopt a 'trial and error' method, and have the defects of long time consumption, low efficiency, poor repeatability, great influence of environmental and human factors and the like.

The high-throughput material screening method is to obtain the material component-structure-performance relationship by high-throughput synthesis material, high-throughput scale and high-throughput data analysis, and quickly discover new materialsMaterials or methods of optimizing the properties of materials. Among them, the quad-template method is a commonly used method for obtaining discrete deposition catalysts (documents 2Wang, J., et al. identification of a blue phosphor composite material from a composite library, science1998, 279(5357):1712 and 1714.), and has N kinds of masks, each of which can be used for four kinds of sequential deposition at most, and after each deposition, the mask is rotated by 90 DEG, only N masks are needed, 4N deposition steps are needed, and 4 deposition steps can be generated^NDifferent components of catalyst.

Raman spectroscopy is a common means of characterizing the quality, conductive properties, and chirality of carbon nanotubes and can be used for high-throughput characterization of carbon nanotube samples. Through Raman spectrum, the diameter, quality, purity, conductive property, chirality and other structural information of the carbon nano tube can be obtained. In the Raman spectral characterization of carbon nanotubes, the G mode (wavelength 1596 cm)^-1Left and right) is the tangential vibration of the molecules in the graphite sheet surface, and can reflect the crystallinity of the carbon nano tube; d mode (wavelength 1350 cm)^-1Left and right) are associated with defects such as vacancies, atomic substitutions and amorphous carbon in the graphite sheet layer, and thus the strength ratio (I) of the G-mode and D-mode is generally used_G/I_D) To judge the purity and quality of the carbon nano tube.

Disclosure of Invention

The invention aims to provide a high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes, which improves the efficiency of screening catalysts, reduces the influence of human or environment and prepares the high-quality carbon nanotubes.

The technical scheme of the invention is as follows:

a high-throughput method for efficiently screening the growth conditions of high-quality carbon nanotubes combines an ion beam deposition method with a quaternary template method, and prepares catalyst films with different thicknesses or component combinations on the same marked silicon wafer substrate by rotating a mask plate more than twice in the process of preparing the catalyst films by physical deposition, wherein the thickness of the catalyst films generally determines the size of catalyst particles; pretreating a catalyst at a series of temperatures and in a reaction atmosphere, and catalytically growing by adopting a chemical vapor deposition method to obtain a carbon nano tube horizontal network;then, performing Raman spectrum surface scanning analysis on the sample, and taking the obtained G, D mode intensity ratio of the carbon nanotube as a basis for judging the quality of the carbon nanotube; further establish G, D mode strength ratio (I) of Excel template to carbon nanotubes grown with multiple catalyst thicknesses_G/I_D) Carrying out automatic analysis; positioning the relation between the thickness or the component of the associated catalyst film and the quality of the carbon nano tube by using a marked silicon wafer; the quality of the carbon nano tube is regulated and controlled through the optimized thickness or components, the growth temperature of the carbon nano tube and the pretreatment condition of the catalyst; screening the optimal catalyst film thickness or components for growing the high-quality carbon nano-tube, and the optimal growth conditions of temperature and atmosphere.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nanotubes comprises the following specific steps:

(1) designing a 'quaternary mask plate' and a marking silicon wafer which are matched with an ion beam coating instrument;

(2) combines the ion beam deposition method with the quaternary template method to prepare 4 on the same marked silicon wafer^N(N is more than or equal to 1) catalyst film with more than one thickness or component, the thickness range of the film is 0-20 nm, and the component range of the film is 1-20 (such as iron, cobalt, nickel, molybdenum, tungsten, platinum, gold, copper, rhodium and binary and ternary … N-element alloy thereof);

(3) carrying out oxidation treatment on the sample in air atmosphere at 300-700 ℃; introducing argon gas into the reaction furnace for protection, and raising the temperature of the furnace to the growth temperature of the carbon nano tube; carrying out reduction treatment in a hydrogen atmosphere to form catalyst nanoparticles on the surface of the marked silicon wafer substrate; then introducing a carbon source and a carrier gas, wherein the carbon source is subjected to catalytic cracking, nucleation and growth of the carbon nano tube on the catalyst particles;

(4) performing Raman spectrum surface scanning analysis on the sample; normalizing the surface scanning data by using Raman spectrum software, removing cosmic rays and removing background; then, the data are imported into an established Excel template for analysis, and I of the carbon nano tube with different thicknesses or component catalyst growth is obtained_G/I_D；

(5) Optimizing the growth temperature of the carbon nano tube and the pretreatment condition of the catalyst, and enabling more than two groups of growing carbonI of nanotubes_G/I_DThe results are summarized and compared, and the optimal catalyst film thickness or component, and the optimal growth conditions of temperature and atmosphere for growing the high-quality carbon nano-tube are screened.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nano tubes comprises a quaternary template method and a high-throughput screening method, wherein the quaternary template method comprises N mask plates (N is more than or equal to 1), each mask plate is used for four kinds of sequential deposition at most, after each deposition, the mask plates are rotated by 90 degrees, only the N mask plates are needed, 4N deposition steps are needed, and 4 deposition steps are generated^NDifferent components of catalyst.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nano tubes comprises the following steps of: the quaternary mask plate comprises 3 parts, namely a sample placing chamber, a bolt and a mask plate; the lofting chamber and the bolts are respectively an auxiliary fixing mark silicon chip and a mask plate device, the lofting chamber is 10.1mm multiplied by 0.3mm, and each mask plate is provided with 4^N-1(N is more than or equal to 1) gaps.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nanotubes adopts N (N is more than or equal to 1) mask plates, a marked silicon wafer is placed in a sample placing chamber, an A mask plate is covered and sent into a coating instrument, the A mask plate is rotated by 90 degrees clockwise after a sample is deposited by ion beams, the deposition is carried out for 4 times in sequence, then B, C, D … N mask plates are sequentially replaced, the A mask plate operation is repeated, and 4 times of preparation are carried out^NA catalyst of a certain thickness or composition.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nano tube comprises the following steps of: the size of the marked silicon chip is 10mm multiplied by 10mm, and the marked silicon chip is internally provided with a T-shaped mark and 1-4^NRoman numerals (N is more than or equal to 1), T-shaped mark as the starting point of Raman spectrum surface scanning, 4^NRoman numerals are 4^NThe location of the catalyst sample.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nano tube comprises the following steps: the growth temperature is 800-950 ℃, the carbon source is argon-loaded ethanol steam, and the carrier gas is argon or hydrogen.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nano tube comprises the following steps of: the T-shaped mark of the marked silicon chip is used as the starting point of Raman spectrum surface scanning, the surface scanning range is 10mm multiplied by 10mm, and the step length range is 0.005 mm-0.2 mm.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nanotubes comprises the following steps of: importing data into Excel; summary 4^N(N is more than or equal to 1) sample data points; respectively selecting the wavelength ranges from 1310 cm to 1370cm^-1And 1570-1610 cm^-1The maximum value of the data is used as the intensity value of a D mode and a G mode, and the I of each data point is calculated_G/I_D(ii) a Claim 4^NSample I_G/I_DMaximum, mean and variance.

The high-throughput method for efficiently screening the growth conditions of the high-quality carbon nanotubes comprises the steps of screening the optimal catalyst film thickness or components for growing the high-quality carbon nanotubes and the optimal growth conditions of temperature and atmosphere, wherein in order to obtain the high-quality carbon nanotubes, the optimal thickness interval of a cobalt catalyst is 0.1-0.6 nm, the growth temperature is 850-900 ℃, and the optimal carbon source/hydrogen ratio is 30-50 sccm: 100 sccm.

The design idea of the invention is as follows:

the invention combines a quaternary template method and ion beam deposition, prepares a certain amount of catalyst films with different thicknesses or component combinations on the same marked silicon wafer substrate by rotating a mask plate for many times in the process of preparing the catalyst films by physical deposition, wherein the thickness of the catalyst film generally determines the size of catalyst particles, pretreats the catalyst under a series of temperatures and reaction atmospheres, and obtains a carbon nano tube horizontal network by adopting a chemical vapor deposition method for catalytic growth. And then performing Raman spectrum surface scanning analysis on the sample, taking the obtained G, D mode intensity ratio of the carbon nanotube as a basis for judging the quality of the carbon nanotube, and positioning the relation between the thickness or the components of the associated catalyst film and the quality of the carbon nanotube by using a marked silicon wafer substrate. Establishing Excel template pair 4^N(N is more than or equal to 1) G, D mode strength ratio of carbon nano tube grown by catalyst with different thicknesses or components (I)_G/I_D) Performing automatic analysis, screening the optimal catalyst film thickness or component for growing high-quality carbon nanotubes, and temperatureOptimal growth conditions such as temperature and atmosphere.

The invention has the advantages and beneficial effects that:

1. the invention provides a high-throughput method for efficiently screening growth conditions of high-quality carbon nanotubes, which improves the efficiency of screening catalysts, reduces the influence of human or environment and prepares the high-quality carbon nanotubes.

2. The invention designs a quaternary mask plate and a marking silicon chip which are matched with an ion beam coating instrument, and 4. the invention prepares on the same marking silicon chip substrate^N(N is more than or equal to 1) discrete catalyst films with different thicknesses or components, and the relationship between the thickness of the catalyst film and the like and the quality of the carbon nano tube is positioned and associated by utilizing the marked substrate.

3. The invention provides a high-throughput characterization method, which is characterized in that a sample in a 10mm multiplied by 10mm area is subjected to surface scanning analysis through Raman spectrum, and an obtained carbon nano tube G, D model is used as a basis for judging the quality of the carbon nano tube.

4. The invention provides a data analysis method, which comprises the steps of establishing an Excel template, analyzing Raman spectrum surface scanning data and obtaining I of a catalyst film growing carbon nano tube with different thicknesses or components_G/I_D。

Drawings

FIG. 1 is a flow chart of a design of a high throughput method for efficient screening of high quality carbon nanotube growth conditions.

Fig. 2(a) is a photograph of a real object containing 3 quaternary masks, in which 1 mask a; 2, a mask plate B; 3, a mask plate C; 4, gaps; 5, a sample placing chamber; 6, bolts; (b) a coating operation flow chart containing 3 quaternary mask plates; (c) marking the silicon wafer optical photo; (d) scanning electron microscope pictures of samples after growing the carbon nano tubes; (e) and (5) transmission electron microscope photographs.

FIG. 3 is a schematic diagram of a carbon nanotube production system. In the figure, 7 is an air inlet end; 8 depositing marking silicon wafers of catalyst films with different thicknesses on the surface; 9, an air outlet end; 10 horizontal reacting furnace; 11 heating the tube.

FIG. 4 is a Raman spectral profile. Wherein, (a) the Raman spectrum G peak intensity spectra of 64 samples, the abscissa X represents the transverse scanning range (mum) of the Raman spectrum, and the ordinate Y represents the longitudinal scanning range (mum) of the Raman spectrum; (b) raman spectra of individual samples.

FIG. 5 is a flowchart of an Excel template for automatic analysis of Raman spectrum scan data.

FIG. 6 high-flux preparation of catalyst with different components for growing carbon nanotubes I_G/I_DFigure (a). Wherein, (a) a monobasic Co catalyst; (b) a binary Co-Mo catalyst; (c) a ternary Co-Pt-Mo catalyst.

Detailed Description

In the specific implementation process, the invention combines an ion beam deposition method with a quaternary template method, prepares a certain amount of catalyst films with different thicknesses or component combinations on the same marked silicon wafer substrate by rotating a mask plate for many times in the process of preparing the catalyst film by physical deposition, wherein the thickness of the catalyst film generally determines the size of catalyst particles, pretreats the catalyst under a series of temperatures and reaction atmospheres, and obtains the carbon nano tube horizontal network by adopting a chemical vapor deposition method for catalytic growth. Then, performing Raman spectrum surface scanning analysis on the sample, taking the obtained G, D mode intensity ratio of the carbon nanotubes as a basis for judging the quality of the carbon nanotubes, and further establishing the intensity ratio (I) of the Excel template to a plurality of groups of G, D modes_G/I_D) And carrying out automatic analysis, and positioning the relation between the thickness or the components of the associated catalyst film and the quality of the carbon nano tube by using the marked silicon wafer. The quality of the carbon nano tube is regulated and controlled by optimizing the growth temperature of the carbon nano tube and the pretreatment condition of the catalyst, and the optimal catalyst film thickness and the optimal growth condition for growing the high-quality carbon nano tube are screened.

The method comprises the following specific steps:

(1) designing a 'quaternary mask plate' and a marking silicon wafer which are matched with an ion beam coating instrument;

(2) combines the ion beam deposition method with the quaternary template method to prepare 4 on the same marked silicon wafer^N(N is more than or equal to 1) catalyst film with more than one thickness or component, the film thickness range is 0-20 nm, and the film component range is as follows: 1-20 kinds (such as iron, cobalt, nickel, molybdenum, tungsten, platinum, gold, copper, rhodium and binary and ternary … N-element alloy);

(3) carrying out oxidation treatment on the sample in air atmosphere at 300-700 ℃; introducing argon gas into the reaction furnace for protection, and raising the temperature of the furnace to the growth temperature of the carbon nano tube; carrying out reduction treatment in a hydrogen atmosphere to form catalyst nanoparticles on the surface of the marked silicon wafer substrate; then introducing a carbon source and a carrier gas, wherein the carbon source is subjected to catalytic cracking, nucleation and growth of the carbon nano tube on the catalyst particles;

(4) performing Raman spectrum surface scanning analysis on the sample; normalizing the surface scanning data by using Raman spectrum software, removing cosmic rays and removing background; then, the data are imported into an established Excel template for analysis, and I of the carbon nano tube with different thicknesses or component catalyst growth is obtained_G/I_D；

(5) Optimizing the growth temperature and catalyst pre-treatment condition of carbon nanotube and making two or more groups of carbon nanotube I grow_G/I_DThe results are summarized and compared, and the optimal catalyst film thickness or component, and the optimal growth conditions of temperature and atmosphere for growing the high-quality carbon nano-tube are screened.

As shown in fig. 1, a design flow chart of a high-throughput method for efficiently screening high-quality carbon nanotube preparation conditions prepares a high-throughput sample by combining the design of a quaternary mask plate and a marking silicon wafer with ion beam deposition; pretreating a catalyst at a series of temperatures and in a reaction atmosphere, and catalytically growing by adopting a chemical vapor deposition method to obtain a carbon nano tube horizontal network; performing Raman spectrum surface scanning analysis on the sample, and performing high-throughput characterization; establishing an Excel template to analyze Raman spectrum surface scanning data and obtain I of the carbon nano tube with different thicknesses or component catalyst growth_G/I_DAnd then screening the catalyst to prepare the high-quality carbon nano tube.

As shown in FIG. 2, the invention designs a quaternary mask plate and a marking silicon wafer which are matched with an ion beam coating instrument and are used for high-throughput preparation of a catalyst film. Putting a marked silicon wafer into a lofting chamber of a quaternary mask plate, fixing the mask plate above the marked silicon wafer through 4 bolts, sending samples into an ion beam coating instrument for coating, controlling the thickness of a catalyst film through clockwise 90-degree rotation of the mask plate, coating 4 samples on each mask plate, and plating N (N is more than or equal to N)1 integer) mask plates are used in sequence, and 4 mask plates are plated on the same marked silicon chip^NA catalyst film of a certain thickness or composition.

The design method of the marking silicon chip comprises the following steps: the size of the marked silicon chip is 10mm multiplied by 10mm, and the marked silicon chip is internally provided with a T-shaped mark and 1-4^N(N is an integer greater than or equal to 1) Roman numerals, T-shaped as the starting point of Raman spectral sweep, 4^NRoman numerals are 4^NThe location of the catalyst sample.

As can be seen from fig. 2(a) showing a physical photograph containing 3 quaternary masks, the structure of the mask includes: the silicon wafer marking device comprises six parts, namely a mask plate A1, a mask plate B2, a mask plate C3, a gap 4, a lofting chamber 5 for placing a marking silicon wafer and bolts 6, wherein the lofting chamber 5 and the bolts 6 are respectively auxiliary fixing marking silicon wafers and a mask plate device, the marking silicon wafer is placed in the lofting chamber 5, four bolts 6 are uniformly arranged on the periphery of the lofting chamber 5, and the mask plate A1, the mask plate B2 or the mask plate C3 penetrates through the bolts 6 and is fixed above the marking silicon wafer. The sample chamber 5 is 10.1mm × 10.1mm × 0.3mm in size, each mask plate has 16 gaps 4, the gap size is 0.8mm × 0.8mm, and the gap interval is 0.4 mm.

FIG. 2(b) is a flow chart of coating operation including 3 quaternary mask plates, wherein A, B, C total 3 mask plates are adopted, a marked silicon wafer substrate is placed in a sample chamber, firstly, the mask plate A is covered and sent into a coating instrument, after a sample is deposited by ion beams, the mask plate A is rotated clockwise by 90 degrees and sequentially deposited for 4 times, and 4 catalysts with the thicknesses or components of A1, A2, A3 and A4 are obtained; replacing a mask plate B, and repeating the operation of the mask plate A to obtain 16 kinds of catalysts with the thicknesses or components of A1B1, A1B2, A1B3, A1B4, A2B1, A2B2, A2B3, A2B4, A3B1, A3B2, A3B3, A3B4, A4B1, A4B2, A4B3 and A4B 4; thirdly, replacing the mask plate C, and repeating the operation of the mask plate A to prepare the catalyst with 64 thicknesses or components. In the invention, the meaning of the quaternary mask plate is as follows: each mask plate can assist in depositing four thicknesses or component catalysts with 4 rotations. As can be seen from the flow chart of the coating operation in fig. 2(b), 64 catalysts with different thicknesses or compositions can be prepared by sequentially using 3 masks.

As can be seen from the optical photo of the marked silicon slice in FIG. 2(c), the marked silicon slice has T-shaped marks and 1-64 Roman numerals. As can be seen from the scanning electron micrograph of the sample after the carbon nanotubes grow in fig. 2(d), the density of the carbon nanotubes grown by the catalyst with different components or thicknesses is different, and the carbon nanotubes do not exist between the adjacent samples, so that the mutual interference generated when the carbon nanotubes grow by the catalyst with different thicknesses or components is reduced. As can be seen from the transmission electron micrograph of fig. 2(e), the single-walled carbon nanotube having a smaller amorphous carbon content is grown.

As shown in fig. 3, the carbon nanotube preparing system mainly includes: the method comprises the following steps of providing an air inlet end 7, a marked silicon wafer 8 with catalyst films of different thicknesses deposited on the surface, providing an air outlet end 9, a horizontal type reaction furnace 10, a heating pipe 11 and the like, wherein the heating pipe 11 is transversely arranged in the horizontal type reaction furnace 10, one end of the heating pipe 11 is the air inlet end 7, the other end of the heating pipe 11 is the air outlet end 9, and a sample is subjected to chemical vapor deposition in the middle of the heating pipe 11 to obtain the marked silicon wafer 8 with the catalyst films of different thicknesses deposited on the surface.

The invention adopts a horizontal reaction furnace, and a catalyst film sample prepared by high flux is arranged in a high-temperature area of the horizontal reaction furnace. Firstly, oxidizing a catalyst sample at 500 ℃ in an air atmosphere, and withdrawing the sample from a high-temperature region; then, heating the reaction furnace in an argon atmosphere to a reaction temperature, pushing the sample into a high-temperature region after the furnace temperature is raised to the reaction temperature, and reducing in a hydrogen atmosphere; and closing the hydrogen atmosphere, and starting to grow the carbon nano tube by using the mixed gas of the ethanol vapor carried by the argon and the argon or the hydrogen.

The invention utilizes Raman spectrum to obtain 4^NG, D model of carbon nano tube prepared by (N is more than or equal to 1) catalyst. As shown in fig. 4(a), the raman spectra G peak intensities of the carbon nanotubes obtained by the growth of 64 catalysts are different; carrying out normalization, cosmic ray removal and background removal on data by using Raman spectrum software; and importing the data into an Excel template for data analysis. As can be seen from the Raman spectrum of the single sample in FIG. 4(b), the selected sample had a higher G peak intensity, a lower D peak intensity, and I_G/I_DThe average value was 59, indicating that the carbon nanotubes had fewer defects or amorphous carbon and the quality of the carbon nanotubes was higher.

As shown in fig. 5, a flow chart of automated analysis of Excel templates from raman spectral scan data. Book (I)Introducing processed Raman spectrum surface scanning data into Excel; summary 4^N(N is more than or equal to 1) sample data points; the selected wavelength range is 1310-1370 cm^-1And 1570-1610 cm^-1The maximum value of (a) is the intensity of the D mode and the G mode respectively, and the I of each data point is calculated_G/I_D(ii) a For each sample I_G/I_DMaximum, mean and variance of; outputting I corresponding to catalysts with different thicknesses or compositions_G/I_DAverage value.

As shown in FIG. 6, the present invention combines different growth parameters to grow carbon nanotubes with I_G/I_DVisual comparison shows that the high-throughput method can be used for growing carbon nanotubes by using one-component, two-component and three-component catalysts. As can be seen from FIG. 6(a), I of the carbon nanotubes obtained by growing the C-catalyst Co with a single metal at different thicknesses and growth temperatures_G/I_DValues different, I of carbon nanotubes grown with 900 degree 0.2nmCo catalyst_G/I_DThe value is highest; as can be seen from FIG. 6(b), I of the carbon nanotubes obtained by the Co-Mo binary metal catalyst growth with different thickness_G/I_DThe values are different; as can be seen from FIG. 6(c), I of carbon nanotubes obtained by growing Co-Pt-Mo ternary metal catalysts of different thicknesses_G/I_DDifferent values, wherein Co: pt: when Mo is 0.6:0.27:0.13, I of the obtained carbon nanotube_G/I_DThe highest value was 37.

The present invention will be described in detail below with reference to examples and the accompanying drawings.