CN103011130B - The method of hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes - Google Patents
The method of hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes Download PDFInfo
- Publication number
- CN103011130B CN103011130B CN201210566068.7A CN201210566068A CN103011130B CN 103011130 B CN103011130 B CN 103011130B CN 201210566068 A CN201210566068 A CN 201210566068A CN 103011130 B CN103011130 B CN 103011130B
- Authority
- CN
- China
- Prior art keywords
- walled carbon
- hydrogen
- carbon nanotube
- semi
- carbon nanotubes
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The present invention relates to the preparation field of high-quality semiconductor Single Walled Carbon Nanotube, be specially the method for a kind of hydrogen in-situ weak etching direct growth high-quality semiconductor Single Walled Carbon Nanotube.With under the condition that ferrocene etc. is catalyst precursor, sulphur powder is growth stimulant, organic lower carbon number hydrocarbons is carbon source, by regulating the flow optimizing carrier gas hydrogen, original position metallicity and minor diameter Single Walled Carbon Nanotube can be etched away under certain temperature of reaction, the Single Walled Carbon Nanotube that final acquisition high quality, semiconductive are dominant, wherein content >=the 91wt% of semi-conductive single-walled carbon nanotubes, diameter Distribution is between 1.5-2.5nm, and concentrated oxidizing temperature is up to 800 DEG C.Present invention achieves and control growth compared with a large amount of, quick, the low cost of narrow diameter distribution, high quality, semi-conductive single-walled carbon nanotubes, effectively prevent selectivity prepares in the Single Walled Carbon Nanotube process that conductive properties is dominant, strong etching agent to specimen breakdown serious and complicated process of preparation, yield poorly, the problem such as cost is higher.
Description
Technical field
The present invention relates to direct, a large amount of, the controlled synthesis field of high-quality semiconductor Single Walled Carbon Nanotube, be specially the method for a kind of hydrogen in-situ weak etching direct growth high-quality semiconductor Single Walled Carbon Nanotube, in floating catalytic agent chemical vapor deposition growth Single Walled Carbon Nanotube process, original position regulates the flow of carrier gas and etching gas-hydrogen, achieves magnanimity, the controllable growth of the semi-conductive single-walled carbon nanotubes compared with narrow diameter distribution.
Background technology
Single Walled Carbon Nanotube is formed around a certain vector is curling by single-layer graphene, and according to the difference of chirality and diameter, Single Walled Carbon Nanotube can be divided into metallicity or semi-conductive single-walled carbon nanotubes.Because Single Walled Carbon Nanotube has excellent electron transport property, thus be considered to the ideal material building nanometer electronic device, but the key issue that restricting current Single Walled Carbon Nanotube is applied in nanometer electronic device field is the selective growth how realizing Single Walled Carbon Nanotube.The ultimate aim of selective growth is exactly a large amount of, the homogeneity preparation that realize single chiral or conductive properties Single Walled Carbon Nanotube, and then can build the consistent nanometer electronic device of performance and design and printing goes out large-scale integrated circuit.Therefore, the preparation research of the Single Walled Carbon Nanotube that single conductive properties, structure are homogeneous receives much attention.
Current, for how preparing electrical properties and the homogeneous Single Walled Carbon Nanotube of mechanical property has been subjected to increasing concern.The method of the single conductive properties Single Walled Carbon Nanotube of current acquisition mainly divides two kinds: i.e. aftertreatment separation method and direct growth method.Wherein, aftertreatment separation method (document 1, TTanaka, HJin, YMiyata, SFujii, HSuga, YNaitoh, TMinari, TMiyadera, KTsukagoshi, HKataura.NanoLett.9 (4): 1497-1500 (2009); Document 2, YYZhang, YZhang, XJXian, JZhang, ZFLiu.J.Phys.Chem.C112 (10): 3849-3856 (2008)) inevitably relate to chemistry and the physical processes such as some functionalisation of surfaces process, high speed centrifugations, in carbon nanotube, easily introduce textural defect and impurity, thus affect its intrinsic performance and practical application; Meanwhile, separating technology is usually comparatively complicated, also higher to equipment requirements.On the other hand, the research of the single conductive properties Single Walled Carbon Nanotube of direct growth achieves greater advance in recent years.Especially the selectivity preparation (document 3, LDing, ATselev, JYWang, DNYuan, HBChu, TPMcnicholas, YLi, JLiu.NanoLett.9 (2): 800-8055 (2009) of semi-conductive single-walled carbon nanotubes; Document 4, Wei-HungChiangandR.MohanSankaran.NatureMaterials8,882-886 (2009)), but the semi-conductive single-walled carbon nanotubes that these methods obtain or amount are seldom or diameter is very little or diameter Distribution is very wide, and the semi-conductive single-walled carbon nanotubes preparation in macroscopic quantity narrower for diameter Distribution rarely has report.Recently, this research group utilizes oxygen to assist floating catalytic agent chemical Vapor deposition process direct growth semi-conductive single-walled carbon nanotubes, the breakthrough of the amount of achieving.But due to the strong oxidizing property of oxygen, can etched portions semi-conductive single-walled carbon nanotubes, cause the structural homogeneity of carbon pipe and structural integrity poor, directly impact is by the performance of its structure nanometer electronic device and stability.
Current subject matter is: how to select suitable growth in situ etching agent, under the precursor not destroying semi-conductive single-walled carbon nanotubes intrinsic structure, situ selective removes metallicity and minor diameter Single Walled Carbon Nanotube, for use in constructing the electron devices such as the unit molecule field-effect transistor with higher on-off ratio and mobility.
Summary of the invention
The object of the present invention is to provide the method for a kind of hydrogen in-situ weak etching direct growth high quality, semi-conductive single-walled carbon nanotubes, under the prerequisite not destroying major diameter, semi-conductive single-walled carbon nanotubes intrinsic structure, selective removal metallicity, minor diameter Single Walled Carbon Nanotube, the method of original position preparation in macroscopic quantity high-quality semiconductor attribute Single Walled Carbon Nanotube, achieves convenient, the efficient controlled synthesis of high quality, low stain, low-loss semiconductor Single Walled Carbon Nanotube first.
The technical problem that the present invention solves overcomes complex steps in current preparation and sepn process, cost is higher and brings the problems such as havoc to Single Walled Carbon Nanotube intrinsic structure; Another technical problem that the present invention solves be overcome existing directly prepare few, the loss of output that semi-conductive single-walled carbon nanotubes method exists large, introduce the problems such as impurity.
Technical scheme of the present invention is:
The method of a kind of hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, with ferrocene, nickelocene, dicyclopentadienylcobalt or cuprocene are catalyst precursor, sulphur powder is growth stimulant, hydrogen is carrier gas and etching gas, pass into carbon-source gas at temperature 1000-1100 DEG C simultaneously, and regulate and control growth and the original position etching that hydrogen flowing quantity carries out Single Walled Carbon Nanotube, remove minor diameter semi-conductive single-walled carbon nanotubes and metallic single-wall carbon nano-tube, the sample that final acquisition semi-conductive single-walled carbon nanotubes is dominant, semi-conductive single-walled carbon nanotubes content >=91wt%.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, is first transferred directly on quartz plate by the Single Walled Carbon Nanotube sample prepared with transmittance 80%-90%, carries out infrared-visible-ultra-violet absorption spectrum test; Then measured curve being carried out background subtraction, and by going the absorption spectrum quantitative Analysis after back end, obtaining in Single Walled Carbon Nanotube sample prepared by this method, semi-conductive single-walled carbon nanotubes content >=91wt%.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, carbon nanotube diameter distribution adopts transmission, Raman Characterization, and carbon nanotube diameter is between 1.5-2.5nm; Transmission, Raman spectrum are also for characterizing the quality of micro-example, and high quality refers to that carbon-coating structural integrity is good, I
g/ I
dratio is higher than 78, I
g/ I
dfor the ratio of G peak intensity and D peak intensity.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, concrete steps are as follows:
Under hydrogen shield, first chemical gas phase furnace temperature is risen to 1000-1100 DEG C, regulate hydrogen flowing quantity to analog value again, and pass into carbon-source gas, then by ferrocene, nickelocene, it is 80-90 DEG C of place that dicyclopentadienylcobalt or cuprocene and sulphur powder are placed in furnace temperature simultaneously, ferrocene, nickelocene, dicyclopentadienylcobalt or cuprocene decomposite catalyst nano iron particle at said temperatures, nano nickle granules, nano cobalt granule or nano copper particle, while the growth of catalysis Single Walled Carbon Nanotube, also hydrogen catalyzed decomposition hydroperoxyl radical, then original position etching is carried out to metallicity and minor diameter Single Walled Carbon Nanotube, hydrogen flowing quantity is 500-4000 ml/min, ferrocene, nickelocene, the weight ratio of dicyclopentadienylcobalt or cuprocene and sulphur powder is 200-50, the flow of carbon-source gas is 1-30 ml/min, time is 5-60 minute.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, preferably, hydrogen flowing quantity is 1700-3000 ml/min, the weight ratio of ferrocene, nickelocene, dicyclopentadienylcobalt or cuprocene and sulphur powder is 200-100, the flow of carbon-source gas is 10-30 ml/min, and the time is 20-40 minute.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, with organic low-carbon (LC) hydrocarbon gas: methane, acetylene, ethene or propylene are for carbon-source gas, and Microamounts of Hydrogen free radical and the alkyl diradical of organic low-carbon (LC) hydrocarbon gas Pintsch process also can etch metallicity and minor diameter Single Walled Carbon Nanotube.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes; hydrogen is not only as carrier gas but also as etching property gas; under the etching of hydrogen comes from high temperature more than 1000 DEG C and catalyst nano iron particle, nano nickle granules, nano cobalt granule or nano copper particle effect; hydrogen catalyzedly be dissociated into hydroperoxyl radical, and react with carbon nanotube.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, the high-quality characteristics of magnanimity sample is characterized by thermal analysis experiment, and the concentrated oxidizing temperature of high-quality semiconductor Single Walled Carbon Nanotube is higher than 720 DEG C; Before thermal analysis experiment, semi-conductive single-walled carbon nanotubes adopts low-temperature oxidation to purify, step is: by the Single Walled Carbon Nanotube sample prepared in air atmosphere low temperature, be oxidized to remove amorphous carbon impurity for a long time, temperature is 350-380 DEG C, and oxidization time is 3-10 hour; Above-mentioned sample is soaked to remove metal catalyst particles again with the hydrochloric acid soln that concentration is 15-35wt%, and the clean and vacuum-drying by washed with de-ionized water.
The method of described hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, realize high quality by hydrogen flowing quantity when controlling carbon nano tube growth, semi-conductive single-walled carbon nanotubes controls growth, reactivity ratio's major diameter semi-conductive single-walled carbon nanotubes of metallic single-wall carbon nano-tube and minor diameter Single Walled Carbon Nanotube is high, by hydrogen in-situ corrasion, preferential situ selective etches away metallicity and minor diameter Single Walled Carbon Nanotube, thus obtains high quality, large diameter semi-conductive single-walled carbon nanotubes.
The content of the high-quality semiconductor attribute Single Walled Carbon Nanotube that the weak etching growing high-quality every batch of described hydrogen in-situ obtains is determined by the diameter of reaction boiler tube, and be the reaction boiler tube of 50mm for diameter, every batch of sample size obtained is 10-30mg.
Design philosophy of the present invention is:
Carrier gas airshed is regulated to be realize the key that semi-conductive single-walled carbon nanotubes controls growth in the inventive method.Under high temperature, iron nano-particle particles such as (or) nickel, cobalt, copper exist, the hydrogen of minute quantity dissociates into hydroperoxyl radical, and the hydroperoxyl radical of these free states can to react Formed hydrogen compound with carbon nanotube.Because metallic single-wall carbon nano-tube is higher than the reactive behavior of semi-conductive single-walled carbon nanotubes, minor diameter carbon pipe is higher than the reactive behavior of major diameter carbon pipe; Therefore, regulate hydrogen flowing quantity to respective value, the free state hydroperoxyl radical of dissociation original position can etch away minor diameter and metallic single-wall carbon nano-tube just, and does not react with major diameter semi-conductive single-walled carbon nanotubes, thus realizes the enrichment of high-quality semiconductor Single Walled Carbon Nanotube.
The inventive method is adopted to obtain in product, evaluate the semiconductive of Single Walled Carbon Nanotube or metallic characterization technique has: wavelength Raman spectrum, absorption spectrum and field-effect transistor performance are tested, assess sample is that original position is collected, without the Single Walled Carbon Nanotube sample of any aftertreatment.The high-quality characterization technique evaluating Single Walled Carbon Nanotube has: high-resolution-ration transmission electric-lens, wavelength Raman spectrum, thermogravimetric analysis, wherein except thermogravimetric analysis characterize specimen in use be through low-temperature oxidation purify after sample except, other characterization techniques institute adopt sample be original position collection Single Walled Carbon Nanotube sample.The characterization technique evaluating diameter of single-wall carbon nano tube distribution has: high-resolution-ration transmission electric-lens, wavelength Raman spectrum.
In the present invention, the diameter of minor-diameter carbon nanotube is <1.5nm, and the diameter of major diameter carbon nanotube is 1.5-2.5nm.The diameter Distribution of semi-conductive single-walled carbon nanotubes of the present invention is at the preferred 1.8-2.5nm of 1.5-2.5nm() between, the carbon pipe stability of this diameter Distribution is compared with high, contact resistance the is little (transmittance of 80%-90%, contact resistance reaches 60 Ω/-300 Ω/, and (this is the phraseology of sheet resistance, represent square resistance), be suitable for building nanometer electronic device.
In the present invention, high quality Single Walled Carbon Nanotube refers to tube wall straight (high-resolution-ration transmission electric-lens observation), Raman spectrum I
g/ I
dhigh (the I of ratio
g/ I
dfor the ratio of G peak intensity and D peak intensity, I
g/ I
d> 78), the differential thermogravimetric curve of magnanimity sample is the peak of sharp-pointed a, narrowly distributing, and its peak position is higher than 700 DEG C.Wherein, thermal analysis experiment specimen in use is the magnanimity sample after simple, harmless purification.
Advantage of the present invention is:
1, the present invention utilizes floating catalytic agent legal system for Single Walled Carbon Nanotube, employing hydrogen is carrier gas, the iron of ferrocene (or nickelocene, dicyclopentadienylcobalt, cuprocene) pyrolytic decomposition (or nickel, cobalt, copper) nano particle is this feature of catalyzer, the hydroperoxyl radical generated in conjunction with the high growth temperature condition and iron nano-particle situ catalytic dissociates hydrogen of preparing carbon nanotube has this characteristic of etching carbon nanotube, by regulation and control hydrogen flowing quantity, the i.e. content of hydroperoxyl radical, achieves the magnanimity controlled synthesis of high quality, semi-conductive single-walled carbon nanotubes.
2, the inventive method regulates and controls the level of response of Single Walled Carbon Nanotube by the content regulating and controlling hydrogen flowing quantity and hydroperoxyl radical, both the selective etch of metallicity and minor diameter Single Walled Carbon Nanotube had been achieved, maintain again the complete structure of major diameter, semi-conductive single-walled carbon nanotubes, overcome and existingly prepare the problems such as the strong etching of semi-conductive single-walled carbon nanotubes, many defects and strong doping.
3, present invention achieves high-quality semiconductor Single Walled Carbon Nanotube a large amount of (different according to the size of chemical vapor deposition stove pipe used, output be milligram-Ke/batch), convenient, efficient selective preparation.The method has simply, cost is low, output is large, be easy to the features such as mass-producing, has good prospects for commercial application.
In a word, the weak etching of hydrogen in-situ of the present invention directly prepares the floating catalytic chemical gaseous phase depositing process of high quality, semi-conductive single-walled carbon nanotubes, in the process of floating catalytic agent chemical Vapor deposition process growing single-wall carbon nano tube, original position regulation and control have the flow of the hydrogen of weak corrasion, realize the preparation in macroscopic quantity of high quality, narrow diameter distribution semi-conductive single-walled carbon nanotubes.With under the condition that ferrocene, nickelocene, dicyclopentadienylcobalt or cuprocene are catalyst precursor, appropriate sulphur powder is growth stimulant, organic lower carbon number hydrocarbons is carbon source, by regulating the flow optimizing carrier gas hydrogen, original position metallicity and minor diameter Single Walled Carbon Nanotube can be etched away under certain temperature of reaction, the Single Walled Carbon Nanotube that final acquisition high quality, semiconductive are dominant, wherein content >=the 91wt% of semi-conductive single-walled carbon nanotubes, diameter Distribution is between 1.5-2.5nm, and concentrated oxidation resistance temperature is up to 800 DEG C.Present invention achieves and control growth compared with a large amount of, quick, the low cost of narrow diameter distribution, high quality, semi-conductive single-walled carbon nanotubes, effectively prevent selectivity prepares in the Single Walled Carbon Nanotube process that conductive properties is dominant, strong etching agent to specimen breakdown serious and complicated process of preparation, yield poorly, the problem such as cost is higher.
Accompanying drawing explanation
Fig. 1. the principle schematic of hydrogen in-situ weak etching direct growth high-quality semiconductor Single Walled Carbon Nanotube.
Fig. 2 (a). the transmission electron microscope photo of high quality, semi-conductive single-walled carbon nanotubes.Fig. 2 (b). from transmission electron microscope photo, add up the diameter distribution profile of the semiconductor properties Single Walled Carbon Nanotube obtained.
Fig. 3. the Raman spectrum RBM peak (excitation wavelength is 633nm) of Single Walled Carbon Nanotube sample prepared under different hydrogen flow and helium.
Fig. 4. the differential thermogravimetric curve of high quality, semi-conductive single-walled carbon nanotubes.
Embodiment
Below by embodiment in detail the present invention is described in detail.
Embodiment 1.
(1) Fig. 1 is for preparing high quality, the principle schematic of semi-conductive single-walled carbon nanotubes, specific experiment step is: by the ferrocene (weight ratio of sulphur powder and ferrocene is 1:200) of a slice sulfur-bearing powder, (diameter is 50mm to be placed on chemical vapour deposition reactor furnace, flat-temperature zone length is 10cm) cold zone, 1100 DEG C are raised in a hydrogen atmosphere with the temperature rise rate of 22 DEG C/min, pass into the methane of 30ml/min, and hydrogen flowing quantity is adjusted to 2000ml/min, ferrocene is shifted onto furnace temperature is 80 DEG C of places simultaneously, carry out the growth of Single Walled Carbon Nanotube, growth time is 30 minutes.After chemical vapour deposition terminates, close methane and turn down hydrogen flowing quantity to 400ml/min, allowing Reaktionsofen drop to room temperature in the mode of naturally cooling.
(2) sample obtained step (1) carries out transmission electron microscope respectively, and (Fig. 2 a), Raman spectrum and absorption spectrum characterize.Under transmission electron microscope, carried out diameter measurement and statistics to 150 Single Walled Carbon Nanotube, as shown in Figure 2 b, the diameter Distribution of Single Walled Carbon Nanotube is 1.5-2.5nm to statistics, and carbon-coating structural integrity is good, I
g/ I
dratio is 81.6, Raman (Fig. 3,3#) show with absorption spectrum, the Single Walled Carbon Nanotube prepared under this condition is that semiconductive is dominant, according to metallicity and semi-conductive single-walled carbon nanotubes, the peak area at corresponding peak in absorption spectrum carries out integration, quantitatively calculate the content 91wt% of semiconductor properties Single Walled Carbon Nanotube, contact resistance is 60 Ω/.
In the present invention, the high quality of magnanimity Single Walled Carbon Nanotube sample is characterized by thermal analysis experiment, and the sample obtained step (1) is 360 DEG C, oxidation 5 hours under air atmosphere; Hydrochloric acid soln (concentration is 20wt%) is used to soak above-mentioned sample to remove metal catalyst particles and repeatedly to clean and vacuum-drying with deionized water again.Get the thermogravimetric analysis experiment that dried sample 5mg carries out under air atmosphere, as shown in Figure 4, sample starts weightless its thermogravimetric/differential thermogravimetric curve at 600 DEG C, starts to concentrate oxidation at 800 DEG C of samples.This high oxidation resistance temperature, the Single Walled Carbon Nanotube only having arc process to prepare at present or the Single Walled Carbon Nanotube after greying just can reach.
Comparative example 1.
(1) by the ferrocene (weight ratio of sulphur powder and ferrocene is 1:200) of a slice sulfur-bearing powder, (diameter is 50mm to be placed on chemical vapour deposition reactor furnace, flat-temperature zone length is 10cm) cold zone, 950 DEG C are raised in a hydrogen atmosphere with the temperature rise rate of 22 DEG C/min, pass into the methane of 30ml/min, and hydrogen flowing quantity is adjusted to 500ml/min, ferrocene is shifted onto furnace temperature is 80 DEG C of places simultaneously, and carry out the growth of Single Walled Carbon Nanotube, growth time is 30 minutes.After chemical vapour deposition terminates, close methane and turn down hydrogen flowing quantity, allowing Reaktionsofen drop to room temperature in the mode of naturally cooling.
(2) sample obtained step (1) carries out transmission electron microscope, Raman spectrum and absorption spectrum respectively and characterizes.Under transmission electron microscope to the carrying out of 124 Single Walled Carbon Nanotube diameter measurement and statistics, the diameter Distribution recording Single Walled Carbon Nanotube is 0.8-2.5nm, Raman (Fig. 3,1#) show with absorption spectrum, the Single Walled Carbon Nanotube prepared under this condition there is no selectivity in conductive properties, according to metallicity and semi-conductive single-walled carbon nanotubes, the peak area at corresponding peak in absorption spectrum carries out integration, and the content quantitatively calculating semiconductor properties Single Walled Carbon Nanotube is 69wt%.After the Methods For Purification described in embodiment 1, the concentrated oxidation resistance temperature of sample is 700 DEG C.
Comparative example 2.
(1) by the ferrocene (weight ratio of sulphur powder and ferrocene is 1:200) of a slice sulfur-bearing powder, (diameter is 50mm to be placed on chemical vapour deposition reactor furnace, flat-temperature zone length is 10cm) cold zone, 1100 DEG C are raised to the temperature rise rate of 22 DEG C/min under helium atmosphere, pass into the methane of 30ml/min, and helium gas flow is adjusted to 2000ml/min, ferrocene is shifted onto furnace temperature is 80 DEG C of places simultaneously, and carry out the growth of Single Walled Carbon Nanotube, growth time is 30 minutes.After chemical vapour deposition terminates, close methane and again reduce helium gas flow, allowing Reaktionsofen drop to room temperature in the mode of naturally cooling.
(2) sample obtained step (1) carries out transmission electron microscope, Raman spectrum and absorption spectrum respectively and characterizes.Under transmission electron microscope to the carrying out of 90 Single Walled Carbon Nanotube diameter measurement and statistics, the diameter Distribution recording Single Walled Carbon Nanotube is 0.8-1.6nm, Raman (Fig. 3,2#) show with absorption spectrum, the Single Walled Carbon Nanotube prepared under this condition does not have selectivity in conductive properties, according to metallicity and semi-conductive single-walled carbon nanotubes, the peak area at corresponding peak in absorption spectrum carries out integration, and the content quantitatively calculating semiconductor properties Single Walled Carbon Nanotube is 68wt%.After the Methods For Purification described in embodiment 1, the concentrated oxidation resistance temperature of sample is 680 DEG C.
The result of comparative example 1 and 2 shows at lower H
2under the helium-atmosphere of flow (500ml/min) or same traffic, the growth of Single Walled Carbon Nanotube does not have selectivity, diameter Distribution scope broadens, minor diameter carbon pipe ratio increases and its concentrated oxidation resistance temperature step-down, this further illustrates hydrogen and appropriate amount of hydrogen can etch minor diameter, metallic single-wall carbon nano-tube by situ selective, and maintains the structure of major diameter, semi-conductive single-walled carbon nanotubes.
Embodiment 2.
(1) by the nickelocene (weight ratio of sulphur powder and nickelocene is 1:100) of a slice sulfur-bearing powder, (diameter is 50mm to be placed on chemical vapour deposition reactor furnace, flat-temperature zone length is 10cm) cold zone, 1100 DEG C are raised in a hydrogen atmosphere with the temperature rise rate of 22 DEG C/min, pass into the methane of 20ml/min, and hydrogen flowing quantity is adjusted to 2300ml/min, nickelocene is shifted onto furnace temperature is 85 DEG C of places simultaneously, and carry out the growth of Single Walled Carbon Nanotube, growth time is 40 minutes.After chemical vapour deposition terminates, close methane and again turn down hydrogen flowing quantity to 400ml/min, allowing Reaktionsofen drop to room temperature in the mode of naturally cooling.
(2) sample obtained step (1) carries out transmission electron microscope, Raman spectrum and absorption spectrum respectively and characterizes.Under transmission electron microscope, carried out diameter measurement and statistics to 146 Single Walled Carbon Nanotube, statistics shows, the diameter Distribution of Single Walled Carbon Nanotube is 1.8-2.4nm, and carbon-coating structural integrity is good, I
g/ I
dratio is 80.2, Raman and absorption spectrum show, the Single Walled Carbon Nanotube prepared under this condition is that semiconductive is dominant, according to metallicity and semi-conductive single-walled carbon nanotubes, the peak area at corresponding peak in absorption spectrum carries out integration, quantitatively calculates the content 92wt% of semiconductor properties Single Walled Carbon Nanotube.
(3) sample obtained step (1) is 350 DEG C, oxidation 10 hours under air atmosphere; Hydrochloric acid soln (concentration is 35wt%) is used to soak above-mentioned sample to remove metal catalyst particles and repeatedly to clean and vacuum-drying with deionized water again.Get the thermogravimetric analysis experiment that dried sample 5mg carries out under air atmosphere, sample starts weightless at 580 DEG C, start to concentrate oxidation at 780 DEG C of samples.
Embodiment 3.
(1) by the dicyclopentadienylcobalt (weight ratio of sulphur powder and dicyclopentadienylcobalt is 1:150) of a slice sulfur-bearing powder, (diameter is 50mm to be placed on chemical vapour deposition reactor furnace, flat-temperature zone length is 10cm) cold zone, 1050 DEG C are raised in a hydrogen atmosphere with the temperature rise rate of 22 DEG C/min, pass into the ethene of 25ml/min, and hydrogen flowing quantity is adjusted to 2500ml/min, dicyclopentadienylcobalt is shifted onto furnace temperature is 90 DEG C of places simultaneously, and carry out the growth of Single Walled Carbon Nanotube, growth time is 50 minutes.After chemical vapour deposition terminates, close ethene, turn down hydrogen flowing quantity to 400ml/min, allow Reaktionsofen drop to room temperature in the mode of naturally cooling.
(2) sample obtained step (1) carries out transmission electron microscope, Raman spectrum and absorption spectrum respectively and characterizes.Under transmission electron microscope, diameter measurement and statistics are carried out to 132 Single Walled Carbon Nanotube, statistics can be found out, the diameter Distribution of Single Walled Carbon Nanotube is 2.0-2.4nm, and carbon-coating structural integrity is good, IG/ID ratio is 78.6, Raman and absorption spectrum show, the Single Walled Carbon Nanotube prepared under this condition is that semiconductive is dominant, according to metallicity and semi-conductive single-walled carbon nanotubes, the peak area at corresponding peak in absorption spectrum carries out integration, quantitatively calculates the content 90wt% of semiconductor properties Single Walled Carbon Nanotube.
(3) sample obtained step (1) is 380 DEG C, oxidation 3 hours under air atmosphere; Hydrochloric acid soln (concentration is 15wt%) is used to soak above-mentioned sample to remove metal catalyst particles and repeatedly to clean and vacuum-drying with deionized water again.Get the thermogravimetric analysis experiment that dried sample 5mg carries out under air atmosphere, sample starts weightless at 580 DEG C, start to concentrate oxidation at 740 DEG C of samples.
Embodiment 4.
(1) by the cuprocene (weight ratio of sulphur powder and cuprocene is 1:120) of a slice sulfur-bearing powder, (diameter is 50mm to be placed on chemical vapour deposition reactor furnace, flat-temperature zone length is 10cm) cold zone, 1100 DEG C are raised in a hydrogen atmosphere with the temperature rise rate of 22 DEG C/min, pass into the propylene of 15ml/min, and hydrogen flowing quantity is adjusted to 3100ml/min, cuprocene is shifted onto furnace temperature is 90 DEG C of places simultaneously, and carry out the growth of Single Walled Carbon Nanotube, growth time is 40 minutes.After chemical vapour deposition terminates, close propylene, turn down hydrogen flowing quantity to 400ml/min, allow Reaktionsofen drop to room temperature in the mode of naturally cooling.
(2) sample obtained step (1) carries out transmission electron microscope, Raman spectrum and absorption spectrum respectively and characterizes.Under transmission electron microscope, carried out diameter measurement and statistics to 136 Single Walled Carbon Nanotube, statistics shows, the diameter Distribution of Single Walled Carbon Nanotube is 2.0-2.5nm, and carbon-coating structural integrity is good, I
g/ I
dratio is 80.5, Raman and absorption spectrum show, the Single Walled Carbon Nanotube prepared under this condition is that semiconductive is dominant, according to metallicity and semi-conductive single-walled carbon nanotubes, the peak area at corresponding peak in absorption spectrum carries out integration, quantitatively calculates the content 90wt% of semiconductor properties Single Walled Carbon Nanotube.
(3) sample obtained step (1) is 350 DEG C, oxidation 10 hours under air atmosphere; Hydrochloric acid soln (concentration is 35wt%) is used to soak above-mentioned sample to remove metal catalyst particles and repeatedly to clean and vacuum-drying with deionized water again.Get the thermogravimetric analysis experiment that dried sample 5mg carries out under air atmosphere, sample starts weightless at 590 DEG C, start to concentrate oxidation at 770 DEG C of samples.
Embodiment result shows, under the high temperature and granules of catalyst existent condition of Single Walled Carbon Nanotube growth, hydrogen has weak corrasion, and the power of its corrasion is relevant with the hydroperoxyl radical concentration of its decomposition; Hydrogen in-situ weak etching floating catalytic agent legal system is in Single Walled Carbon Nanotube process, and it is competitive relation that the growth of Single Walled Carbon Nanotube and its original position etch.By regulating hydrogen flowing quantity and hydroperoxyl radical concentration at Single Walled Carbon Nanotube process of growth situ, alternative removal metallicity and minor diameter Single Walled Carbon Nanotube, realize the preparation of high quality, larger diameter, semi-conductive single-walled carbon nanotubes.In addition, the present invention adopts the metal (such as: Ni, Fe, Co, Cu etc.) that at high temperature hydrogen catalyzedly can be dissociated into hydroperoxyl radical, is all applicable to hydrogen in-situ weak etching direct growth high-quality semiconductor Single Walled Carbon Nanotube.The present invention compared with prior art maximum feature is: the quality of semi-conductive single-walled carbon nanotubes is high, and oxidation resistance temperature reaches 800 DEG C, and what general method did does not have optionally single-walled pipe to be difficult to reach this temperature yet.
Claims (6)
1. the method for a hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes, it is characterized in that, with ferrocene, nickelocene, dicyclopentadienylcobalt or cuprocene are catalyst precursor, sulphur powder is growth stimulant, hydrogen is carrier gas and etching gas, pass into carbon-source gas at temperature 1000-1100 DEG C simultaneously, and regulate and control growth and the original position etching that hydrogen flowing quantity carries out Single Walled Carbon Nanotube, remove minor diameter semi-conductive single-walled carbon nanotubes and metallic single-wall carbon nano-tube, the sample that final acquisition semi-conductive single-walled carbon nanotubes is dominant, semi-conductive single-walled carbon nanotubes content >=91wt%,
Under hydrogen shield, first chemical gas phase furnace temperature is risen to 1000-1100 DEG C, regulate hydrogen flowing quantity to analog value again, and pass into carbon-source gas, then by ferrocene, nickelocene, it is 80-90 DEG C of place that dicyclopentadienylcobalt or cuprocene and sulphur powder are placed in furnace temperature simultaneously, ferrocene, nickelocene, dicyclopentadienylcobalt or cuprocene decomposite catalyst nano iron particle at said temperatures, nano nickle granules, nano cobalt granule or nano copper particle, while the growth of catalysis Single Walled Carbon Nanotube, also hydrogen catalyzed decomposition hydroperoxyl radical, then original position etching is carried out to metallicity and minor diameter Single Walled Carbon Nanotube, hydrogen flowing quantity is 1700-3000 ml/min, ferrocene, nickelocene, the weight ratio of dicyclopentadienylcobalt or cuprocene and sulphur powder is 200-100, the flow of carbon-source gas is 10-30 ml/min, time is 20-40 minute,
Hydrogen is not only as carrier gas but also as etching property gas, under the etching of hydrogen comes from high temperature more than 1000 DEG C and catalyst nano iron particle, nano nickle granules, nano cobalt granule or nano copper particle effect, hydrogen catalyzedly be dissociated into hydroperoxyl radical, and react with carbon nanotube;
The high-quality characteristics of magnanimity sample is characterized by thermal analysis experiment, and the concentrated oxidizing temperature of high-quality semiconductor Single Walled Carbon Nanotube is higher than 720 DEG C; Before thermal analysis experiment, semi-conductive single-walled carbon nanotubes adopts low-temperature oxidation to purify, step is: by the Single Walled Carbon Nanotube sample prepared in air atmosphere low temperature, be oxidized to remove amorphous carbon impurity for a long time, temperature is 350-380 DEG C, and oxidization time is 3-10 hour; Above-mentioned sample is soaked to remove metal catalyst particles again with the hydrochloric acid soln that concentration is 15-35wt%, and the clean and vacuum-drying by washed with de-ionized water.
2. according to the method for hydrogen in-situ according to claim 1 weak etching growing high-quality semi-conductive single-walled carbon nanotubes, it is characterized in that, first the Single Walled Carbon Nanotube sample prepared is transferred directly on quartz plate with transmittance 80%-90%, carries out infrared-visible-ultra-violet absorption spectrum test; Then measured curve being carried out background subtraction, and by going the absorption spectrum quantitative Analysis after back end, obtaining in Single Walled Carbon Nanotube sample prepared by this method, semi-conductive single-walled carbon nanotubes content >=91wt%.
3. according to the method for hydrogen in-situ according to claim 1 weak etching growing high-quality semi-conductive single-walled carbon nanotubes, it is characterized in that, carbon nanotube diameter distribution adopts transmission, Raman Characterization, and carbon nanotube diameter is between 1.5-2.5nm; Transmission, Raman spectrum are also for characterizing the quality of micro-example, and high quality refers to that carbon-coating structural integrity is good, I
g/ I
dratio is higher than 78, I
g/ I
dfor the ratio of G peak intensity and D peak intensity.
4. according to the method for hydrogen in-situ according to claim 1 weak etching growing high-quality semi-conductive single-walled carbon nanotubes, it is characterized in that, with organic low-carbon (LC) hydrocarbon gas: methane, acetylene, ethene or propylene are for carbon-source gas, and Microamounts of Hydrogen free radical and the alkyl diradical of organic low-carbon (LC) hydrocarbon gas Pintsch process also can etch metallicity and minor diameter Single Walled Carbon Nanotube.
5. according to the method for hydrogen in-situ according to claim 1 weak etching growing high-quality semi-conductive single-walled carbon nanotubes, it is characterized in that, high quality is realized by hydrogen flowing quantity when controlling carbon nano tube growth, semi-conductive single-walled carbon nanotubes controls growth, reactivity ratio's major diameter semi-conductive single-walled carbon nanotubes of metallic single-wall carbon nano-tube and minor diameter Single Walled Carbon Nanotube is high, by hydrogen in-situ corrasion, preferential situ selective etches away metallicity and minor diameter Single Walled Carbon Nanotube, thus obtain high quality, large diameter semi-conductive single-walled carbon nanotubes.
6. according to the method for hydrogen in-situ according to claim 1 weak etching growing high-quality semi-conductive single-walled carbon nanotubes, it is characterized in that, the content of every batch of high-quality semiconductor attribute Single Walled Carbon Nanotube obtained is determined by the diameter of reaction boiler tube, be the reaction boiler tube of 50mm for diameter, every batch of sample size obtained is 10-30mg.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210566068.7A CN103011130B (en) | 2012-12-24 | 2012-12-24 | The method of hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210566068.7A CN103011130B (en) | 2012-12-24 | 2012-12-24 | The method of hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103011130A CN103011130A (en) | 2013-04-03 |
| CN103011130B true CN103011130B (en) | 2016-01-20 |
Family
ID=47960314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210566068.7A Active CN103011130B (en) | 2012-12-24 | 2012-12-24 | The method of hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103011130B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103466597B (en) * | 2013-09-02 | 2016-01-13 | 中国科学院金属研究所 | The method of a small amount of doped growing metallic single-wall carbon nano-tube of nitrogen on carbon grid |
| JP6162631B2 (en) * | 2014-03-14 | 2017-07-12 | トヨタ自動車株式会社 | Method for producing carbon nanofiber |
| CN107089652B (en) * | 2016-02-17 | 2019-05-10 | 中国科学院金属研究所 | Narrow band gap distribution, high-purity semi-conductive single-walled carbon nanotubes preparation method |
| CN105642917A (en) * | 2016-03-15 | 2016-06-08 | 苏州赛福德备贸易有限公司 | Preparation method for metal-clad carbon nano tube |
| CN107601458B (en) * | 2017-09-12 | 2020-07-28 | 刘云芳 | Preparation method of single-walled carbon nanotube |
| KR20200099131A (en) * | 2017-12-19 | 2020-08-21 | 니폰 제온 가부시키가이샤 | Fibrous carbon nanostructure, evaluation method of fibrous carbon nanostructure, and manufacturing method of surface-modified fibrous carbon nanostructure |
| CN113213454B (en) * | 2021-04-21 | 2022-06-24 | 温州大学 | Method for preparing single-walled carbon nanotube by taking graphene as catalyst |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102320594B (en) * | 2011-09-02 | 2013-02-27 | 中国科学院金属研究所 | Method for directly growing semiconductor type single-walled carbon nanotube with floating catalyst and auxiliary oxygen |
-
2012
- 2012-12-24 CN CN201210566068.7A patent/CN103011130B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN103011130A (en) | 2013-04-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103011130B (en) | The method of hydrogen in-situ weak etching growing high-quality semi-conductive single-walled carbon nanotubes | |
| Liu et al. | Chirality-controlled synthesis and applications of single-wall carbon nanotubes | |
| Zhang et al. | Horizontally aligned carbon nanotube arrays: growth mechanism, controlled synthesis, characterization, properties and applications | |
| Yang et al. | Templated synthesis of single-walled carbon nanotubes with specific structure | |
| CN101164874B (en) | Method for purifying multi-wall carbon nano pipe | |
| Long et al. | Carbon nanotubes as a superior sorbent for nitrogen oxides | |
| Chen et al. | Purification of multi-walled carbon nanotubes by microwave digestion method | |
| Journet et al. | Carbon nanotube synthesis: from large-scale production to atom-by-atom growth | |
| Kang et al. | Growth of horizontal semiconducting SWNT arrays with density higher than 100 tubes/μm using ethanol/methane chemical vapor deposition | |
| Hong et al. | Controlling the growth of single-walled carbon nanotubes on surfaces using metal and non-metal catalysts | |
| Tian et al. | Growth of single-walled carbon nanotubes with controlled diameters and lengths by an aerosol method | |
| Kumar et al. | Exfoliated single-walled carbon nanotube-based hydrogen sensor | |
| Sun et al. | Growth of carbon nanotubes on carbon paper by Ohmically heating silane-dispersed catalytic sites | |
| Wang et al. | Chirality-controlled synthesis of single-walled carbon nanotubes—From mechanistic studies toward experimental realization | |
| CN102320594B (en) | Method for directly growing semiconductor type single-walled carbon nanotube with floating catalyst and auxiliary oxygen | |
| CN104005004B (en) | The growth method of a kind of minor diameter, metallic single-wall carbon nano-tube and application | |
| CN111170309A (en) | Preparation method of ultra-long few-wall carbon nanotube array | |
| CN102139872A (en) | Method for non-invasive efficient purification of single-wall carbon nano tube | |
| CN102320593A (en) | Controllable preparation method of high-oxidation-resistance high-purity single/double-wall carbon nanotube | |
| Salavati-Niasari et al. | Synthesis, characterization and catalytic oxidation properties of multi-wall carbon nanotubes with a covalently attached copper (II) salen complex | |
| Dai et al. | Surface activation on multi-wall carbon nanotube for electrochemical capacitor applications | |
| CN101891184A (en) | Method for continuously synthesizing single-wall carbon nano tube by high temperature chemical vapor deposition method | |
| CN103449405B (en) | Method for selectively growing metal-enriched single-wall carbon nanotube by using floating catalyst method | |
| Zeng et al. | Growth and morphology of carbon nanostructures by microwave-assisted pyrolysis of methane | |
| Wang et al. | Catalytic synthesis of a high aspect ratio carbon nanotubes bridging carbon felt composite with improved electrical conductivity and effective surface area |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |