CN1304280C

CN1304280C - Cobaltosic oxide nano-crystalline coated carbon nano-tube composite powder and preparation method thereof

Info

Publication number: CN1304280C
Application number: CNB2004100255187A
Authority: CN
Inventors: 高濂; 单研
Original assignee: Shanghai Institute of Ceramics of CAS
Current assignee: Shanghai Institute of Ceramics of CAS
Priority date: 2004-06-25
Filing date: 2004-06-25
Publication date: 2007-03-14
Anticipated expiration: 2024-06-25
Also published as: CN1594211A

Abstract

The present invention provides an available method for wrapping a carbon nanometer tube at an original position by nanometer cobaltic-cobaltous oxide magnetic material, which is mainly characterized in that obaltous nitrate hexahydrate is used as raw material, hexanol is used as a solvent, and the carbon nanometer tube is wrapped at the original position under the reflux condition of 140 to 180 DEG C. A preparing process is simple and does not need to be added with any surfactant, only the carbon nanometer tube needs to be acidized, active groups, such as-OH,-COOH,-CO, etc. are introduced in, cobalt ions are adsorbed on the surface of the carbon nanometer tube at the original position by the active groups on the surface of the carbon nanometer tube through the electrostatic attraction action and the hydrophilic compatibility, and Co (NO3) 2 and 6H2O adsorbed on the surface of the carbon tube under the reflux condition of 140 to 180 DEG C are decomposed into cobaltic-cobaltous oxide, so the nanometer cobaltic-cobaltous oxide can be uniformly wrapped on the surface of the carbon nanometer tube. Composite powder with a grain size of 8 nm of the cobaltic-cobaltous oxide for wrapping the carbon nanometer tube can be obtained under the optimization condition, and a wrapping layer is about 15 to 20cm. The method realizes the tight combination of cobaltic-cobaltous oxide nanometer crystals and the carbon nanometer tube, is an efficient path for preparing carbon nanometer tube/cobaltic-cobaltous oxide composite material and also has the characteristics of simple manufacturing process, low production cost, etc.

Description

Cobaltosic oxide nano brilliant parcel carbon nano-tube composite powder and preparation method

Technical field

The present invention relates to brilliant original position parcel carbon nano-tube composite powder of a kind of cobaltosic oxide nano and preparation method, belongs to field of nanocomposite materials.

Background technology

Since S.Iijima in 1991 found carbon nanotube, carbon nanotube had caused that people pay close attention to greatly.It has unique metal or semi-conductive electroconductibility, high physical strength, toughness, bigger specific surface area (120-300m ²/ g), better adsorption capability, catalysis characteristics and stronger microwave absorption capacity and unique vestibule structure, can be widely used in various high-tech areas, be a kind of new-type functional material and structured material.But, its a lot of performances, it is very big influenced by its surface tissue as electricity, mechanics and optical property etc., in order to improve the carbon nano tube surface structure, the general surface modification method that adopts, thereby improve or change carbon nanotube dispersiveness, stability and and other materials between consistency, give its new physics, chemistry, mechanical property and new function.Recently, not only organic decoration is modified or is wrapped up carbon nanotube with inorganic species and also caused people's very big concern, carbon nanotube is coated last layer organic or inorganic functive and is had more wide application prospect (Lei Fu later on, Zhimin Liu, Yunqi Liu, Buxing Han, Jiaqiu Wang, Pingqn Hu, Lingchao Cao and Daoben Zhu, Adv.Mater.2004,16 (2), p350-352).

Tricobalt tetroxide is a kind of important P-type semiconductor magneticsubstance, is widely used in aspects such as solid state sensor, catalyzer, sun power sorbent material, lithium cell, beramic color.Its application prospects makes the tricobalt tetroxide of preparation nanoscale become one of current research focus (Xu.R.; Zeng, H.C.J.Phys.Chem.B 2003,107, p926).But the report that does not still have tricobalt tetroxide/carbon pipe matrix material at present.The carbon nanotube complex function powder of nano-cobaltic-cobaltous oxide parcel will have broad application prospects aspect heterogeneous catalysis, sun power sorbent material, ultra-capacitor and the lithium cell.And carbon nanotube/tricobalt tetroxide is expected to become the novel magnetic matrix material with high electric property.

Summary of the invention

The object of the present invention is to provide brilliant original position enveloping carbon nanotube composite powder of a kind of cobaltosic oxide nano and preparation method.The present invention is by the acidification carbon nanotube, make its surface produce electronegative active group, utilize the consistency and the electrostatic attraction effect of the active group and the cobalt ion of carbon nano tube surface, make the cobalt ion original position be adsorbed in carbon nano tube surface, and then form the composite granule of the nanocrystalline original position parcel of nano-cobaltic-cobaltous oxide carbon nanotube.The method that is provided is simple, and is easy to operate, do not need special equipment, and realized combining closely of cobaltosic oxide nano crystalline substance and carbon nanotube, is the effective way of preparation carbon nanotube/tricobalt tetroxide complex function powder.

Characteristics of the present invention are: with the Cobaltous nitrate hexahydrate is raw material, is solvent with the n-hexyl alcohol, original position parcel carbon nanotube under reflux conditions between 140-180 ℃.

Concrete steps are:

(1) with the carbon nanotube oven dry, removes the moisture that is contained;

(2) dried carbon nano-tube with concentrated nitric acid in 140 ℃ of reflow treatment 6-8 hours carbon nano tube surface introducing-OH ,-COOH or-the CO active group, use deionized water wash, dry for standby then;

(3) Cobaltous nitrate hexahydrate is dissolved in the n-hexyl alcohol, forms red clear solution, Cobaltous nitrate hexahydrate concentration is 0.02-0.08M in its solution;

(4) step (2) carbon nano tube modified is joined in the above-mentioned solution ultrasonic 15-60 minute; The mixing solutions that step (4) obtains is put into three-necked bottle, in 140-180 ℃ silicone oil bath backflow 5-10 hour, be adsorbed on the Co (NO of carbon nano tube surface ₃) ₂6H ₂O resolves into tricobalt tetroxide, thus the carbon nanotube dust of the synthetic tricobalt tetroxide parcel of reaction in.

(5) product respectively washs 2-5 time through cyclohexane, dehydrated alcohol, promptly obtains the composite granule of the brilliant parcel of cobaltosic oxide nano carbon nanotube after the drying.

The three-necked bottle experimental installation that the present invention uses is successively by three-necked bottle (round-bottomed flask), drying tube and prolong, has 4A type molecular sieve to be used for absorbing moisture content (Fig. 1) in the drying tube.

The characteristics of the method for nano-cobaltic-cobaltous oxide parcel carbon nanotube provided by the invention are:

(1) by acidification carbon nano tube surface introduce introducing-OH ,-COOH ,-CO isoreactivity group, and make the carbon nano tube surface bear.Electrostatic interaction and aqueous favoring capacitive by reactive ion and active group make the cobalt ion original position cover carbon nano tube surface, and then cover one deck cobaltosic oxide nano crystalline substance in carbon nano tube surface.

(2) realized the full coating of carbon nanotube, coating thickness is the 15-20 nanometer.The particle diameter of tricobalt tetroxide is 5-10nm, and mean sizes is 8nm.Parcel back carbon nanotube diameter is 90nm, and length is 500nm-1um.

(3) technology is simple, need not specific installation; And need not add any tensio-active agent.

Description of drawings

The synoptic diagram of the three-necked bottle experimental installation that Fig. 1 the present invention uses

The X-ray diffraction spectrogram of the brilliant parcel of Fig. 2 cobaltosic oxide nano carbon nano-tube composite powder

The composite granule transmission electron microscope photo of the brilliant parcel of Fig. 3 cobaltosic oxide nano carbon nanotube

Patent working

Further specify embodiment and effect with following indefiniteness embodiment:

Embodiment 1

Carbon nanotube is put into 140 ℃ baking oven baking 24 hours to remove the moisture of carbon nanotube, with its reflow treatment 6 hours in concentrated nitric acid, use deionized water wash then, dry.0.5g Co (NO ₃) ₂6H ₂O is dissolved in the 40mL n-hexyl alcohol, obtains a red clear solution.Carbon nanotube after the 150mg acid treatment is added in the above-mentioned solution, and ultra-sonic dispersion is poured into after 45 minutes in the experimental installation shown in Figure 1 and to be mixed above-mentioned mixing solutions and refluxed 10 hours in 160 ℃ silicone oil bath, naturally cools to room temperature then.The product that obtains respectively washs three times through hexanaphthene, dehydrated alcohol, promptly obtains the composite granule of nano-cobaltic-cobaltous oxide parcel carbon nanotube after the oven dry.Fig. 2 is the composite granule X-ray diffraction spectrogram of the parcel carbon nanotube of present embodiment preparation.Except a peak that belongs to the carbon pipe, other are all corresponding to the diffraction peak of tricobalt tetroxide among the figure.The diffraction peak of tricobalt tetroxide has tangible broadening, shows that the grain-size of tricobalt tetroxide is very little, and according to the Scherrer formula, its grain-size is 8nm.Fig. 3 is the transmission electron microscope photo of the composite granule of tricobalt tetroxide parcel carbon nanotube, and the tricobalt tetroxide uniform crystal particles covers carbon nano tube surface, and the tricobalt tetroxide grain-size is about 8nm, and cover thickness is 20nm.

Claims

1. the preparation method of the composite granule of the brilliant parcel of cobaltosic oxide nano carbon nanotube, comprise by the acidification carbon nanotube, make its surface produce electronegative active group, it is characterized in that: utilize the consistency and the electrostatic attraction effect of the active group and the cobalt ion of carbon nano tube surface, make the cobalt ion original position be adsorbed in carbon nano tube surface, and then form the composite granule of the nanocrystalline original position parcel of nano-cobaltic-cobaltous oxide carbon nanotube; It is characterized in that concrete steps are:

(a) with the carbon nanotube oven dry, remove the moisture that is contained;

(b) dried carbon nano-tube with concentrated nitric acid in 140 ℃ of reflow treatment 6-8 hours, carbon nano tube surface introducing-OH ,-COOH or-the CO active group, use deionized water repetitive scrubbing, dry for standby then;

(c) Cobaltous nitrate hexahydrate is dissolved in the n-hexyl alcohol, forms red clear solution, Cobaltous nitrate hexahydrate concentration is 0.02-0.08M in its solution;

(d) step (b) carbon nano tube modified is joined in the above-mentioned solution ultrasonic 15-60 minute;

(e) mixing solutions that step (d) is obtained is put into three-necked bottle, in 140-180 ℃ silicone oil bath backflow 5-10 hour, is adsorbed on the Co (NO of carbon nano tube surface ₃) ₂6H ₂O resolves into tricobalt tetroxide, thus the carbon nanotube dust of the synthetic tricobalt tetroxide parcel of reaction in;

(f) product promptly obtains the composite granule of the brilliant parcel of cobaltosic oxide nano carbon nanotube through hexanaphthene, each washing of dehydrated alcohol after the drying.

2. by the preparation method of the brilliant parcel of the described cobaltosic oxide nano of claim 1 carbon nano-tube composite powder, it is characterized in that the reaction in synthetic time is 5-20 hour.