CN101728045B - Cobalt oxide/carbon composite nano wave-absorbing material and preparation method thereof - Google Patents
Cobalt oxide/carbon composite nano wave-absorbing material and preparation method thereof Download PDFInfo
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- CN101728045B CN101728045B CN2009101127808A CN200910112780A CN101728045B CN 101728045 B CN101728045 B CN 101728045B CN 2009101127808 A CN2009101127808 A CN 2009101127808A CN 200910112780 A CN200910112780 A CN 200910112780A CN 101728045 B CN101728045 B CN 101728045B
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Abstract
The invention discloses a cobalt oxide/carbon composite nano wave-absorbing material and a preparation method thereof and relates to a magnet/dielectric composite nano wave-absorbing material. The cobalt oxide/carbon composite nano wave-absorbing material has a core-shell structure, wherein the core is magnetic cobalt oxide; and the shell is a carbon layer. The preparation method comprises: adding a cobalt salt into a solvent, and after the cobalt salt is dissolved, filling the solution into a reaction kettle; placing the reaction kettle in an outer cover and heating the reaction kettle; after the reaction kettle cools naturally to room temperature, taking out supernatant liquor, carrying out centrifugal separation on lower precipitate, washing and drying the precipitate to obtain a flaky/flower-shaped cobalt hydroxide precursor; mixing the precursor and oleylamine in a quartz tube; after the precursor is dissolved, inserting the quartz tube in a tubular furnace to heat the quartz tube at a constant temperature for at least 20 minutes; and taking out the quartz tube, adding absolute ethanol, standing the mixture, carrying out centrifugal separation on the mixture, and washing and drying the precipitate to obtain the cobalt oxide/carbon magnet/dielectric composite nano wave-absorbing material.
Description
Technical field
The present invention relates to a kind of ferromagnetic/the dielectric composite nano wave-absorbing material, especially relating to a kind of amorphous carbon or graphitic carbon that is kernel to have ferromagnetic cobalt oxide, has a dielectricity is core/shell type composite nano wave-absorbing material of shell and preparation method thereof.
Background technology
Absorbing material has a wide range of applications in military field, has become the key of various countries' military equipment stealth technology research; And along with the development of electronics industry; The harm of electromagnetic radiation is serious day by day; Electromagnetic radiation has become the 4th pollutant sources after air pollution, water pollution and noise pollution; Biological environment and health have been caused serious harm, and using absorbing material is the effective way that solves electromagnetic pollution harm.Therefore the research to absorbing material has very important significance.Desirable absorbing material should have characteristics such as strong absorption, wideband section, thin thickness and light weight, and in order to satisfy these requirements better, preparation novel nano composite wave-suction material becomes current research focus.
State of development from present absorbing material; One type material is difficult to satisfy the composite request of " thin, light, wide, strong " that stealth technology proposed of improving day by day; Dielectric type absorbing material and the main coverage of magnetic absorbing material are respectively at the low side of superhigh frequency band and high-end; Therefore need multiple absorbing material be carried out compound best stealth effect, the raising absorbing property of obtaining of various ways.The nano combined two-phase absorbing material of ferromagnetic/dielectric has comprehensively been brought into play the excellent properties of two kinds of materials.In addition, exist a large amount of heterogeneous interfaces in ferromagnetic/dielectric composite construction, can produce electromagnetic consumable mechanism such as multiple refraction-multiple absorption and interfacial polarization, so ferromagnetic/dielectric nano composite material has huge development space and good prospects for application.Ferromagnetic/the dielectric nano composite material, like α-Fe/Fe
3B/Y
2O
3Composite particles, Fe/CNT etc. have demonstrated outstanding absorbing property, though because the individual layer absorbing material that contains heterogeneous wave-absorber is optimal absorbing material, if will directly obtain, from principle and technical all be difficulty very.
In the research in present this field, mainly through vapour deposition (Che, R.C.; Peng, L.M.; Duan; X.F.Microwave absorption enhancement and complex permittivity and permeability of Fe encapsulated within carbon nanotubes [J] .Adv.Mater; 401.), arc discharge (Liu, X.G. 2004,16 (5):; Geng, D.Y.; Zhang.Z.D.Microwave-absorption properties of ZnO-coated iron nanocapsules [J] .Appl.Phys.Lett, 2008,92:1731171.), heat treatment-ball milling (Liu, J.R.; Ltoh, M.; Machida.K.I.Elecrtomagnetic wave absorption properties of α-Fe/Fe
3B/Y
2O
3Nanocomposites in gigahertz range [J] .Appl.Phys.Lett; 4017.) etc. 2000,83 (19): method prepares ferromagnetic/dielectric nano composite material, these method complex process; Reaction condition is harsh relatively; Operating process is loaded down with trivial details relatively, and productive rate is lower, thereby in practical application, has received restriction to a certain degree.
Summary of the invention
The purpose of this invention is to provide a kind of cobalt oxide/carbon composite nano absorbing material and preparation method thereof.
Cobalt oxide according to the invention/carbon composite nano absorbing material is a nucleocapsid structure, and kernel is a ferromagnetism cobalt oxide kernel, and shell is a carbon-coating, and kernel is coated in the shell; Said ferromagnetism cobalt oxide kernel is the cobalt oxide nano particle, or nanometer sheet, or the aggregation that is made up of nano particle or nanometer sheet, and the particle diameter of said ferromagnetism cobalt oxide kernel is 10～300nm; Said carbon-coating is an amorphous carbon layer, or the graphite carbon-coating, or amorphous carbon and graphitic carbon mixing carbon-coating, and the thickness of said carbon-coating is 1～100nm.
The preparation method of cobalt oxide according to the invention/carbon composite nano absorbing material may further comprise the steps:
1) cobalt salt is added in the solvent, after the cobalt salt dissolving, in the agitated reactor of packing into;
2) with the agitated reactor overcoat of packing into, heating;
3) after the question response still naturally cools to room temperature, take out supernatant liquor, the centrifugation lower sediment is cleaned, and oven dry promptly gets sheet/flower-shaped cobalt hydroxide predecessor.
4) in quartz ampoule, predecessor is mixed with oleyl amine, the dissolving back is inserted quartz ampoule in the tube furnace and is heated, and constant temperature behind the 20min takes out quartz ampoule at least; Add absolute ethyl alcohol, leave standstill, the centrifugation deposition; Dry after the washing and precipitating; Promptly get cobalt oxide/carbon ferromagnetic/the dielectric composite nano wave-absorbing material, this product be a kind of ferromagnetic/the dielectric composite nano materials, kernel is for having ferromagnetic cobalt oxide kernel; Shell is to have the amorphous carbon layer of dielectricity or the mixed layer of graphite carbon-coating and amorphous carbon and graphitic carbon, and kernel is coated in the shell.
In step 1), said cobalt salt preferably is selected from a kind of in cobalt nitrate, cobalt chloride, the cobalt acetate etc.; Said alcohol preferably is selected from a kind of in ethanol, normal propyl alcohol, n-butanol, the n-amyl alcohol etc.; Said hydramine preferably is selected from a kind of in monoethanolamine, diethanol amine, the triethanolamine etc.; Said solvent is preferably water, pure and mild hydramine mixed solvent, and by volume, water: alcohol: hydramine can be 20: (1～20): (1～20) is preferably 10: 5: 4.
In step 2) in, the temperature of said heating can be 170～200 ℃, but constant temperature 2h at least after the heating; The temperature of said heating is preferably 180 ℃, and the heating back is constant temperature 12h preferably.
In step 3), said cleaning preferably successively water and ethanol clean repeatedly at least 3 times, the temperature of said oven dry is preferably 80 ℃.
In step 4), the consumption of said predecessor and oleyl amine, by volume; Predecessor: oleyl amine can be 1: (25～50), predecessor: oleyl amine is preferably 1: 25, and ultrasonic dissolution is preferably adopted in said dissolving; The temperature of said heating can be 260～350 ℃, is preferably 300 ℃, and the time of said constant temperature is preferably 20min; Said cleaning is preferably cleaned 1 time with cyclohexane and absolute ethyl alcohol successively repeatedly at least, and the temperature of said oven dry is preferably 80 ℃.
The present invention carries out solvent thermal reaction through inorganic cobalt salt is dissolved in the mixed solvent, obtains the predecessor of nanoscale, and heat treatment in organic amine then obtains the product that the surface has coated carbon-coating equably, has formed ferromagnetic/dielectric composite nano wave-absorbing material.With respect to the preparation method of the ferromagnetic/dielectric composite nano wave-absorbing material of present report and the carbon method for coating on the surface, outstanding advantage of the present invention is:
What 1) the present invention adopted is a kind of simple liquid chemical method; Have easy and simple to handle, condition and be easy to characteristics such as control; And at present the preparation method of the ferromagnetic/dielectric composite nano wave-absorbing material of bibliographical information mainly is main (needing accurately strictly control conditions such as air-flow in the preparation process, air pressure) with the vapour deposition process; By contrast, condition and range of the present invention is looser.
2) at present the method for the coated with carbon of report need be passed through the multistep operations such as hydrolysis, high-temperature heat treatment of glucose, and to the strictness of required conditions such as hydrolysis pH value, heat treatment temperature, and the present invention is in the process of carbon coated, and conditions needed is simple.
3) product productive rate of the present invention is high, and with respect to the high temperature of vapour deposition more than 1000 ℃, mild condition of the present invention, this can be large-scale production and reduces cost.
4) because the prepared cobalt oxide of the present invention/carbon composite nano absorbing material adopts ferromagnetic material and dielectric material compound, therefore not only have loose structure, and have excellent absorbing property, can satisfy the actual needs of the relevant military project and the product for civilian use.
Description of drawings
Fig. 1 is the SEM figure of the predecessor of the embodiment of the invention.In Fig. 1; The gained predecessor is that cabaltous nitrate hexahydrate adds (water: ethanol: diethanol amine=20: 10: 1) in the mixed solvent that entry, ethanol and diethanol amine form under magnetic agitation; After treating to dissolve fully, the solution agitated reactor of packing into is heated to 180 ℃, keeps obtaining behind the 12h; Predecessor is a sheet, and thickness is 10～50nm, and size is about 300nm.
Fig. 2 is the product S EM figure that the predecessor of the embodiment of the invention after heat treatment obtains.Can find out that by Fig. 2 product has still kept the laminated structure of predecessor well.
Fig. 3 is the HRTEM figure of single sheet product.In Fig. 3, wherein several groups of interplanar distances have been measured, 0.087nm=d
CoO (422), 0.212nm=d
CoO (200), 0.113nm=d
CoO (400),, determine that it is CoO (JCPDS43-1004), space group Fm-3m, cell parameter according to these d values
Fig. 4 is the high resolution picture of sheet product marginal portion.In Fig. 4, select the outermost layer place to measure interplanar distance, 0.359nm is corresponding to the crystal face of graphitic carbon (JCPDS 02-0456); Visible exterior has coated the thick carbon-coating of 1～5nm, and graphitization takes place the existing part of carbon-coating.
Fig. 5 is the magnetic hysteresis loop of sheet product under low temperature (2K) and room temperature (300K).In Fig. 5, abscissa is magnetic field intensity H [T], and ordinate is M (magnetization) [emu/g]; ■ is 2K, ● be 300K; Can see that product is in 2K and 300
All demonstrate ferromagnetism during K.
Fig. 6 is a ZFC-FC curve under the sheet product 200Oe.In Fig. 6, ordinate is M (magnetization) [emu/g]; is ZFC (null field cooling), and zero is FC (cooling); The phase transition temperature of product is very high, about 300K; Abscissa is temperature T [K].
Fig. 7 inhales the three-dimensional cloud atlas of ripple for the sheet product.In Fig. 7, the loss of sheet product maximum reflection is 55dB; Abscissa is frequency Frequency (G Hz), and left ordinate is thickness T hickness (mm), right ordinate be reflection loss Reflectloss (dB).
Fig. 8 is that ripple figure is inhaled at the single thickness place of sheet product.In Fig. 8, abscissa is frequency Frequency (G Hz), ordinate be reflection loss Reflectloss (dB); Inhaling the thickness that the ripple curve represents respectively from left to right is 3mm, 2.5mm, 2mm, 4.496mm; The sheet product is at thickness 4.496mm, and frequency 16.41GHz place reaches maximum reflection loss 55dB.
Fig. 9 is the SEM figure of the predecessor of the embodiment of the invention.In Fig. 9, predecessor is that cabaltous nitrate hexahydrate adds in the mixed solvent that entry, ethanol and diethanol amine form (water: ethanol: diethanol amine=20: 10: 8), the solution agitated reactor of packing into is heated to 180 ℃, keeps obtaining behind the 12h under magnetic agitation; The flower-shaped thing of predecessor as shown in the figure for being self-assembled into by sheet, size is about 2 μ m, and is dispersed fine.
The product S EM figure that Figure 10 after heat treatment obtains for predecessor.In Figure 10, product still keeps the flower-like structure of predecessor well, but the surface becomes coarse by smooth.
Figure 11 is the TEM figure of single flower-shaped product.In Figure 11, can be clear that coating has all taken place on the surface of every flower.
Figure 12 is the HRTEM figure of flower-shaped product marginal portion.In Figure 12, can see that the carbon-coating thickness of coating is about 100nm.
Figure 13 is the magnetic hysteresis loop of flower-shaped product under low temperature (2K) and room temperature (300K).In Figure 13, abscissa is magnetic field intensity H [T], and ordinate is M (magnetization) [emu/g]; ■ is 2K, ● be 300K; Can see that product all is different from the antiferromagnetism of general CoO when 2K and 300K, but demonstrate ferromagnetism.
Figure 14 is a ZFC-FC curve under the flower-shaped product 200Oe.In Figure 14, abscissa is temperature T [K], and ordinate is M (magnetization) [emu/g]; is ZFC (null field cooling), and zero is FC (cooling); The phase transition temperature of product is very high, about 300K.
Figure 15 is that flower-shaped product is inhaled the three-dimensional cloud atlas of ripple.In Figure 15, abscissa is frequency Frequency (G Hz), and left ordinate is thickness T hickness (mm), right ordinate be reflection loss Reflectloss (dB); Flower-shaped product maximum reflection loss 40dB.And when thickness 2.5mm was following, flower-shaped product can reach the absorption more than the 10dB in 8～18GHz band limits, in 10～15GHz scope internal reflection loss value greater than 30dB.
Figure 16 is that ripple figure is inhaled at the single thickness place of flower-shaped product.In Figure 16, abscissa is frequency Frequency (G Hz), ordinate be reflection loss Reflectloss (dB); Inhaling the thickness that the ripple curve represents respectively from left to right is 3.0mm, 2.5mm, 2.398mm, 2.0mm; At thickness 2.4mm, frequency 12.79GHz place reaches maximum reflection loss value 40dB.
Embodiment
Through embodiment combination figure the present invention is described further below.
Embodiment 1
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 31mL form (water: ethanol: diethanol amine=20: 10: 1), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain hydroxide flake cobalt precursor thing.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
Predecessor and product carry out systematic research through modern nanometer test and analysis technologies such as SEM, TEM, HRTEM to its pattern, composition, micro-structural, and product has used the SQUID magnetometer to carry out magnetic characterization, and the network vector analyzer carries out the absorbing property analysis.SEM characterizes as illustrated in fig. 1 and 2, and predecessor and product are laminated structure, and diameter is about 300nm.Choose single tablet it is carried out the high resolution picture analysis; Fig. 3 and 4 is the HRTEM figure of in the middle of the selected sheet product and marginal portion; Determine that it is CoO (JCPDS 43-1004) through measuring interplanar distance at mid portion; Space group Fm-3m; Cell parameter
is through after the oleyl amine heat treatment, and the products therefrom surface is coated with the thick carbon-coating of 1-5nm.
Fig. 5 and 6 is magnetic characterization of product, can see that resulting product has strong ferromagnetism, and it all demonstrates ferromagnetism and has higher phase transition temperature when 2K and 300K.
Fig. 7 and 8 is that the absorbing property of product characterizes, and can see resulting product as dielectric/ferromagnetic composite nano wave-absorbing material, and it is at thickness 4.5mm, and frequency 16.41GHz place reaches maximum reflection loss 55dB, has excellent absorbing property.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 38mL form (water: ethanol: diethanol amine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain flower-shaped cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
SEM characterizes shown in Fig. 9 and 10, and predecessor and product are the flower-shaped thing that the sheet of serving as reasons is formed, and size is about 2um.Choose single flower-shaped thing it is carried out the high resolution picture analysis; Figure 11 and 12 is the HRTEM figure of selected flower-shaped product and marginal portion; Can be clearly seen that by the TEM figure of flower-shaped product and the high resolution picture of marginal portion carbon-coating all coats the surface of every flower, carbon-coating thickness is about 100 nanometers.
Figure 13 and 14 is the magnetic characterization of product, can see that resulting product has strong ferromagnetism, and it all demonstrates ferromagnetism and has higher phase transition temperature when 2K and 300K.
Figure 15 and 16 is that the absorbing property of product characterizes; Can see that resulting product is as dielectric/ferromagnetic composite nano wave-absorbing material; When thickness 2.5mm is following, in 8～18GHz band limits, can reach the absorption more than the 10dB, in 10～15GHz scope internal reflection loss value greater than 30dB.At thickness 2.4mm, frequency 12.79GHz place reaches maximum reflection loss value 40dB.This shows that resulting product work has excellent absorbing property.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 31mL form (water: ethanol: diethanol amine=20: 1: 10), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 60min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 38mL form (water: ethanol: diethanol amine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 170 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 38mL form (water: ethanol: diethanol amine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 200 ℃ in the baking oven, keep 2h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 31mL form (water: ethanol: diethanol amine=20: 1: 10), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 50 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 45min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
Embodiment 7
(1) takes by weighing 0.3g CoCl
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 31mL form (water: ethanol: diethanol amine=20: 1: 10), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 260 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g CoAc
24H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the diethanol amine of 32mL form (water: ethanol: diethanol amine=20: 1: 20), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 360 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
Embodiment 9
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the monoethanolamine of 38mL form (water: ethanol: monoethanolamine=20: 20: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, ethanol and the triethanolamine of 38mL form (water: ethanol: triethanolamine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
Embodiment 11
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, normal propyl alcohol and the diethanol amine of 38mL form (water: normal propyl alcohol: diethanol amine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, n-butanol and the diethanol amine of 38mL form (water: n-butanol: diethanol amine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
Embodiment 13
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, n-amyl alcohol and the diethanol amine of 38mL form (water: n-amyl alcohol: diethanol amine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, normal propyl alcohol and the monoethanolamine of 38mL form (water: normal propyl alcohol: monoethanolamine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
(1) takes by weighing 0.3g Co (NO
3)
26H
2O, under magnetic agitation, add in the mixed solvent that water, n-butanol and the triethanolamine of 38mL form (water: n-butanol: triethanolamine=20: 10: 8), after treating to dissolve fully, with the solution polytetrafluoroethylene agitated reactor of packing into.
(2) with the agitated reactor stainless steel outer sleeve of packing into, be put in and be heated to 180 ℃ in the baking oven, keep 12h.
(3) after the question response still naturally cools to room temperature, take out and pour out supernatant liquor, the centrifugation lower sediment is cleaned 3 times with absolute ethyl alcohol, and 80 ℃ of oven dry promptly obtain the cobalt hydroxide predecessor.
(4) in quartz ampoule, predecessor and oleyl amine were mixed in 1: 25 by volume, ultrasonic dissolution inserts quartz ampoule in the vertical tube furnace then and is heated to 300 ℃ rapidly; Behind the 30min quartz ampoule is taken out; Add absolute ethyl alcohol and leave standstill, the centrifugation deposition is with cyclohexane/absolute ethyl alcohol washing and precipitating repeatedly; 80 ℃ of oven dry promptly obtain target product.
Claims (14)
1. cobalt oxide/carbon composite nano absorbing material is characterized in that being nucleocapsid structure, and kernel is a ferromagnetism cobalt oxide kernel, and shell is a carbon-coating, and kernel is coated in the shell; Said ferromagnetism cobalt oxide kernel is the cobalt oxide nano particle, or nanometer sheet, or the aggregation that is made up of nano particle or nanometer sheet, and the particle diameter of said ferromagnetism cobalt oxide kernel is 10～300nm; Said carbon-coating is an amorphous carbon layer, or the graphite carbon-coating, or amorphous carbon and graphitic carbon mixing carbon-coating, and the thickness of said carbon-coating is 1～100nm.
2. the preparation method of cobalt oxide as claimed in claim 1/carbon composite nano absorbing material is characterized in that may further comprise the steps:
1) cobalt salt is added in the solvent, after the cobalt salt dissolving, in the agitated reactor of packing into;
2) with the agitated reactor overcoat of packing into, heating;
3) after the question response still naturally cools to room temperature, take out supernatant liquor, the centrifugation lower sediment is cleaned, and oven dry promptly gets sheet or flower-shaped cobalt hydroxide predecessor;
4) in quartz ampoule, predecessor is mixed with oleyl amine, the dissolving back is inserted quartz ampoule in the tube furnace and is heated, and constant temperature behind the 20min takes out quartz ampoule at least; Add absolute ethyl alcohol, leave standstill, the centrifugation deposition; Dry after the washing and precipitating, promptly get the ferromagnetic and dielectric composite nano wave-absorbing material that is made up of cobalt oxide and carbon, this product is a kind of ferromagnetic and dielectric composite nano materials; Kernel is for having ferromagnetic cobalt oxide kernel, and shell is the amorphous carbon layer with dielectricity, or the graphite carbon-coating; Or the mixed layer of amorphous carbon and graphitic carbon, kernel is coated in the shell.
3. the preparation method of cobalt oxide as claimed in claim 2/carbon composite nano absorbing material is characterized in that in step 1), and said cobalt salt is selected from a kind of in cobalt nitrate, cobalt chloride, the cobalt acetate.
4. the preparation method of cobalt oxide as claimed in claim 2/carbon composite nano absorbing material is characterized in that in step 1), and said solvent is water, pure and mild hydramine mixed solvent, and by volume, water: alcohol: hydramine is 20: (1～20): (1～20).
5. the preparation method of cobalt oxide as claimed in claim 4/carbon composite nano absorbing material is characterized in that by volume water: alcohol: hydramine is 10: 5: 4.
6. the preparation method of cobalt oxide as claimed in claim 4/carbon composite nano absorbing material is characterized in that in step 1), and said alcohol is selected from a kind of in ethanol, normal propyl alcohol, n-butanol, the n-amyl alcohol.
7. the preparation method of cobalt oxide as claimed in claim 4/carbon composite nano absorbing material is characterized in that in step 1), and said hydramine is selected from a kind of in monoethanolamine, diethanol amine, the triethanolamine.
8. the preparation method of cobalt oxide as claimed in claim 2/carbon composite nano absorbing material is characterized in that in step 2) in, the temperature of said heating is 170～200 ℃, heating back constant temperature is 2h at least.
9. the preparation method of cobalt oxide as claimed in claim 8/carbon composite nano absorbing material, the temperature that it is characterized in that said heating is 180 ℃, heating back constant temperature 12h.
10. the preparation method of cobalt oxide as claimed in claim 2/carbon composite nano absorbing material is characterized in that in step 3), and said cleaning water and ethanol is successively cleaned 3 times repeatedly at least, and the temperature of said oven dry is 80 ℃.
11. the preparation method of cobalt oxide as claimed in claim 2/carbon composite nano absorbing material is characterized in that in step 4), the consumption of said predecessor and oleyl amine, and by volume, predecessor: oleyl amine is 1: 25～50.
12. the preparation method of cobalt oxide as claimed in claim 11/carbon composite nano absorbing material is characterized in that the consumption of said predecessor and oleyl amine, by volume, predecessor: oleyl amine is 1: 25.
13. the preparation method of cobalt oxide as claimed in claim 2/carbon composite nano absorbing material; It is characterized in that in step 4); Said dissolving is to adopt ultrasonic dissolution, and the temperature of said heating is 260～350 ℃, and the time of said constant temperature is 20min; Said cleaning is to clean repeatedly at least 1 time with cyclohexane and absolute ethyl alcohol successively, and the temperature of said oven dry is 80 ℃.
14. the preparation method of cobalt oxide as claimed in claim 13/carbon composite nano absorbing material, the temperature that it is characterized in that said heating is 300 ℃.
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| CN102527303B (en) * | 2011-12-21 | 2014-04-09 | 中国科学院合肥物质科学研究院 | Ferromagnetic Co3C@C core-shell nanostructure and continuous preparation method thereof |
| CN102554257B (en) * | 2012-01-16 | 2013-10-30 | 北京航空航天大学 | Amorphous core-shell structure nanoparticle and preparation method thereof |
| CN103086441A (en) * | 2013-01-15 | 2013-05-08 | 西安交通大学 | Preparation method of nano Co3O4 octahedron powder |
| CN103725073B (en) * | 2013-12-31 | 2016-01-20 | 张锦碧 | A kind of invisible coating |
| CN105885784A (en) * | 2016-04-18 | 2016-08-24 | 青岛大学 | Preparation method of wave-absorbing material adopting core-shell structure |
| CN109650933B (en) * | 2019-01-28 | 2021-03-30 | 陕西科技大学 | Porous Co3O4/Al2SiO5Low-density wave-absorbing type complex phase ceramic and preparation method thereof |
| CN109663930B (en) * | 2019-02-12 | 2022-03-08 | 闽江师范高等专科学校 | Spontaneous combustion micro-nano metal material and preparation method thereof |
| CN115233170B (en) * | 2022-06-22 | 2023-12-12 | 中国科学院宁波材料技术与工程研究所 | Ultrathin metal oxide-based nanomaterial with high catalytic performance as well as preparation method and application thereof |
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