A kind of iridium nanoparticle and its application in catalytic growth carbon nanotube
Technical field
The invention belongs to carbon nano-tube catalyst preparation technical fields, and in particular to a kind of iridium nanoparticle and its be catalyzed
Grow the application in carbon nanotube.
Background technique
Carbon nanotube suffers from many due to its excellent physical and chemical performance, in the energy, catalysis, environment and electronic field
Potential application value.Different carbon nanotubes has different structure and helical angle, and then shows different electricity and light
Learn performance.For example, the single-walled carbon nanotube of certain structures shows metallicity, and the carbon nanotube of other structures shows half
Conductor performance.While the diversity of carbon nano tube structure expands its application range to a certain extent, also inevitably it is
Its practical application is promoted to bring many difficulties.The structure separation method of carbon pipe achieved in past more than ten years it is considerable into
Exhibition.However, these separation methods tend to rely on complicated physical and chemical process, the structure for inevitably affecting carbon pipe is complete
Whole property and intrinsic performance, cost is very high, is unfavorable for the application study of carbon nanotube in integrated circuits.Therefore, how directly to make
The carbon nanotube of standby structure-controllable is the key points and difficulties of current carbon pipe preparation field.
Chemical vapour deposition technique is the main method of current preparation carbon nanotube due to the advantages that at low cost, controllability is high.
In the growth course of carbon pipe, catalyst is played a crucial role, because the surface texture of catalyst determines carbon nanometer
Pipe at nuclear thermodynamics.For the catalyst of specific components, the carbon that unique surface texture determines that catalytic growth comes out is received
The structure distribution of mitron.Therefore, the carbon nanotube that prepare specific structure needs to prepare the consistent catalyst of the Nomenclature Composition and Structure of Complexes and receives
Rice corpuscles.Metal nanoparticle size uniformity, structure made from Microwave reduction method are consistent, are that can provide to grow the excellent of carbon nanotube
The important method of good catalyst.
The catalyst of conventional growth carbon pipe be mainly containing iron, cobalt, nickel nanoparticle, then developed a series of expensive
Metal nanoparticle and non pinetallic nano particle-catalytic grow carbon nanotube.But most catalyst nanoparticles exist
It can all be in a liquid state under normal reaction temperature, be unfavorable for the control of carbon nano tube structure.It is therefore desirable to develop a kind of new life
The long effective catalyst of carbon is to realize the accurate control to carbon nano tube structure.
Summary of the invention
In view of the above shortcomings of the prior art, the present invention provides a kind of iridium nanoparticle and its in catalytic growth carbon nanotube
In application.The present invention is prepared for a kind of dystectic iridium nanoparticle, using it as carbon nano-tube catalyst is made, using chemistry
The carbon nanotube that vapour deposition process is prepared has many advantages, such as to grow uniform, structure-controllable, therefore has good industrialization
Application prospect.
One of the objects of the present invention is to provide a kind of preparation methods of iridium nanoparticle.
The second object of the present invention is to provide the iridium nanoparticle that the above method is prepared.
The third object of the present invention is to provide the application of above-mentioned iridium nanoparticle.
The fourth object of the present invention is to provide a kind of using iridium nanoparticle as the method for catalyst preparation carbon nanotube.
To achieve the above object, the present invention relates to following technical schemes:
The first aspect of the invention provides a kind of preparation method of iridium nanoparticle, which comprises
S1. lye is slowly added in iridium salting liquid, simultaneously ultrasonic vibration obtains deep brown solution for strong stirring;
S2. the solution of iridium nanoparticle must be contained by the deep brown solution that step S1 is prepared being carried out microwave treatment.
Preferably, in the step S1,
The concentration of lye is 0.1~0.3mol/L (preferably 0.2mol/L);
Preferably, the lye is dissolved in organic solvent for sodium hydroxide and being made, and the organic solvent is more preferably
Ethylene glycol;
Preferably, in the iridium salting liquid, iridium salt includes but is not limited to iridium chloride, sulfuric acid iridium, nitric acid iridium, carbonic acid iridium;Into
One step is preferably iridium chloride;Solvent selects organic solvent, further preferably ethylene glycol;
It is furthermore preferred that the iridium salting liquid is the preparation method comprises the following steps: take three chloride hydrate iridium and polyvinylpyrrolidone to be dissolved in second
In glycol, after stirring ultrasound to obtain the final product;
Wherein, polyvinylpyrrolidone Mw is 40,000.
Preferably, in the step S2,
Microwave treatment conditions are 2400~2500MHz (preferably 2450MHz), and 1~3min of microwave treatment is (preferably
2min)。
The second aspect of the invention provides the iridium nanoparticle that the above method is prepared.The iridium nanoparticle seed
Diameter is uniform, and average grain diameter is in 2~4nm.
The third aspect of the invention provides above-mentioned iridium nanoparticle as catalyst and is preparing answering in carbon nanotube
With.
The fourth aspect of the invention provides a kind of preparation method of carbon nanotube, and the method includes with iridium nanoparticle
Son is used as catalyst, using chemical vapor deposition for carbon nanotubes.
Specifically, the described method includes:
S1. iridium nano-particle solution is coated on titanium dioxide silicon chip surface, heating removal surface irregularities;
S2. by step S1, treated that titanium dioxide silicon wafer carries out heating treatment in an inert gas atmosphere, after be passed through an oxygen
Change carbon, carry out chemical vapor deposition, after cooling to obtain the final product.
Wherein, the inert gas is preferably argon gas, and ventilatory capacity is 200~400cm3/ min (preferably 300cm3/min);
Warming temperature control is 950-1050 DEG C;
The control of chemical vapor deposition time is 0.5~1.5h (preferably 1h), is not passed through inert gas during this period.
The invention has the advantages that:
The present invention successfully prepares nanoscale iridium particle for the first time, and directly using single nanoscale iridium particle as
Catalyst is used to prepare carbon nanotube.Iridium nanoparticle fusing point with higher is used using it as carbon nano-tube catalyst is made
The carbon nanotube that chemical vapour deposition technique is prepared has many advantages, such as to grow uniform, structure-controllable, carbon pipe diameter and nanometer
Grade iridium particle catalyst is suitable, therefore has good industrial applications prospect.
Detailed description of the invention
Fig. 1 is the transmission electron microscope picture of iridium nanoparticle prepared by embodiment 1;
Fig. 2 is the atomic force microscope phenogram of carbon nanotube prepared by embodiment 4.
Specific embodiment
It is noted that following detailed description is all illustrative, it is intended to provide further instruction to the application.Unless another
It indicates, all technical and scientific terms used herein has usual with the application person of an ordinary skill in the technical field
The identical meanings of understanding.
It should be noted that term used herein above is merely to describe specific embodiment, and be not intended to restricted root
According to the illustrative embodiments of the application.As used herein, unless the context clearly indicates otherwise, otherwise singular
Also it is intended to include plural form, additionally, it should be understood that, when in the present specification using term "comprising" and/or " packet
Include " when, indicate existing characteristics, step, operation, device, component and/or their combination.
As previously mentioned, catalyst nanoparticles can all be in a liquid state under normal reaction temperature, it is unfavorable for carbon nanotube knot
The control of structure.It is therefore desirable to develop a kind of new growth effective catalyst of carbon thus accurate control of the realization to carbon nano tube structure
System.
In view of this, a kind of preparation method of iridium nanoparticle is provided in an exemplary embodiment of the invention, it is described
Method includes:
S1. lye is slowly added in iridium salting liquid, simultaneously ultrasonic vibration obtains deep brown solution for strong stirring;
S2. the solution of iridium nanoparticle must be contained by the deep brown solution that step S1 is prepared being carried out microwave treatment.
Preferably, in the step S1,
The concentration of lye is 0.1~0.3mol/L (preferably 0.2mol/L);
In still another embodiment of the invention, the lye is dissolved in organic solvent for sodium hydroxide to be made, described
Organic solvent is more preferably ethylene glycol;
In still another embodiment of the invention, in the iridium salting liquid, iridium salt includes but is not limited to iridium chloride, sulfuric acid
Iridium, nitric acid iridium, carbonic acid iridium;Further preferably iridium chloride;Solvent selects organic solvent, further preferably ethylene glycol;
In still another embodiment of the invention, the iridium salting liquid is the preparation method comprises the following steps: taking three chloride hydrate iridium and gathering
Vinylpyrrolidone is dissolved in ethylene glycol, after stirring ultrasound to obtain the final product;
Wherein, polyvinylpyrrolidone Mw is 40,000.
In still another embodiment of the invention, in the step S2,
Microwave treatment conditions are 2400~2500MHz (preferably 2450MHz), and 1~3min of microwave treatment is (preferably
2min)。
In still another embodiment of the invention, the iridium nanoparticle that the above method is prepared is provided.The iridium is received
Rice corpuscles uniform particle sizes, average grain diameter is in 2~4nm.Iridium nanoparticle is prepared using Microwave reduction method in the present invention, and size is equal
Even, structure is consistent, is the excellent catalyst for preparing carbon nanotube.
In still another embodiment of the invention, above-mentioned iridium nanoparticle is provided as catalyst in preparation carbon nanotube
In application.
In still another embodiment of the invention, provide a kind of preparation method of carbon nanotube, the method includes with
Iridium nanoparticle is as catalyst, using chemical vapor deposition for carbon nanotubes.
Specifically, the described method includes:
S1. iridium nano-particle solution is coated on titanium dioxide silicon chip surface, heating removal surface irregularities;
S2. by step S1, treated that titanium dioxide silicon wafer carries out heating treatment in an inert gas atmosphere, after be passed through an oxygen
Change carbon, carry out chemical vapor deposition, after cooling to obtain the final product.
Wherein, the inert gas is preferably argon gas, and ventilatory capacity is 200~400cm3/ min (preferably 300cm3/min);
Warming temperature control is 950-1050 DEG C;
The control of chemical vapor deposition time is 0.5~1.5h (preferably 1h), is not passed through inert gas during this period.
Explanation is further explained to the present invention by the following examples, but is not construed as limiting the invention.It should be understood that
These examples are only for illustrating the present invention and are not intended to limit the scope of the present invention.Actual conditions are not specified in the following example
Test method, carry out usually according to normal condition.
The preparation of 1 iridium nanoparticle of embodiment
(1) sodium hydroxide for taking 0.04g, is dissolved in the ethylene glycol of 5ml, ultrasonic vibration 30min, and concentration is made and is
The sodium hydroxide solution of 0.2mol/L is as reducing agent;
(2) the three chloride hydrate iridium of 0.00176g and the polyvinylpyrrolidone (Mw=40,000) of 0.0287g are taken, are dissolved in
In the ethylene glycol of 4.8ml, 5min is stirred, then ultrasound 10min;
(3) sodium hydroxide solution for taking 0.2ml is slowly dropped in above-mentioned solution, will be along with strong during dropwise addition
Stirring, then ultrasonic vibration 10min, solution are in light brown;
(4) above-mentioned solution is placed in micro-wave oven (2450MHz, WP700), microwave 2min, solution becomes dark brown, cooling
It is spare.
Attached drawing 1 is the iridium nanoparticle TEM figure being prepared, it can be seen that iridium Nanoparticle Size is consistent, and distribution is equal
Even, average grain diameter is 2~4nm.
The preparation of 2 iridium nanoparticle of embodiment
(1) sodium hydroxide for taking 0.02g, is dissolved in the ethylene glycol of 5ml, ultrasonic vibration 20min, and concentration is made and is
The sodium hydroxide solution of 0.1mol/L is as reducing agent;
(2) the three chloride hydrate iridium of 0.00176g and the polyvinylpyrrolidone (Mw=40,000) of 0.0287g are taken, are dissolved in
In the ethylene glycol of 4.8ml, 5min is stirred, then ultrasound 10min;
(3) sodium hydroxide solution for taking 0.2ml is slowly dropped in above-mentioned solution, will be along with strong during dropwise addition
Stirring, then ultrasonic vibration 10min, solution are in light brown;
(4) above-mentioned solution is placed in micro-wave oven (2450MHz, WP700), microwave 2min, solution becomes dark brown, cooling
It is spare.
The preparation of 3 iridium nanoparticle of embodiment
(1) sodium hydroxide for taking 0.06g, is dissolved in the ethylene glycol of 5ml, ultrasonic vibration 30min, and concentration is made and is
The sodium hydroxide solution of 0.3mol/L is as reducing agent;
(2) the three chloride hydrate iridium of 0.00176g and the polyvinylpyrrolidone (Mw=40,000) of 0.0287g are taken, are dissolved in
In the ethylene glycol of 4.8ml, 5min is stirred, then ultrasound 10min;
(3) sodium hydroxide solution for taking 0.2ml is slowly dropped in above-mentioned solution, will be along with strong during dropwise addition
Stirring, then ultrasonic vibration 10min, solution are in light brown;
(4) above-mentioned solution is placed in micro-wave oven (2450MHz, WP700), microwave 2min, solution becomes dark brown, cooling
It is spare.
The preparation of 4 carbon nanotube of embodiment
(1) iridium nano-particle solution prepared by embodiment 1 is spin-coated on to the titanium dioxide silicon chip surface handled well, then in sky
600 DEG C of heating in gas, remove the organic matter of surface attachment;
(2) the titanium dioxide silicon wafer for being attached with iridium catalyst is placed in chemical vapour deposition reactor furnace, in inert gas (argon
Gas, 300cm3/ min) protection under be warming up to 950 DEG C;
(3) after rising to reaction temperature, carbon monoxide (300cm3/ min) it is passed through in reaction chamber, during which maintain temperature not
Become, and inert gas is turned off, reacts 1.2 hours;
(4) it is passed through inert gas again, closes carbon monoxide, is cooled to room temperature under inert gas protection.
Attached drawing 2 is the AFM figure for the carbon nanotube being prepared, it can be seen that carbon nanotube thickness is uniform, stable structure.
The preparation of 5 carbon nanotube of embodiment
(1) iridium nano-particle solution prepared by embodiment 2 is spin-coated on to the titanium dioxide silicon chip surface handled well, then in sky
600 DEG C of heating in gas, remove the organic matter of surface attachment;
(2) the titanium dioxide silicon wafer for being attached with iridium catalyst is placed in chemical vapour deposition reactor furnace, in inert gas (argon
Gas, 200cm3/ min) protection under be warming up to 1000 DEG C;
(3) after rising to reaction temperature, carbon monoxide (200cm3/ min) it is passed through in reaction chamber, during which maintain temperature not
Become, and inert gas is turned off, reacts 1 hour;
(4) it is passed through inert gas again, closes carbon monoxide, is cooled to room temperature under inert gas protection.
The preparation method of 6 carbon nanotube of embodiment:
(1) iridium nano-particle solution prepared by embodiment 3 is spin-coated on to the titanium dioxide silicon chip surface handled well, then in sky
700 DEG C of heating in gas, remove the organic matter of surface attachment;
(2) the titanium dioxide silicon wafer for being attached with iridium catalyst is placed in chemical vapour deposition reactor furnace, in inert gas (argon
Gas, 300cm3/ min) protection under be warming up to 1050 DEG C;
(3) after rising to reaction temperature, carbon monoxide (300cm3/ min) it is passed through in reaction chamber, during which maintain temperature not
Become, and inert gas is turned off, reacts 1 hour;
(4) it is passed through inert gas again, closes carbon monoxide, is cooled to room temperature under inert gas protection.
It should be noted that above example is only used to illustrate the technical scheme of the present invention rather than is limited.Although ginseng
It is described the invention in detail according to given example, but those skilled in the art can be as needed to this hair
Bright technical solution is modified or replaced equivalently, without departing from the spirit and scope of the technical solution of the present invention.