CN111498836A - Preparation method of nitrogen-doped reduced graphene oxide field emission cathode - Google Patents
Preparation method of nitrogen-doped reduced graphene oxide field emission cathode Download PDFInfo
- Publication number
- CN111498836A CN111498836A CN202010228089.2A CN202010228089A CN111498836A CN 111498836 A CN111498836 A CN 111498836A CN 202010228089 A CN202010228089 A CN 202010228089A CN 111498836 A CN111498836 A CN 111498836A
- Authority
- CN
- China
- Prior art keywords
- graphene oxide
- nitrogen
- field emission
- placing
- chitosan
- 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.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/184—Preparation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/194—After-treatment
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/198—Graphene oxide
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
- H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
Abstract
The invention discloses a preparation method of a nitrogen-doped reduced graphene oxide field emission cathode, which comprises the steps of adding graphene oxide into an organic solution, and adhering the graphene oxide to one end of a conductive graphite rod; and placing the conductive graphite rod stained with the graphene oxide in a quartz tube, carrying out chemical vapor deposition with excessive chitosan, and introducing hydrogen for reduction to obtain the nitrogen-doped redox graphene. Can be used for preparing the cathode of a field emission device. By doping nitrogen atoms, the invention can reduce the work function and introduce more emission sites on the surface of the graphene, effectively reduce the starting voltage of field emission, improve the emission enhancement factor, and can be used for electron sources in field emission flat-panel displays, field emission light sources, vacuum electronic devices and the like.
Description
Technical Field
The invention relates to a field emission technology, in particular to a preparation method of a nitrogen-doped reduced graphene oxide field emission cathode and the nitrogen-doped reduced graphene oxide field emission cathode.
Background
Graphene is a novel two-dimensional carbon nanomaterial, is formed by tightly stacking carbon atoms into hexagonal honeycomb lattices, and has good electrical conductivity and heat conductivity. Graphene theoretically has a large field enhancement factor, has rich edge structures, has strong field emission capability, and is expected to be utilized in the field emission fields of field emission flat panel displays, field emission light sources, vacuum electronic devices and the like. However, the field emission current intensity obtained by simply using graphene as a field emission cathode is not high, and the field enhancement factor is not large. Research shows that emission sites can be properly increased by doping nitrogen atoms into graphene, the starting voltage is reduced, and the field enhancement factor is improved, so that the field emission current intensity of the nitrogen-doped redox graphene is improved. The method is beneficial to the application of the graphene material in the field emission field.
At present, the method for manufacturing nitrogen-doped graphene mainly comprises a Chemical Vapor Deposition (CVD) method. However, the nitrogen content of the nitrogen-doped graphene obtained by the conventional method of placing the surface of the catalyst of the nitrogen precursor and the carbon precursor in a high-temperature furnace for chemical vapor deposition is not high, so that the effective emission site is not sufficient, an improvement space still exists in the aspect of improving the field emission performance, and meanwhile, the graphene on the substrate needs to be subjected to a complex transfer process, which is not favorable for manufacturing an actual device of the graphene field emission cathode.
Disclosure of Invention
The invention aims to provide a preparation method of a nitrogen-doped reduced graphene oxide field emission cathode, which effectively improves the nitrogen content of graphene and provides more emission sites for field emission.
The specific technical scheme for realizing the purpose of the invention is as follows:
a preparation method of a nitrogen-doped reduced graphene oxide field emission cathode comprises the following specific steps:
step 1: preparation of graphene oxide Dispersion
Mixing ethyl cellulose and terpineol in a mass ratio of 1:5-20 in a water bath at 60-100 ℃ for 2-6h, and stirring for 2-4h by using a magnetic controller to prepare an organic adhesive; mixing graphene oxide and an organic adhesive in a mass ratio of 1: 10-20 to obtain graphene oxide paste, and ultrasonically dispersing and dissolving for 0.5-2h to form graphene oxide dispersion liquid; dipping the dispersion liquid by using one end of a graphite stick;
step 2: doping with nitrogen
Drying the graphite rod in the step 1 for 30 minutes in a vacuum environment with the drying condition of 60-120 ℃; placing the dried graphite rod with graphene oxide at one end and chitosan in a quartz tube, and then placing the quartz tube in a tube furnace, wherein the opening direction of the quartz tube is opposite to the air inlet direction; a small tube filled with chitosan is placed in the quartz tube, and one end of the quartz tube is closed; placing a graphite rod with graphene oxide at one end at the closed end of a quartz tube, and placing a small tube filled with chitosan at the open end of the quartz tube and opposite to the graphite rod; introducing argon at the temperature of 300-; wherein the argon flow is 10-200 sccm;
and step 3: reduced nitrogen-doped graphene oxide
Placing the graphite rod in the step 2 in a quartz boat, placing the quartz boat in a 600-plus-one 1000 ℃ high-temperature furnace, introducing 5-100sccm hydrogen, and carrying out a reduction reaction in a hydrogen atmosphere of 5-100Pa to obtain the nitrogen-doped reduced graphene oxide field emission cathode; wherein: the chitosan is powder, and the mass of the chitosan is 0.1-5 g.
The graphene oxide is prepared by Hummer.
Compared with the existing scheme, the invention has the beneficial effects that:
(1) compared with the traditional nitrogen doping mode, the nitrogen doping mode provided by the invention effectively improves the nitrogen content of graphene, provides more emission sites for field emission, and simultaneously obtains a proper amount of defects, thereby being beneficial to reducing emission work function, improving the field emission capability of a cathode, reducing the starting voltage, improving the field enhancement factor and obviously improving the field emission current.
(2) Compared with the traditional CVD method for preparing the nitrogen-doped graphene, the chitosan is natural, non-toxic and environment-friendly. The method has the advantages of safer use of chitosan as the nitrogen precursor, environmental pollution avoidance, lower requirement on temperature for reaction conditions, safer and more effective use, low cost and good controllability.
Drawings
FIG. 1 is a schematic view of a process for preparing a nitrogen-doped reduced graphene oxide field emission cathode according to the present invention;
fig. 2 is a graph of variation of emission current density J with electric field E for the field emission cathode of the present invention and a conventional graphene field emission cathode.
FIG. 3 is a representation of the doping profile of nitrogen in accordance with the present invention.
Detailed Description
The present invention will be described in further detail below with reference to the accompanying drawings by way of specific embodiments.
Referring to fig. 1, the present invention specifically includes:
mixing graphene oxide with an organic solvent to obtain a graphene oxide dispersion liquid, dipping the dispersion liquid by using one end of a graphite rod 2, drying in vacuum, putting the dried dispersion liquid and chitosan 4 into a high-temperature heating furnace, introducing argon gas 1, heating and decomposing the chitosan 4 to generate a nitrogen-containing product, and reacting the nitrogen-containing product with graphene oxide 3 to dope nitrogen atoms;
and then placing the obtained sample in a quartz boat in a high-temperature furnace, and carrying out reduction reaction in the atmosphere of hydrogen 5 to obtain the nitrogen-doped reduced graphene oxide 6 field emission cathode.
The oxygen content of the graphene oxide is 56%, and the graphene oxide is prepared by using an improved Hummers method.
The preparation method comprises the following steps of mixing ethyl cellulose and terpineol in a water bath at 6-100 ℃ for 2-6h according to the mass ratio of 1:5-20, and then stirring the mixture with a magnetic controller for 2-4h to prepare the organic adhesive; mixing graphene oxide with an organic binder in a ratio of 1: 10-20 to obtain graphene oxide paste, and ultrasonically dispersing and dissolving for 0.5-2h to form graphene oxide dispersion liquid.
The drying condition of the dispersion liquid is drying for 0.5h in a vacuum environment at the temperature of 60-120 ℃.
The chitosan is powder, and the mass of the chitosan is 0.1-5 g.
The specific operation of the nitrogen atom doping reaction is that the graphite rod 1 and the chitosan 4 are respectively placed in a quartz tube, the chitosan 4 is placed at the bottom of a small test tube, an opening of the small test tube is opposite to the bottom of a large test tube, and the graphite rod 2 is placed at the bottom of the large test tube.
The reaction conditions in the process of reducing the nitrogen-doped graphene oxide by using the hydrogen are as follows: introducing 5-100sccm hydrogen into a high temperature furnace at 600-1000 ℃ to perform a reduction reaction under the hydrogen atmosphere of 5-100 Pa.
Example 1
1) Preparation of graphene oxide dispersion liquid
Mixing ethyl cellulose and terpineol in a mass ratio of 1: 20 in a water bath at 80 ℃ for 4 hours, and stirring for 4 hours by using a magnetic controller to prepare an organic adhesive; adding 1g of graphene oxide into 19g of organic binder, performing ultrasonic dispersion and dissolution for 0.5h to form graphene oxide dispersion liquid, and dipping a small amount of dispersion liquid on one end by using a graphite rod to obtain a graphene oxide dispersion liquid sample;
2) doping with nitrogen atoms
And (3) drying the graphite rod for 0.5h in a vacuum environment at 80 ℃. The dried sample and 0.5g of chitosan were placed in a quartz tube as shown in FIG. 1, and then placed in a high temperature furnace, the valve was closed, vacuum was slowly pulled, and argon gas was introduced at a flow rate of 20 sccm. Heating to 500 ℃ within 50 minutes, preserving the temperature for half an hour at 500 ℃, and taking out a sample after the temperature is reduced to room temperature;
3) reduction of oxygen atoms
And placing the sample in a quartz boat and then in a high-temperature furnace, vacuumizing the tube, performing reduction reaction for 1h at 900 ℃ under the hydrogen atmosphere of 50Pa, and cooling to room temperature to obtain the nitrogen-doped reduced graphene oxide field emission cathode.
Example 2
1) Preparation of graphene oxide dispersion liquid
Mixing ethyl cellulose and terpineol in a mass ratio of 1: 20 in a water bath at 80 ℃ for 4 hours, and stirring for 4 hours by using a magnetic controller to prepare an organic adhesive; adding 0.5g of graphene oxide into 10g of organic binder, performing ultrasonic dispersion and dissolution for 0.5h to form graphene oxide dispersion liquid, and dipping a small amount of dispersion liquid on one end by using a graphite rod to obtain a graphene oxide dispersion liquid sample;
2) doping with nitrogen atoms
And (3) drying the graphite rod for 0.5h in a vacuum environment at 70 ℃. The dried sample and 0.5g of chitosan were placed in a quartz tube as shown in FIG. 1, and then placed in a high temperature furnace, the valve was closed, vacuum was slowly pulled, and argon gas was introduced at a flow rate of 20 sccm. Heating to 600 ℃ within 60 minutes, preserving the temperature for half an hour at 600 ℃, and taking out a sample after the temperature is reduced to room temperature;
3) reduction of oxygen atoms
And placing the sample in a quartz boat and then in a high-temperature furnace, vacuumizing the tube, performing reduction reaction for 1h at 900 ℃ under a 50Pa hydrogen atmosphere, and cooling to room temperature to obtain the nitrogen-doped redox graphene field emission cathode.
Comparative example 3
1) Preparation of graphene oxide dispersion liquid
Mixing ethyl cellulose and terpineol in a mass ratio of 1: 20 in a water bath at 80 ℃ for 4 hours, and stirring for 4 hours by using a magnetic controller to prepare an organic adhesive; adding 1g of graphene oxide into 19g of organic binder, performing ultrasonic dispersion and dissolution for 0.5h to form graphene oxide dispersion liquid, and dipping a small amount of dispersion liquid on one end by using a graphite rod to obtain a graphene oxide dispersion liquid sample;
2) traditional nitrogen-doped redox graphene
And (3) drying the graphite rod for 0.5h in a vacuum environment at 80 ℃. Placing the dried sample in a high-temperature furnace for vacuumizing, introducing 10Pa hydrogen, heating to 1000 ℃ for 1.5h, preserving the temperature for 30 minutes in the atmosphere of 1000 ℃, and introducing 45PaC2H3Reacting for 1 hour by using N, and cooling to room temperature to obtain nitrogen-doped graphene oxide;
3) reduction of oxygen atoms
And placing the sample in a quartz boat and then in a high-temperature furnace, vacuumizing the tube, performing reduction reaction for 1h at 900 ℃ under a 50Pa hydrogen atmosphere, and cooling to room temperature to obtain the nitrogen-doped redox graphene field emission cathode.
And carrying out a field emission performance test on the prepared field emission cathode:
ITO glass is used as a cathode and an anode, the graphite rods obtained in the embodiment 1 and the comparative example are fixed on the cathode ITO glass through a conductive adhesive tape to be used as emitting electrodes, a device for measuring the field emission performance is obtained, and the field emission performance, the starting voltage and the field enhancement factor of different emitting electrodes are measured respectively. As can be seen from fig. 2, the nitrogen-doped reduced graphene oxide field emission cathode prepared by the method has the advantages of stronger field emission capability, lower turn-on voltage, significantly enhanced emission current and stronger field emission performance. FIG. 3 shows XPS characterization of example 1 with nitrogen doping levels as high as 4%.
While the invention has been described in further detail with reference to specific embodiments thereof, it will be understood by those skilled in the art that the present invention is not limited to the details of construction and that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims (2)
1. A preparation method of a nitrogen-doped reduced graphene oxide field emission cathode is characterized by comprising the following specific steps:
step 1: preparation of graphene oxide Dispersion
Mixing ethyl cellulose and terpineol in a mass ratio of 1:5-20 in a water bath at 60-100 ℃ for 2-6h, and stirring for 2-4h by using a magnetic controller to prepare an organic adhesive; mixing graphene oxide and an organic adhesive in a mass ratio of 1: 10-20 to obtain graphene oxide paste, and ultrasonically dispersing and dissolving for 0.5-2h to form graphene oxide dispersion liquid; dipping the dispersion liquid by using one end of a graphite stick;
step 2: doping with nitrogen
Drying the graphite rod in the step 1 for 30 minutes in a vacuum environment with the drying condition of 60-120 ℃; placing the dried graphite rod with graphene oxide at one end and chitosan in a quartz tube, and then placing the quartz tube in a tube furnace, wherein the opening direction of the quartz tube is opposite to the air inlet direction; a small tube filled with chitosan is placed in the quartz tube, and one end of the quartz tube is closed; placing a graphite rod with graphene oxide at one end at the closed end of a quartz tube, and placing a small tube filled with chitosan at the open end of the quartz tube and opposite to the graphite rod; introducing argon at the temperature of 300-; wherein the argon flow is 10-200 sccm;
and step 3: reduced nitrogen-doped graphene oxide
Placing the graphite rod in the step 2 in a quartz boat, placing the quartz boat in a 600-plus-one 1000 ℃ high-temperature furnace, introducing 5-100sccm hydrogen, and carrying out a reduction reaction in a hydrogen atmosphere of 5-100Pa to obtain the nitrogen-doped reduced graphene oxide field emission cathode; wherein: the chitosan is powder, and the mass of the chitosan is 0.1-5 g.
2. The method of making a nitrogen-doped reduced graphene oxide field emission cathode according to claim 1, wherein the graphene oxide is made by Hummer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010228089.2A CN111498836A (en) | 2020-03-27 | 2020-03-27 | Preparation method of nitrogen-doped reduced graphene oxide field emission cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010228089.2A CN111498836A (en) | 2020-03-27 | 2020-03-27 | Preparation method of nitrogen-doped reduced graphene oxide field emission cathode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111498836A true CN111498836A (en) | 2020-08-07 |
Family
ID=71878187
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010228089.2A Pending CN111498836A (en) | 2020-03-27 | 2020-03-27 | Preparation method of nitrogen-doped reduced graphene oxide field emission cathode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111498836A (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120149897A1 (en) * | 2010-12-10 | 2012-06-14 | Jeon In Yup | Method of preparing nitrogen-doped graphene and nitrogen-doped graphene prepared thereby |
| CN103407989A (en) * | 2013-06-24 | 2013-11-27 | 温州医学院 | Low-temperature environmentally-friendly preparation method of nitrogen edge doped graphene |
| CN105552371A (en) * | 2016-01-20 | 2016-05-04 | 福州大学 | Preparation and application of nitrogen-doped graphene-carbon nanohorn composite material |
| CN106700136A (en) * | 2016-11-18 | 2017-05-24 | 武汉理工大学 | Graphene/chitosan composite material and preparation method thereof |
| CN108335955A (en) * | 2018-01-11 | 2018-07-27 | 北京科技大学 | A kind of graphene-based field emission cold-cathode and preparation method |
| CN108831759A (en) * | 2018-06-26 | 2018-11-16 | 桂林电子科技大学 | One kind is based on graphene/chitosan multi-porous carbon composite and its preparation method and application |
| JP2019052083A (en) * | 2017-09-13 | 2019-04-04 | 東レ株式会社 | Graphene powder, graphene powder/organic solvent dispersion, graphene-electrode active material composite particle, electrode paste, and electrode |
| CN110155991A (en) * | 2019-04-24 | 2019-08-23 | 华东师范大学 | A kind of preparation method of redox graphene and nitrogen-doped graphene |
-
2020
- 2020-03-27 CN CN202010228089.2A patent/CN111498836A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120149897A1 (en) * | 2010-12-10 | 2012-06-14 | Jeon In Yup | Method of preparing nitrogen-doped graphene and nitrogen-doped graphene prepared thereby |
| CN103407989A (en) * | 2013-06-24 | 2013-11-27 | 温州医学院 | Low-temperature environmentally-friendly preparation method of nitrogen edge doped graphene |
| CN105552371A (en) * | 2016-01-20 | 2016-05-04 | 福州大学 | Preparation and application of nitrogen-doped graphene-carbon nanohorn composite material |
| CN106700136A (en) * | 2016-11-18 | 2017-05-24 | 武汉理工大学 | Graphene/chitosan composite material and preparation method thereof |
| JP2019052083A (en) * | 2017-09-13 | 2019-04-04 | 東レ株式会社 | Graphene powder, graphene powder/organic solvent dispersion, graphene-electrode active material composite particle, electrode paste, and electrode |
| CN108335955A (en) * | 2018-01-11 | 2018-07-27 | 北京科技大学 | A kind of graphene-based field emission cold-cathode and preparation method |
| CN108831759A (en) * | 2018-06-26 | 2018-11-16 | 桂林电子科技大学 | One kind is based on graphene/chitosan multi-porous carbon composite and its preparation method and application |
| CN110155991A (en) * | 2019-04-24 | 2019-08-23 | 华东师范大学 | A kind of preparation method of redox graphene and nitrogen-doped graphene |
Non-Patent Citations (2)
| Title |
|---|
| SHUXIAN YU ET.AL: "One-step synthesis of tunable nitrogen-doped graphene from graphene oxide and its high performance field emission properties", 《VACUUM》 * |
| SUBODHKUMAR ET.AL: "Doping and reduction of graphene oxide using chitosan-derived volatile N-heterocyclic compounds for metal-free oxygen reduction reaction", 《CARBON》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107204445B (en) | A kind of lithium ion battery three-dimensional porous silicon-carbon cathode material and preparation method thereof | |
| CN103864057B (en) | Phosphorus doping Graphene and its preparation method and application | |
| CN109830659B (en) | Te-doped MXene material and preparation method thereof | |
| CN102157315B (en) | Emitting cathode based on composite material of graphene/zinc oxide nanowire and preparation of same | |
| KR20120070973A (en) | N-doped transparent graphene film and method for preparing the same | |
| CN104923796A (en) | Method for industrially preparing graphene coated aluminum nanopowders | |
| CN108831757B (en) | A kind of preparation method of N and S codope graphene/carbon nano-tube aeroge | |
| CN108821331B (en) | Preparation method and product of gallium oxide nanorod | |
| Zeng et al. | Field emission of silicon nanowires | |
| CN103236324A (en) | Method for preparing reduced graphene oxide-based flexible transparent conductive thin film | |
| CN104103821A (en) | Preparation method for silicon-carbon anode material | |
| CN102623677A (en) | Process for producing high capacity molybdenum dioxide/carbon cathode materials | |
| CN111261431A (en) | Preparation method of nano cobaltosic oxide/nitrogen-doped three-dimensional porous carbon skeleton composite material for super capacitor | |
| CN109003826A (en) | N and S codope graphene-graphene nanobelt aeroge preparation method | |
| KR20130134123A (en) | Boron-doped reduction graphine of adjusting physical properties of semiconductor and electric conductivity, and preparation thereof | |
| CN101049932A (en) | Method for preparing one dimension SiC Nano fiber | |
| CN106847364A (en) | A kind of preparation method and application of the laminated film of copper-zinc-tin-sulfur and three-dimensional grapheme | |
| CN112794310B (en) | Potassium ion battery anode material and preparation method and application thereof | |
| CN111498836A (en) | Preparation method of nitrogen-doped reduced graphene oxide field emission cathode | |
| CN111223982B (en) | Preparation method of n-type multi-walled carbon nanotube thermoelectric material with stable air and high performance | |
| CN110911665B (en) | Boron and nitrogen doped lithium ion battery negative electrode material and preparation method thereof | |
| CN108321371A (en) | A kind of preparation method of silica and molybdenum trioxide composite positive pole | |
| CN105513921B (en) | Carbon nanometer field-transmitting cathode and its preparation method and application | |
| CN104477895A (en) | Preparation method of nitrogen-doped graphene for cathode of lithium ion battery | |
| KR100929433B1 (en) | Method of manufacturing carbon nanotube conductive film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200807 |