CN107603606B - Preparation method of nitride red nanowire - Google Patents

Abstract

The invention provides a growth method of a nitride red nanowire luminescent material, which mainly comprises the following steps of uniformly mixing an alkaline earth compound, a rare earth compound, aluminum oxide and a small amount of fluxing agent, then filling mixed raw materials into a small crucible, placing a mixture of carbon powder and ammonium citrate at two sides of the small crucible, preserving heat for 2-6 hours at 1300 ℃ and 1500 ℃ in a nitrogen atmosphere, depositing a red nanowire after the reaction is finished, and collecting a sample to obtain a finished product.

Description

Preparation method of nitride red nanowire

Technical Field

The invention belongs to the technical field of rare earth luminescent materials, and particularly relates to a preparation method of a nitride red nanowire.

Background

The methods for preparing nanowires currently can be broadly divided into two major categories, namely, vapor phase growth methods, which can be classified into chemical deposition (V L S) and physical deposition (VS), and liquid phase synthesis methods, which can be classified into template-assisted synthesis and melt-solution direct synthesis₂0₃Preparing GaN nanowires on a substrate; synthesizing ZnO nanowire on Si substrate by adopting chemical vapor growth method and preparing ZnO nanowire by utilizing hydrothermal methodExamples of CuO nanowires are given. Due to the novel physical properties, such as thermodynamic property, electron transport property, gas-sensitive property, photoelectric property and the like, presented by the one-dimensional nano material, electronic devices such as field effect transistors, chemical sensors, light emitting diodes, solar cells and the like can be manufactured on the basis of the unique excellent performance of the nano wires. The growth and synthesis of nanowires is one of the research hotspots in the current material science.

However, although some of the current nanowires can be observed to have photoluminescence, the application of the nanowires is mainly focused on directly preparing electronic devices, and the research reports of the application of the nanowires to fluorescence are relatively few, and the one-dimensional nitride nano fluorescent material capable of being excited to emit red light is more rarely reported. At present, fluorescent luminescent materials on the market mainly comprise different types of fluorescent powder, and meanwhile, zero-dimensional material quantum dot luminescent materials are gradually researched and applied. The one-dimensional fluorescent material can be used for the field of luminescence, and the development of the one-dimensional fluorescent material in the luminescence is relatively slow.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the invention aims to provide a preparation method of a nitride red nanowire, which is a one-dimensional nanowire luminescent material capable of being excited by light from a part of near ultraviolet region to visible region to emit red light and is grown and synthesized based on a V L S growth mechanism, and the one-dimensional nanowire luminescent material can be used for white light L ED illumination or other luminescent fields.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of nitride red nanowires comprises the following steps:

(1) weighing reaction raw materials and uniformly mixing to obtain a mixture; wherein the reaction raw materials are alkaline earth compounds, rare earth compounds, aluminum oxide and fluxing agents;

(2) loading the mixture into a crucible;

(3) placing a mixture of carbon powder and ammonium citrate at two sides of a crucible, and placing the mixture in a nitrogen atmosphere for reaction;

(4) and after cooling, collecting the red nanowires deposited on the edge of the crucible to obtain a finished product.

Referring to fig. 1, in order to improve reaction efficiency, the preparation method of the present invention preferably includes the steps of: weighing reaction raw materials, uniformly mixing the reaction raw materials, and then placing the mixture in one or more crucibles 2 to ensure that the reaction raw materials are just fully paved on the crucibles (or only paved on the bottoms of the crucibles to improve the utilization rate and the reaction efficiency of the raw materials); uniformly mixing carbon powder and ammonium citrate, placing the mixture in other 2 or more than 2 crucibles 1, respectively placing the crucibles 1 filled with the mixture of the carbon powder and the ammonium citrate at two sides of the crucible 2 filled with reaction raw materials, then placing the crucibles in a nitrogen atmosphere for reaction, and arranging the crucibles 1-2-1 in sequence from a nitrogen inlet to a nitrogen exhaust port; after cooling, the red nanowires deposited on the edge of the crucible 2 are collected, and the finished product is obtained.

Preferably, the preparation method of the nitride red nanowire comprises the following steps:

(1) weighing the reaction raw materials according to the formula M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Weighing raw materials and fluxing agent according to the stoichiometric ratio of the elements, and uniformly mixing to obtain a mixture;

(2) loading the mixture into a crucible;

(3) placing a mixture of carbon powder and ammonium citrate at two sides of a crucible, and placing the mixture in a nitrogen atmosphere for reaction;

(4) after cooling, collecting the red nanowires deposited on the edge of the crucible to obtain a finished product;

wherein M is an alkaline earth element, Re³⁺Is rare earth ions, x is more than or equal to 0.01 and less than or equal to 0.50, y is more than or equal to 0 and less than or equal to 0.5, a is more than or equal to 0.5 and less than or equal to 4, and b is more than or equal to 2.5 and less than or equal to 6.

More preferably, M is one or more of Ca, Sr and Ba alkaline earth elements, and Re³⁺Is Dy³⁺、Ho³⁺、Er³⁺、Nd³⁺、Pr³⁺、Ce³⁺One or more of them.

More preferably, the M is derived from oxides or carbonates of Ca, Sr and Ba, and the purity is analytically pure or more; re³⁺Derived from Dy³⁺、Ho³⁺、Er³⁺、Nd³⁺、Pr³⁺、Ce³⁺The purity of the oxide of (4N) or more; al is derived from alumina, the purity is more than analytical purity, and N is derived from nitrogen.

Preferably, the fluxing agent in the step (1) is SrCl₂、H₃BO₃One or two of the raw materials are added, and the added amount is 0.5 to 10 percent of the total mass of the reaction raw materials.

Preferably, the total amount of the carbon powder and the ammonium citrate is 1-5 times of the total mass of the reaction raw materials. The ammonium citrate adopted in the invention has two main functions, namely providing a synthetic raw material and providing a non-metal catalyst for growing the nano-wires.

More preferably, the mass ratio of the carbon powder to the ammonium citrate is 0.7-1.2.

Preferably, the reaction temperature of the reaction in the nitrogen atmosphere in the step (3) is 1300-1500 ℃, and the temperature is kept for 2-6 hours.

Preferably, the nitrogen atmosphere is high-purity nitrogen with a purity of 99.9% or more.

A nitride red nanowire with a chemical formula of M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Wherein M is one or more of Ca, Sr and Ba alkaline earth elements, Re³⁺Is Dy³⁺、Ho³⁺、Er³⁺、Nd³⁺、Pr³⁺、Ce³⁺One or more rare earth ions, x is more than or equal to 0.01 and less than or equal to 0.50, y is more than or equal to 0 and less than or equal to 0.5, a is more than or equal to 0.5 and less than or equal to 4, and b is more than or equal to 2.5 and less than or equal to 6.

Preferably, M is derived from oxides or carbonates of Ca, Sr and Ba, and the purity is analytically pure or higher; re³⁺Derived from Dy³⁺、Ho³⁺、Er³⁺、Nd³⁺、Pr³⁺、Ce³⁺The purity of the oxide of (4N) or more; al is derived from alumina, the purity is more than analytical purity, and N is derived from nitrogen.

The invention has the beneficial effects that:

(1) the invention is based on the growth mechanism of V L S to grow and synthesize nitride red nano-wire, which is different from the traditional method and provides a new synthesis mode for luminescent materials;

(2) the method uses raw materials with stable properties and low price, does not need harsh reaction conditions, and has simple preparation process;

(3) the nanowire grown and synthesized by the method of the invention has a vertical intersection reticular structure, good stability, high luminous efficiency, good color rendering property and excellent performance;

(4) the nitride red nanowire grown and synthesized by the method has the emission wavelength of between 600 and 640nm and the excitation spectrum of between 280 and 570 nm;

(5) the nitride red nanowire grown and synthesized by the method can be used for white L ED illumination or other light emitting fields.

Drawings

FIG. 1 is a schematic reaction scheme of the present invention;

(wherein 1 is ammonium citrate and carbon powder, 2 is reaction raw material)

FIG. 2 is a schematic representation of nanowires prepared according to the present invention;

fig. 3 excitation and emission spectra of red nitride nanowires of example 1 of the present invention;

(excitation spectrum with emission wavelength of 618nm (left) and emission spectrum with excitation wavelength of 500nm (right));

fig. 4 is a Scanning Electron Microscope (SEM) image of red nitride nanowires of example 1 of the present invention.

Detailed Description

Example 1

Alkaline earth nitride red nanowire Sr_2.99Al_0.5N_2.5:0.01Eu²⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Wherein, M is Sr, x is 0.01, a is 0.50, and b is 2.50), the raw materials are weighed according to the stoichiometric ratio:

SrCO₃：4.4141g

Al₂O₃：0.2549g

Eu₂O₃：0.0176g

SrCl₂：0.5193g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 2.2754g of carbon powder and 2.0268g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere at 1300 ℃ and is kept warm for 6 hours, red nanowires are deposited along the edge of the small crucible.

Example 2

Alkaline earth nitride red nanowire Sr_2.96Al_0.5N_2.5:0.03Eu²⁺，0.01Dy³⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe^{3 +}Where M ═ Sr, Re³⁺＝Dy³⁺X is 0.03, y is 0.01, a is 0.50, b is 2.50), the raw materials are weighed according to the stoichiometric ratio:

SrCO₃：4.3698g

Al₂O₃：0.2549g

Eu₂O₃：0.0529g

Dy₂O₃：0.0186g

SrCl₂：0.4162g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 2.2709g of carbon powder and 2.0268g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere and is kept at 1350 ℃ for 5 hours, red nanowires are deposited along the crucible.

Example 3

Alkaline earth nitride red nanowire Sr_2.88AlN₃:0.07Eu²⁺，0.05Ho³⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Where M ═ Sr, Re³⁺＝Ho³⁺X is 0.07, y is 0.05, a is 1.00, b is 3.00) by stoichiometric ratio:

SrO：2.9842g

Al₂O₃：0.5098g

Eu₂O₃：0.1232g

Ho₂O₃：0.0945g

SrCl₂：0.2160g

the weighed reaction raw materials are uniformly mixed and then are put into a small crucible, a mixture of 1.6694g of carbon powder and 2.4322g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere and is kept at 1350 ℃ for 5 hours, red nanowires are deposited along the crucible.

Example 4

Alkaline earth nitride red nanowire Ca_2.9Al_1.5N_3.5:0.10Eu²⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Where M ═ Ca, x ═ 0.10, a ═ 1.50, b ═ 3.50) preparation, the starting materials were weighed in stoichiometric proportions:

CaCO₃：2.9026g

Al₂O₃：0.7647g

Eu₂O₃：0.1760g

SrCl₂:0.2276g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 2.8123g of carbon powder and 2.8376g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere and is kept at 1400 ℃ for 4 hours, red nanowires are deposited along the crucible.

Example 5

Alkaline earth nitride red nanowire CaSr_1.5Al₂N₄:0.30Eu²⁺，0.20Ho³⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe^{3 +}Wherein M ═ Ca, Sr, Re³⁺＝Er³⁺X is 0.30, y is 0.20, a is 2.00, b is 4.00) by stoichiometric ratio:

SrO：1.5543g

CaO：0.5608g

Al₂O₃：1.0196g

Eu₂O₃：0.5279g

Er₂O₃：0.3825g

SrCl₂：0.1457g

H₃BO₃：0.0486g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 2.2769g of carbon powder and 3.2429g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere and is kept at 1400 ℃ for 4 hours, red nanowires are deposited along the crucible.

Example 6

Alkaline earth nitride red nanowire Ca_1.2SrAl_2.5N_4.5:0.50Eu²⁺，0.30Nd³⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Wherein M ═ Ca, Sr, Re³⁺＝Nd³⁺X is 0.50, y is 0.30, a is 2.50, b is 4.50) by stoichiometric ratio:

SrCO₃：1.4763g

CaCO₃：1.2011g

Al₂O₃：1.2745g

Eu₂O₃：0.8798g

Nd₂O₃：0.5047g

SrCl₂：0.0625g

H₃BO₃：0.1250g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 3.2577g of carbon powder and 3.6483g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere and is kept at 1450 ℃ for 4 hours, red nanowires are deposited along the crucible.

Example 7

Alkaline earth nitride red nanowire Ba_2.3Al₃N₅:0.20Eu²⁺，0.50Pr³⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Where M is Ba, Re³⁺＝Pr³⁺X is 0.20, y is 0.50, a is 3.00, b is 5.00) by stoichiometric ratio:

BaCO₃：4.5388g

Al₂O₃：1.5014g

Eu₂O₃：0.3519g

Pr₂O₃：0.8245g

SrCl₂：0.0412g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 2.2838g of carbon powder and 4.0537g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere at 1500 ℃ and kept warm for 4 hours, red nanowires are deposited along the crucible.

Example 8

Alkaline earth nitride red nanowire Ca_1.9Ba₂Al_3.5N_5.5:0.05Eu²⁺，0.03Dy³⁺，0.02Ho³⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Where M ═ Ca, Ba, Re³⁺＝Dy³⁺，Ho³⁺X is 0.05, y is 0.05, a is 3.50, b is 5.50) by stoichiometric ratio:

BaO：3.0665g

CaO：1.0655g

Al₂O₃：1.7843g

Eu₂O₃：0.0880g

Dy₂O₃：0.0560g

Ho₂O₃：0.0378g

H₃BO₃：0.3606g

the weighed raw materials are uniformly mixed and then are put into a small crucible, 3.3428g of carbon powder and 4.4590g of ammonium citrate mixture are respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere and is kept at 1450 ℃ for 3 hours, red nanowires are deposited along the crucible.

Example 9

Alkaline earth nitride red nanowire Sr_1.94BaAl₄N₆:0.03Eu²⁺，0.03Ce³⁺(M_(3-x-y)Al_aN_b：xEu²⁺，yRe^{3 +}Wherein M ═ Sr, Ba, Re³⁺＝Ce³⁺X is 0.03, y is 0.03, a is 4.00, b is 6.00) according toWeighing raw materials in a stoichiometric ratio:

SrCO₃：2.8640g

BaCO₃：1.9734g

Al₂O₃：2.0018g

Eu₂O₃：0.0528g

CeO₂：0.0516g

H₃BO₃：0.5712g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 8.6364g of carbon powder and 11.6745g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere at 1500 ℃ and is kept warm for 2 hours, red nanowires are deposited along the crucible.

Example 10

Alkaline earth nitride red nanowire Ba_2.8Al₄N₆:0.10Eu²⁺，0.05Pr³⁺，0.05Ce³⁺(M_(3-x-y)Al_aN_b：xEu^{2 +}，yRe³⁺Where M is Ba, Re³⁺＝Pr³⁺，Ce³⁺X is 0.10, y is 0.10, a is 4.00, b is 6.00) by stoichiometric ratio:

BaO：4.2931g

Al₂O₃：2.0018g

Eu₂O₃：0.1760g

Pr₂O₃：0.0825g

CeO₂：0.0861g

H₃BO₃：0.0786g

the weighed raw materials are uniformly mixed and then are put into a small crucible, a mixture of 12.6931g of carbon powder and 18.4847g of ammonium citrate is respectively placed at two sides of the small crucible, and after the mixture is placed in a nitrogen atmosphere at 1500 ℃ and is kept warm for 2 hours, red nanowires are deposited along the crucible.

Claims (6)

1. A preparation method of nitride red nanowires is characterized by comprising the following steps:

(1) weighing the reaction raw materials according to the chemical formula M_(3-x-y)Al_aN_b：xEu²⁺，yRe³⁺Weighing alkaline earth compounds, rare earth compounds, alumina and fluxing agents according to the stoichiometric ratio of the elements, and uniformly mixing to obtain a mixture;

(2) loading the mixture into a crucible;

(3) placing a mixture of carbon powder and ammonium citrate at two sides of a crucible, and placing the mixture in a nitrogen atmosphere for reaction;

(4) after cooling, collecting the red nanowires deposited on the edge of the crucible to obtain a finished product;

wherein M is alkaline earth elements, the M is one or more of Ca, Sr and Ba alkaline earth elements, and the M is derived from oxides or carbonates of Ca, Sr and Ba; re³⁺Is a rare earth ion, Re³⁺Is Dy³⁺、Ho³⁺、Er³⁺、Nd³⁺、Pr³⁺、Ce³⁺One or more of them, Re³⁺Derived from Dy³⁺、Ho³⁺、Er³⁺、Nd³⁺、Pr³⁺、Ce³⁺An oxide of (a); the fluxing agent in the step (1) is SrCl₂、H₃BO₃One or two of them; the reaction temperature of the step (3) in the nitrogen atmosphere is 1300-1500 ℃, and the temperature is kept for 2-6 hours; x is more than or equal to 0.01 and less than or equal to 0.50, y is more than or equal to 0 and less than or equal to 0.5, a is more than or equal to 0.5 and less than or equal to 4, and b is more than or equal to 2.5 and less than or equal to 6.

2. The method of claim 1, wherein M is derived from an oxide or carbonate of Ca, Sr, Ba, and has a purity of analytically pure or higher; re³⁺Derived from Dy³⁺、Ho³⁺、Er³⁺、Nd³⁺、Pr³⁺、Ce³⁺The purity of the oxide of (4N) or more; the purity of the alumina is analytically pure or higher.

3. The method of claim 1, wherein the flux in step (1) is SrCl₂、H₃BO₃One or two ofAnd the added amount is 0.5-10% of the total mass of the reaction raw materials.

4. The method for preparing nitride red nanowires according to claim 1, wherein the total amount of the carbon powder and the ammonium citrate is 1-5 times of the total mass of the reaction raw materials.

5. The method for preparing nitride red nanowires according to claim 4, wherein the mass ratio of the carbon powder to the ammonium citrate is 0.7-1.2.

6. The method of claim 1, wherein the nitrogen atmosphere is high purity nitrogen with a purity of 99.9% or more.

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