Preparation method of lanthanum europium molybdate red luminescent powder

A technology of red luminescence and lanthanum molybdate, which is applied in the direction of luminescent materials, chemical instruments and methods, and the use of gas discharge lamps, can solve the problems of reduced luminous efficiency and difficulty in accurately perfecting the chemical composition, and achieve regular powder morphology, Uniform particle size effect

Inactive Publication Date: 2011-02-16
HEBEI NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Since the atoms or ions participating in the reaction are limited by the cohesion of the crystal, it is impossible to move freely like in the liquid phase reaction, and the chemical composition inside the product is difficult to be perfected accurately. These factors will lead to a decrease in luminous efficiency.

Method used

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  • Preparation method of lanthanum europium molybdate red luminescent powder
  • Preparation method of lanthanum europium molybdate red luminescent powder
  • Preparation method of lanthanum europium molybdate red luminescent powder

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Embodiment 1

[0020] (1) Lanthanum oxide and europium oxide are dissolved in nitric acid respectively to make lanthanum nitrate and europium nitrate solutions, the concentration of lanthanum nitrate solution is 0.3mol / L, and the concentration of europium nitrate solution is 0.2mol / L; dissolve heptamolybdenum with 18ml deionized water Ammonium heptamolybdate 1.410g is mixed with ammonium heptamolybdate solution to make the ammonium heptamolybdate solution concentration 0.06mol / L;

[0021] (2) Take 18.6ml of lanthanum nitrate solution and 12.0ml of europium nitrate solution, add 15ml of water and stir to form a mixed solution, then add 3.2ml of surfactant (PEG 400) to the mixed solution, and keep stirring;

[0022] (3) Ammonium heptamolybdate solution is added dropwise in the above-mentioned mixed solution, and then a small amount of 6mol / L ammonia water is added to adjust the pH value of the solution to 8.5 to form a suspension;

[0023] (4) Transfer the suspension to a 100ml high-pressure r...

Embodiment 2

[0026] (1) Lanthanum oxide and europium oxide are dissolved in nitric acid respectively to make lanthanum nitrate and europium nitrate solution, the concentration of lanthanum nitrate solution is 0.3mol / L, and the concentration of europium nitrate solution is 0.2mol / L; dissolve heptamolybdenum with 12ml deionized water Ammonium heptamolybdate 1.130g is mixed with ammonium heptamolybdate solution to make the ammonium heptamolybdate solution concentration 0.08mol / L;

[0027] (2) Take 14.9ml of lanthanum nitrate solution and 9.6ml of europium nitrate solution, add 20ml of water and stir to form a mixed solution, then add 2.6ml of surfactant (PEG 400) into the mixed solution and keep stirring.

[0028] (3) Add the ammonium heptamolybdate solution dropwise to the above mixed solution, and then add a small amount of 6mol / L ammonia water to adjust the pH value of the solution to 8.5 to form a suspension.

[0029] (4) Transfer the suspension to a 100ml high-pressure reactor, and condu...

Embodiment 3

[0032] (1) Lanthanum oxide and europium oxide are dissolved in nitric acid respectively to make lanthanum nitrate and europium nitrate solutions, the concentration of lanthanum nitrate solution is 0.3mol / L, and the concentration of europium nitrate solution is 0.2mol / L; dissolve heptamolybdenum with 15ml deionized water Ammonium heptamolybdate 1.805g is mixed with ammonium heptamolybdate solution to make the ammonium heptamolybdate solution concentration 0.10mol / L;

[0033] (2) Take 23.8ml of lanthanum nitrate solution and 15.3ml of europium nitrate solution, add 5ml of water and stir to form a mixed solution, then add 4.1ml of surfactant (PEG 400) to the mixed solution and keep stirring.

[0034] (3) The ammonium heptamolybdate solution was added dropwise to the above mixed solution, and then a small amount of 6 mol / L ammonia water was added to adjust the pH value of the solution to 8.5. A suspension was formed.

[0035] (4) Transfer the suspension to a 100ml high-pressure r...

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Abstract

The invention discloses a hydrothermal preparation method of beta-type lanthanum europium molybdate red luminescent powder. The method comprises the following steps: adding appropriate concentrations of surfactant in the aqueous solution of the reactant, performing hydrothermal process to ensure that the generated precursor powder of the luminescent powder is effectively dispersed, and finally obtaining the product which has relatively regular shape, uniform size distribution and a particle size range of 0.8-1.0mu m. The product does not need to be grinded through ball-milling and can be directly used in the industrial production. In addition, the effective excitation wavelength of the product is in the blue region; the emission spectrum tests prove that the effective emission spectrum of the europium molybdate luminescent powder is in the red 616nm area under the blue 465nm radiation. The luminous intensity of the sample prepared by the preparation method is 3 times of the luminous intensity of the sample prepared by the high temperature solid-phase reaction, and the product is matched with the blue LED and can promote the increase of the color rendering index of the white LED possibly.

Description

technical field [0001] The invention relates to a preparation method of lanthanum europium molybdate red luminescent powder, belonging to the technical field of luminescent material preparation. Background technique [0002] Pure La 2 Mo 2 o 9 Cubic β-La at high temperature 2 Mo 2 o 9 structure, has good thermal stability and thermodynamic stability, and is more suitable as a matrix material for phosphors. Add activator Eu 3+ Ion substitution part La 3+ For the ion site, since the two ions are replaced by the same valence state, there is no need to consider charge compensation. Activator Eu 3+ After doping, it can be effectively excited by blue light to produce Eu 3+ The unique spectrum of the 4f configuration. The activator Eu 3+ Incorporate La 2 Mo 2 o 9 The optical properties of the phosphor, the former prepared the sample by freeze-drying method, and found that after the sample was excited by ultraviolet light, it showed Eu 3+ characteristic emission peak...

Claims

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Application Information

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IPC IPC(8): C09K11/78
CPCY02B20/181Y02B20/00
Inventor 石士考宫慧丽
Owner HEBEI NORMAL UNIV
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