Preparation method of small size and high brightness lanthanum phosphate activated by cerium and terbium, green phosphor

Abstract

A preparation method of small size and high brightness lanthanum phosphate activated by cerium and terbium, green phosphor comprises following steps: rare earth soluble salt containing crystal water, and chloride or nitrate, are mixed with alkali metal or phosphatic of ammonium and then the mixture is grinded or ball milled at the room temperature, the precursor of lanthanum phosphate activated by cerium and terbium is obtained after a drying process, then the precursor is sintered for 1 to 24 hours in the presence of auxiliary agent Li2(CO3)3 in a reduction atmosphere at the temperature of 950 to 1250 DEG C, and finally the phosphor product is produced after a washing post-treatment. The substrate of the phosphor is LaPO4, Ce3+ is the sensitization particle, and Tb3+ is the activating center. The chemical formula of the phosphor is La<x>Ce<y>Tb<1-x-y>PO4. The phosphor can give off strong green light with a wavelength around 545 nm under the activation of ultraviolet. The phosphor has the advantages that the particles of the synthesis phosphor are small, the diameters of the median particles are smaller than 1 micrometer, and the light intensity of the phosphor is higher than that of aluminate green phosphor in the present market.

Description

technical field [0001] The invention belongs to the technical field of rare earth luminescent materials, and in particular relates to a method for preparing small-sized, high-brightness lanthanum cerium terbium phosphate green fluorescent powder by a wet solid phase mechanochemical method. Background technique [0002] LaPO 4 : Ce, Tb (LAP) is a very important class of high-efficiency green luminescent materials in trichromatic phosphors. At present, there are two main ways of synthesis: one is dry synthesis or high-temperature solid-phase chemical reaction synthesis, which is burning at high temperature (LaCeTb) x o y and (NH 4 ) 2 HPO 4 A mixture of (LaCeTb)PO 4 ; The second is wet synthesis or precursor high-temperature calcination synthesis, which is to directly use the chloride or nitrate solution of La, Ce, Tb with H 3 PO 4 or (NH 4 ) 2 HPO 4 Precipitate to give (LaCeTb)PO 4 The precursor is washed and dried or calcined and then reduced and calcined at...

AI Technical Summary

Problems solved by technology

At present, there are two main synthesis routes: one is dry synthesis or high-temperature solid-phase chemical reaction synthesis, which is burning (LaCeTb)xOy at high temperature sub> and (NH4)2HPO4 mixture to generate (LaCeTb)PO4; the second is Wet synthesis or precursor high-temperature calcination synthesis is to directly use H3PO4 or (NH4)2HPO4 precipitated to obtain (LaCeTb)PO4 precursor, washed and dried or calcined Reduction calcination at a certain temperature; the first method is easy to operate and has a large output, but the synthesis temperature is high, the energy consumption is high, the requirements for equipment and raw materials are high, and the product particles are large, which must be ball milled

And ball milling will cause the decline of the fluorescent performance of the product, so it is difficult to solve the problems of impurity phase generation and particle size control; the second method seems simple, the synthesis temperature is also greatly reduced, and the cost is low, but in fact due to the formed Small precipitated particles, difficult to filter, incomplete washing of chlorine radicals, very large water consumption

Moreover, it is easy to agglomerate during calcination, so that the product particle size is large and unevenly distributed, and the product quality is not stable enough; therefore, it is of great significance to explore a simple, effective, low-cost, and environmentally friendly preparation method of lanthanum cerium terbium phosphate

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