CN109777413B

CN109777413B - Inorganic particles with multiple photoresponse and blue long afterglow luminescence and preparation method thereof

Info

Publication number: CN109777413B
Application number: CN201910164250.1A
Authority: CN
Inventors: 史晨; 葛明桥
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2019-03-05
Filing date: 2019-03-05
Publication date: 2021-08-20
Anticipated expiration: 2039-03-05
Also published as: CN109777413A

Abstract

The invention relates to an inorganic particle with multiple light responses and blue long afterglow luminescence and a preparation method thereof, belonging to the technical field of functional materials. The chemical molecular formula of the inorganic particles with multiple light responses and blue long afterglow luminescence prepared by the present invention is Na ₂ CaGe ₂ O ₆ : Pb ²⁺ , Y ³⁺ , which are white powders under natural light, and are 250nm-320nm under natural light. It has a continuous photoresponse under ultraviolet light irradiation, and the luminescence color gradually changes from light blue to dark blue, and after the ultraviolet light irradiation ends, the dark blue afterglow can last for more than 30 min. The invention adopts the high-temperature solid-phase method, the operation method is simple, the production process is short, the prepared inorganic microparticle powder with dual response mode has the advantages of fast response, can be recycled and the like, and can be widely used in the fields of anti-counterfeiting, information encryption, optical display and the like , is expected to achieve large-scale industrial production, and has broad commercial application prospects.

Description

Luminescent inorganic particle with multiple photoresponse and blue long afterglow and preparation method thereof

Technical Field

The invention belongs to the technical field of functional materials, and particularly relates to a luminescent inorganic particle with multiple light responses and a blue long afterglow and a preparation method thereof.

Background

The photoresponse luminescent material is widely applied to the fields of laser dyes, light-emitting diodes, data storage and recording, anti-counterfeiting printing and the like. These materials can be applied to different surfaces at low cost and have very wide application in the fields of protecting high-value goods, government documents, bank checks and the like. However, the conventional photoresponsive material can only emit one kind of light under a specific excitation condition, and the material is gradually familiar to counterfeiters, so that the development of a material with multiple photoresponsive characteristics has wide application prospect.

In recent years, a series of luminescent materials with photoresponse have been prepared, including thermochromism, mechanochromism, electrochromism and solution photochromism, and the stimulus response of the materials to the outside is caused by the change of chemical structure or chemical composition, so that the change of fluorescence color is caused. However, most of the current photoresponse materials show monochromatic response, and cannot meet the requirement of higher-level anti-counterfeiting. Therefore, the development of materials with multiple photoresponses is highly desirable.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a luminescent inorganic particle with multiple light responses and blue long afterglow and a preparation method thereof, aiming at the defects of the prior art. The method adopts a high-temperature solid phase method, has simple operation method and short production process, and the prepared inorganic microparticle powder with double response modes has the advantages of quick response, recycling and the like, can be widely applied to the fields of anti-counterfeiting, information encryption, optical display and the like, is expected to realize large-scale industrial production, and has wide commercial application prospect.

In order to solve the technical problems, the invention adopts the technical scheme that: the inorganic particle and the preparation method thereof are characterized in that:

inorganic particles with multiple photoresponse and blue long-afterglow luminescence, wherein the chemical molecular formula of the inorganic particles is Na₂CaGe₂O₆:Pb²⁺,Y³⁺The blue phosphor powder is white powder under natural light, has continuous light response under the irradiation of ultraviolet light of 250-320 nm, gradually changes the light-emitting color from light blue to dark blue, and can sustain the afterglow light-emitting of the dark blue for more than 30 min after the irradiation of the ultraviolet light is finished.

A preparation method of inorganic particles with multiple photoresponse and blue long afterglow luminescence comprises the following steps:

(1) weighing a certain amount of Na₂CO₃, CaCO₃, GeO₂PbO and Y₂O₃In which Na₂CO₃, CaCO₃, GeO₂PbO and Y₂O₃The mass ratio of (2): 1: 2: 1.5%: 9 percent;

(2) weighing boric acid accounting for 1 percent of the total mass of the mixture in the step (1), mixing the boric acid with the raw materials weighed in the step (1), putting the mixture into a ball milling tank, and ball milling for 0.5 to 1 hour at the rotating speed of 1000 and 1100 r/min;

(3) pre-sintering the powder uniformly mixed in the step (2) at the temperature of 500-;

(4) and (3) crushing the sintered powder by a ball mill to ensure that the average particle size of the powder is 1-25 microns, thus obtaining the inorganic microparticles with both photoresponse and long-afterglow luminescence effects.

The inorganic microparticles can be applied to the fields of anti-counterfeiting, information encryption and optical display.

Compared with the prior art, the invention has the following advantages:

the inorganic microparticles prepared by the invention have continuous light response luminescence to ultraviolet light within the range of 250nm-320nm, and have blue afterglow light for at least 30 minutes after stopping the excitation of the ultraviolet light; the invention adopts a high-temperature solid phase method, has simple operation method and short production process, and the prepared inorganic microparticles with double response modes have the advantages of quick response, recycling and the like, can be widely applied to the fields of anti-counterfeiting, information encryption and optical display, have wide commercial application prospect and are expected to realize large-scale industrial production.

Drawings

FIG. 1 is an electron micrograph of inorganic fine particles obtained in example 1 of the present invention.

FIG. 2 shows the inorganic microparticles prepared in example 1 of the present invention and Na as a standard₂CaGe₂O₆XRD contrast pattern of (a).

FIG. 3 is a photo-response spectrum of inorganic fine particles obtained in example 1 of the present invention.

FIG. 4 is a graph of afterglow intensity of inorganic microparticles obtained in example 1 of the present invention as a function of time.

FIG. 5 is a photo-response spectrum of inorganic fine particles obtained in example 2 of the present invention.

FIG. 6 is a photo-response spectrum of inorganic fine particles obtained in example 3 of the present invention.

The invention is further described with reference to the following drawings and detailed description.

Detailed Description

Example 1:

(1) weighing Na₂CO₃ 2.65g, CaCO₃ 2.5g, GeO₂5.2g, PbO 0.08g and Y₂O₃ 0.25g；

(2) Weighing 1.06g of boric acid, mixing the boric acid with the raw materials weighed in the step (1), putting the mixture into a ball milling tank, and carrying out ball milling for 1 hour at the rotating speed of 1000 revolutions per minute;

(3) placing the powder uniformly mixed in the step (2) in a corundum crucible, presintering for 2 hours at 600 ℃, cooling to room temperature, performing secondary sintering, and preserving heat for 6 hours at 1000 ℃;

(4) and (3) crushing the sintered powder by a ball mill to ensure that the average particle size of the powder is 20 microns, thus obtaining the inorganic microparticles with both photoresponse and long-afterglow luminescence effects.

FIG. 1 is an electron microscope scanning photograph of the inorganic fine particles prepared in this example. FIG. 2 shows the inorganic microparticles prepared in this example and Na as a standard₂CaGe₂O₆Comparing the XRD patterns, it can be seen that the material synthesized in this example is Na₂CaGe₂O₆According to the crystal structure, through X-ray energy spectrum distribution analysis, Pb element and Y element are uniformly distributed on the surface of the particles, and the Pb element and the Y element are successfully doped in the powder.

FIG. 3 is a graph showing the photoresponse spectrum of the fine inorganic particle powder obtained in this example, in which the luminescent material obtained in this example has a continuous photoresponse under ultraviolet light in the range of 250nm to 320nm, the luminescent color gradually changes from light blue to deep blue, and under 254nm irradiation, two peaks, one at 400nm, are observed, and the peak is represented by Pb²⁺In (1)³P₁-¹S₀Due to electron transition (c), this peak is the main cause of blue fluorescence. In addition, a weak broad shoulder peak is positioned at 550nm, and the peak is caused by the self-transition process of the host material and is the main reason for the formation of white fluorescence. With increasing excitation wavelength, the peak at 550nm decreases and the peak at 400nm increases, eventually resulting in a color change from light blue to dark blue.

FIG. 4 is a graph showing the afterglow intensity of the inorganic microparticles obtained in example 1 as a function of time,as can be seen from FIG. 4, after the UV excitation was stopped, there was a deep blue afterglow luminescence for 30 minutes because the white fluorescence disappeared immediately after the excitation was stopped, but the blue fluorescence was Y-fluorescence³⁺The blue fluorescence is slowly released by doping the powder to generate a proper trap energy level, and the process comprises three attenuation processes of fast attenuation, medium attenuation and slow attenuation. The inorganic fine particle powders obtained at the temperature of this example showed less difference in the photoresponse effect.

Example 2:

(3) placing the powder uniformly mixed in the step (2) in a corundum crucible, presintering for 2 hours at 600 ℃, cooling to room temperature, performing secondary sintering, and preserving heat for 6 hours at 1050 ℃;

FIG. 5 is a graph showing a photoresponse spectrum of the inorganic fine particle powder obtained in this example, and the luminescent material obtained in this example has a continuous photoresponse under ultraviolet light in the range of 250nm to 320nm, and the luminescent color gradually changes from white to deep blue. Under 254nm irradiation, two peaks appeared, one at 400nm, which was represented by Pb²⁺In (1)³P₁-¹S₀Due to electron transition (c), this peak is the main cause of blue fluorescence. In addition, a strong broad shoulder peak is positioned at 550nm, and the peak is caused by the self-transition process of the host material and is the main reason for the formation of white fluorescence. With the increase of synthesis temperature, the main material Na₂CaGe₂O₆Resulting in a stronger white fluorescence emission, but with increasing excitation wavelengthAdditionally, the intensity of the white fluorescence decreases, and the blue fluorescence gradually increases, eventually resulting in a gradual change of the emission color from white to deep blue. And after stopping the ultraviolet excitation, the deep blue afterglow can emit light for 30 minutes. The photoresponse effect of the inorganic fine particle powder obtained at the temperature of this example was greatly different.

Example 3:

(3) placing the powder uniformly mixed in the step (2) in a corundum crucible, presintering for 2 hours at 600 ℃, cooling to room temperature, performing secondary sintering, and preserving heat for 6 hours at 1100 ℃;

FIG. 6 is a graph showing a photoresponse spectrum of the inorganic fine particle powder obtained in this example, and the luminescent material obtained in this example has a continuous photoresponse under ultraviolet light in the range of 250nm to 320nm, and the luminescent color gradually changes from white to deep blue. Under 254nm irradiation, two peaks appeared, one at 400nm, which was represented by Pb²⁺In (1)³P₁-¹S₀Due to electron transition (c), this peak is the main cause of blue fluorescence. In addition, a strong broad shoulder peak is positioned at 550nm, and the peak is caused by the self-transition process of the host material and is the main reason for the formation of white fluorescence. With the increase of synthesis temperature, the main material Na₂CaGe₂O₆The crystal structure of (1) is changed, so that stronger white fluorescence emission is caused, but the intensity of the white fluorescence is weakened and the blue fluorescence is gradually enhanced along with the increase of the excitation wavelength, and finally, the light-emitting color is gradually changed from white to deep blue. And stopping the ultraviolet lightAfter excitation, a deep blue afterglow luminescence lasts for 30 minutes. The light response effect of the inorganic fine particle powder produced at the temperature of this example was most different.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the principles of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. The inorganic particle with multiple photoresponse and blue long-afterglow luminescence is characterized in that the chemical molecular formula of the inorganic particle is Na₂CaGe₂O₆:Pb²⁺,Y³⁺The blue phosphor powder is white powder under natural light, has continuous light response under the irradiation of ultraviolet light of 250-320 nm, gradually changes the light-emitting color from light blue to dark blue, and can sustain the afterglow light-emitting of the dark blue for more than 30 min after the irradiation of the ultraviolet light is finished.

2. The method for preparing the inorganic particles with multiple photoresponse and blue long-afterglow luminescence according to claim 1, which comprises the following steps:

3. The inorganic particle with multiple light responses and blue long-afterglow luminescence according to claim 1, wherein the inorganic microparticle can be applied to the fields of anti-counterfeiting, information encryption and optical display.