Dual-fuel combustion one-step synthesis technology of bluish violet CaAl2O4: Eu < 2 + >, Nd < 3 + > long-afterglow luminescent material
Through the dual-fuel combustion method, the fuel ratio and reaction temperature are adjusted, and the one-step synthesis of CaAl2O4:Eu2+, Nd3+ long afterglow luminescent materials is achieved, solving the problems of high cost, complex operation and inconsistent performance when preparing materials in the prior art, and an efficient and economical process method is obtained.
Patent Information
- Application Number
- CN202510127132.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-31
- Publication Date
- 2025-05-02
AI Technical Summary
In the prior art, when preparing CaAl2O4:Eu2+, Nd3+ long afterglow luminescent materials, there are high cost and complex operations of high-temperature solid phase methods, the cost of sol-gel methods is high and difficult to control, and the reaction of the combustion method is not easy to accurately control, which affects the consistency of material performance.
The dual-fuel combustion method is adopted, CO(NH2)2 and C2H5NO2 are used as fuels, and by adjusting the fuel ratio and reaction temperature, CaAl2O4:Eu2+, Nd3+ long afterglow luminescent materials are synthesized in one step.
The preparation of CaAl2O4:Eu2+, Nd3+ long afterglow luminescent materials with pure phase, high crystallinity and high brightness is achieved, which reduces costs, simplifies the process, avoids carbon residue and secondary calcination, and improves the performance consistency of the material.
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Figure CN119912943A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a blue-purple CaAl2O4:Eu 2+ ,Nd 3+ A dual-fuel combustion one-step synthesis method for long afterglow luminescent materials. This method can prepare fine-grained CaAl2O4:Eu in one step by selecting and adjusting the ratio of added fuel. 2+ ,Nd 3+ Long afterglow luminescent materials belong to the field of optoelectronic functional materials. Background Art
[0002] In recent years, great progress has been made in the research of rare earth doped long afterglow luminescent materials, among which green luminescent SrAl2O4:Eu 2+ ,Dy 3+ The most mature, and has achieved industrial production. However, there are relatively few studies on long afterglow materials with other colors of light. Among them, rare earth doped calcium aluminate long afterglow luminescent material is a blue-violet luminescent material with excellent performance, stable chemical properties, safe and non-toxic, simple preparation method, mature process, and is favored by researchers.
[0003] At present, researchers have studied CaAl2O4:Eu 2+ ,Nd 3+ The preparation methods mainly focus on high-temperature solid-phase method, sol-gel method and combustion method. The high-temperature solid-phase method has a high synthesis temperature, generally above 1300°C, and its product is usually in a ceramic state and cannot be used directly. It needs to be ball-milled before it can be used normally, but ball-milling will reduce the luminescence intensity and the cost is too high. The sol-gel method is a typical wet chemical synthesis method. The CaAl2O4:Eu prepared 2+ ,Nd 3+ The particle size is fine, but the operation is complicated, the cost is too high, there are too many variables that are difficult to control, and the luminous intensity is not high. The combustion method is a low-temperature synthesis method with fast reaction, short time, self-heating during the combustion process, and no long-term external heating is required. The required equipment is simple and low cost, and the product has a large specific surface area and high activity. However, the combustion method has certain limitations. The combustion is violent, and it is difficult to accurately control the reaction conditions, which affects the consistency of material properties; it has high requirements on the ratio of fuel and raw materials, and requires fine control. In 2004, Yang Zhiping et al. used the urea combustion method to synthesize CaAl2O4:Eu with a micron-sized particle size. 2+ ,Nd 3+ Long afterglow luminescent powder, but due to the uneven heat release of urea, the obtained powder particle size varies greatly and the powder crystallinity is poor. In 2006, Sun Jiayue et al. used microwave combustion to synthesize ultrafine CaAl2O4:Eu 2 + ,Nd 3+Long afterglow luminescent powder has low grain size and high crystallinity, but requires microwave pretreatment, which is troublesome. In 2013, Wang Yan et al. synthesized blue CaAl2O4:Eu for PDP using urea as fuel. 2+ ,Nd 3+ Long afterglow luminescent powder, the influence of ignition temperature and urea dosage on the luminescent properties of powder is discussed in detail. However, due to the insufficient temperature provided by a single fuel, the crystallinity of the powder is poor. Due to the insufficient reducing atmosphere provided by a single fuel, a large amount of Eu 3+ Cannot be restored to Eu 2+ , the Eu required for the powder with the best luminescence performance 2+ The doping concentration is high and not economical enough.
[0004] Therefore, a blue-purple CaAl2O4:Eu was developed. 2+ ,Nd 3+ The dual-fuel combustion one-step synthesis technology of long afterglow luminescent materials promotes the combustion method to prepare CaAl2O4:Eu 2+ ,Nd 3+ Long afterglow luminescent materials are of great significance. Summary of the invention
[0005] The present invention provides a blue-purple CaAl2O4:Eu 2+ ,Nd 3+ Dual-fuel combustion one-step synthesis technology for long afterglow luminescent materials. Using Ca(NO3)2·4H2O, Al(NO3)3·9H2O, CO(NH2)2, C2H5NO2, Eu2O3 and Nd2O3 as raw materials, the dual-fuel combustion method is used to directly synthesize CaAl2O4:Eu 2+ ,Nd 3+ Long afterglow luminescent material. CO(NH2)2 and C2H5NO2 are used as fuels, the amount of fuel CO(NH2)2 and C2H5NO2 is 1 to 5 times the theoretical amount, the amount of flux NH4B5O8 is 2 to 10% of the mass of the target product, and the reaction is carried out at an ignition temperature of 400 to 600℃ for 5 to 25 minutes to obtain CaAl2O4:Eu with pure phase, high crystallinity and high brightness. 2+ ,Nd 3+ Long afterglow luminescent material.
[0006] The present invention combines CO(NH2)2 and C2H5NO2 as two fuels, thereby increasing the flame temperature during the combustion process, prolonging the oxidation-reduction reaction time, and making CaAl2O4:Eu 2+ ,Nd 3+During the synthesis process, it can be better crystallized to obtain pure phase powder and improve the luminous brightness. The process of the present invention is convenient and efficient, and can produce pure phase, high crystallinity and high brightness CaAl2O4:Eu 2+ ,Nd 3+ Long afterglow luminescent material with no carbon residue, no need for secondary calcination, and no need for ball milling. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 The synthesized CaAl2O4:Eu 2+ ,Nd 3+ XRD pattern of long afterglow luminescent material sample.
[0008] Figure 2 The synthesized CaAl2O4:Eu 2+ ,Nd 3+ Scanning electron microscope image of a long afterglow luminescent material sample.
[0009] Figure 3 The synthesized CaAl2O4:Eu 2+ ,Nd 3+ Excitation spectrum of long afterglow luminescent material sample.
[0010] Figure 4 The synthesized CaAl2O4:Eu 2+ ,Nd 3+ Emission spectrum of long afterglow luminescent material sample.
[0011] Figure 5 The synthesized CaAl2O4:Eu 2+ ,Nd 3+ Afterglow decay curve of long afterglow luminescent material sample. DETAILED DESCRIPTION
[0012] In the present invention, CaAl2O4:Eu 2+ ,Nd 3+ The specific process of long afterglow luminescent materials is described in detail as follows:
[0013] (1) The present invention uses Ca(NO3)2·4H2O, Al(NO3)3·9H2O, CO(NH2)2, C2H5NO2, Eu2O3 and Nd2O3 as raw materials. Among them, CO(NH2)2 and C2H5NO2 are fuel and reducing agent. According to CaAl2O4:0.02Eu 2+ ,0.01Nd 3+ The amount of each raw material is calculated based on the stoichiometric ratio. The amount of fuel CO(NH2)2 and C2H5NO2 used is 1 to 5 times the theoretical amount.
[0014] (2) According to the stoichiometric ratio for preparing 5 g of product, a precision electronic balance was used to weigh the corresponding amounts of Ca(NO3)2·4H2O, Al(NO3)3·9H2O, CO(NH2)2, C2H5NO2, Eu2O3 and Nd2O3 raw materials.
[0015] (3) Place the weighed Ca(NO3)2·4H2O, Al(NO3)3·9H2O, CO(NH2)2, and C2H5NO2 in a beaker and add 15 ml of deionized water to dissolve them. Place the weighed Eu2O3 and Nd2O3 in a beaker and add appropriate amount of nitric acid to dissolve them. Then mix the two solutions, stir them evenly, and place them in a 300 ml large crucible.
[0016] (4) Place the 300 ml crucible containing the raw materials into a muffle furnace preheated to 400-600° C. and react for 5-25 minutes.
[0017] (5) After the combustion reaction is completed, take it out and cool it down. After washing with ethanol, pure phase, high crystallinity and high brightness CaAl2O4:Eu can be obtained. 2+ ,Nd 3+ Samples of long afterglow luminescent materials.
[0018] Figure 1 CaAl2O4:Eu prepared after washing and drying with ethanol 2+ ,Nd 3+ The XRD spectrum of the long afterglow luminescent material sample is consistent with the diffraction peak of the standard card PDF#04-010-5400, indicating that the monoclinic phosphotidic CaAl2O4 phase with good crystallinity has been successfully synthesized.
[0019] Figure 2 The prepared CaAl2O4:Eu 2+ ,Nd 3+ From the scanning electron microscope image of the long afterglow luminescent material sample, it can be seen that the particle size of the sample prepared by the present invention is between 2 and 3 μm, with good dispersibility and fine particle size.
[0020] Figure 3 The prepared CaAl2O4:Eu 2+ ,Nd 3+ Excitation spectrum of the long afterglow luminescent material sample. The excitation spectrum of the sample is a broadband spectrum at 348nm.
[0021] Figure 4 The prepared CaAl2O4:Eu 2+ ,Nd 3+ Emission spectrum of the long afterglow luminescent material sample. The sample has the highest emission peak at 440nm and can emit bright blue-violet light under ultraviolet and visible light excitation.
[0022] Figure 5 The prepared CaAl2O4:Eu 2+ ,Nd 3+ The afterglow decay curve of the long afterglow luminescent material sample shows that the sample has good long afterglow performance.
Claims
1. A blue-purple CaAl2O4:Eu 2+ ,Nd 3+ The dual-fuel combustion one-step synthesis technology of long afterglow luminescent materials uses Ca(NO3)2·4H2O, Al(NO3)3·9H2O, CO(NH2)2, C2H5NO2, Eu2O3 and Nd2O3 as raw materials, CO(NH2)2 and C2H5NO2 as fuels, and the amount of fuel CO(NH2)2 and C2H5NO2 is 1 to 5 times the theoretical amount. The reaction is carried out at an ignition temperature of 400 to 600°C for 5 to 25 minutes to obtain CaAl2O4:Eu with pure phase, high crystallinity and high brightness. 2+ ,Nd 3+ Long afterglow luminescent material.