Preparation method of low-temperature long-afterglow material with heterogeneous structure

Abstract

The application discloses a preparation method of a low-temperature long-afterglow material with a heterogeneous structure, and the specific process is as follows: lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), praseodymium carbonate [Pr2(CO3)3] and niobium pentoxide (Nb2O5) are weighed according to a proportion, put into an agate mortar and ground, the mixture is moved into a corundum crucible and put into a tube furnace for high-temperature reaction, and NaLiNbO3:Pr is obtained after the reaction 3+ coarse product; the obtained product is further ground and screened through a 200-mesh screen, excess water is added to the product and stirred, the upper liquid is poured out, the lower precipitate is taken out and dried, and grinding and screening treatment is carried out, so that NaLiNbO3:Pr 3+ product. The product prepared by the application shows red fluorescence under 365nm ultraviolet light, shows red afterglow after stopping irradiation, and has a good application prospect in biological marking and imaging application, security and anti-counterfeiting and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of inorganic rare earth luminescent materials, and relates to a preparation method of a low-temperature long afterglow material with a heterogeneous structure. BACKGROUND

[0002] Persistent luminescent material is a material that can be observed to emit light for several seconds to several hours in the dark after the excitation light source is turned off, and it has been widely applied to emergency signs, decoration, imaging, storage, pressure sensors, medical applications, in vivo imaging and the like. At present, high-efficiency LPL systems have been developed in aluminate, silicate and gallate systems, but the application of these fluorescent powders is limited to room temperature environments. Higher temperatures can cause rapid release of photons in traps, and when the ambient temperature is lower than room temperature, if the activation energy cannot meet the standard for releasing photons, the carriers cannot be released, both of which affect the LPL (Long persistent luminescence) performance of the fluorescent powder and limit the application of the LPL fluorescent powder at low temperatures. Therefore, it is a very meaningful research to design LPL materials to have good afterglow performance at low temperatures. SUMMARY

[0003] The purpose of the present application is to provide a preparation method of a low-temperature long afterglow material with a heterogeneous structure, which is to introduce Na + Construct a heterogeneous structure and design the stoichiometric ratio of the whole reaction, so as to improve the afterglow performance of the material at low temperatures.

[0004] The technical scheme adopted by the present application is a preparation method of a low-temperature long afterglow material with a heterogeneous structure, characterized in that it specifically comprises the following steps:

[0005] Step 1, preparation of NaLiNbO3:Pr 3+ Coarse product;

[0006] Step 2, grinding and sieving the product obtained in step 1, adding excess water to the sieved product and stirring, settling, pouring out the upper layer liquid, taking the lower layer precipitate and drying, and then grinding and sieving to obtain NaLiNbO3:Pr 3+ Product.

[0007] The present application is also characterized in that:

[0008] The specific process of step 1 is:

[0009] Li2CO3, Na2CO3, Pr2(CO3)3 and Nb2O5 are weighed according to the proportion, put into an agate mortar and ground, the mixture is moved into a corundum crucible and put into a tube furnace for reaction, and NaLiNbO3:Pr is obtained after the reaction is completed.3+ Crude product.

[0010] In step 1, the amount of Li2CO3 used is 36mg to 360mg, the amount of Na2CO3 used is 0mg to 470mg, the amount of Pr2(CO3)3 used is 7mg to 20mg, and the amount of Nb2O5 used is 1310mg to 1330mg.

[0011] In step 1, the reaction temperature in the tube furnace is 1000–1200℃, and the reaction time is 2–4 hours.

[0012] In step 1, the reaction environment is an N2 atmosphere.

[0013] The beneficial effect of this invention is that it introduces Na into the LiNbO3 system. + By constructing heterostructures and designing the stoichiometry of the entire reaction, the afterglow properties of the material at low temperatures can be improved. NaLiNbO3:Pr 3+ The material exhibits good afterglow properties at 253 K. This invention utilizes the introduction of Na into the LiNbO3 system. + The method of constructing heterostructures and designing the stoichiometry of the entire reaction not only reduces the complexity of the experiment but also improves safety. It exhibits red fluorescence under 365nm ultraviolet light and displays a red afterglow after irradiation is stopped, showing great promise for applications in biolabeling and imaging, as well as security and anti-counterfeiting. Attached Figure Description

[0014] Figure 1 This is from Example 1 of the preparation method of the low-temperature long afterglow material with heterostructure of the present invention, NaLiNbO3:Pr 3 + Fluorescence spectrum;

[0015] Figure 2 This is from Example 1 of the preparation method of the low-temperature long afterglow material with heterostructure of the present invention, NaLiNbO3:Pr 3 + Afterglow lifetime of the material at RT and 253K temperatures, respectively;

[0016] Figure 3 This is from Example 1 of the preparation method of the low-temperature long afterglow material with heterostructure of the present invention, NaLiNbO3:Pr 3 + HRTEM and SAED diagrams. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] The present invention discloses a method for preparing a low-temperature long afterglow material with a heterostructure, which specifically includes the following steps:

[0019] Weigh out 36–360 mg of lithium carbonate (Li₂CO₃), 0–470 mg of sodium carbonate (Na₂CO₃), 7–20 mg of praseodymium carbonate [Pr₂(CO₃)₃], and 1310–1330 mg of niobium pentoxide (Nb₂O₅) according to the specified ratio, place them in an agate mortar, and grind for 15 min. Transfer the mixture to a corundum crucible and place it in a tube furnace. React at 1000–1200 °C for 2–4 h in an N₂ atmosphere. After the reaction is complete, NaLiNbO₃:Pr₂CO₃ is obtained. 3+ Crude product.

[0020] The obtained product was further ground and passed through a 200-mesh sieve. Excess water was added to the product and stirred for 30 minutes. After settling for 24 hours, the supernatant was poured off, and the lower precipitate was dried. It was then ground and sieved (200-mesh) again to obtain NaLiNbO3:Pr 3+ product.

[0021] Example 1

[0022] 145 mg of lithium carbonate (Li₂CO₃), 310 mg of sodium carbonate (Na₂CO₃), 13 mg of praseodymium carbonate [Pr₂(CO₃)₃], and 1330 mg of niobium pentoxide (Nb₂O₅) were weighed according to the specified ratio and ground in an agate mortar for 15 min. The mixture was then transferred to a corundum crucible and placed in a tube furnace for high-temperature reaction at 1050 °C for 3 h. After the reaction was completed, NaLiNbO₃:Pr₂CO₃ was obtained. 3+ Crude product.

[0023] The obtained product was further ground and passed through a 200-mesh sieve. Excess water was added to the product and stirred for 30 minutes. After settling for 24 hours, the supernatant was poured off, and the lower precipitate was dried. The precipitate was then ground and sieved again to obtain NaLiNbO3:Pr 3+ product.

[0024] Figure 1 It is NaLiNbO3:Pr 3+ The fluorescence spectrum shows that under 365 nm excitation, the material exhibits red emission at 611 nm, attributed to Pr. 3+ of 1 D2→ 3 H4 transition; Figure 2 It is NaLiNbO3:Pr 3+ The afterglow lifetime of the material at RT and 253K temperatures are shown. After charging at 365nm for 5 minutes, the afterglow lifetime of the material at 253K temperature is much higher than that at RT, indicating that the afterglow performance of the material is better at low temperature than at room temperature. Figure 3 It is NaLiNbO3:Pr3+ The lattice spacing of NaNbO3 and LiNbO3 is 0.391 nm and 0.374 nm, respectively, Figure 3 The black deepened area in the upper left corner is the SEAD pattern corresponding to the (240) crystal plane of NaNbO3 and the (110) and (134) crystal planes of LiNbO3, respectively, thereby proving the formation of the material heterostructure.

[0025] Example 2

[0026] Put 36 mg of lithium carbonate (Li2CO3), 470 mg of sodium carbonate (Na2CO3), 20 mg of praseodymium carbonate [Pr2(CO3)3], and 1330 mg of niobium pentoxide (Nb2O5) into an agate mortar and grind for 15 min, then move the mixture into a corundum crucible and put it into a tube furnace for high-temperature reaction at 1200 DEG C for 4 h, and obtain NaLiNbO3:Pr after the reaction is completed. 3+ The crude product.

[0027] Further grind the obtained product through a 200-mesh sieve, add excess water to the product and stir for 30 min, and then settle for 24 h, pour out the upper liquid, and dry the lower precipitate, and then grind and sieve to obtain NaLiNbO3:Pr. 3+ The product.

[0028] Example 3

[0029] Put 360 mg of lithium carbonate (Li2CO3), 0 mg of sodium carbonate (Na2CO3), 7 mg of praseodymium carbonate [Pr2(CO3)3], and 1310 mg of niobium pentoxide (Nb2O5) into an agate mortar and grind for 15 min, then move the mixture into a corundum crucible and put it into a tube furnace for high-temperature reaction at 1000 DEG C for 2 h, and obtain NaLiNbO3:Pr after the reaction is completed. 3+ The crude product.

[0030] Further grind the obtained product through a 200-mesh sieve, add excess water to the product and stir for 30 min, and then settle for 24 h, pour out the upper liquid, and dry the lower precipitate, and then grind and sieve to obtain NaLiNbO3:Pr. 3+ The product.

[0031] The present application takes LiNbO3 as the research object, introduces Na + The stoichiometric ratio of the entire reaction is designed to improve the afterglow performance of the material at low temperature, which not only reduces the complexity of the experiment, but also improves the safety, and the material shows red fluorescence under 365 nm ultraviolet light and displays red afterglow after stopping irradiation, and has good application prospect in biological labeling and imaging application, security and anti-counterfeiting, etc.

Claims

1. A method for preparing low-temperature long afterglow materials with heterogeneous structures, characterized in that: Specifically, the steps include the following: 145 mg of lithium carbonate, 310 mg of sodium carbonate, 13 mg of praseodymium carbonate, and 1330 mg of niobium pentoxide were ground in an agate mortar for 15 min. The mixture was then transferred to a corundum crucible and placed in a tube furnace for a high-temperature reaction at 1050 ℃ for 3 h under a nitrogen atmosphere. The reaction yielded NaLiNbO3:Pr 3+ Crude product; The obtained product was ground and passed through a 200-mesh sieve. Excess water was added to the product and stirred for 30 minutes. After settling for 24 hours, the supernatant was poured off, and the lower precipitate was dried. The precipitate was then ground and sieved again to obtain NaLiNbO3:Pr 3+ product.

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