A method for preparing zinc gallium germanate long afterglow nanomaterial

Abstract

The invention discloses a method for preparing a zinc gallium germanate long afterglow nano material, wherein the zinc gallium germanate long afterglow nano material Zn is prepared by a hydrothermal method combined with a sol-gel-acid hydrolysis method. 1.3 Ga 1.4 Ge 0.3 O 4 :0.5%Cr 3+ , avoiding the problems of large particles and easy agglomeration of materials prepared by the sol-gel method. The prepared products are of high purity. At the same time, the weak afterglow intensity of the materials prepared by the hydrothermal method is significantly improved, making them present double emission peaks within the biological imaging window range, with long afterglow time and high luminescence intensity. Compared with existing materials, their luminescence intensity is enhanced by 5‑6 times.

Description

Technical Field

[0001] The invention relates to a method for preparing a zinc gallium germanate long afterglow nano material, and belongs to the field of material synthesis. Background Art

[0002] Long afterglow luminescent materials have the advantages of long afterglow, no background autofluorescence, high sensitivity, deep tissue penetration, etc., and have broad application prospects in the field of luminescence. They are a type of photoluminescent materials with a long history. Among these materials, zinc gallium germanate long afterglow materials have attracted much attention due to their long afterglow time and high luminescence intensity within the biological imaging window range (650-1800nm).

[0003] Current zinc gallium germanate long afterglow materials generally have the problem of insufficient luminescence intensity and are easily interfered with when used in the biological imaging window range.

[0004] There are many methods for preparing zinc gallium germanate long afterglow materials. Currently, most of them are synthesized by a single method. The mainstream preparation methods are high-temperature solid-phase method, hydration method, and sol-gel method. The materials prepared by these methods either have large particles and are easy to agglomerate, or the luminescence center is not sufficiently embedded, resulting in insufficient afterglow intensity, which seriously limits the further application of zinc gallium germanate long afterglow materials in the field of biological imaging. Summary of the invention

[0005] The purpose of the present invention is to solve the above technical problems and provide a zinc gallium germanate long afterglow nanomaterial which has good dispersion, is not easy to agglomerate, and can emit light in the biological imaging window range.

[0006] The technical solution to achieve the purpose of the present invention is: a method for preparing a zinc gallium germanate long afterglow nano material, comprising the following steps:

[0007] S1: Mix zinc acetate solution, gallium nitrate solution, chromium nitrate solution and sodium germanate solution in a 1 mmol system according to the chemical formula Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ The ratio of was added into a beaker to prepare a solution, and the pH value was adjusted with aqueous ammonia to obtain solution a;

[0008] S2: Stir the solution in S1 and heat it under closed conditions to react, wash with water and centrifuge to obtain product A;

[0009] S3: After dissolving GeO2 in ammonia water, add Zn(NO3)2 solution and C6H 10 O8, dissolve, and adjust pH to obtain solution b;

[0010] S4: mixing the solution b obtained in S3 and the reaction product A obtained in S2 in a certain proportion, and vigorously stirring under heating conditions until the solvent is completely evaporated to obtain a gel;

[0011] S5: placing the gel obtained in S4 into an oven and drying it in stages, then placing it into a muffle furnace for annealing, and grinding it after cooling to obtain a reaction product B;

[0012] S6: The reaction product B obtained in S5 is subjected to acid hydrolysis, water washing and centrifugation to obtain the final product C.

[0013] Furthermore, the pH value in step S1 is 8.0.

[0014] Furthermore, in step S2, the stirring time is 1 hour, the heating temperature is 220° C., and the reaction time is 12 hours.

[0015] Furthermore, in step S3, Zn 2+ Ion, Ge 4+ Ion, C6H 10 The molar ratio of O8 is 2:1:6 and the pH concentration is 5.0-6.0.

[0016] Furthermore, in step S4, the mixing ratio of solution b to reaction product A is 1:1, and the heating and stirring temperature is 75°C.

[0017] Furthermore, in step S5, the oven drying stage is drying in an oven at 130° C. for 3 hours, and then heating in an oven at 200° C. for 7 hours, and the muffle furnace annealing temperature is 800° C. and the annealing time is 3 hours.

[0018] Furthermore, in step S6, the acid used in the acidolysis is dilute hydrochloric acid or dilute nitric acid.

[0019] The above technical solution is adopted, and the present invention has the following beneficial effects: the present invention adopts a hydrothermal method combined with a sol-gel-acid hydrolysis method to prepare a zinc gallium germanate long afterglow nanomaterial Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ The acid hydrolysis process only reacts with the shell Zn2GeO4 synthesized by the sol-gel method without destroying the core Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ The characteristics of the material prepared by the sol-gel method are avoided, and the problem of large particles and easy agglomeration is avoided. The prepared product has high purity. At the same time, it significantly improves the weak afterglow intensity of the material prepared by the hydrothermal method, so that the afterglow time is long and the luminescence intensity is high within the biological imaging window range (650-1800nm). Compared with the existing preparation scheme, its luminescence intensity is enhanced by 5-6 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0021] Figure 1 TEM morphology of zinc gallium germanate long afterglow nanomaterials prepared in Examples 1 and 2 of the present invention.

[0022] Figure 2 This is the XRD diffraction pattern of the zinc gallium germanate long afterglow nanomaterial prepared in Example 1 and Example 2 of the present invention.

[0023] Figure 3 This is a comparison chart of the luminescence intensities of zinc gallium germanate long afterglow nanomaterials prepared in Example 1 and Example 2 of the present invention. DETAILED DESCRIPTION

[0024] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] (Example 1)

[0028] The preparation method of the zinc gallium germanate long afterglow nano material of this embodiment comprises the following steps:

[0029] S1: Mix zinc acetate solution, gallium nitrate solution, chromium nitrate solution and sodium germanate solution in a 1 mmol system according to the chemical formula Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ into a beaker, and then adding ammonia water to adjust the pH of the solution to 8.0 to obtain solution a;

[0030] S2: The solution a obtained in S1 was stirred for 1 hour and then reacted under closed conditions at 220°C for 12 hours, and then washed with water and centrifuged to obtain the reaction product Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ ;

[0031] S3: After dissolving germanium dioxide in ammonia water, zinc nitrate solution and citric acid monohydrate are added thereto, wherein Zn 2+ Ion, Ge 4+ The molar ratio of ions and citric acid·monohydrate is 2:1:6, and then ammonia water is added to adjust the pH of the solution to 5.0-6.0 to obtain solution b;

[0032] S4: The solution b obtained in S3 and the reaction product obtained in S2 are mixed in a ratio of 1:1, and stirred vigorously at a temperature of 75°C until the solvent is completely evaporated to obtain a gel;

[0033] S5: The gel obtained in S4 was first placed in a 130°C oven to dry for 3 h, then placed in a 200°C oven to heat for 7 h, and then placed in a 800°C muffle furnace to anneal for 3 h. After cooling, the reaction product Zn was ground. 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ @Zn2GeO4;

[0034] S6: The reaction product obtained in S5 is hydrolyzed with dilute hydrochloric acid or dilute nitric acid until the solution is nearly transparent, stirred vigorously for 30 minutes, washed with water and centrifuged to obtain the zinc gallium germanate long afterglow nanomaterial Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ .

[0035] (Example 2)

[0036] This embodiment is basically the same as Embodiment 1, except that:

[0037] S1: Mix zinc acetate solution, gallium nitrate solution, chromium nitrate solution and sodium germanate solution in a 1 mmol system according to the chemical formula Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ into a beaker, and then adding ammonia water to adjust the pH of the solution to 8.0 to obtain solution a;

[0038] S2: The solution a obtained in S1 was stirred for 1 hour and then reacted under closed conditions at 220°C for 12 hours, washed with water and centrifuged to obtain the product Zn 1.3 Ga1.4 Ge 0.3 O4:0.5%Cr 3+ .

[0039] The zinc gallium germanate long afterglow nanomaterial obtained in Example 1-2 was analyzed using a transmission electron microscope. The results are shown in the attached figure. Figure 1 As shown in the figure, it can be seen that the particle morphology of the zinc gallium germanate long afterglow nanomaterial prepared in Example 1 is uniform, evenly distributed, and has good dispersibility, which is basically consistent with the morphology of the zinc gallium germanate long afterglow nanomaterial prepared by the hydrothermal method in Example 2.

[0040] The zinc gallium germanate long afterglow nanomaterial obtained in Example 1-2 was analyzed by X-ray diffractometer. The results are shown in the attached figure. Figure 2 As shown in the figure, it can be seen that the diffraction pattern is consistent with the standard diffraction pattern of ZnGa2O4 (PDF#38-1240), and there is almost no diffraction peak matching with Zn2GeO4 (PDF#11-0687), which proves that Examples 1-2 both obtained pure-phase spinel-structured internal core ZnGa2O4, and the external shell Zn2GeO4 of Example 1 was completely acid-lyzed and had good chemical stability.

[0041] After the zinc gallium germanate long afterglow nanomaterials prepared in Example 1 and Example 2 were irradiated with 650nm red light for 2 minutes, the long afterglow emission spectra were tested and the results were as follows: Figure 3 ,Depend on Figure 3 It can be seen that the afterglow emission spectra of Examples 1-2 are in the range of 600-800nm, and the spectra both show a broadband emission peak with a central wavelength at 719nm and a sharp emission peak with a central wavelength at 699nm, and the afterglow intensity of the zinc gallium germanate long afterglow nanomaterial obtained in Example 1 is 6 times higher than that in Example 2.

[0042] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a zinc gallium germanate long afterglow nanomaterial, characterized in that: The following steps are involved: S1: Mix zinc acetate solution, gallium nitrate solution, chromium nitrate solution and sodium germanate solution in a 1 mmol system according to the chemical formula Zn 1.3 Ga 1.4 Ge 0.3 O4:0.5%Cr 3+ The ratio of was added into a beaker to prepare a solution, and the pH value was adjusted with aqueous ammonia to obtain solution a; S2: Stir the solution in S1 and heat it under closed conditions to react, wash with water and centrifuge to obtain product A; S3: After dissolving GeO2 in ammonia water, add Zn (NO3)2 solution and C6H 10 O8, dissolve, and adjust pH to obtain solution b; S4: mixing the solution b obtained in S3 and the reaction product A obtained in S2 in a certain proportion, and vigorously stirring under heating conditions until the solvent is completely evaporated to obtain a gel; S5: placing the gel obtained in S4 into an oven and drying it in stages, then placing it into a muffle furnace for annealing, and grinding it after cooling to obtain a reaction product B; S6: acid hydrolyze the reaction product B obtained in S5, wash with water and centrifuge to obtain the final product C; The C6H in S3 10 O8 is citric acid monohydrate.

2. The method for preparing a zinc gallium germanate long afterglow nano material according to claim 1, characterized in that: The pH in step S1 is 8.

0.

3. The method for preparing a zinc gallium germanate long afterglow nano material according to claim 1, characterized in that: In step S2, the stirring time is 1 hour, the heating temperature is 220° C., and the reaction time is 12 hours.

4. The method for preparing a zinc gallium germanate long afterglow nano material according to claim 1, characterized in that: In step S3, Zn 2+ Ion, Ge 4+ Ion, C6H 10 The molar ratio of O8 is 2:1:6 and the pH concentration is 5.0-6.

0.

5. The method for preparing a zinc gallium germanate long afterglow nano material according to claim 1, characterized in that: In the step S4, the mixing ratio of solution b to reaction product A is 1:1, and the heating and stirring temperature is 75°C.

6. The method for preparing a zinc gallium germanate long afterglow nano material according to claim 1, characterized in that: In step S5, the oven drying stage is drying in an oven at 130° C. for 3 h, and then heating in an oven at 200° C. for 7 h. The muffle furnace annealing temperature is 800° C., and the annealing time is 3 h.

7. The method for preparing a zinc gallium germanate long afterglow nano material according to claim 1, characterized in that: In step S6, the acid used in the acidolysis is dilute hydrochloric acid or dilute nitric acid.

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