Preparation method of visible-light-excited room-temperature phosphorescent carbon dot-silicon dioxide-aluminum oxide composite material
The one-step calcination method is used to prepare visible-light-excited room temperature phosphorescence carbon spots @ silica @ alumina composite material, which solves the problem of limited application of existing materials under ultraviolet excitation, achieves a long-life phosphorescence effect under visible light, and simplifies the preparation process and reduces costs.
Patent Information
- Application Number
- CN202510073140.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2025-06-20
AI Technical Summary
The existing room temperature phosphorescence carbon dot material emits light under ultraviolet excitation, which limits its practical application field. It has a complex preparation process, is expensive, and has a short phosphorescence life, making it difficult to meet the actual application needs.
A visible light-excited room temperature phosphorescence carbon spots @ silica @ alumina composite material was prepared by a one-step calcination method, using 1,3,6-trinitropyrene, boric acid, tetraethyl orthosilicate and aluminum chloride hexahydrate as raw materials, and the composite material was obtained through a simple and easy process.
It realizes the excitation of room temperature phosphorescence under visible light. After the material is turned off the 430nm visible light, yellow phosphorescence can be seen in the naked eye for up to 21 seconds. The process is simple and low-cost, and it is suitable for industrial large-scale production and commercial applications.
Smart Images
Figure CN120173600A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of the preparation of carbon dot materials, and particularly relates to a method for preparing a visible light-excited room temperature phosphorescent carbon dot@silica@aluminum oxide composite material. Background Art
[0002] Room temperature phosphorescent materials refer to materials that can emit phosphorescence at room temperature and belong to the phenomenon of photoluminescence. Its characteristic is that triplet excitons in the excited state emit light when returning to the ground state through radiative transition. Different from fluorescent materials, room temperature phosphorescent materials have a longer luminescence lifetime and have the advantages of eliminating short-lived fluorescence and reducing background noise, and have great advantages in the fields of new generation information anti-counterfeiting, time resolution, optoelectronic sensing, biological imaging, etc. Traditional phosphorescent materials are mainly inorganic materials based on rare earth elements and pure organic materials with molecular structures as the luminescence centers. However, due to the non-renewability of rare earth resources, high raw material costs, and problems such as the optical instability of organic room temperature phosphorescent materials, the need for a large amount of organic reagents, and complex preparation processes, it brings inevitable challenges to researchers, resulting in a great limitation in the application prospects of phosphorescent materials mainly based on rare earth inorganic materials and organic materials. Therefore, it is very necessary to explore new room temperature phosphorescent materials that simultaneously have low cost, easy manufacturability, and excellent optical properties.
[0003] Carbon dots (CDs) are a new type of zero-dimensional luminescent nanomaterial. Due to advantages such as rich precursor sources, simple preparation processes, high photostability, and low toxicity, they have become a very promising luminescent material. In recent years, researchers have proposed various strategies to enhance the phosphorescent properties of CDs, such as heteroatom doping, heavy atom effects, and matrix assistance. Among them, embedding CDs into a matrix to form hydrogen bonds or covalent bonds, thereby stabilizing triplet excitons and suppressing non-radiative transitions, is a relatively common and effective strategy to obtain highly efficient and long-lived room temperature phosphorescent CDs. However, most room temperature phosphorescent CDs materials are only excited under ultraviolet light, which greatly limits their actual application fields. Compared with ultraviolet light, visible light sources are everywhere, such as mobile phone flashlights, fluorescent lamps, flashlights, etc., and have the advantages of less harm to biological tissues such as eyes and skin, convenience, and higher precision. Therefore, developing visible light-excited room temperature phosphorescent materials will greatly promote the room temperature phosphorescent materials to meet the actual application requirements, and at the same time, it is of great significance to expand the excitation range to a wider visible light region.
[0004] At present, the methods reported for preparing CDs@matrix room temperature phosphorescent materials still have disadvantages such as complex preparation processes, high prices, and short phosphorescent lifetimes, which are not conducive to practical applications. Therefore, a simple preparation method is needed for preparing long-lived room temperature phosphorescent carbon dot nanomaterials under visible light. Summary of the Invention
[0005] To avoid the deficiencies of the prior art, the present invention provides a method for preparing a visible light-excited room temperature phosphorescent carbon dots@silica@aluminum oxide composite material.
[0006] One of the objectives of the present invention is to provide a simple and easy one-step calcination method.
[0007] Another objective of the present invention is to provide a visible light-excited room temperature phosphorescent carbon dots@silica@aluminum oxide composite material.
[0008] A visible light-excited room temperature phosphorescent carbon dots@silica@aluminum oxide composite material prepared by the present invention uses 1,3,6-trinitropyrene, boric acid, tetraethyl orthosilicate, and aluminum chloride hexahydrate as raw materials and is prepared by a one-step calcination method. The preparation process includes the following specific steps: 1. First, take 0.1 - 0.5 g of 1,3,6-trinitropyrene, 0.6 - 1 g of boric acid, and 14.2 - 16.2 mL of tetraethyl orthosilicate, add them to a mixed solution of 120 - 160 mL of ultrapure water and 20 - 40 mL of absolute ethanol, and then add 0.6 - 1 mL of ammonia water and stir for 0.5 hours to obtain a yellow transparent solution; 2. During the stirring process, add 1.61 - 2.01 g of aluminum chloride hexahydrate to the transparent solution obtained in step 1 and stir for 5 - 10 hours to obtain a yellow transparent solution; 3. Cover the yellow transparent solution obtained in step 2 with aluminum foil paper, place it in an oven at 160 - 200 °C for reaction for 2 - 4 hours, and after cooling to room temperature, grind it to obtain a yellow powder; 4. Place the yellow powder obtained in step 3 in a covered crucible and calcine it in a muffle furnace at 600 - 800 °C for 1 - 3 hours to obtain a visible light-excited room temperature phosphorescent carbon dots@silica@aluminum oxide composite material.
[0009] Advantages of the present invention: 1. The present invention provides a method for preparing a visible light-excited room temperature phosphorescent carbon dots@silica@aluminum oxide composite material. It is characterized by using 1,3,6-trinitropyrene, boric acid, tetraethyl orthosilicate, and aluminum chloride hexahydrate as raw materials and being prepared by a one-step calcination method. Only ordinary equipment commonly used in laboratories is required, and no special equipment is needed. The process is simple and easy to operate; 2. The visible light-excited room temperature phosphorescent carbon dots@silica@aluminum oxide composite material obtained by this method shows visible yellow phosphorescence for up to 21 s with the 430 nm visible light lamp turned off; 3. The drugs used in the present invention are all non-toxic, harmless, and inexpensive. The preparation is simple and takes a short time. After preparation, no complex and cumbersome steps are required. It is especially suitable for batch and low-cost preparation and is suitable for industrial-scale production and commercial applications; 4. The visible light-excitable room temperature phosphorescent carbon dot@silica@aluminum oxide composite material provided by the present invention can be successfully applied to fields such as information encryption. Description of the Drawings
[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings in the description of the embodiments or the prior art. However, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0011] Figure 1 Transmission electron microscopy image of the visible light-excitable room temperature phosphorescent carbon dot@silica@aluminum oxide composite material prepared in Example 1 of the present invention.
[0012] Figure 2 X-ray diffraction pattern of the visible light-excitable room temperature phosphorescent carbon dot@silica@aluminum oxide composite material prepared in Example 1 of the present invention.
[0013] Figure 3 Fourier transform infrared spectroscopy pattern of the visible light-excitable room temperature phosphorescent carbon dot@silica@aluminum oxide composite material prepared in Example 1 of the present invention.
[0014] Figure 4 Ultraviolet absorption spectroscopy pattern of the visible light-excitable room temperature phosphorescent carbon dot@silica@aluminum oxide composite material prepared in Example 1 of the present invention.
[0015] Figure 5 State diagrams of the visible light-excitable room temperature phosphorescent carbon dot@silica@aluminum oxide composite materials prepared in Examples 1-3 and Comparative Example 1 under sunlight, irradiated by a 430 nm visible light lamp, and after turning off the light.
[0016] Figure 6 Application photo of the visible light-excitable room temperature phosphorescent carbon dot@silica@aluminum oxide composite material prepared in Example 1 of the present invention in information resolution anti-counterfeiting. Detailed Description of the Embodiments
[0017] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0018] All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.
[0019] In the following embodiments, unless otherwise specified, the experimental methods are all conventional methods; the reagents and materials, unless otherwise specified, can all be purchased on the market.
[0020] Example 1: First, take 0.3 g of 1,3,6-trinitropyrene, 0.8 g of boric acid, and 15.2 mL of tetraethyl orthosilicate and add them to a mixed solution of 140 mL of ultrapure water and 30 mL of absolute ethanol. Then add 0.8 mL of ammonia water and stir for 0.5 hour to obtain a yellow transparent solution. Add 1.81 g of aluminum chloride hexahydrate to the obtained transparent solution and stir for 8 hours to obtain a yellow transparent solution. Wrap the obtained yellow transparent solution with aluminum foil paper, place it in an oven at 180 °C for reaction for 3 hours, and grind it after cooling to room temperature to obtain a powder. Place the obtained powder in a crucible with a lid and calcine it in a muffle furnace at 700 °C for 2 hours to obtain a visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite material.
[0021] Example 2: First, take 0.1 g of 1,3,6-trinitropyrene, 1 g of boric acid, and 14.2 mL of tetraethyl orthosilicate and add them to a mixed solution of 120 mL of ultrapure water and 40 mL of absolute ethanol. Then add 1 mL of ammonia water and stir for 0.5 hour to obtain a yellow transparent solution. Add 2.01 g of aluminum chloride hexahydrate to the obtained transparent solution and stir for 5 hours to obtain a yellow transparent solution. Wrap the obtained yellow transparent solution with aluminum foil paper, place it in an oven at 200 °C for reaction for 2 hours, and grind it after cooling to room temperature to obtain a powder. Place the obtained powder in a crucible with a lid and calcine it in a muffle furnace at 600 °C for 3 hours to obtain a visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite material.
[0022] Example 3: First, take 0.5 g of 1,3,6-trinitropyrene, 0.6 g of boric acid, and 16.2 mL of tetraethyl orthosilicate and add them to a mixed solution of 160 mL of ultrapure water and 20 mL of absolute ethanol. Then add 0.5 mL of ammonia water and stir for 0.5 hour to obtain a yellow transparent solution. Add 1.61 g of aluminum chloride hexahydrate to the obtained transparent solution and stir for 8 hours to obtain a yellow transparent solution. Wrap the obtained yellow transparent solution with aluminum foil paper, place it in an oven at 160 °C for reaction for 4 hours, and grind it after cooling to room temperature to obtain a powder. Place the obtained powder in a crucible with a lid and calcine it in a muffle furnace at 800 °C for 1 hour to obtain a visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite material.
[0023] Figure 1 Transmission electron microscope image of the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite material prepared for Example 1. From Figure 1It can be seen that the CDs are evenly distributed in the boron oxide matrix.
[0024] Figure 2 X-ray diffraction pattern of the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite prepared in Example 1. From Figure 2 It can be seen that the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite exhibits an amorphous structure.
[0025] Figure 3 Fourier transform infrared spectrum of the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite prepared in Example 1. From Figure 3 It can be seen that at 700 cm -1 the stretching vibration of the Al-O bond is shown, indicating the successful formation of the aluminum oxide matrix.
[0026] Figure 4 Ultraviolet absorption spectrum of the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite prepared in Example 1. From Figure 4 It can be seen that there is an absorption peak at 273 nm, which can be attributed to the structural transition of the C = C bond in the sp 2 aromatic conjugated system region.
[0027] Figure 5 Pictures of the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composites prepared in Examples 1-3 under sunlight, under 430 nm visible light irradiation, and after turning off the lights. From Figure 5 It can be seen that the prepared Example 1 exhibits the longest visible time to the naked eye, up to 21 s; the visible times of the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composites prepared in other Examples 2-3 are relatively short.
[0028] Figure 6 Photo of the application of the visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite prepared in Example 1 in information encryption and anti-counterfeiting. From Figure 6 It can be seen that "8888" consists of two parts. Under 430 nm visible light irradiation, "8888" all shows fluorescence. When the light is turned off, the final encrypted term "2025" is recognized. The results show that the prepared visible-light-excited room-temperature phosphorescent carbon dots@silica@aluminum oxide composite is successfully used in encryption and anti-counterfeiting applications.
[0029] Obviously, those skilled in the art can make various changes and modifications to the preparation method of a visible light-excited room temperature phosphorescent carbon dots@silica@aluminum oxide composite described in the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention also intends to include these modifications and variations.
Claims
1. A method for preparing a visible light excited room temperature phosphorescent carbon dot@silicon dioxide@alumina composite material, comprising the following steps: First, 0.1-0.5 g of 1,3,6-trinitropyrene, 0.2-0.8 g of boric acid and 14.2-16.2 mL of tetraethyl orthosilicate are added to a mixed solution of 120-160 mL of ultrapure water and 20-40 mL of anhydrous ethanol, and then 0.6-1 mL of ammonia water is added and stirred for 0.5 hours to obtain a yellow transparent solution. Under stirring conditions, 1.61-2.01 g of aluminum chloride hexahydrate is added to the transparent solution and stirred for 5-10 hours to obtain a yellow transparent solution. The yellow transparent solution was wrapped with aluminum foil, placed in an oven at 160-200°C for reaction for 2-4 hours, and ground to obtain powder after cooling to room temperature. The powder was placed in a covered crucible and calcined in a muffle furnace at 600-800°C for 1-3 hours to obtain a visible light excited room temperature phosphorescent carbon dot@silicon dioxide@alumina composite material.
2. The method for preparing the visible light excited room temperature phosphorescent carbon dots@silicon dioxide@alumina composite material according to claim 1, characterized in that: The amount of 1,3,6-trinitropyrene used is 0.3 g, and the amount of boric acid used is 0.6 g.
3. The method for preparing the visible light excited room temperature phosphorescent carbon dots@silicon dioxide@alumina composite material according to claim 1, characterized in that: The amount of tetraethyl orthosilicate used was 15.2 mL, and the amount of aluminum chloride hexahydrate used was 1.81 g.
4. The method for preparing the visible light excited room temperature phosphorescent carbon dots@silicon dioxide@alumina composite material obtained by the preparation method according to claim 1, characterized in that: The visible light excited room temperature phosphorescent carbon dots@silicon dioxide@aluminum oxide composite material is applied to information encryption.