Phosphorus-doped long-life feather-derived phosphorescent carbon dots as well as preparation method and application thereof

Abstract

The invention discloses a preparation method of phosphorus-doped long-life feather-derived phosphorescent carbon dots. The preparation method comprises the following steps: S1, carrying out hydrothermal reaction in deionized water by taking feather meal as a carbon source and taking acid containing phosphorus element as a phosphorus source; s2, cooling a reaction product obtained after the hydrothermal reaction to room temperature, and filtering to obtain a carbon dot solution; s3, purifying the carbon dot solution obtained in the step S2 by using column chromatography; and S4, freezing the purified carbon dot solution, and freeze-drying in a freeze dryer to obtain the phosphorus-doped long-life feather-derived phosphorescent carbon dots. The preparation method is wide in raw material source, low in cost, green, environment-friendly, low in toxicity, simple, mild in reaction condition, high in yield, green, pollution-free and suitable for batch production; the blue fluorescent light can be displayed under ultraviolet light, green phosphorescence is generated after an ultraviolet light source is removed, the service life of the green phosphorescence can reach 1.15 s along with the phosphorescence, and the fluorescent / phosphorescence dual-mode anti-counterfeiting effect and information encryption can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of luminescent material preparation, and particularly relates to a phosphorus-doped long-lifetime feather-derived phosphorescent carbon dot, a preparation method and application thereof. BACKGROUND

[0002] Counterfeiting has become a major hidden danger threatening the safety of modern society. To address this challenge, the scientific community has developed a variety of anti-counterfeiting technologies, including DNA-labeled packaging materials, magnetically responsive plasmonic security tags, RFID smart tags, and luminescent printing. However, existing technologies still have obvious limitations: some anti-counterfeiting methods are easily imitated due to their predictable encoding mechanisms. Against this background, luminescent materials play an important role in the field of anti-counterfeiting technology due to their unique optical properties. These materials can produce controllable spectral and lifetime changes in response to external stimuli, providing secure features that are difficult to imitate, and thus exhibit significant advantages in optical data storage and security anti-counterfeiting fields.

[0003] Researchers have developed a variety of luminescent materials, including organic dyes, lanthanide-doped nanomaterials, quantum dots, and metal-organic frameworks, for anti-counterfeiting printing. However, these materials generally face challenges such as high preparation costs, heavy metal pollution, and complex synthesis processes. In contrast, carbon quantum dots (carbon dots) are a new type of carbon nanomaterial with a particle size generally less than 10 nm. They not only have good biocompatibility, optical stability, and water solubility, but also can achieve other new anti-counterfeiting modes in addition to ordinary static fluorescence anti-counterfeiting mode due to their wide range of raw material sources, small size, and easy functionalization. Compared with traditional anti-counterfeiting technologies, light functional materials with stimulus-responsive properties exhibit obvious advantages in the field of anti-counterfeiting or information encryption.

[0004] Currently, how to prepare high-yield, multi-mode luminescent carbon quantum dots using a simple and environmentally friendly process is an important challenge faced by those skilled in the art. In the prior art, a super-long phosphorescent cuticle protein-derived carbon quantum dot and a preparation method thereof are disclosed in CN111573652A. A multi-mode luminescent carbon quantum dot with both fluorescence and super-long phosphorescence is prepared using cuticle protein waste as a precursor and deionized water as a solvent through a simple hydrothermal process and purification treatment, and the phosphorescent lifetime can reach 0.493 s. However, the inventors found that the lifetime is still relatively short and cannot meet the application in the field of anti-counterfeiting. Therefore, how to prepare phosphorescent carbon dots with a longer lifetime through a simple method and effectively apply them in the field of anti-counterfeiting is still a technical problem that needs to be solved at present. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a phosphorus-doped long-lifetime feather-derived phosphorescent carbon dot and a preparation method, so as to solve the technical problem that the phosphorescent lifetime of the traditional carbon dot material is short and cannot effectively meet the application in the field of anti-counterfeiting.

[0006] To achieve the object of the present application, the present application adopts the following technical solutions:

[0007] The first aspect of the present application is to provide a preparation method of phosphorus-doped long-life feather-derived phosphorescent carbon dots, comprising the following steps:

[0008] S1, hydrothermal reaction of feather powder as a carbon source and an acid containing phosphorus elements as a phosphorus source in deionized water;

[0009] S2, cooling the obtained reaction product to room temperature after the hydrothermal reaction, and obtaining a carbon dot solution by filtration;

[0010] S3, purifying the carbon dot solution obtained in step S2 by column chromatography;

[0011] S4, freezing the purified carbon dot solution and freeze-drying it in a freeze-drying machine to obtain phosphorus-doped long-life feather-derived phosphorescent carbon dots.

[0012] In an alternative embodiment, in step S1, the acid containing phosphorus elements is phytic acid.

[0013] In an alternative embodiment, in step S1, feather powder: acid containing phosphorus elements: deionized water = 1g: (0.4-1) g: 125mL.

[0014] In an alternative embodiment, in step S3, the eluent in the column chromatography is deionized water and anhydrous ethanol, and the volume ratio is 1:1-3.

[0015] The second aspect of the present application is to provide a phosphorus-doped long-life feather-derived phosphorescent carbon dot, which is prepared according to the above-mentioned preparation method of phosphorus-doped feather-derived phosphorescent carbon dots. The phosphorus-doped feather-derived phosphorescent carbon dots can emit blue fluorescence and green phosphorescence.

[0016] In an alternative embodiment, the particle size of the phosphorescent carbon dots is 2-20nm.

[0017] In an alternative embodiment, the lifetime of the phosphorescent carbon dots is ≥1.15s.

[0018] The third aspect of the present application is to provide the application of phosphorus-doped long-life feather-derived phosphorescent carbon dots in anti-counterfeiting and information encryption.

[0019] In an alternative embodiment, the application comprises the following steps:

[0020] (1) dissolving polyvinyl alcohol in deionized water, mixing and stirring uniformly to obtain a polyvinyl alcohol solution;

[0021] (2) Disperse the obtained phosphorescent carbon dot powder in water to make a phosphorescent carbon dot aqueous dispersion, add the phosphorescent carbon dot aqueous dispersion to a polyvinyl alcohol solution, stir quickly until the mixture is uniform, and make a water-based anti-counterfeiting ink.

[0022] (3) The water-based anti-counterfeiting ink is printed on the substrate using screen printing, gravure printing or inkjet printing. After natural drying, the anti-counterfeiting pattern is formed. The anti-counterfeiting pattern produces bright blue fluorescence under ultraviolet light and green phosphorescence after the excitation light stops.

[0023] In one optional embodiment, the phosphorescent carbon dot aqueous dispersion has a mass percentage of 1 to 6%.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention uses waste feather powder and phytic acid containing phosphorus as raw materials. The raw materials are widely available, inexpensive, environmentally friendly, and have low toxicity. A novel phosphorus-doped feather-derived phosphorescent carbon dot luminescent material is synthesized using a one-step hydrothermal method. The preparation method is simple, the reaction conditions are mild, the yield is high, and it is green and pollution-free, making it suitable for large-scale production applications. The carbon dot material is made into a dispersion and then combined with a hydrophilic polymer to form an ink. The pattern printed with this ink can show blue fluorescence under ultraviolet light. After the ultraviolet light source is removed, green phosphorescence is generated. The emitted phosphorescence intensity is strong enough to be visible to the naked eye, and the phosphorescence lifetime can be as long as 1.15s, achieving a dual-mode anti-counterfeiting effect and information encryption of fluorescence / phosphorescence. Attached Figure Description

[0026] Figure 1 This is a transmission electron microscope image and size distribution diagram of phosphorus-doped feather-derived phosphorescent carbon dots from Example 1 of the present invention.

[0027] Figure 2 This is a high-resolution transmission electron microscope image of phosphorus-doped feather-derived phosphorescent carbon dots from Example 1 of the present invention.

[0028] Figure 3 This is the Raman spectrum of the phosphorus-doped feather-derived phosphorescent carbon dots from Example 1 of the present invention;

[0029] Figure 4 This is the X-ray diffraction pattern of phosphorus-doped feather-derived phosphorescent carbon dots from Example 1 of the present invention;

[0030] Figure 5 The X-ray photoelectron spectroscopy spectrum of the phosphorus-doped feather-derived phosphorescent carbon dots in Example 1 of the present invention is shown.

[0031] Figure 6 The fluorescence emission spectra of phosphorus-doped feather-derived phosphorescent carbon dots under different wavelength excitations are shown in Example 1 of the present invention.

[0032] Figure 7 Phosphorescence emission spectrum of phosphorus-doped feather-derived phosphor carbon dots of Example 1 of the present application under excitation at different wavelengths;

[0033] Figure 8 Phosphorescence lifetime spectrum of phosphorus-doped feather-derived phosphor carbon dots of Example 1 of the present application;

[0034] Figure 9 Luminescence state of the anti-counterfeiting pattern printed by the anti-counterfeiting ink of Example 1 of the present application under sunlight, ultraviolet light irradiation and after removal of the ultraviolet light, respectively;

[0035] Figure 10 Phosphorescence emission spectrum of phosphorus-doped feather-derived phosphor carbon dots of Comparative Example 2 of the present application under excitation at different wavelengths;

[0036] Figure 11 Phosphorescence lifetime spectrum of phosphorus-doped feather-derived phosphor carbon dots of Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application and should not be regarded as specific limitations on the present application.

[0038] Example 1

[0039] A preparation method of phosphorus-doped long-lifetime feather-derived phosphor carbon dots, comprising the following steps:

[0040] (1) Crush the washed and dried feather for use, add 0.4 g of the feather powder and 50 mL of deionized water in a beaker, stir for 12 h to make them uniformly dispersed, add 0.36 g of phytic acid in the mixture, stir for 30 min, and then transfer to a polytetrafluoroethylene hydrothermal reaction kettle, heat at 220℃ for 10 h.

[0041] (2) After the reaction kettle is cooled to room temperature, filter the obtained solution with filter paper until the large particulate matter in the solution is completely removed, to obtain a yellow transparent liquid.

[0042] (3) Use deionized water / ethanol (volume ratio 1:1) as the mobile phase, and purify the obtained solution by column chromatography.

[0043] (4) Freeze and vacuum dry the purified solution to obtain phosphorus-doped long-lifetime feather-derived phosphor carbon dot powder.

[0044] I. Characterization of phosphor carbon dots

[0045] Figure 1 The transmission electron microscope image of the phosphor carbon dots obtained in the present example is shown in Figure 1. Figure 1As can be seen, the carbon dots are uniformly distributed spherical nanoparticles with an average diameter of approximately 6.69 nm.

[0046] Figure 2 This is a high-resolution transmission electron microscope image of the phosphorescent carbon dots obtained in this embodiment. From... Figure 2 As can be seen, the carbon dots exhibit clear lattice edges with a lattice spacing of 0.21 nm, corresponding to the (100) crystal plane in the graphite structure, indicating that the carbon dots have a certain graphite lattice structure.

[0047] Figure 3 This is the Raman spectrum of the phosphorescent carbon dots obtained in this embodiment. From... Figure 3 Two characteristic peaks can be observed, one located at 1330 cm⁻¹. -1 The D-band at 1580cm and the D-band at 1580cm -1 The G bands at the locations represent amorphous carbon and crystalline graphitic carbon, respectively. The calculation of ID:IG proves that the carbon dots have a good degree of graphitization.

[0048] Figure 4 This is the X-ray diffraction spectrum of the phosphorescent carbon dots obtained in this embodiment. From... Figure 4 It can be seen that there is a sharp peak at 21°, which corresponds to the (002) crystal plane of graphite, proving that it conforms to the structural characteristics of standard carbon points.

[0049] Figure 5 This is the X-ray photoelectron spectroscopy spectrum of the phosphorescent carbon dots obtained in this embodiment. From... Figure 5 As can be seen, the carbon dots have characteristic peaks of C 1s, N 1s, O 1s, and P 2p, proving the successful doping of P element.

[0050] II. Fluorescence and phosphorescence emission spectra of phosphorescent carbon dots

[0051] Figure 6 The images show the fluorescence emission spectra of the phosphorescent carbon dots obtained in this embodiment under different wavelengths of excitation. Figure 6 It can be seen that the fluorescence emission center of the carbon dot is 468 nm, and it exhibits blue fluorescence.

[0052] Figure 7 The images show the long-lifetime phosphorescent emission spectra of the phosphorescent carbon dots obtained in this embodiment under different wavelength excitations. Figure 7 As can be seen, the carbon dots exhibit a distinct green phosphorescence, with a central emission peak wavelength of 540 nm.

[0053] III. Phosphorescence Lifetime of Phosphorescent Carbon Dots

[0054] Figure 8 This is the phosphorescence lifetime spectrum of the phosphorescent carbon dots obtained in this embodiment. From... Figure 8As can be seen, the carbon dots have a room temperature phosphorescence lifetime of 1.15s, with an ultra-long room temperature phosphorescence lifetime.

[0055] Example 2

[0056] A preparation method of phosphorus-doped long-life feather-derived phosphorescent carbon dots, comprising the following steps:

[0057] (1) The washed and dried feather was crushed for use. 0.4g of the feather powder was added to 50mL of deionized water in a beaker, and stirred for 12h to disperse uniformly. 0.2g of phytic acid was added to the mixture, and stirred for 30min before being transferred to a polytetrafluoroethylene hydrothermal reactor. The mixture was heated at 180℃ for 15h.

[0058] (2) After the reactor was cooled to room temperature, the obtained solution was filtered with filter paper until the large particulate matter in the solution was completely removed, to obtain a yellow transparent liquid.

[0059] (3) The obtained solution was purified by column chromatography using deionized water / ethanol (volume ratio of 1:3) as the mobile phase.

[0060] (4) The purified solution was freeze-dried to obtain phosphorus-doped long-life feather-derived phosphorescent carbon dot powder.

[0061] Example 3

[0062] A preparation method of phosphorus-doped long-life feather-derived phosphorescent carbon dots, comprising the following steps:

[0063] (1) The washed and dried feather was crushed for use. 0.4g of the feather powder was added to 50mL of deionized water in a beaker, and stirred for 12h to disperse uniformly. 0.28g of phytic acid was added to the mixture, and stirred for 30min before being transferred to a polytetrafluoroethylene hydrothermal reactor. The mixture was heated at 250℃ for 8h.

[0064] (2) After the reactor was cooled to room temperature, the obtained solution was filtered with filter paper until the large particulate matter in the solution was completely removed, to obtain a yellow transparent liquid.

[0065] (3) The obtained solution was purified by column chromatography using deionized water / ethanol (volume ratio of 1:2) as the mobile phase.

[0066] (4) The purified solution was freeze-dried to obtain phosphorus-doped long-life feather-derived phosphorescent carbon dot powder.

[0067] Application test example

[0068] The phosphorescent carbon dot powder prepared in Example 1, Example 2 and Example 3 was used as a composite to prepare anti-counterfeiting ink, and the specific steps were as follows:

[0069] (1) 5 g of polyvinyl alcohol and 40 g of deionized water were added into a round-bottom flask, stirred at 95°C for 2 h to obtain a polyvinyl alcohol solution.

[0070] (2) 5 g of phosphorescent carbon dot powder (Example 1, Example 2 or Example 3) aqueous dispersion (3%) was added into the polyvinyl alcohol solution, and stirred constantly to prepare a uniform anti-counterfeiting ink.

[0071] The anti-counterfeiting inks prepared from the phosphorescent carbon dot powder of Example 1, Example 2 and Example 3 were used to screen-print custom-made two-dimensional codes on cotton fabric, non-fluorescent cellulose paper and A4 printing paper respectively. After printing, the samples were dried in a ventilated environment for 30 min, and then irradiated with sunlight and 365 nm ultraviolet light. The colors emitted by the two-dimensional codes under the irradiation of the two kinds of light were observed, and then the color emitted by the two-dimensional codes was observed again after the ultraviolet light irradiation was turned off. The results are shown in Figure 9 Figure 9 In , from top to bottom are the luminescence of the two-dimensional code printed on the cotton fabric using the anti-counterfeiting ink prepared from the phosphorescent carbon dot of Example 1, the luminescence of the two-dimensional code printed on the non-fluorescent cellulose paper using the anti-counterfeiting ink prepared from the phosphorescent carbon dot of Example 2, and the luminescence of the two-dimensional code printed on the non-fluorescent cellulose paper using the anti-counterfeiting ink prepared from the phosphorescent carbon dot of Example 3.

[0072] Figure 9 As can be seen from , under the irradiation of sunlight, the two-dimensional code is almost invisible, and under the irradiation of ultraviolet light, the two-dimensional code all presents blue fluorescence. When the ultraviolet light is turned off, the two-dimensional code all presents green phosphorescence, indicating that the anti-counterfeiting ink prepared from the phosphorescent carbon dot of the present application has a dual-mode luminescence function under the action of ultraviolet light.

[0073] Comparative Example 1

[0074] I. Preparation of phosphorescent carbon dots

[0075] The preparation method of the phosphorescent carbon dots provided in the present comparative example is the same as that of Example 1, except that no phytic acid is added.

[0076] II. Preparation of anti-counterfeiting ink

[0077] The preparation process of the anti-counterfeiting ink is the same as that of the above application test example, except that the phosphorescent carbon dot powder prepared in the present comparative example is used to prepare an aqueous dispersion (3%).

[0078] III. Application of anti-counterfeiting ink

[0079] The anti-counterfeiting ink prepared above was used to screen-print custom-made two-dimensional codes on non-fluorescent cellulose paper. After printing, the samples were dried in a ventilated environment for 30 min.

[0080] Comparative Example 2

[0081] I. Preparation of phosphorescent carbon dots

[0082] The preparation method of the phosphorescent carbon dots provided by the present comparative example is different from that of Example 1 in that phytic acid is replaced by phosphoric acid, and the rest is the same as that of Example 1.

[0083] II. Preparation of anti-counterfeiting ink

[0084] The preparation process of the anti-counterfeiting ink is the same as that of the above application test example, except that the phosphorescent carbon dot powder prepared in the present comparative example is used to prepare a water dispersion (3%).

[0085] III. Application of anti-counterfeiting ink

[0086] The anti-counterfeiting ink prepared above is used to screen print a custom two-dimensional code on a non-fluorescent cellulose paper, and after printing is completed, the sample is dried in a ventilated environment for 30 min.

[0087] IV. Phosphorescence emission spectrum of phosphorescent carbon dots

[0088] Figure 10 The long lifetime phosphorescence emission spectrum of the feather-derived carbon dots doped with phosphoric acid used in the present comparative example under different wavelength excitations is shown in the figure. As can be seen from the figure, the carbon dots exhibit obvious green phosphorescence, and the emission center peak wavelength is 562 nm. Compared with the phosphorescence intensity of the carbon dots prepared by using phytic acid as the phosphorus source in Comparative Example 1 (refer to Figure 7 ), the phosphorescence intensity of the feather-derived carbon dots obtained by doping with phosphoric acid is greatly reduced.

[0089] V. Phosphorescence lifetime of phosphorescent carbon dots

[0090] Figure 11 The phosphorescence lifetime spectrum of the feather-derived carbon dots doped with phosphoric acid used in the present comparative example is shown in the figure. As can be seen from the figure, the phosphorescence lifetime of the feather-derived carbon dots doped with phosphoric acid is 0.33 s, which is reduced by 0.82 s compared with the phosphorescence lifetime of the feather-derived carbon dots doped with phytic acid in Comparative Example 1 (refer to Figure 8 ).

[0091] Comparative Example 3

[0092] I. Preparation of phosphorescent carbon dots

[0093] The preparation method of the phosphorescent carbon dots provided by the present comparative example is different from that of Example 1 in that the amount of phytic acid added is different. In the present comparative example, the amount of phytic acid added is 0.12 g, and the rest is the same as that of Example 1.

[0094] II. Preparation of anti-counterfeiting ink

[0095] The preparation process of the anti-counterfeiting ink is the same as the above application test example, except that the phosphorescent carbon dot powder prepared by the present comparative example is made into a water dispersion (3%).

[0096] III. Application of the Anti-counterfeiting Ink

[0097] The anti-counterfeiting ink prepared above is used for screen printing a customized two-dimensional code on non-fluorescent cellulose paper. After printing is completed, the sample is dried in a ventilated environment for 30 min.

[0098] Comparative Example 4

[0099] I. Preparation of Phosphorescent Carbon Dots

[0100] The preparation method of the phosphorescent carbon dots provided by the present comparative example is different from that of Example 1 in that the amount of phytic acid added is 0.45 g, and the rest is the same as that of Example 1.

[0101] II. Preparation of Anti-counterfeiting Ink

[0102] The preparation process of the anti-counterfeiting ink is the same as the above application test example, except that the phosphorescent carbon dot powder prepared by the present comparative example is made into a water dispersion (3%).

[0103] III. Application of the Anti-counterfeiting Ink

[0104] The anti-counterfeiting ink prepared above is used for screen printing a customized two-dimensional code on non-fluorescent cellulose paper. After printing is completed, the sample is dried in a ventilated environment for 30 min.

[0105] Effect Verification Example

[0106] I. Luminescence of the Ink Printed into a Two-dimensional Code by Phosphorescent Carbon Dots

[0107] The two-dimensional codes printed by Examples 2-3 and Comparative Examples 1-4 are irradiated with sunlight and 365 nm ultraviolet light, respectively, and the state of the two-dimensional codes after the ultraviolet light is turned off and the lifetime of the luminescence are observed. The results are shown in Table 1 below.

[0108] Table 1 Luminescence of the Ink Printed into a Two-dimensional Code by Different Phosphorescent Carbon Dots

[0109] Sample Natural light irradiation UV light irradiation UV light off Room temperature phosphorescence lifetime (s) Example 2 Not visible Blue fluorescent emission Green phosphorescent emission 1.11 Example 3 Not visible Blue fluorescent emission Green phosphorescent emission 1.13 Comparative Example 1 Not visible Blue fluorescent emission Green phosphorescent emission 0.50 Comparative Example 2 Not visible Blue fluorescent emission Green phosphorescent emission 0.33 Comparative Example 3 Not visible Blue fluorescent emission Green phosphorescent emission 0.65 Comparative Example 4 Not visible Blue fluorescent emission Not visible /

[0110] From the above table 1, it can be seen that examples 2 and 3 can emit dual light, and the phosphorescent light lifetime is more than 1.1s; comparative example 1 uses phosphorescent carbon dot powder without adding phytic acid to prepare ink, and the printed two-dimensional code can emit fluorescence and phosphorescence after the ultraviolet light is turned on and off, respectively, indicating that the phosphorescent carbon dots can emit dual light, but the phosphorescent light lifetime is only 0.50s, which is more than one time different from the phosphorescent light lifetime of examples 2 and 3; comparative example 2 replaces phytic acid with phosphoric acid, and the printed two-dimensional code can also emit dual light, but the phosphorescent light lifetime is only 0.33s, which is lower than that of comparative example 1 without adding phosphorus source, indicating that it has a certain inhibition effect on the phosphorescent light, and is more than two times different from the phosphorescent light lifetime of examples 2 and 3, indicating that the effect of using phytic acid as a phosphorus source is greatly improved compared with phosphoric acid; comparative examples 4 and 5 are more than the limited range of the addition amount of phytic acid compared with examples 2 and 3, and when the addition amount is too low, the two-dimensional code can also emit dual light, but the phosphorescent light lifetime is also short, only 0.65s, and when the addition amount is too high, it will lead to phosphorescence quenching, and the green phosphorescence cannot be emitted after the ultraviolet light is removed, indicating that only when the appropriate amount of phytic acid is added, the carbon dots can be prepared into dual-mode light-emitting and long-lifetime anti-counterfeiting ink.

[0111] The preferred embodiments of the application are described in detail above, but the application is not limited to the specific details in the above-described embodiments, and within the technical concept of the application, various simple modifications can be made to the technical solutions of the application, and these simple modifications all belong to the protection scope of the application.

Claims

1. A method for preparing phosphorus-doped long-lifetime feather-derived phosphor carbon dots, characterized in that, The method comprises the following steps: S1, hydrothermal reaction of feather powder as a carbon source and an acid containing phosphorus elements as a phosphorus source in deionized water; S2, cooling the obtained reaction product to room temperature after the hydrothermal reaction, and obtaining a carbon dot solution by filtration; S3, purifying the carbon dot solution obtained in step S2 by column chromatography; S4, freezing the purified carbon dot solution and freeze-drying it in a freeze dryer to obtain phosphorus-doped long-life feather-derived phosphorescent carbon dots.

2. The method for preparing phosphorus-doped long-lifetime feather-derived phosphor carbon dots according to claim 1, characterized in that, In step S1, the acid containing phosphorus elements is phytic acid.

3. The method for preparing phosphorus-doped long-lifetime feather-derived phosphor carbon dots according to claim 1, characterized in that, In step S1, feather powder: acid containing phosphorus elements: deionized water = 1g: (0.4-1) g: 125mL.

4. The method for preparing phosphorus-doped long-lifetime feather-derived phosphor carbon dots according to claim 1, characterized in that, In step S3, the eluent in the column chromatography is deionized water and anhydrous ethanol, and the volume ratio is 1:1-3.

5. A phosphorus doped long-lived feather-derived phosphor carbon dot, characterized in that, The phosphorus-doped feather-derived phosphorescent carbon dots prepared by the method of any one of claims 1-4 can emit blue fluorescence and green phosphorescence.

6. The phosphorus-doped long-lifetime feather-derived phosphor carbon dots according to claim 5, characterized in that, The particle size of the phosphorescent carbon dots is 2-20nm.

7. The phosphorus-doped long-lifetime feather-derived phosphor carbon dots according to claim 5, characterized in that, The lifetime of the phosphorescent carbon dots is ≥1.15s.

8. The application of the phosphorus-doped long-life feather-derived phosphorescent carbon dots in anti-counterfeiting and information encryption according to claim 5.

9. Use according to claim 8, characterized in that, The method comprises the following steps: (1) Dissolve polyvinyl alcohol in deionized water, mix and stir uniformly to obtain a polyvinyl alcohol solution; (2) Disperse the prepared phosphorescent carbon dot powder in water to prepare a phosphorescent carbon dot water dispersion, add the phosphorescent carbon dot water dispersion to the polyvinyl alcohol solution, and quickly stir until mixed uniformly to prepare an aqueous anti-counterfeiting ink; (3) Print the required pattern on the substrate by silk printing, intaglio printing or jet printing using the aqueous anti-counterfeiting ink, and form an anti-counterfeiting pattern after natural drying, which produces bright blue fluorescence under the irradiation of ultraviolet light and green phosphorescence after the excitation light stops irradiating.

10. Use according to claim 9, characterized in that, The mass percentage of the phosphorescent carbon dot water dispersion is 1-6%.

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