CN113214833B

CN113214833B - Europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material and preparation method and application thereof

Info

Publication number: CN113214833B
Application number: CN202110467194.6A
Authority: CN
Inventors: 叶柿; 李曼; 杨瑞瑞; 赵逸飞; 张勤远
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2021-04-28
Filing date: 2021-04-28
Publication date: 2022-07-26
Anticipated expiration: 2041-04-28
Also published as: CN113214833A

Abstract

The invention discloses a europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material as well as a preparation method and application thereof. The composite material comprises europium-doped porous metal oxide and halide perovskite, wherein the pore diameter of the europium-doped porous metal oxide is 30-500 nm; the halide perovskite is lead cesium halide perovskite; the halide perovskite is deposited within the channels of the europium-doped porous metal oxide. Firstly synthesizing PMMA microspheres, performing suction filtration and assembly, then dripping metal oxide precursor sol on the PMMA microspheres, performing suction filtration, and calcining a product; then immerging the precursor solution of halide perovskite, and obtaining the composite material through heat treatment. The luminescent material of the invention has photochromic phenomena from red light to green light under ultraviolet light or purple light, can recover in a short time after stopping irradiation, has stable material property and high luminescent efficiency, and has wide application prospect in the fields of color change anti-counterfeiting and the like.

Description

Europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of luminescent materials, and particularly relates to a europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material, and a preparation method and application thereof.

Background

Photochromic material refers to a material that changes in appearance color or fluorescent property under the action of external light. At present, photochromic materials have great application prospects in the fields of information storage, anti-counterfeiting technology, safety ink, photoswitch, biological imaging and the like. Halide perovskite materials have received great attention in the color change response field and anti-counterfeiting due to the fact that the halide perovskite materials rely on the fluorescent properties of simple and tunable component control and high quantum efficiency.

The porous material provides sufficient space for various chemical reactions due to the higher specific surface area. As a base material, can be more effectively improvedThe stability of the perovskite and the promotion of the diffusion of perovskite halide ions. The composite halide perovskite material taking the porous europium-doped metal oxide fluorescent material as the matrix has the following advantages: the oxide matrix can preferentially adsorb/coordinate Cl < - > ions; the large specific surface area of the porous material allows the oxide and the halide to fully interact; rare earth ion Eu ³⁺ Not only provides red light color, but also its valence-change Eu ²⁺ Can also react with Pb ²⁺ The oxidation reduction of-Pb can realize high-efficiency color-changing process. Recoverable photoinduced Phase splitting of perovskite components in the pore channels is effectively realized, and the luminescence property of the material is changed (Michael C.Brennan, et al.light-Induced nucleation Phase Segregation in Mixed Halide peroxides, ACS Energy Lett.2018,3,1, 204-213), but related phenomena are not paid attention in the field of photoinduced anti-counterfeiting application. Compared with thermochromism, light is an ideal external stimulus for regulating and controlling material performance, and has the remarkable characteristics of precise regulation, remote controllability, safety, no pollution and the like. Therefore, how to combine the synthesized simple porous metal oxide luminescent matrix material with halide perovskite to prepare the recoverable photochromic luminescent material and further apply the recoverable photochromic luminescent material to the field of anti-counterfeiting codes has great theoretical significance and application value.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method of a europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material and an anti-counterfeiting coding photochromic application.

The purpose of the invention is realized by the following technical scheme:

a europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material comprises a europium-doped porous metal oxide and a halide perovskite, wherein the aperture of the europium-doped porous metal oxide is 30nm-500 nm; the halide perovskite is lead cesium halide perovskite; the halide perovskite is deposited within the channels of the europium-doped porous metal oxide.

Preferably, the europium-doped porous metal oxide is an oxide of europium and one or more of Y, Ca, Cd, V, Co, Ce, Ba and Mo.

The preparation method of the europium-doped porous metal oxide and halide perovskite discoloration luminescent composite material is characterized by comprising the following steps of:

(1) adding an initiator into a solvent I, adding a monomer methyl methacrylate in an inert gas atmosphere, heating in a water bath to obtain a microsphere colloidal solution, stirring, centrifuging, drying and grinding to obtain monodisperse PMMA microspheres;

(2) dispersing the monodisperse PMMA microspheres in the step (1) in a solvent II, and performing suction filtration;

(3) dissolving metal salt and citric acid in water, stirring, heating and aging to obtain sol;

(4) dripping the sol obtained in the step (3) onto the self-assembled PMMA microspheres obtained in the step (2), and performing suction filtration;

(5) calcining and carbonizing the suction filtration product in a protective atmosphere; transferring the carbonized product to an air atmosphere to calcine and remove carbon deposition to obtain europium-doped porous metal oxide;

(6) dissolving lead halide and cesium halide in a solvent III to prepare a halide perovskite precursor solution, and soaking the europium-doped porous metal oxide obtained in the step (5) in the halide perovskite precursor solution to diffuse the halide perovskite precursor solution into the pore channels of the europium-doped porous metal oxide;

(7) and (4) washing, purifying and thermally treating the europium-doped porous metal oxide obtained in the step (6) to obtain the europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material.

Preferably, the initiator in the step (1) is potassium persulfate (K) ₂ S ₂ O ₈ ) Ammonium persulfate ((NH) ₄ ) ₂ S ₂ O ₈ ) Azobisisobutyronitrile (AIBN), Azobisisoheptonitrile (ABVN), dibenzoyl peroxide (BPO), hydrogen peroxide (H) ₂ O ₂ ) One or more of (a); further preferably, the initiator is K ₂ S ₂ O ₈ Or AIBN.

Preferably, the solvent I in the step (1) is deionized water;

preferably, the molar ratio of the initiator to the methyl methacrylate in the step (1) is 1: 2-20; further preferably, the molar ratio of the initiator to the methyl methacrylate is 1 (5-10).

Preferably, the volume ratio of the methyl methacrylate to the solvent I in the step (1) is 1: 2-20; further preferably, the volume ratio of the methyl methacrylate to the solvent I is 1 (5-15).

Preferably, after the initiator is added into the solvent I in the step (1), stirring the mixture for 15min to 5h in a water bath at the temperature of between 40 and 90 ℃ at the rotating speed of 200 and 1000 r; more preferably, stirring is carried out in a water bath at 50-90 ℃ for 15min-3h at the rotating speed of 200-600 r.

Preferably, the temperature of the water bath heating in the step (1) is 40-90 ℃; further preferably, the temperature of the water bath is 50-90 ℃.

Preferably, the rotation speed of the stirring in the step (1) is 200-1000 r; the stirring time is 15min-5 h; further preferably, the rotation speed of the stirring is 200-600 r; the stirring time is 15min-3 h.

Preferably, the speed of the centrifugation in the step (1) is 3000-12000 r; further preferably, the speed of the centrifugation is 5000-.

Preferably, the drying temperature in the step (1) is 30-80 ℃; the drying time is 3-24 h. Further preferably, the drying temperature is 40-60 ℃; the drying time is 6-12 h.

Preferably, the ratio of the mass of the PMMA microspheres in the step (2) to the volume of the solvent II is 0.1-1.0 g: 2-10 mL;

preferably, the solvent II in the step (2) is one or more of deionized water, ethanol, cyclohexane and n-hexane; further preferably, the solution II is deionized water or ethanol.

Preferably, the pore diameter of the filter membrane for suction filtration in the step (2) is 200-500 nm.

Preferably, the time for suction filtration in the step (2) is 1-15 min.

Preferably, the concentration of the PMMA microspheres in the step (2) is 0.1-0.3 mol/L;

preferably, the metal salt in step (3) is one or more of metal salts of Y, Ca, Cd, V, Co, Ce, Ba and Mo, and Eu metal salt; further preferably, the metal salt is Y (NO) ₃ ) ₃ 、Y(NO ₃ ) ₃ ·6H ₂ O、YCl ₃ 、Y(CH ₃ COO) ₃ ·4H ₂ O、Ce(NO ₃ ) ₃ ·6H ₂ O、CaSO ₄ 、CaCO ₃ 、CaCl ₂ 、Ca(NO ₃ ) ₂ ·nH ₂ O、Cd(CH ₃ COO) ₃ ·2H ₂ O、(NH ₄ )Mo ₇ O ₂₄ ·4H ₂ O、NH ₄ VO ₃ 、Co(NO ₃ ) ₂ 、Ba(NO ₃ ) ₂ And Eu (NO) ₃ ) ₃ ·6H ₂ And O. More preferably, the metal salt is Y (NO) ₃ ) ₃ ·6H ₂ O and Eu (NO) ₃ ) ₃ ·6H ₂ O or CaCO ₃ 、Eu(NO ₃ ) ₃ ·6H ₂ O and (NH) ₄ )Mo ₇ O ₂₄ ·4H ₂ O。

Preferably, the europium ion content of the metal ions in the aqueous solution obtained in the step (3) is 1-50%; further preferably, the proportion of europium ions in the metal ions in the obtained aqueous solution is 1-20%; more preferably, the proportion of europium ions in the metal ions in the obtained aqueous solution is 5-15%; more preferably, the ratio of europium ion in the metal ions in the aqueous solution obtained is 9%.

Preferably, the molar ratio of the metal salt to the citric acid in the step (3) is 1: 1-1.5;

preferably, the concentration of the sol in the step (3) is 5-15 mol/L;

preferably, the stirring time in the step (3) is 0.5-3 h; the heating temperature is 40-70 ℃;

preferably, the aging time in step (3) is 2-8 h.

Preferably, the suction filtration time in the step (4) is 15-60 min;

preferably, the volume ratio of the sol dropping amount in the step (4) to the microsphere colloidal solution in the step (1) is 1:10-2: 1;

preferably, the volume of the dropwise added sol in the step (4) is 0.5-2 mL;

preferably, the temperature of the calcination carbonization in the step (5) is 200-600 ℃; the calcining and carbonizing time is 1-8 h; the temperature of the air atmosphere calcination is 500-1000 ℃; the air atmosphere calcination time is 0.5-6 h.

Preferably, the lead halide in the step (6) is one or more of lead chloride and lead bromide, and the cesium halide is one or more of cesium chloride and cesium bromide;

preferably, the solvent III in the step (6) is one or more of dimethyl sulfoxide, dimethylformamide and gamma-butyrolactone; further preferably, the solvent III is DMSO;

preferably, the molar concentration ratio of ions in the halide perovskite precursor solution in step (6) is Cs: pb ═ 0.5-2, Cl: br is 0.5-2; further preferably, the molar concentration ratio of ions in the halide perovskite precursor solution is Cs: pb ═ 1, Cl: br is 1;

preferably, the diffusion method in step (6) is one or more of ultrasound, shaking table vibration, heating and stirring; further preferably, the diffusion method is shaking table vibration.

Preferably, the washing in the step (7) is one or more of solvent III centrifugal washing, solvent III washing and suction filtration.

Preferably, the temperature of the heat treatment in the step (7) is 100-140 ℃.

The application of the europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material in preparing the encrypted anti-counterfeiting coding pattern comprises the following steps:

and filling the europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material on a black pixel part in the anti-counterfeiting coding substrate, and filling the europium-doped porous metal oxide on a white pixel part in the anti-counterfeiting coding substrate to obtain the photochromic encrypted anti-counterfeiting coding pattern.

Preferably, the encrypted anti-counterfeiting coding pattern is as follows: two-dimensional code, bar code, number sequence, character sequence, anti-counterfeiting pattern and anti-counterfeiting pattern.

Preferably, the photochromic encryption anti-counterfeiting coding pattern is decrypted under the continuous excitation of ultraviolet light or purple light with the wavelength less than or equal to 400 nm.

The invention discloses an anti-counterfeiting application of a europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material, which comprises the following specific anti-counterfeiting processes:

under the excitation of blue light (460nm), all pixel points in the encrypted anti-counterfeiting coding pattern are Eu ³⁺ Characteristic red emission of (1).

Under the excitation of ultraviolet light or purple light (less than or equal to 400nm), black pixel points formed by europium-doped porous metal oxide and halide perovskite color-changing luminescent composite materials in the encrypted anti-counterfeiting coding patterns emit light by Eu ³⁺ The characteristic red light of (2) rapidly changes into strong blue-green light emission of halide perovskite, so that the encrypted anti-counterfeiting code can be identified and read by the intelligent device.

After the ultraviolet light source is turned off, the photoinduced split-phase of the perovskite is restored within a short time (3-5 min), and the encryption/decryption process can be repeated again.

In the encryption/decryption process, the europium-doped porous metal oxide, halide perovskite color-changing luminescent composite material and the europium-doped porous metal oxide are all whitish under the fluorescent lamp, and no obvious appearance difference exists.

The composite material obtained by the invention has photochromic property in the wavelength range from ultraviolet light to blue light. Specifically, the composite material can be irradiated by exciting light in a wavelength range from ultraviolet light to blue light from Eu ³⁺ The characteristic red emission of (a) is changed to a bright halide perovskite blue-green emission, the rate of change increasing with increasing photon energy. After the irradiation is stopped. The composite material can recover to the property before irradiation after 3-5 min. The composite material has no obvious difference in appearance under sunlight.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the preparation method of the invention can obtain the europium-doped porous metal oxide porous material with uniform aperture.

(2) The preparation method of the invention can obtain the europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material.

(3) The anti-counterfeiting realization method is simple and effective, and has great application potential in the aspect of photochromic anti-counterfeiting patterns.

Drawings

FIG. 1 is a scanning electron micrograph of PMMA microspheres prepared in example 1;

FIG. 2 is Y prepared in example 1 ₂ O ₃ :9％Eu ³⁺ Porous material and porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 XRD diffraction pattern of the color-changing luminescent composite material;

FIG. 3 is porous Y prepared in example 1 ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material;

FIG. 4 is porous Y prepared in example 1 ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A transmission electron microscope image of the color-changing luminescent composite material;

FIG. 5 is porous Y prepared in example 1 ₂ O ₃ :9％Eu ³⁺ (ii) an emission spectrum of;

FIG. 6 is porous Y prepared in example 1 ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photochromic spectrogram of the photochromic luminescent composite material;

FIG. 7 is porous Y prepared in example 1 ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photodynamic diagram of a color-changing luminescent composite material;

FIG. 8 is porous Y prepared in example 1 ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The multiple reversible recovery spectrogram of the color-changing luminescent composite material;

fig. 9 is a schematic view of an anti-counterfeit implementation method of the anti-counterfeit coded two-dimensional code in embodiment 1;

FIG. 10 is a scanning electron micrograph of PMMA microspheres prepared in example 2;

FIG. 11 shows CaMoO prepared in example 2 ₄ :10％Eu ³⁺ 、CaMoO ₄ :10％Eu ³⁺ /CsPbBr _1.5 Cl _1.5 XRD diffractogram of (a);

FIG. 12 is porous CaMoO prepared in example 2 ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material;

FIG. 13 is porous CaMoO prepared in example 2 ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A transmission electron microscope image of the color-changing luminescent composite material;

FIG. 14 shows porous CaMoO prepared in example 2 ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photochromic spectrogram of the color-changing luminescent composite material;

FIG. 15 is porous CaMoO prepared in example 2 ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photodynamic diagram of a color-changing luminescent composite material;

FIG. 16 is a schematic view of an implementation method for anti-counterfeit of the digital sequence of anti-counterfeit codes in embodiment 2;

FIG. 17 is a scanning electron micrograph of PMMA microspheres prepared according to example 3;

FIG. 18 is Y prepared in example 3 ₂ O ₃ :7％Eu ³⁺ Porous material and porous Y ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ XRD diffraction pattern of the color-changing luminescent composite material;

FIG. 19 is porous Y prepared in example 3 ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ Scanning electron microscope images of the color-changing luminescent composite material;

FIG. 20 is porous Y prepared in example 3 ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ A photochromic spectrogram of the photochromic luminescent composite material;

FIG. 21 is porous Y prepared in example 3 ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ Of colour-changing luminescent compositesA photodynamic diagram;

fig. 22 is a schematic view of an anti-counterfeit implementation method of the anti-counterfeit coded barcode in embodiment 3;

FIG. 23 is a scanning electron micrograph of PMMA microspheres prepared according to example 4;

FIG. 24 is Y prepared in example 4 ₂ O ₃ :9％Eu ³⁺ Porous material and porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ XRD diffraction pattern of the color-changing luminescent composite material;

FIG. 25 is porous Y prepared in example 4 ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ Scanning electron microscope images of the color-changing luminescent composite material;

FIG. 26 is porous Y prepared in example 4 ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ A photochromic spectrogram of the color-changing luminescent composite material;

FIG. 27 is porous Y prepared in example 4 ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ A photodynamic diagram of a color-changing luminescent composite material;

FIG. 28 is a scanning electron micrograph of PMMA microspheres prepared according to example 5;

FIG. 29 is Y prepared in example 5 ₂ O ₃ :3％Eu ³⁺ Porous material and porous Y ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 XRD diffraction pattern of the color-changing luminescent composite material;

FIG. 30 is porous Y prepared in example 5 ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material;

FIG. 31 is porous Y prepared in example 5 ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photochromic spectrogram of the photochromic luminescent composite material;

FIG. 32 is porous Y prepared in example 5 ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photodynamic diagram of a color-changing luminescent composite material;

FIG. 33 is porous Y prepared in example 6 ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material;

FIG. 34 is porous Y prepared in example 6 ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photochromic spectrogram of the photochromic luminescent composite material;

FIG. 35 is porous Y prepared in example 6 ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A photodynamic diagram of a color-changing luminescent composite material;

FIG. 36 is porous Y prepared in example 7 ₂ O ₃ :12％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 Scanning electron microscope images of the color-changing luminescent composite material;

FIG. 37 is a scanning electron micrograph of PMMA microspheres prepared according to example 8.

Detailed Description

The following examples further illustrate the practice of the present invention, but are not intended to limit the practice or protection of the invention. It is noted that the processes described below, if not specifically described in detail, are all realizable or understandable by those skilled in the art with reference to the prior art. The reagents or apparatus used are not indicated to the manufacturer, and are considered to be conventional products available by commercial purchase.

Example 1

Porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(1) accurately weighing 0.05g K ₂ S ₂ O ₈ Dissolving in 80mL of water, vacuumizing, introducing nitrogen after no bubbles exist in the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400 r;

(2) adding 10ml of methyl methacrylate into the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400r to prepare PMMA microsphere colloidal suspension;

(3) transferring the colloidal suspension into a centrifuge tube, centrifuging at 8000r for 10min, removing supernatant, washing with deionized water for 3 times, transferring into a 60 ℃ oven, drying for 12h, and grinding to obtain PMMA microspheres;

(4) accurately weighing 0.1g of PMMA microspheres, dissolving in 5mL of deionized water, and performing ultrasonic dispersion to obtain a PMMA microsphere dispersion solution;

(5) accurately selecting a Buchner funnel with the diameter of 60mm and an organic microporous filter membrane with the diameter of 60mm, adding two layers of filter membranes into the Buchner funnel, transferring the PMMA microsphere solution into the filter membranes, and performing suction filtration for 5min to obtain an assembled multilayer-arranged compact PMMA microsphere solid material;

(6) 0.6971gY (NO) are weighed accurately ₃ ) ₃ ·6H ₂ O、0.0803gEu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.3842g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotation speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain the sol.

(7) Dripping the precursor sol onto the assembled PMMA microsphere solid material, and performing suction filtration for 30min to obtain an inorganic substance-filled PMMA microsphere solid material;

(8) transferring the suction filtration product and the organic filter membrane to a culture dish, heating to 250 ℃ at the speed of 1 ℃/min in a high-temperature tube furnace filled with nitrogen, calcining for 2h, heating to 500 ℃ at the speed of 5 ℃/min, and calcining for 2h to obtain a carbonized sample;

(9) putting the carbonized sample into a corundum crucible, calcining for 2h in a high-temperature box type furnace at 800 ℃ to obtain the final porous Y ₂ O ₃ ：Eu ³⁺ A light-emitting base material.

(10) 1mmol CsBr, 0.25mmol PbBr ₂ And 0.75mmol of PbCl ₂ The precursor was dissolved in 10mL of DMSO to prepare a halide perovskite precursor. Porous Y ₂ O ₃ ：Eu ³⁺ And soaking the luminescent substrate material in the perovskite precursor, and placing the perovskite precursor on a shaking table with 100rpm to shake for 24 hours to ensure that the perovskite precursor completely enters the pore channel.

(11) Porous Y ₂ O ₃ ：Eu ³⁺ And (4) washing and purifying the luminescent matrix material by centrifuging at 5000rpm for 3min, and taking a precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtainThe product is porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A color-changing luminescent composite material.

FIG. 1 is a scanning electron microscope image of PMMA microspheres prepared in this example; as can be seen from the figure, the PMMA microspheres prepared by the embodiment have the diameter of about 230 nm.

FIG. 2 shows Y prepared in this example ₂ O ₃ :9％Eu ³⁺ Porous material and porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 XRD diffraction pattern of the color-changing luminescent composite material;

FIG. 3 is a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material; FIG. 4 shows a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A transmission electron microscope image of the color-changing luminescent composite material; as can be seen in the figure, porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The aperture of the color-changing luminescent composite material is about 150nm, and the color-changing luminescent composite material is uniformly distributed.

FIG. 5 shows a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ The emission spectrum of (a);

FIG. 6 is a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The photochromic spectrogram of the color-changing luminescent composite material can show that the green light emission intensity is gradually increased;

FIG. 7 shows a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The luminous intensity of the color-changing luminous composite material is gradually increased until the luminous intensity is unchanged;

FIG. 8 is a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The multiple reversible recovery spectrogram of the color-changing luminescent composite material;

FIG. 9 is a schematic diagram of the two-dimension code of the anti-counterfeit code in this embodimentA pseudo implementation method schematic diagram; under the excitation of blue light (460nm), all pixel points in the encrypted anti-counterfeiting coding pattern are Eu ³⁺ Characteristic red emission of (1).

Under the excitation of ultraviolet light or purple light (less than or equal to 400nm), the black pixel point consisting of europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material in the encrypted anti-counterfeiting coding pattern emits light by Eu ³⁺ The characteristic red light of (2) rapidly changes into strong blue-green light emission of halide perovskite, so that the encrypted anti-counterfeiting code can be identified and read by the intelligent device.

Porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The characteristic emission peak position of the color-changing luminescent composite material Eu is 613nm, and the final emission peak position of the perovskite is 514nm through ultraviolet light excitation.

Example 2

Porous CaMoO ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(2) adding 8ml of methyl methacrylate into the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400r to prepare PMMA microsphere colloidal suspension;

(3) transferring the colloidal suspension into a centrifuge tube, centrifuging for 10min at the rotating speed of 8000r, removing supernatant, washing with deionized water for 3 times, transferring into a drying oven at 60 ℃, drying for 12h, and grinding to obtain PMMA microspheres;

(4) accurately weighing 0.15g of PMMA microspheres, dissolving in 5mL of deionized water, and performing ultrasonic dispersion to obtain a PMMA microsphere dispersion solution;

(6) accurately weigh 0.09g CaCO ₃ Dissolving nitric acid into Ca (NO) ₃ ) ₂ ·nH ₂ O，0.0337gEu(NO ₃ ) ₃ ·6H ₂ O、0.1766g(NH ₄ )Mo ₇ O ₂₄ ·4H ₂ Dissolving O and 0.252g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotation speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain sol.

(9) putting the carbonized sample into a corundum crucible, and calcining for 2 hours in a high-temperature box type furnace at 800 ℃ to obtain the final porous CaMoO ₄ :10％Eu ³⁺ A light-emitting base material.

(10) 1mmol CsBr, 0.25mmol PbBr ₂ And 0.75mmol of PbCl ₂ The precursor was dissolved in 10mL of DMSO to prepare a halide perovskite precursor. Mixing the porous CaMoO ₄ :10％Eu ³⁺ And soaking the luminescent substrate material in the perovskite precursor, and placing the perovskite precursor on a shaking table with 100rpm to shake for 24 hours to ensure that the perovskite precursor completely enters the pore channel.

(11) Mixing the porous CaMoO ₄ :10％Eu ³⁺ Centrifuging the luminescent matrix material at 5000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous CaMoO ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A color-changing luminescent composite material.

FIG. 10 is a scanning electron microscope image of PMMA microspheres prepared in this example; as can be seen from the figure, the PMMA microspheres prepared by the embodiment have the diameter of about 300 nm.

FIG. 11 shows CaMoO prepared in this example ₄ :10％Eu ³⁺ 、CaMoO ₄ :10％Eu ³⁺ /CsPbBr _1.5 Cl _1.5 An XRD diffractogram of (a);

FIG. 12 shows the porous CaMoO prepared in this example ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material; FIG. 13 shows the porous CaMoO prepared in this example ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A transmission electron microscope image of the color-changing luminescent composite material; as can be seen from the figure, the porous CaMoO ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The aperture of the color-changing luminescent composite material is about 250nm, and the distribution is uniform.

FIG. 14 shows the porous CaMoO prepared in this example ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The photochromic spectrogram of the color-changing luminescent composite material can show that the green light emission intensity is gradually increased;

FIG. 15 shows the porous CaMoO prepared in this example ₄ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 In the photodynamic diagram of the color-changing luminescent composite material, the color-changing luminescent intensity is gradually increased until the intensity is unchanged;

FIG. 16 is a schematic diagram of an implementation method of anti-counterfeit by using an anti-counterfeit coded digital sequence in this embodiment; under the excitation of blue light (460nm), all pixel points in the encrypted anti-counterfeiting coding pattern are Eu ³⁺ Characteristic red emission.

Under the excitation of ultraviolet light or purple light (less than or equal to 400nm), black pixel points formed by europium-doped porous metal oxide and halide perovskite color-changing luminescent composite materials in the encrypted anti-counterfeiting coding patterns emit light by Eu ³⁺ The characteristic red light of (2) is rapidly changed into strong blue-green light emission of halide perovskite, so that the encrypted anti-counterfeiting code number is identified.

Porous CaMoO prepared in this example ₄ :10％Eu ³⁺⁺ And CsPbBr _1.5 Cl _1.5 The characteristic emission peak position of the color-changing luminescent composite material Eu is 613nm, and the final emission peak position of the perovskite is 514nm through ultraviolet light excitation.

Example 3

A kind ofPorous Y ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(1) accurately weighing 0.08g K ₂ S ₂ O ₈ Dissolving in 80mL of water, vacuumizing, introducing nitrogen after no bubbles exist in the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400 r;

(2) adding 8ml of methyl methacrylate into the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 2 hours at the rotation speed of 400r to obtain PMMA microsphere colloidal suspension;

(6) 0.7124gY (NO) are weighed accurately ₃ ) ₃ ·6H ₂ O、0.0624gEu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.3856g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotation speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain sol.

(9) putting the carbonized sample into a corundum crucible at the temperature of 800 DEG CCalcining in a temperature chamber furnace for 2h to obtain the final porous Y ₂ O ₃ ：Eu ³⁺ A light-emitting base material.

(10) 1mmol CsBr and 1mmol PbCl ₂ The precursor was dissolved in 10mL of DMSO to prepare a halide perovskite precursor. Porous Y ₂ O ₃ ：Eu ³⁺ And soaking the luminescent substrate material in the perovskite precursor, and placing the perovskite precursor on a shaking table with 100rpm to shake for 24 hours to ensure that the perovskite precursor completely enters the pore channel.

(11) Porous Y ₂ O ₃ ：Eu ³⁺ And (4) centrifuging the luminescent substrate material at 5000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous Y ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ A color-changing luminescent composite material.

FIG. 17 is a scanning electron micrograph of PMMA microspheres prepared in this example; as can be seen from the figure, the PMMA microspheres prepared by the embodiment have the diameter of about 160 nm.

FIG. 18 shows Y prepared in this example ₂ O ₃ :7％Eu ³⁺ Porous material and porous Y ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ XRD diffraction pattern of the color-changing luminescent composite material; FIG. 19 is a porous Y prepared in this example ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ Scanning electron microscope images of the color-changing luminescent composite material; as can be seen in the figure, porous Y ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ The aperture of the color-changing luminescent composite material is about 130nm, and the distribution is uniform.

FIG. 20 is a porous Y prepared in this example ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ The photochromic spectrogram of the color-changing luminescent composite material can show that the green light emission intensity is gradually increased;

FIG. 21 is a porous Y prepared in this example ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ The luminous intensity of the color-changing luminous composite material is gradually increased until the luminous intensity is unchanged;

FIG. 22 is the anti-counterfeit code strip of this embodimentSchematic diagram of the shape code anti-counterfeiting realization method; under the excitation of blue light (460nm), all pixel points in the encrypted anti-counterfeiting code bar code are Eu ³⁺ Characteristic red emission.

Under the excitation of ultraviolet light or purple light (less than or equal to 400nm), the black pixel point consisting of europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material in the encrypted anti-counterfeiting coding pattern emits light by Eu ³⁺ The characteristic red light of (10s) is rapidly changed into strong blue-green light emission of halide perovskite, so that the encrypted anti-counterfeiting code bar code is identified and read by the intelligent device.

Porous Y prepared in this example ₂ O ₃ :7％Eu ³⁺ And CsPbBrCl ₂ The characteristic emission peak position of the color-changing luminescent composite material Eu is 612nm, and the final emission peak position of the perovskite is 514nm through ultraviolet light excitation.

Example 4

Porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(1) accurately weigh 0.1g BPO and 0.2mL 20% H ₂ O ₂ Putting the solution in 80mL of water, vacuumizing, introducing nitrogen after no bubbles exist in the three-necked bottle, heating in a water bath at 50 ℃, and stirring for 1h at the rotation speed of 400 r;

(3) transferring the colloidal suspension into a centrifuge tube, centrifuging at 8000r for 10min, removing supernatant, washing with ethanol for 2 times, transferring into a 60 ℃ oven, drying for 12h, and grinding to obtain PMMA microspheres;

(4) accurately weighing 0.1g of PMMA microspheres, and ultrasonically dispersing the PMMA microspheres in 5mL of n-hexane to obtain a PMMA microsphere dispersion solution;

(5) accurately selecting a Buchner funnel with the diameter of 80mm and an organic microporous filter membrane with the diameter of 80mm, adding two layers of filter membranes into the Buchner funnel, transferring the PMMA microsphere solution into the filter membranes, and performing suction filtration for 5min to obtain an assembled multilayer-arranged compact PMMA microsphere solid material;

(6) accurately weighed 0.6971gY (NO) ₃ ) ₃ ·6H ₂ O、0.0803gEu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.3842g of citric acid in 40mL of deionized water, stirring for 2h under the condition of the rotating speed of 300r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain sol.

(7) Dripping the precursor sol onto the assembled PMMA microsphere solid material, and performing suction filtration for 25min to obtain an inorganic substance-filled PMMA microsphere solid material;

(9) putting the carbonized sample into a corundum crucible, calcining for 2h in a high-temperature box type furnace at 800 ℃ to obtain the final porous Y ₂ O ₃ ：Eu ³⁺ A luminescent base material.

(10) 1mmol CsBr and 1mmol PbCl ₂ The halide perovskite precursor was dissolved in 25mL of GBL. Porous Y ₂ O ₃ ：Eu ³⁺ The luminescent substrate material is soaked in the perovskite precursor, and is heated and assisted by 50 ℃ oil bath under the stirring of 400rpm, so that the perovskite precursor completely enters the pore channel.

(11) Porous Y ₂ O ₃ ：Eu ³⁺ The luminescent matrix material is centrifuged at 6000rpm for 2.5min for purification, and the precipitate is taken. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ A color-changing luminescent composite material.

FIG. 23 is a scanning electron micrograph of PMMA microspheres prepared according to this example; as can be seen from the figure, the PMMA microspheres prepared by the embodiment have the diameter of about 100 nm.

FIG. 24 shows Y prepared in this example ₂ O ₃ :9％Eu ³⁺ Porous material and porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ X of color-changing luminescent composite materialAn RD diffractogram;

FIG. 25 is a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ Scanning electron microscope images of the color-changing luminescent composite material; as can be seen in the figure, porous Y ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ The aperture of the color-changing luminescent composite material is about 50nm, and the distribution is uniform.

FIG. 26 is a porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ The photochromic spectrogram of the color-changing luminescent composite material can show that the green light emission intensity is gradually increased;

FIG. 27 is porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ The luminous intensity of the color-changing luminous composite material is gradually increased until the luminous intensity is unchanged;

porous Y prepared in this example ₂ O ₃ :9％Eu ³⁺ And CsPbBrCl ₂ The characteristic emission peak position of the color-changing luminescent composite material Eu is 613nm, and the final emission peak position of the perovskite is 513nm after ultraviolet light excitation.

Example 5

Porous Y ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(1) accurately weigh 0.08g (NH) ₄ ) ₂ S ₂ O ₈ Dissolving in 70mL of water, vacuumizing, introducing nitrogen after no bubbles exist in the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400 r;

(2) adding 8ml of methyl methacrylate into the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400r to obtain PMMA microsphere colloidal suspension;

(5) accurately selecting a Buchner funnel with the diameter of 60mm and an organic microporous filter membrane with the diameter of 60mm, adding two layers of filter membranes into the Buchner funnel, transferring the PMMA microsphere solution into the filter membranes, and performing suction filtration for 5min to obtain an assembled multilayer compact PMMA microsphere solid material;

(6) 0.7430g Y (NO) are weighed accurately ₃ ) ₃ ·6H ₂ O、0.0268g Eu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.3842g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotating speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain sol.

(7) Dripping the precursor sol on the assembled PMMA microsphere solid material, and performing suction filtration for 30min to prepare an inorganic substance filled PMMA microsphere solid material;

(10) 1mmol CsBr, 0.25mmol PbBr ₂ And 0.75mmol of PbCl ₂ The halide perovskite precursor was dissolved in 10mL of DMSO. Porous Y ₂ O ₃ ：Eu ³⁺ And soaking the luminescent substrate material in the perovskite precursor, and placing the perovskite precursor on a shaking table with 100rpm to shake for 24 hours to ensure that the perovskite precursor completely enters the pore channel.

(11) Porous Y ₂ O ₃ ：Eu ³⁺ And (4) centrifuging the luminescent substrate material at 5000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous Y ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Color-changing luminous compositeA material.

FIG. 28 is a scanning electron micrograph of PMMA microspheres prepared according to example 5; as can be seen from the figure, the PMMA microspheres prepared by the embodiment have the diameter of about 160 nm.

FIG. 30 is porous Y prepared in example 5 ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material; as can be seen in the figure, porous Y ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The aperture of the color-changing luminescent composite material is about 100nm, and the distribution is uniform.

FIG. 31 is porous Y prepared in example 5 ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The photochromic spectrogram of the color-changing luminescent composite material can show that the green light emission intensity is gradually increased;

FIG. 32 is porous Y prepared in example 5 ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The luminous intensity of the color-changing luminous composite material is gradually increased until the luminous intensity is unchanged;

porous Y prepared in this example ₂ O ₃ :3％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The characteristic emission peak position of the color-changing luminescent composite material Eu is 609nm, and the final emission peak position of perovskite is 514nm after ultraviolet light excitation.

Example 6

Porous Y ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(1) accurately weighing 0.05g K ₂ S ₂ O ₈ Dissolving in 80mL of water, vacuumizing, introducing nitrogen after no bubbles exist in the three-necked bottleHeating in 70 deg.C water bath, stirring at 400r for 1 hr;

(2) adding 12ml of methyl methacrylate into the three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400r to obtain PMMA microsphere colloidal suspension;

(6) 0.6818gY (NO) are weighed accurately ₃ ) ₃ ·6H ₂ O、0.0981gEu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.3842g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotation speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain the sol.

(8) transferring the suction filtration product and the organic filter membrane into a culture dish, heating to 250 ℃ at the speed of 1 ℃/min in a high-temperature tubular furnace filled with nitrogen, calcining for 2h, heating to 500 ℃ at the speed of 5 ℃/min, and calcining for 2h to obtain a carbonized sample;

(11) Porous Y ₂ O ₃ ：Eu ³⁺ Centrifuging the luminescent matrix material at 5000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous Y ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A color-changing luminescent composite material.

The PMMA microspheres prepared by the embodiment have the diameter of about 280 nm.

FIG. 33 is a porous Y prepared in this example ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 Scanning electron microscope images of the color-changing luminescent composite material; as can be seen in the figure, porous Y ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The aperture of the color-changing luminescent composite material is about 180nm, and the color-changing luminescent composite material is uniformly distributed.

FIG. 34 shows porous Y prepared in this example ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The photochromic spectrogram of the color-changing luminescent composite material can show that the green light emission intensity is gradually increased;

FIG. 35 shows porous Y prepared in this example ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The luminous intensity of the color-changing luminous composite material is gradually increased until the luminous intensity is unchanged;

porous Y prepared in this example ₂ O ₃ :11％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The characteristic emission peak position of the color-changing luminescent composite material Eu is 613nm, and the final emission peak position of perovskite is 514nm through ultraviolet light excitation.

Example 7

Porous Y ₂ O ₃ :12％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(6) accurately weighed 0.6741gY (NO) ₃ ) ₃ ·6H ₂ O、0.1071gEu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.3842g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotation speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain the sol.

(10) 0.9mmol CsBr, 0.6mmol CsCl, 0.9mmol PbBr ₂ And 0.6mmol of PbCl ₂ The halide perovskite precursor was dissolved in 10mL of DMSO. Porous Y ₂ O ₃ ：Eu ³⁺ And soaking the luminescent substrate material in the perovskite precursor, and placing the perovskite precursor on a shaking table with 100rpm to shake for 24 hours to ensure that the perovskite precursor completely enters the pore channel.

(11) Porous Y ₂ O ₃ ：Eu ³⁺ And (4) centrifuging the luminescent substrate material at 5000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous Y ₂ O ₃ :12％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 A color-changing luminescent composite material.

FIG. 35 is porous Y prepared in example 7 ₂ O ₃ :12％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 Scanning electron microscope images of the color-changing luminescent composite material;

the PMMA microspheres prepared by the embodiment have the diameter of about 300 nm.

FIG. 36 is a porous Y prepared in this example ₂ O ₃ :12％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 Scanning electron microscope images of the color-changing luminescent composite material; as can be seen in the figure, porous Y ₂ O ₃ :12％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 The aperture of the color-changing luminescent composite material is about 200nm, and the color-changing luminescent composite material is uniformly distributed.

Porous Y prepared in this example ₂ O ₃ :12％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 The characteristic emission peak position of the color-changing luminescent composite material Eu is 613nm, and the final emission peak position of perovskite is 514nm through ultraviolet light excitation.

Example 8

Porous CaMoO ₄ :10％Eu ³⁺ And CsPbBrCl ₂ The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(1) accurately weighing 0.05g K ₂ S ₂ O ₈ Dissolving in 80mL of water, vacuumizing, introducing nitrogen after no bubbles exist in the three-necked bottle, heating in 70 ℃ water bath,stirring for 1h at the rotating speed of 400 r;

(6) accurately weigh 0.09g CaCO ₃ Dissolving nitric acid into Ca (NO) ₃ ) ₂ ·nH ₂ O，0.0446gEu(NO ₃ ) ₃ ·6H ₂ O、0.1766g(NH ₄ )Mo ₇ O ₂₄ ·4H ₂ Dissolving O and 0.252g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotating speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain sol.

(9) putting the carbonized sample into a corundum crucible, calcining for 2h in a high-temperature box type furnace at 800 ℃ to obtain the final porous CaMoO ₄ :10％Eu ³⁺ A luminescent base material.

(10) 1mmol CsBr and 1mmol PbCl ₂ Dissolving in 10mL DMSO to prepare halide perovskite precursorA body. Mixing the porous CaMoO ₄ :10％Eu ³⁺ And soaking the luminescent matrix material in the perovskite precursor, and placing the perovskite precursor on a shaking table at 100rpm for 24 hours to enable the perovskite precursor to completely enter the pore channel.

(11) Mixing the porous CaMoO ₄ :10％Eu ³⁺ And (4) centrifuging the luminescent substrate material at 5000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous CaMoO ₄ :10％Eu ³⁺ And CsPbBrCl ₂ A color-changing luminescent composite material.

Fig. 37 is a scanning electron microscope image of the PMMA microsphere prepared in this example, and it can be seen from the image that the PMMA microsphere prepared in this example has a diameter of about 220 nm.

Porous CaMoO ₄ :10％Eu ³⁺ And CsPbBrCl ₂ The aperture of the color-changing luminescent composite material is about 150nm, and the distribution is uniform.

Porous CaMoO prepared in this example ₄ :10％Eu ³⁺ And CsPbBrCl ₂ The characteristic emission peak position of the color-changing luminescent composite material Eu is 613nm, and the final emission peak position of the perovskite is 514nm through ultraviolet light excitation.

Example 9

(1) accurately weighing 0.05g AIBN to dissolve in 80mL water, vacuumizing, introducing nitrogen after no bubbles exist in a three-necked bottle, heating in a water bath at 70 ℃, and stirring for 1h at the rotation speed of 400 r;

(6) accurately weigh 0.09g CaCO ₃ Dissolving nitric acid into Ca (NO) ₃ ) ₂ ·nH ₂ O，0.0446gEu(NO ₃ ) ₃ ·6H ₂ O、0.1766g(NH ₄ )Mo ₇ O ₂₄ ·4H ₂ Dissolving O and 0.252g of citric acid in 30mL of deionized water, stirring for 1h under the condition of the rotation speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 50 ℃ to obtain sol.

(10) 1mmol CsBr and 1mmol PbCl ₂ The halide perovskite precursor was dissolved in 10mL of DMSO. Porous Y ₂ O ₃ ：Eu ³⁺ And soaking the luminescent matrix material in the perovskite precursor, and placing the perovskite precursor on a shaking table at 100rpm for 24 hours to enable the perovskite precursor to completely enter the pore channel.

(11) Mixing the porous CaMoO ₄ :10％Eu ³⁺ Centrifuging the luminescent matrix material at 5000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 120 deg.C to evaporate solvent to obtain porous CaMoO ₄ :10％Eu ³⁺ And CsPbBrCl ₂ A color-changing luminescent composite material.

PMMA prepared in this exampleThe diameter of the microspheres is about 160 nm. Porous CaMoO ₄ :10％Eu ³⁺ And CsPbBrCl ₂ The aperture of the color-changing luminescent composite material is about 100nm, and the color-changing luminescent composite material is uniformly distributed.

Porous CaMoO prepared in this example ₄ :10％Eu ³⁺ And CsPbBrCl ₂ The characteristic emission peak position of the color-changing luminescent composite material Eu is 612nm, and the final emission peak position of the perovskite is 514nm through ultraviolet light excitation.

Example 10

Porous Y ₂ O ₃ :6％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The preparation of the color-changing luminescent composite material specifically comprises the following steps:

(1) accurately weighing 0.08g K ₂ S ₂ O ₈ Dissolving in 60mL of water, vacuumizing, introducing nitrogen after no bubbles exist in the three-necked bottle, heating in water bath at 60 ℃, and stirring for 45min at the rotation speed of 300 rpm;

(2) adding 10mL of methyl methacrylate into the three-necked bottle, heating in a water bath at 60 ℃, and stirring for 1h under the condition that the rotating speed is 400rpm to prepare PMMA microsphere colloidal suspension;

(3) transferring the colloidal suspension into a centrifuge tube, centrifuging at 9000r for 10min, removing supernatant, washing with deionized water for 2 times, transferring into a 60 ℃ oven, drying for 9h, and grinding to obtain PMMA microspheres;

(4) accurately weighing 0.15g of PMMA microspheres, dissolving in 15mL of PMMA microspheres, and performing ultrasonic dispersion to obtain a PMMA microsphere dispersion solution;

(5) accurately selecting a Buchner funnel with the diameter of 90mm and an organic microporous filter membrane with the diameter of 90mm, adding two layers of filter membranes into the Buchner funnel, transferring the PMMA microsphere solution into the filter membranes, and performing suction filtration for 5min to obtain an assembled multilayer-arranged compact PMMA microsphere solid material;

(6) 0.3601gY (NO) are weighed accurately ₃ ) ₃ ·6H ₂ O、0.0268gEu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.1921g of citric acid in 20mL of deionized water, stirring for 1h at the rotating speed of 300r, and heating and aging for 6h on a constant-temperature heating table at 45 ℃ to obtain sol.

(7) Dripping the precursor sol on the assembled PMMA microsphere solid material, and performing suction filtration for 15min to prepare an inorganic substance filled PMMA microsphere solid material;

(8) transferring the suction filtration product and the organic filter membrane to a culture dish, heating to 250 ℃ at the speed of 1 ℃/min in a high-temperature tube furnace filled with nitrogen, calcining for 2h, heating to 500 ℃ at the speed of 5 ℃/min, and calcining for 3h to obtain a carbonized sample;

(9) putting the carbonized sample into a corundum crucible, calcining for 3h in a high-temperature box type furnace at 800 ℃ to obtain the final porous Y ₂ O ₃ ：Eu ³⁺ A luminescent base material.

(10) Adding 1mmol CsBr and 1mmol PbBr ₂ 1mmol CsCl and 1mmol PbCl ₂ The halide perovskite precursor was dissolved in 20mL of DMF. Porous Y ₂ O ₃ ：Eu ³⁺ And soaking the luminescent matrix material in the perovskite precursor, and performing ultrasonic treatment for 15min to ensure that the perovskite precursor completely enters the pore channel.

(11) Porous Y ₂ O ₃ ：Eu ³⁺ And (3) centrifuging the luminescent matrix material at 6000rpm for 3min for purification, and taking the precipitate. Placing the precipitate in a watch glass, heating at 100 deg.C to evaporate solvent to obtain porous Y ₂ O ₃ :6％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 A color-changing luminescent composite material.

The diameter of the PMMA microsphere prepared by the embodiment is about 220 nm. Porous Y ₂ O ₃ :10％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The aperture of the color-changing luminescent composite material is about 150nm, and the color-changing luminescent composite material is uniformly distributed.

Porous Y prepared in this example ₂ O ₃ :6％Eu ³⁺ And CsPbBr _1.5 Cl _1.5 The characteristic emission peak position of the color-changing luminescent composite material Eu is 611nm, and the final emission peak position of the perovskite is 514nm through ultraviolet light excitation.

Example 11

Porous Y ₂ O ₃ :6％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 Color-changing luminous composite materialThe preparation method of the material comprises the following steps:

(1) accurately weighing 0.1g AIBN, dissolving in 100mL water, vacuumizing, introducing nitrogen after no bubbles exist in a three-necked bottle, heating in a water bath at 60 ℃, and stirring for 30min at the rotation speed of 600 r;

(2) adding 12mL of methyl methacrylate into the three-necked bottle, heating in a water bath at 60 ℃, and stirring for 2h at the rotating speed of 300r to obtain PMMA microsphere colloidal suspension;

(3) transferring the colloidal suspension into a centrifuge tube, centrifuging for 5min at a rotating speed of 12000r, removing supernatant, washing for 2 times by using deionized water, transferring into a drying oven at 50 ℃, drying for 8h, and grinding to obtain PMMA microspheres;

(4) accurately weighing 0.08g of PMMA microspheres, and ultrasonically dispersing in 4mL of deionized water to obtain a PMMA microsphere dispersion solution;

(5) accurately selecting a Buchner funnel with the diameter of 60mm and an organic microporous filter membrane with the diameter of 60mm, adding two layers of filter membranes into the Buchner funnel, transferring the PMMA microsphere solution into the filter membranes, and performing suction filtration for 3min to obtain an assembled multilayer-arranged compact PMMA microsphere solid material;

(6) 0.3601gY (NO) are weighed accurately ₃ ) ₃ ·6H ₂ O、0.0268gEu(NO ₃ ) ₃ ·6H ₂ Dissolving O and 0.1921g of citric acid in 25mL of deionized water, stirring for 1.5h under the condition of the rotation speed of 400r, and heating and aging for 3h on a constant-temperature heating table at 60 ℃ to obtain sol.

(8) transferring the suction filtration product and the organic filter membrane to a culture dish, heating to 250 ℃ at the speed of 1 ℃/min in a high-temperature tube furnace filled with nitrogen, calcining for 2h, heating to 600 ℃ at the speed of 2.5 ℃/min, and calcining for 3h to obtain a carbonized sample;

(9) putting the carbonized sample into a corundum crucible, calcining for 2h in a high-temperature box type furnace at 900 ℃ to obtain the final porous Y ₂ O ₃ ：Eu ³⁺ A luminescent base material.

(10) 0.9mmol CsBr, 0.6mmol CsCl, 0.9mmol PbBr ₂ And 0.6mmol of PbCl ₂ The halide perovskite precursor was dissolved in 20mL of DMSO. Porous Y ₂ O ₃ ：Eu ³⁺ And soaking the luminescent matrix material in the perovskite precursor, and placing on a shaking table at 120rpm to vibrate for 12 hours to ensure that the perovskite precursor completely enters the pore channel.

(11) Wash well Y with 1mL DMSO ₂ O ₃ ：Eu ³⁺ A luminescent base material. Placing the precipitate in a watch glass, heating at 110 deg.C to evaporate solvent to obtain porous Y ₂ O ₃ :6％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 A color-changing luminescent composite material.

The PMMA microspheres prepared by the embodiment have the diameter of about 200 nm. Porous Y ₂ O ₃ :6％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 The aperture of the color-changing luminescent composite material is about 120nm, and the color-changing luminescent composite material is uniformly distributed.

Porous Y prepared in this example ₂ O ₃ :6％Eu ³⁺ And CsPbBr _1.8 Cl _1.2 The characteristic emission peak position of the color-changing luminescent composite material Eu is 614nm, and the final emission peak position of the perovskite is 516nm through ultraviolet light excitation.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material is characterized by comprising a europium-doped porous metal oxide and a halide perovskite, wherein the aperture of the europium-doped porous metal oxide is 30nm-500 nm; the halide perovskite is lead cesium halide perovskite, and the halogen in the lead cesium halide perovskite is chlorine and bromine; the halide perovskite is deposited in the pore channel of the europium-doped porous metal oxide;the metal oxide in the europium-doped porous metal oxide is Y ₂ O ₃ Or CaMoO ₄ 。

2. The method of preparing a europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material of claim 1, comprising the steps of:

(1) adding an initiator into a solvent I, adding a monomer methyl methacrylate in an inert gas atmosphere, heating in a water bath to obtain a microsphere colloidal solution, stirring, centrifuging, drying and grinding to obtain monodisperse PMMA microspheres; the initiator is one or more of potassium persulfate, ammonium persulfate, azobisisobutyronitrile, azobisisoheptonitrile, dibenzoyl peroxide and hydrogen peroxide; the solvent I is deionized water;

(2) dispersing the monodisperse PMMA microspheres in the step (1) in a solvent II, and performing suction filtration; the solvent II is one or more of deionized water, ethanol, cyclohexane and normal hexane,

(3) dissolving metal salt and citric acid in water, stirring, heating and aging to obtain sol; the metal salt is Y and Eu metal salt or Ca, Mo and Eu metal salt;

(5) calcining and carbonizing the suction filtration product in a protective atmosphere; transferring the carbonized product to an air atmosphere for calcining to remove carbon deposition to obtain europium-doped porous metal oxide;

(6) dissolving lead halide and cesium halide in a solvent III to prepare a halide perovskite precursor solution, and soaking the europium-doped porous metal oxide obtained in the step (5) in the halide perovskite precursor solution to diffuse the halide perovskite precursor solution into the pore channels of the europium-doped porous metal oxide; the lead halide is one or more of lead chloride and lead bromide, and the cesium halide is one or more of cesium chloride and cesium bromide; the solvent III is one or more of dimethyl sulfoxide, dimethylformamide and gamma-butyrolactone; the molar concentration ratio of ions in the halide perovskite precursor solution is Cs: pb = 0.5-2, Cl: br = 0.5-2;

(7) and (5) washing, purifying and thermally treating the europium-doped porous metal oxide obtained in the step (6) to obtain the europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material.

3. The production method according to claim 2, wherein the molar ratio of the initiator to the methyl methacrylate in the step (1) is 1:2 to 20; the volume ratio of the methyl methacrylate to the solvent I is 1: 2-20; the temperature of the water bath is 40-90 ℃;

the volume ratio of the mass of the PMMA microspheres in the step (2) to the volume of the solvent II is 0.1-1.0 g: 2-10 mL; the aperture of the filter membrane for suction filtration is 200-500 nm; the suction filtration time is 1-15 min.

4. The method according to claim 2, wherein the ratio of europium ion in the aqueous solution obtained in step (3) is 1% to 50%; the molar ratio of the metal salt to the citric acid is 1: 1-1.5; the concentration of the sol is 5-15 mol/L; the stirring time is 0.5-3 h; the heating temperature is 40-70 ℃; the aging time is 2-8 h.

5. The method for preparing the europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material according to claim 2, wherein the volume ratio of the sol dropping amount in the step (4) to the microsphere colloidal solution in the step (1) is 1:10-2:1, and the suction filtration time is 15-60 min;

the temperature of the calcination and carbonization in the step (5) is 200-600 ℃; the calcining and carbonizing time is 1-8 h; the temperature of the air atmosphere calcination is 500-1000 ℃; the air atmosphere calcination time is 0.5-6 h.

6. The method for preparing europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material as claimed in claim 2, wherein the diffusion method in step (6) is one or more of ultrasound, vibration, shaking table vibration, heating and stirring;

and (4) in the step (7), the washing is one or more of solvent III centrifugal washing, solvent III washing and suction filtration.

7. The use of the europium-doped porous metal oxide and halide perovskite color-changing luminescent composite material of claim 1 in the preparation of an encrypted anti-counterfeiting coding pattern, which comprises the following steps:

and filling the europium-doped porous metal oxide and halide perovskite allochroic luminescent composite material on a black pixel part in the anti-counterfeiting coding substrate, and filling the europium-doped porous metal oxide on a white pixel part in the anti-counterfeiting coding substrate to obtain the photochromic encrypted anti-counterfeiting coding pattern.

8. The use according to claim 7, wherein the encrypted anti-counterfeiting code pattern is: two-dimensional code, bar code, number sequence, character sequence and anti-counterfeiting pattern.

9. The use according to claim 7, wherein the photochromic encrypted security coding pattern is decrypted under continuous excitation of ultraviolet or violet light with a wavelength of less than or equal to 400 nm.