CN111073635A

CN111073635A - Multilevel chiral luminescence reinforced composite material and preparation method thereof

Info

Publication number: CN111073635A
Application number: CN201911270495.9A
Authority: CN
Inventors: 王宇; 李震; 颜岩; 赵佳奇
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2019-12-12
Filing date: 2019-12-12
Publication date: 2020-04-28
Anticipated expiration: 2039-12-12
Also published as: CN111073635B

Abstract

An all-inorganic perovskite quantum dot-coated silver nanorod composite silica and cysteine multi-level chiral luminescence enhancement composite material and a preparation method thereof belong to the technical field of chiral luminescence material preparation. One-dimensional silver nanorods are obtained by the reaction of polyols, then AgNR@SiO ₂ is obtained by hydrolysis of TEOS and APTES, and then AgNR@SiO ₂ @L-cys composite is obtained by stirring with cysteine solution at room temperature. The composite was composited with all-inorganic perovskite quantum dots (QDs) prepared by thermal injection method to prepare AgNR@SiO ₂ @L‑cys@QDs chiral light emission-enhancing composites with hierarchical nanostructures. The material has a rod-like morphology with uniform distribution of perovskite quantum dots on the surface, in which AgNR@SiO ₂ @L‑cys@CsPbBr ₃ exhibits an 87-fold luminescence enhancement. The invention has the advantages of low preparation cost, mass preparation, simple method, easy operation, good repeatability and the like.

Description

Multilevel chiral luminescence reinforced composite material and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of chiral luminescent materials, and particularly relates to a multilevel chiral luminescence enhanced composite material (AgNR @ SiO) with perovskite quantum dots coated with silver nanorod composite silicon dioxide and cysteine₂@ L-cys @ QDs) and a preparation method thereof.

Background

Chirality is an essential attribute possessed by asymmetric center, symmetric plane and anti-axial structure, and it exists widely in nature. This property has not only a wide range of applications in the fields of nonlinear optics, spintronics, etc., but also is closely related to biological and pharmaceutical sciences. In the past decades, chiral inorganic nanomaterials have attracted considerable attention due to their excellent optical and chemical properties, compared to chiral organic molecules, and have shown great potential in the fields of displays, lighting, etc. Among them, chiral perovskites have been widely studied by researchers due to their unique physical and chemical properties.

For example, the Tang project group at the university of science and technology in Huazhong successfully synthesized chiral (R-and S- α -PEA) PbI₃Perovskites and have application in the detection of circularly polarised light (Nat commun.2019,10,1927) because they can combine chiral organic-induced circularly polarised light sensitive absorption with efficient charge transport by inorganic scaffolds. The Xu subject group at southern university has prepared chiral lead-perovskite halide nanowires for the study of second-order nonlinear optics, which exhibit high efficiency of Second Harmonic Generation (SHG), high polarizability and chiral nonlinear optical effects. (Nano Lett.2018,18, 5411-5417).

The research results fully show the attractive prospect of the chiral perovskite material. However, nano perovskite materials generally have low quantum efficiency and are not prone to generate chiral structures without the participation of chiral amines. Therefore, the perovskite nano particles and the noble metal nano rods are combined, so that the luminous efficiency can be enhanced, and the luminescent material with the multilevel chiral structure can be prepared by utilizing the chiral arrangement of the nano rods.

Disclosure of Invention

The invention aims to provide a multilevel chiral luminescence enhanced composite material (AgNR @ SiO) with perovskite quantum dots coating silver nanorod composite silicon dioxide and cysteine₂@ L-cys @ QDs) and a preparation method thereof. AgNR stands for silver nanorod, SiO₂Is silicon dioxide, L-cys stands for L-cysteine, and QDs stands for perovskite quantum dots.

The method takes silver nitrate, ethylene glycol, Tetraethoxysilane (TEOS), 3-Aminopropyltriethoxysilane (APTES), ammonia water, L-cysteine, octadecene, oleic acid, oleylamine, lead halide, manganese bromide, zinc bromide, cesium carbonate and the like as raw materials, obtains a one-dimensional silver nanorod through polyol reduction reaction, and then obtains AgNR @ SiO through hydrolysis of TEOS and APTES₂And then stirring with cysteine solution at room temperature to obtain AgNR @ SiO₂The @ L-cys compound is finally compounded with perovskite Quantum Dots (QDs) prepared by a thermal injection method to prepare AgNR @ SiO with a multistage nano structure₂@ L-cys @ QDs chiral luminescence enhanced composite material. The diameter of the silver nanorod is 75-85 nanometers, the length of the silver nanorod is 8-11 micrometers, the thickness of the coated silicon dioxide layer and the thickness of the coated cysteine layer are 1.5-3 nanometers, the synthesized composite material has a rod-shaped appearance, and perovskite quantum dots are uniformly distributed on the surface.

The invention relates to a multilevel chiral luminescence enhanced composite material (AgNR @ SiO)₂@ L-cys @ QDs), which comprises the following steps:

a) adding polyvinylpyrrolidone (PVP), silver nitrate and ferric trichloride into ethylene glycol, dissolving, putting into an oil bath, heating, centrifugally washing to obtain silver nanorods (AgNR), and dispersing in deionized water to obtain a silver nanorod (AgNR) solution;

b) dispersing the silver nanorod (AgNR) solution obtained in the step a) in isopropanol, then adding TEOS and APTES into the solution, stirring uniformly, and then adding ammoniaWater solution, centrifugally washing the reaction crude product, and dispersing in deionized water to obtain silver nanorods (AgNR @ SiO) coated with silicon dioxide₂) A solution;

c) the silver nano rod (AgNR @ SiO) coated by the silicon dioxide obtained in the step b)₂) Mixing the solution and deionized water, adding cysteine solution, mixing, stirring, centrifuging, and drying to obtain composite material (AgNR @ SiO) of cysteine and silicon dioxide coated silver nanorod₂@L-cys)；

d) Adding cesium carbonate and oleic acid into octadecene, and heating and reacting under the atmosphere of nitrogen to obtain a cesium oleate precursor;

e) adding metal halide (lead halide, manganese bromide or zinc bromide) into octadecene, then adding oleic acid and oleylamine, fully stirring at high temperature and under a nitrogen atmosphere, adding the cesium oleate precursor prepared in the step d) after dissolving, immediately putting the cesium oleate precursor into an ice-water bath for cooling after reaction, centrifugally washing a crude product, and dispersing the crude product in n-hexane to obtain perovskite Quantum Dots (QDs);

f) coating the cysteine and silicon dioxide obtained in the step c) on the silver nano rod composite material (AgNR @ SiO)₂Mixing and stirring the normal hexane solution of @ L-cys) and the perovskite Quantum Dots (QDs) obtained in the step e) to obtain the multistage chiral luminescence enhanced composite material (AgNR @ SiO)₂@L-cys@QDs)。

Step a) adding 0.15-0.30 g of PVP into 20-30 mL of ethylene glycol, stirring for dissolving, adding 0.2-0.4 g of silver nitrate, stirring for dissolving, adding 2.5-5.0 g (with the concentration of 400-800 mmol/L) of ethylene glycol solution of ferric trichloride, stirring uniformly, transferring into an oil bath pot, and stirring for 4-8 hours at the temperature of 120-140 ℃; centrifugally washing the crude product, and dispersing the washed crude product in 10-20 ml of deionized water to obtain a silver nanorod (AgNR) water solution;

step b) adding 2-4 mL of silver nanorod aqueous solution into 10-30 mL of isopropanol, then adding 5-20 microliters of TEOS and 5-10 microliters of APTES, uniformly stirring, adding 1-2 mL of ammonia aqueous solution, and stirring and reacting at room temperature for 2-4 hours; centrifugally washing the crude product, and dispersing the washed crude product in 10-20 mL of deionized water to obtain a silver nanorod (AgNR @ SiO) coated with silicon dioxide₂) An aqueous solution;

step c) is to mix 10-20 mL of AgNR @ SiO₂Adding the aqueous solution into 15-25 mL of deionized water, then adding 5-15 mL of 1-5 mM L-cys aqueous solution, and stirring at room temperature for 6-24 hours; centrifugally washing and drying the crude product to obtain the solid composite material (AgNR @ SiO) of the cysteine and silicon dioxide coated silver nanorod₂@L-cys)；

Step d) adding 0.4-1 g of cesium carbonate and 1-3 mL of oleic acid into 20-40 mL of octadecene, stirring for 10-30 minutes at 100-120 ℃ in a nitrogen atmosphere, and then heating to 140-160 ℃ to completely react the oleic acid and the cesium carbonate to obtain a cesium oleate precursor;

step e) adding 0.1-0.4 g of metal halide (one or two of lead halide, manganese bromide and zinc bromide) into 10-30 mL of octadecene, stirring for 0.2-1 hour at 100-120 ℃ under a nitrogen atmosphere, then adding 1-3 mL of oleylamine and 1-3 mL of oleic acid, and heating to 140-160 ℃ until the solid is completely dissolved. Then, quickly adding 1-2 mL of cesium oleate precursor into the solution, reacting for 5-10 s, immediately putting into ice water for cooling, centrifugally washing a crude product, and dispersing in 20-40 mL of n-hexane to obtain a perovskite Quantum Dot (QDs) solution;

step f) is to coat the cysteine and the silicon dioxide on the solid composite material (AgNR @ SiO) of the silver nano rod₂@ L-cys) is added into 20-40 mL of normal hexane, 5-10 mL of perovskite Quantum Dot (QDs) solution is added, and stirring is carried out for 6-24 h to obtain the multistage chiral luminescence enhanced composite material (AgNR @ SiO)₂@L-cys@QDs)。

The invention provides a multilevel chiral luminescence enhanced composite material (AgNR @ SiO)₂@ L-cys @ QDs), has the characteristics of low preparation cost, simple method, easy operation, reliable production process, good repeatability, large yield and the like. The composite material has obvious chiral signals and good luminescence property.

Drawings

FIG. 1: scanning electron micrographs of silver nanorods (AgNRs) prepared in example 1; it can be seen that the silver nanorods have a uniform morphology and a smooth surface, a length of about 10 micrometers, and a diameter of about 80 nanometers;

FIG. 2: an X-ray diffraction (XRD) spectrum of the silver nanorods (AgNRs) prepared in example 1; it can be seen that all diffraction peaks of the sample corresponded to the standard card of silver (JCPDS NO.04-0783) and that there was no impure phase.

FIG. 3: example 1A preparation of a hierarchical nanostructured AgNR @ SiO₂Scanning electron microscope photographs of the composite material; the surface of the nano rod is smooth, which shows that the silicon dioxide can be uniformly coated on the silver nano rod.

FIG. 4: AgNR @ SiO prepared in example 1₂The graph shows that 200-320nm shows an interband absorption enhanced optical activity signal of cysteine (cys) molecular arrangement, and 350-450nm shows a chiral signal of silver nanorod arrangement, which indicates that AgNR @ SiO is₂Successfully compounded with L-cys to form a multilevel chiral composite material AgNR @ SiO₂@L-cys。

FIG. 5: example 1 preparation of perovskite Quantum dots CsPbBr₃The high-resolution transmission electron microscope picture of the QDs shows that the QDs have good crystallinity, and the size of the QDs is about 15-25 nm;

FIG. 6: example 1 preparation of all-inorganic perovskite CsPbBr₃The X-ray diffraction (XRD) spectrum of the QDs material, all diffraction peaks of the sample correspond to a standard card (JCPDS No.54-0752) of a cubic phase thereof;

FIG. 7: example 1A preparation of a hierarchical nanostructured AgNR @ SiO₂@L-cys@CsPbBr₃Transmission electron microscope pictures of the composite material; it can be seen that CsPbBr is uniformly distributed on the surface of the silver nanorod coated with silicon dioxide and cysteine molecules₃QDs；

FIG. 8: AgNR @ SiO prepared in example 1₂@L-cys@CsPbBr₃X-ray diffraction pattern of the material, all peaks with AgNRs and CsPbBr₃Standard spectra correspond (strong peaks correspond to silver nanorods; marked peaks correspond to cubic phase CsPbBr)₃QDs)。

FIG. 9: AgNR @ SiO prepared in example 1₂@L-cys@CsPbBr₃MaterialThe chiral signals of about 200-320nm, 350-450nm and 500nm respectively correspond to the signals of cysteine molecular arrangement, the signals of silver nanorod arrangement and CsPbBr₃The signal caused by exciton absorption proves AgNRs and SiO₂L-cys with CsPbBr₃QDs successfully complex.

FIG. 10: example 1 fluorescence emission spectra of prepared samples; this sample is compared to pure CsPbBr₃QDs has the effect of luminescence enhancement, AgNR @ SiO in example 1₂@L-cys@CsPbBr₃For pure CsPbBr₃Has 87 times enhancement of the luminous intensity.

FIG. 11: CsPbCl prepared in examples 5 to 8₃、CsPbCl_xBr_3-x、CsPbBr_xI_3-x、CsPbI₃Fluorescence emission spectrum of the sample; it can be seen from the above that the emission wavelength of the sample can be adjusted by changing the kind and content of the anions, and the emission wavelengths of the curves 1-4 are 402 nm, 456 nm, 599 nm and 689nm respectively.

FIG. 12: CsMn prepared in example 9 and example 10_xPb_1-xBr₃、CsZn_xPb_1-xBr₃Fluorescence emission spectrum of the sample. The emission wavelengths of curve 1 and curve 2 are 510, 512nm, respectively.

Detailed Description

Example 1

Composite material (AgNR @ SiO) with multistage chiral luminescence enhancement₂@L-cys@CsPbBr₃) The preparation process comprises the following concrete five steps:

1. synthesis of aqueous solution of silver nanorods (AgNRs):

0.2 g of PVP is added into 25mL of ethylene glycol, 0.25 g of silver nitrate is added after stirring and dissolving, 3.75 g (with the concentration of 600 mmol/L) of ethylene glycol solution of ferric trichloride is added after dissolving, the mixture is transferred into an oil bath kettle after even stirring, and the mixture is stirred for 5 hours at the temperature of 130 ℃. The crude product was then washed by centrifugation and finally dispersed in 10ml of deionized water.

2. AgNR @ SiO with multi-stage nano structure₂Synthesis of the composite material:

adding 2mL of the silver nanorod aqueous solution prepared in the step 1 into 20mL of isopropanol, then adding 20 microliters of TEOS and 10 microliters of APTES, stirring uniformly, and adding 1.9mL of ammonia aqueous solution. The solution was stirred at room temperature for 2 h. The crude product was then washed centrifugally and finally dispersed in 10mL deionized water to give AgNR @ SiO₂An aqueous solution.

3. AgNR @ SiO with multi-stage nano structure₂Synthesis of @ L-cys composite:

10mL of AgNR @ SiO obtained in step 2₂The aqueous solution was added to 25mL of deionized water, followed by addition of 12.5mL of an aqueous solution of Cys (concentration: 1mM), and the mixture was stirred at room temperature for 24 hours. After the crude product was washed by centrifugation, it was dried at 60 ℃ to give a solid product, which was dispersed in 40mL of n-hexane solution.

4.CsPbBr₃Synthesis of perovskite quantum dots:

0.814 g of cesium carbonate and 2.5mL of oleic acid were added to 30mL of octadecene, stirred at 120 ℃ for 20 minutes under a nitrogen atmosphere, and then heated to 160 ℃ to completely react the oleic acid with the cesium carbonate, so as to obtain a cesium oleate precursor solution.

0.276 g of lead bromide was added to 20mL of octadecene, stirred at 120 ℃ for 0.5 hour under a nitrogen atmosphere, followed by addition of 2mL of oleylamine and 2mL of oleic acid, and warmed to 160 ℃ until the lead bromide was completely dissolved. And then, quickly adding 1.6mL of cesium oleate precursor solution into the solution, reacting for 5s, immediately putting the solution into ice water for cooling, centrifugally washing the crude product, and dispersing the crude product into 40mL of n-hexane to obtain CsPbBr₃Perovskite quantum dot solution.

5. Multistage chiral nano luminescent reinforced composite AgNR @ SiO₂@L-cys@CsPbBr₃The synthesis of (2):

mixing 40mL of the solution obtained in the step 3 with 5mL of the solution obtained in the step 4 at room temperature, and stirring for 24 hours to obtain the AgNR @ SiO of the invention₂@L-cys@CsPbBr₃And (3) enhancing the composite luminescent material.

A scanning electron microscope photo of the AgNRs with the silver nanorod structure is shown in figure 1, and the AgNRs with the silver nanorod structure can be shown to have a uniform appearance and a smooth surface, wherein the length of the AgNRs is about 8-11 micrometers, and the diameter of the AgNRs is about 75-85 nanometers. X-ray diffraction of AgNRsThe (XRD) spectrum (FIG. 2) shows that all diffraction peaks of the sample can correspond to the standard card for silver (JCPDS 04-0783). AgNR @ SiO₂The scanning electron micrograph of the composite material is shown in fig. 3, and the sample has a smooth surface, which indicates that the silver nanorods are uniformly coated with the silicon dioxide. AgNR @ SiO₂The Circular Dichroism (CD) of the @ L-Cys composite material is shown in figure 4, the CD signal of 200-320nm is the intercand absorption enhanced optical activity of the molecular arrangement of cysteine (Cys), and the CD signal of 350-450nm is the chiral signal of the silver nanorod arrangement. FIG. 5 shows the preparation of an all-inorganic perovskite CsPbBr₃The high resolution transmission electron microscope pictures of QDs show good crystallinity with a size of about 15-25 nm. CsPbBr₃The X-ray diffraction (XRD) pattern of the QDs material (fig. 6) shows that all diffraction peaks of the sample can be mapped to the standard card of its cubic phase (JCPDS 54-0752). AgNR @ SiO with multi-stage nano structure₂@L-cys@CsPbBr₃It can be seen that CsPbBr is uniformly distributed on the surface of the silver nanorod coated with silicon dioxide and cysteine molecules₃QDs, whose X-ray diffraction pattern is shown in FIG. 8, all peaks were observed with silver (JCPDS04-0783) and CsPbBr₃(JCPDS 54-0752) standard spectra. The circular dichroism chromatogram of the material is shown in figure 9, and chiral signals at about 200-320nm, 350-450nm and 500-550 nm respectively correspond to a signal of cysteine molecular arrangement, a signal of silver nanorod arrangement and CsPbBr₃The exciton absorbs the induced signal. AgNR @ SiO₂@L-cys@CsPbBr₃The fluorescence emission spectrum of the sample is shown in FIG. 10, relative to pure CsPbBr₃Has 87 times enhancement of the luminous intensity.

Example 2

Composite material (AgNR @ SiO) with multistage chiral luminescence enhancement₂@L-cys@CsPbCl₃) The preparation process comprises the following concrete five steps:

1. synthesis of aqueous solution of silver nanorods (AgNRs):

2mL of the aqueous silver nanorod solution prepared in step 1 was added to 20mL of isopropanol, followed by 20. mu.L of TEOS and 10. mu.L of APTES, followed by 1.9mL of aqueous ammonia solution. The solution was stirred at room temperature for 2 h. The crude product was then washed by centrifugation and finally dispersed in 10mL of deionized water.

3. AgNR @ SiO with multi-stage nano structure₂Synthesis of @ L-cys composite:

4.CsPbCl₃Synthesis of perovskite quantum dots:

0.814 g of cesium carbonate and 2.5mL of oleic acid were added to 30mL of octadecene, stirred at 120 ℃ for 20 minutes under a nitrogen atmosphere, and then heated to 160 ℃ to completely react the oleic acid with the cesium carbonate, so that a cesium oleate precursor solution was obtained. Then 0.209 g of lead chloride was added to 20mL of octadecene, stirred at 120 ℃ for 0.5 hour under nitrogen, followed by 2mL of oleylamine and 2mL of oleic acid, and warmed to 160 ℃ until the lead chloride was completely dissolved. Then, 1.6mL of cesium oleate precursor is rapidly added into the solution, the solution is immediately placed into ice water for cooling after reacting for 5s, and the crude product is dispersed in 40mL of n-hexane after centrifugal washing.

5. AgNR @ SiO with multi-stage chiral nano luminescent structure₂@L-cys@CsPbCl₃Synthesis of the reinforced composite material:

mixing and stirring the product obtained in the step 3 (40mL) and the product obtained in the step 4 (5 mL) at room temperature for 24 hours to obtain AgNR @ SiO₂@L-cys@CsPbCl₃And (3) enhancing the composite luminescent material.

The product obtained in this example has similar structural characteristics to those of example 1, and is pure CsPbCl₃Compared with perovskite quantum dots, the perovskite quantum dots have the advantages of 38 timesThe luminescence is enhanced.

Example 3

Composite material (AgNR @ SiO) with multistage chiral luminescence enhancement₂@L-cys@CsPbCl_xBr_3-x) The preparation process comprises the following concrete five steps:

1. synthesis of aqueous solution of silver nanorods (AgNRs):

3. AgNR @ SiO with multi-stage nano structure₂Synthesis of @ L-cys composite:

4.CsPbCl_xBr_3-xSynthesis of perovskite quantum dots:

0.814 g of cesium carbonate and 2.5mL of oleic acid were added to 30mL of octadecene, stirred at 120 ℃ for 20 minutes under a nitrogen atmosphere, and then heated to 160 ℃ to completely react the oleic acid with the cesium carbonate, so that a cesium oleate precursor solution was obtained. Then 0.1112 g of lead chloride and 0.1468 g of lead bromide were added to 20mL of octadecene and stirred at 120 ℃ for 0.5 hour under nitrogen, followed by 2mL of oleylamine and 2mL of oleic acid, and warmed to 160 ℃ until the solids were completely dissolved. Then, 1.6mL of cesium oleate precursor is rapidly added into the solution, the solution is immediately placed into ice water for cooling after reacting for 5s, and the crude product is dispersed in 40mL of n-hexane after centrifugal washing.

5. AgNR @ SiO with multi-stage chiral nano luminescent structure₂@L-cys@CsPbCl_xBr_3-xSynthesis of the reinforced composite material:

mixing and stirring the product obtained in the step 3 (40mL) and the product obtained in the step 4 (5 mL) at room temperature for 24 hours to obtain AgNR @ SiO₂@L-cys@CsPbCl_xBr_3-xAnd (3) enhancing the composite luminescent material.

The product obtained in this example has similar structural characteristics to those of example 1, and is pure CsPbCl_xBr_3-xThe perovskite quantum dots have 23 times luminous enhancement compared with the perovskite quantum dots.

Example 4

Composite material (AgNR @ SiO) with multistage chiral luminescence enhancement₂@L-cys@CsPbBr_xI_3-x) The preparation process comprises the following concrete five steps:

1. synthesis of silver nanorods (AgNRs):

3. AgNR @ SiO with multi-stage nano structure₂Synthesis of @ L-cys composite:

10mL of AgNR @ SiO obtained in step 2₂The aqueous solution was added to 25mL of deionized water, followed by addition of 12.5mL of an aqueous solution of Cys (concentration: 1mM), and the mixture was stirred at room temperature for 24 hours. Centrifugal washing of the crude productThereafter, the solid product was dried at 60 ℃ and dispersed in 40mL of an n-hexane solution.

4.CsPbBr_xI_3-xSynthesis of perovskite quantum dots:

0.814 g of cesium carbonate and 2.5mL of oleic acid were added to 30mL of octadecene, stirred at 120 ℃ for 20 minutes under a nitrogen atmosphere, and then heated to 160 ℃ to completely react the oleic acid with the cesium carbonate, so that a cesium oleate precursor solution was obtained. 0.1468 g of lead bromide and 0.1844 g of lead iodide were then added to 20mL of octadecene and stirred at 120 ℃ for 0.5 hour under nitrogen, followed by 2mL of oleylamine and 2mL of oleic acid, and warmed to 160 ℃ until the solids were completely dissolved. Then, 1.6mL of cesium oleate precursor is rapidly added into the solution, the solution is immediately placed into ice water for cooling after reacting for 5s, and the crude product is dispersed in 40mL of n-hexane after centrifugal washing.

5. AgNR @ SiO with multi-stage chiral nano luminescent structure₂@L-cys@CsPbBr_xI_3-xSynthesis of the reinforced composite material:

mixing and stirring the product obtained in the step 3 (40mL) and the product obtained in the step 4 (5 mL) at room temperature for 24 hours to obtain AgNR @ SiO₂@L-cys@CsPbBr_xI_3-xAnd (3) enhancing the composite luminescent material.

The product obtained in this example has similar structural characteristics to those of example 1, and is pure CsPbBr_xI_3-xThe perovskite quantum dots have 10 times luminous enhancement compared with the perovskite quantum dots.

Example 5

Composite material (AgNR @ SiO) with multistage chiral luminescence enhancement₂@L-cys@CsPbI₃) The preparation process comprises the following concrete five steps:

1. synthesis of silver nanorods (AgNRs):

3. AgNR @ SiO with multi-stage nano structure₂Synthesis of @ L-cys composite:

4.CsPbI₃Synthesis of perovskite quantum dots:

0.814 g of cesium carbonate and 2.5mL of oleic acid were added to 30mL of octadecene, stirred at 120 ℃ for 20 minutes under a nitrogen atmosphere, and then heated to 160 ℃ to completely react the oleic acid with the cesium carbonate, so that a cesium oleate precursor solution was obtained. 0.3467 g of lead iodide were then added to 20mL of octadecene and stirred at 120 ℃ for 0.5 hour under nitrogen, followed by 2mL of oleylamine and 2mL of oleic acid, and warmed to 160 ℃ until the solid was completely dissolved. Then, 1.6mL of cesium oleate precursor is rapidly added into the solution, the solution is immediately placed into ice water for cooling after reacting for 5s, and the crude product is dispersed in 40mL of n-hexane after centrifugal washing.

5. AgNR @ SiO with multi-stage chiral nano luminescent structure₂@L-cys@CsPbI₃Synthesis of the reinforced composite material:

mixing and stirring the product obtained in the step 3 (40mL) and the product obtained in the step 4 (5 mL) at room temperature for 24 hours to obtain AgNR @ SiO₂@L-cys@CsPbI₃And (3) enhancing the composite luminescent material.

The product obtained in this example has similar structural characteristics to those of example 1, and is pure CsPbI₃The perovskite quantum dots have 4 times luminous enhancement compared with the perovskite quantum dots.

Example 6

Composite material (AgNR @ SiO) with multistage chiral luminescence enhancement₂@L-cys@CsMn_xPb_1-xBr₃) The preparation process comprises the following concrete five steps:

1. synthesis of silver nanorods (AgNRs):

3. AgNR @ SiO with multi-stage nano structure₂Synthesis of @ L-cys composite:

4.CsMn_xPb_1-xSynthesizing Br perovskite quantum dots:

0.814 g of cesium carbonate and 2.5mL of oleic acid were added to 30mL of octadecene, stirred at 120 ℃ for 20 minutes under a nitrogen atmosphere, and then heated to 160 ℃ to completely react the oleic acid with the cesium carbonate, so that a cesium oleate precursor solution was obtained. Then 0.276 g of lead bromide and 0.1 g of manganese bromide were added to 20mL of octadecene, stirred at 120 ℃ for 0.5 hour under nitrogen, followed by 2mL of oleylamine and 2mL of oleic acid, and warmed to 160 ℃ until the solids were completely dissolved. Then, 1.6mL of cesium oleate precursor is rapidly added into the solution, the solution is immediately placed into ice water for cooling after reacting for 5s, and the crude product is dispersed in 40mL of n-hexane after centrifugal washing.

5. Has multilevel chiral nano hairOptical structure AgNR @ SiO₂@L-cys@CsMn_xPb_1-xBr₃Synthesis of the reinforced composite material:

mixing and stirring the product obtained in the step 3 (40mL) and the product obtained in the step 4 (5 mL) at room temperature for 24 hours to obtain AgNR @ SiO₂@L-cys@CsMn_xPb_1-xBr₃And (3) enhancing the composite luminescent material.

The product obtained in this example has similar structural characteristics to those of example 1, and is pure CsMn_xPb_1-xBr₃The perovskite quantum dots have 3 times luminous enhancement compared with the perovskite quantum dots.

Example 7

Composite material (AgNR @ SiO) with multistage chiral luminescence enhancement₂@L-cys@CsZn_xPb_1-xBr₃) The preparation process comprises the following concrete five steps:

1. synthesis of silver nanorods (AgNRs):

3. AgNR @ SiO with multi-stage nano structure₂Synthesis of @ L-cys composite:

4. All-inorganic CsZn_xPb_1-xBr₃Synthesis of perovskite quantum dots:

0.814 g of cesium carbonate and 2.5mL of oleic acid were added to 30mL of octadecene, stirred at 120 ℃ for 20 minutes under a nitrogen atmosphere, and then heated to 160 ℃ to completely react the oleic acid with the cesium carbonate, so that a cesium oleate precursor solution was obtained. Then 0.276 g of lead bromide and 0.1 g of zinc bromide were added to 20mL of octadecene, stirred at 120 ℃ for 0.5 hour under nitrogen, followed by 2mL of oleylamine and 2mL of oleic acid, and warmed to 160 ℃ until the solids were completely dissolved. Then, 1.6mL of cesium oleate precursor is rapidly added into the solution, the solution is immediately placed into ice water for cooling after reacting for 5s, and the crude product is dispersed in 40mL of n-hexane after centrifugal washing.

5. AgNR @ SiO with multi-stage chiral nano luminescent structure₂@L-cys@CsZn_xPb_1-xBr₃Synthesis of the reinforced composite material:

mixing and stirring the product obtained in the step 3 (40mL) and the product obtained in the step 4 (5 mL) at room temperature for 24 hours to obtain AgNR @ SiO₂@L-cys@CsZn_xPb_1-xBr₃And (3) enhancing the composite luminescent material.

The product obtained in this example has similar structural characteristics to those of example 1, and is pure CsZn_xPb_1-xBr₃The perovskite quantum dots have 19 times luminous enhancement compared with the perovskite quantum dots.

Claims

1. a preparation method of a multi-level chiral luminescence enhanced composite material, the steps are as follows:

a) adding polyvinylpyrrolidone, silver nitrate and ferric chloride to ethylene glycol, dissolving and heating in an oil bath, centrifuging and washing to obtain silver nanorods, and then dispersing in deionized water to obtain an aqueous solution of silver nanorods;

b) Disperse the silver nanorod solution obtained in step a) in isopropanol, then add ethyl orthosilicate and 3-aminopropyltriethoxysilane to the above solution, stir evenly and then add ammonia solution , the reaction crude product is dispersed in deionized water after centrifugal washing to obtain a silica-coated silver nanorod aqueous solution;

c) After mixing the silica-coated silver nanorods solution obtained in step b) with deionized water, add cysteine solution into it, mix and stir, centrifuge and dry to obtain cysteine and silica Composites coated with silver nanorods;

d) adding cesium carbonate and oleic acid to octadecene, under nitrogen atmosphere, heating and reacting to obtain cesium oleate precursor;

e) adding lead halide, manganese bromide or zinc bromide into octadecene, then adding oleic acid and oleylamine, fully stirring under high temperature and nitrogen atmosphere, and adding the cesium oleate precursor prepared in step d) after dissolving After the reaction, it was put into an ice-water bath for cooling, and the crude product was washed by centrifugation and then dispersed in n-hexane to obtain perovskite quantum dots;

f) Mixing and stirring the n-hexane solution of the composite material of cysteine and silica-coated silver nanorods obtained in step c) and the perovskite quantum dots obtained in step e) to obtain a multi-level chiral luminescence enhanced composite Materials AgNR@SiO ₂ @L-cys@QDs, AgNR stands for silver nanorods, SiO ₂ stands for silicon dioxide, L-cys stands for cysteine, and QDs stands for perovskite quantum dots.

2. The method for preparing a multi-stage chiral luminescence-enhancing composite material according to claim 1, wherein in step a), 0.15-0.30 g of polyvinylpyrrolidone is added to 20-30 mL of ethylene glycol, and stirring to dissolve Then add 0.2-0.4 g of silver nitrate, stir and dissolve, add 2.5-5.0 g (concentration 400-800 mmol/L) of ferric chloride ethylene glycol solution, stir evenly and transfer to an oil bath pot, at 120 Stirring for 4-8 hours under the condition of ~140°C; the crude product is centrifuged and washed, and then dispersed in 10-20 ml of deionized water to obtain an aqueous solution of silver nanorods.

3. the preparation method of a kind of multistage chiral luminescence enhancement composite material as claimed in claim 1 is characterized in that: step b) is to add 2～4mL silver nanorod aqueous solution in 10～30mL isopropanol, then Add 5-20 microliters of ethyl orthosilicate and 5-10 microliters of 3-aminopropyltriethoxysilane, stir evenly, add 1-2 mL of ammonia solution, and stir and react at room temperature for 2-4 hours; the crude product is centrifuged After washing, it is dispersed in 10-20 mL of deionized water to obtain a silica-coated silver nanorod aqueous solution.

4. the preparation method of a kind of multistage chiral luminescence enhancement composite material as claimed in claim 1 is characterized in that: step c) is to add 10～20mL silica-coated silver nanorod solution to 15～25mL Deionized water, then add 5-15 mL, 1-5 mM cysteine aqueous solution, and stir at room temperature for 6-24 hours; the crude product is centrifuged, washed and dried to obtain a solid of cysteine and silica-coated silver nanorods composite material.

5. the preparation method of a kind of multistage chiral luminescence enhancement composite material as claimed in claim 1 is characterized in that: step d) is to add 0.4～1g cesium carbonate and 1～3mL oleic acid to 20～40mL 18 In the olefin, the mixture is stirred at 100-120° C. for 10-30 minutes under a nitrogen atmosphere, and then heated to 140-160° C. to complete the reaction between oleic acid and cesium carbonate to obtain a cesium oleate precursor.

6. The method for preparing a multi-level chiral luminescence enhanced composite material according to claim 1, wherein in step e), 0.1-0.4 g of metal halide is added to 10-30 mL of octadecene, and 100 Stir for 0.2 to 1 hour under a nitrogen atmosphere at ~120 °C, then add 1 to 3 mL of oleylamine and 1 to 3 mL of oleic acid, and heat up to 140 to 160 °C until the solid is completely dissolved; then, add 1 to 2 mL of cesium oleate precursor rapidly Add to the above solution, and immediately put it into ice water to cool after reacting for 5-10 s. After centrifugal washing, the crude product is dispersed in 20-40 mL of n-hexane to obtain a perovskite quantum dot solution.

7 . The method for preparing a multi-level chiral light-emitting enhanced composite material according to claim 6 , wherein the metal halide is one or both of lead halide, manganese bromide and zinc bromide. 8 .

8. the preparation method of a kind of multistage chiral luminescence enhanced composite material as claimed in claim 1, is characterized in that: step f) is to add the solid composite material of cysteine and silica-coated silver nanorods into To 20-40 mL of n-hexane, 5-10 mL of perovskite quantum dot solution was added, and after stirring for 6-24 h, the multi-level chiral light-emitting enhanced composite material AgNR@SiO ₂ @L-cys@QDs was obtained.

9 . A method for preparing a multi-level chiral luminescence-enhancing composite material, characterized in that: it is prepared by the method described in any one of claims 1 to 8 .