CN116266998A - Method for preparing stable perovskite on paper base - Google Patents

Abstract

The invention relates to a method for preparing perovskite on a paper base, belonging to the field of nanometer materials. The method comprises the following steps: (1) preparing solution a containing perovskite precursor I; (2) preparing solution b containing perovskite precursor II, perovskite precursor II solvent and aminosilane; (3 ) drop solution b on the surface of the paper base, and then drop solution a on the surface of the paper base at the same position, and obtain perovskite nanocrystals grown on the paper base after the solvent volatilizes; the perovskite precursor I is selected from Cs ₂ CO _3. At least one of MABr; the perovskite precursor II is selected from at least one of PbBr ₂ and PbI ₂ . The invention provides a novel, simple, fast, efficient and low-cost method for growing and protecting perovskite in situ.

Description

A method for preparing stable perovskite on paper base

technical field

The invention relates to the field of nanometer materials, in particular to a method for preparing stable perovskite on a paper base.

Background technique

In recent years, perovskite nanomaterials have attracted people's attention and research because of their excellent photoelectric properties. Perovskite nanomaterials have the advantages of high fluorescence quantum efficiency (PLQY), wide adjustable emission wavelength range, excellent photoelectric transmission performance, simple synthesis and low cost, and have good applications in the field of optoelectronic devices and sensing Foreground, the preparation of perovskite on paper base is also one of the research hotspots.

As a carrier, the paper base can give perovskite more extensive and convenient applications, such as the construction of paper-based sensors to greatly reduce the detection time, and the development of user-friendly portable sensors for online monitoring. However, perovskite quantum dots are greatly affected by the environment and have poor stability. Since perovskite is an ionic crystal, factors such as air, humidity, temperature, and polar solvents can cause the luminous efficiency of perovskite quantum dots to decrease or even completely quench. off. Stability has always been an urgent problem to be solved, and it is also the biggest obstacle restricting its commercialization.

In order to improve the stability of perovskite in the environment, doping, polymer encapsulation, and silicon dioxide (SiO ₂ ) encapsulation have been reported, among which SiO ₂ is a stable perovskite commonly used in the preparation of perovskite LEDs. Usually, the perovskite quantum dots are embedded in the _SiO2 matrix formed by silane hydrolysis, so that the obtained _SiO2- coated perovskite quantum dots can maintain long-term stability in air and have high fluorescence quantum yield. . However, this method of protecting perovskite is generally carried out in solution, and how to protect perovskite on paper still needs further research. It is the lack of such research that has led to paper-based calcium Titanium sensors face the disadvantages of unstable properties and extremely short shelf life, which greatly limit the application of perovskite in the field of sensing.

Contents of the invention

The purpose of the present invention is to make up for the shortcomings of the existing methods for growing perovskite on paper bases, and propose a method that can grow perovskite nanocrystals in situ on paper bases and has good environmental stability .

According to one aspect of the present invention, there is provided a method for preparing stable perovskite on a paper base, comprising the steps of:

(1) Prepare solution a containing perovskite precursor I;

(2) Prepare solution b containing perovskite precursor II, perovskite precursor II solvent, and aminosilane;

(3) drop solution b on the surface of the paper base, then drop solution a on the surface of the paper base at the same position, and obtain perovskite nanocrystals after the solvent evaporates;

The perovskite precursor I is selected from at least one of Cs ₂ CO ₃ and MABr;

The perovskite precursor II is selected from at least one of PbBr ₂ and PbI ₂ .

Optionally, the volume ratio of the solution a to the solution b is 1:10˜10:1.

Optionally, the volume ratio of the solution a to the solution b is selected from 1:1, 1:2, 1:3, 1:5, 1:6, 1:8, 1:9, 2:1, 2: 3, 2:5, 2:8, 2:9, 3:1, 3:4, 3:7, 3:10, 5:1, 5:3, 5:7, 5:9, 8:3, 8:5, 8:7, 8:9, 9:1, 9:2, 9:5, 9:8, or any value between any two of the above.

Optionally, the aminosilane is selected from at least one of 3-aminopropyltriethoxysilane (APTES), 3-aminopropylmethyldimethoxysilane;

The volume fraction of the aminosilane in solution b is 1%-10%.

Optionally, the volume fraction of the aminosilane in solution b is selected from 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or any value between any two points above .

Optionally, the perovskite precursor II solvent is selected from at least one of toluene and n-hexane.

Preferably, when the perovskite precursor II is selected from halides, the perovskite precursor II solvent has the same halogen as the perovskite precursor II.

Optionally, in solution a, the molar concentration of the perovskite precursor I is 0.05-0.2 mmol/L;

In solution b, the molar concentration of the perovskite precursor II is 0.05-0.2 mmol/L; the molar concentration of the perovskite precursor II solvent is 0.1-0.3 mmol/L.

Optionally, the solvent of the solution a is selected from at least one of n-octanoic acid and oleic acid; the solvent of the solution b is selected from at least one of toluene, n-hexane, and cyclohexane.

Optionally, the paper base is selected from one of filter paper, nitrocellulose membrane, and polyvinylidene fluoride (PVDF) membrane.

According to one aspect of the present invention, a paper-based sensor is provided, using a paper base grown with perovskite; the paper base grown with perovskite is prepared by the above method.

The application at least has the following advantages and beneficial effects:

1. Compared with the preparation method of paper-based perovskite that has been reported, the method of the present invention is simple to operate, requires very little organic solvent, and the prepared perovskite can exist stably in the air for 50 days without vacuum or inertness Gas protection, and has certain anti-humidity characteristics.

2. APTES can be rapidly hydrolyzed by the presence of water molecules in the air, and a SiO ₂ network is quickly generated in the perovskite precursor solution, and the perovskite can nucleate and grow in the network, thereby maximizing the perovskite crystal It provides protection to avoid the destruction of the crystal structure induced by oxygen and humidity in the environment. At the same time, the existence of the network avoids the aggregation quenching during the crystal growth process, and stabilizes the high PLQY of perovskite on the paper base from another level. .

3. The present invention provides a simple, fast, efficient and low-cost method for preparing stable perovskite on paper base, which provides a basis for the stable existence of perovskite quantum dots on paper base.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the ultraviolet-visible and fluorescence spectrum diagram of the paper-based perovskite in Example 1 of the present invention.

Fig. 2 is an XRD pattern of paper-based perovskite in Example 2 of the present invention.

Fig. 3 is an infrared spectrogram of the paper-based perovskite in Example 3 of the present invention.

In Fig. 4, (a) is the SEM image of the blank paper base, and (b) is the SEM image of the paper-based perovskite in Example 3 of the present invention.

In Fig. 5, (a) is the humidity test result, (b) is the stability test result.

Detailed ways

In order to make the above objects, features and advantages of the present invention clearer and easier to understand, specific implementations of the present invention will be described in detail below. In the following description, a lot of specific details are set forth in order to fully understand the present invention, in order to prove that the present invention can be implemented, the embodiment can completely introduce the technical content of the present invention to those skilled in the art, so that the technical content of the present invention is clearer and easy to understand. However, the present invention can be embodied in many different forms of embodiments, and those skilled in the art can make similar extensions without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below. The scope of protection of the present invention is not limited to the examples mentioned herein.

Example 1

This example proposes a method that can grow perovskite nanocrystals in situ on a paper base and has good environmental stability. The specific steps are as follows:

Step (1): dissolving Cs ₂ CO ₃ (cesium carbonate) in n-octylic acid to obtain a cesium precursor solution of perovskite, dissolving PbBr ₂ , TOAB, and APTES in toluene to obtain a lead halide precursor solution of perovskite;

The molar concentration of _Cs2CO3 is _0.1mmol /L, the molar concentration of _PbBr2 is 0.1mM/mL, the molar concentration of TOAB is 0.2mM/mL, and the volume fraction of APTES in the lead halide precursor solution of perovskite is 5%;

Step (2): Take 1 μL of the perovskite cesium precursor solution and drop it on the surface of the PVDF film, and then absorb 2 μL of the perovskite lead halide precursor solution and drop it on the surface of the paper base at the same position. After the solvent evaporates, the paper base In situ growth of perovskite nanocrystals.

The ultraviolet-visible and fluorescence spectra of the paper-based perovskite prepared above are shown in Figure 1. The results show that its characteristic absorption peak is at 510nm, indicating that there is no phase transition, and the characteristic emission is at 518nm, with a half-peak width of 21nm, indicating monochromaticity. Better, indicating that the synthesized crystals have a uniform size.

Example 2

This embodiment proposes a method that can grow perovskite nanocrystals in situ on a paper base and has good environmental stability. The preparation method is the same as that in Example 1, the difference is that:

1. The solvent of the lead halide precursor solution of the perovskite in step (1) is n-hexane; the volume fraction of APTES in the lead halide precursor solution of the perovskite is 10%;

② In step (2), the volume of the perovskite lead halide precursor solution absorbed is 1 μL.

The XRD of the paper-based perovskite prepared above is shown in Figure 2. The results show that the CsPbBr ₃ cubic phase crystal is formed. Compared with the blank PVDF film, 15.2°, 21.5°, 30.8° and 34.5° can be observed. Diffraction peaks correspond to (100), (110), (200), and (210) crystal planes of CsPbBr ₃ crystals, and the silica grid does not make the perovskite crystal phase change, and still maintains a good Crystallinity and phase stability.

Example 3

This embodiment proposes a method that can grow perovskite nanocrystals in situ on a paper base and has good environmental stability. The preparation method is the same as that in Example 1, the difference is that:

①The concentrations of PbBr ₂ and TOAB in step 1 are 0.05mM/mL and 0.1mM/mL respectively;

②The volume fraction of APTES in the perovskite lead halide precursor solution is 6%.

The infrared spectrum of the paper-based perovskite prepared above is shown in Fig. 3. The results show that, compared with the blank PVDF film, the absorption at 1107 cm ^-1 can be attributed to the stretching vibration of Si-OC, while the absorption at 1033 cm ^-1 The absorption at can be attributed to the antisymmetric stretching vibration of Si-O-Si, which can explain the successful hydrolysis of APTES.

In Figure 4, (a) is the SEM image of the blank paper base, and (b) is the SEM image of the paper-based perovskite in this example. By comparing (a) and (b), it can be found that the perovskite grown on the paper base The composite of nanocrystals and silica does not change the porous structure of the paper base itself, but maintaining the porous structure makes the paper base have the potential for gas sensing, which provides ideas for the subsequent application of paper-based perovskites.

Figure 5a shows the test results of the resistance of paper-based perovskite to water vapor in the humidity range of 70% to 90%, and the full contact for half an hour under each humidity condition shows that it has good humidity resistance . In the air environment, the material showed more stable properties, as shown in Figure 5b, the fluorescence intensity did not decrease significantly during 50 days of unprotected storage, indicating that the prepared material has good stability .

Claims (8)

1. A method for preparing perovskite on paper substrate, comprising the steps of:

(1) Preparing a solution a of a perovskite precursor I;

(2) Preparing a perovskite precursor II, a perovskite precursor II solvent and an aminosilane solution b;

(3) Dropping the solution b on the surface of the paper base, then dropping the solution a on the surface of the paper base at the same position, and volatilizing the solvent to obtain perovskite nanocrystalline;

the perovskite precursor I is selected from Cs ₂ CO ₃ At least one of MABr;

the perovskite precursor II is selected from PbBr ₂ 、PbI ₂ At least one of them.

2. The method according to claim 1, wherein the volume ratio of the solution a to the solution b is 1:10 to 10:1.

3. The method according to claim 1, wherein the aminosilane is selected from at least one of 3-aminopropyl triethoxysilane (APTES), 3-aminopropyl methyldimethoxysilane;

the volume fraction of the aminosilane in the solution b is 1% -10%.

4. The method according to claim 1, wherein the perovskite precursor ii solvent is selected from at least one of toluene, n-hexane.

5. The method according to claim 1, wherein the molar concentration of the perovskite precursor i in the solution a is 0.05-0.2 mmol/L;

in the solution b, the molar concentration of the perovskite precursor II is 0.05-0.2 mmol/L; the molar concentration of the perovskite precursor II solvent is 0.1-0.3 mmol/L.

6. The method according to claim 1, wherein the solvent of the solution a is selected from at least one of n-octanoic acid, oleic acid; the solvent of the solution b is at least one selected from toluene, normal hexane and cyclohexane.

7. The method of claim 1, wherein the paper substrate is selected from one of filter paper, nitrocellulose membrane, polyvinylidene fluoride (PVDF) membrane.

8. A paper-based sensor characterized by using a paper-based with perovskite grown thereon; the paper base with perovskite grown thereon is prepared by the method of any one of claims 1 to 7.

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