Two-dimensional chiral lead-free silver bismuth-based double perovskite nanobelt and preparation method thereof

Abstract

The application discloses a two-dimensional chiral lead-free silver bismuth-based double perovskite nanobelt and a preparation method thereof, and the specific preparation steps are as follows: S1: taking a chiral ammonium salt, silver halide and bismuth halide as raw materials for perovskite synthesis, taking a long-chain organic ammonium as a surface ligand, and taking N,N'-dimethylformamide as a good solvent to obtain a precursor solution; S2: taking a mixed solvent of chloroform and toluene or dichloromethane and toluene in a certain proportion as an anti-solvent, and injecting the precursor solution obtained in the step S1 into the anti-solvent to synthesize a chiral-enhanced lead-free silver bismuth double perovskite nanobelt. The application has the advantages of simple and convenient synthesis steps, and the obtained chiral lead-free double perovskite nanobelt has a relatively strong circular dichroism signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chiral lead-free perovskite materials, in particular to a two-dimensional chiral lead-free silver bismuth-based double perovskite nanobelt and a preparation method thereof. BACKGROUND

[0002] Chiral two-dimensional organic-inorganic hybrid perovskites (2D OIHPs) are an interesting class of materials that combine the excellent crystallinity and excitonic properties of 2D OIHPs with unique chiral optoelectronic and spintronic properties. However, most of the reported chiral 2D OIHPs contain toxic lead ions, which severely hinder their large-scale production and practical applications. Based on valence considerations, replacing lead with tin (Sn) is an attractive option, but the sensitivity of Sn(II) to oxygen leads to the formation of Sn(IV) and potential material defects within the material, which poses a major obstacle to lead-free tin-based low-dimensional chiral perovskites. Therefore, a new alternative approach must be prioritized - emerging chiral double perovskite two-dimensional analogues, including trivalent cations (such as Bi 3+ ) and monovalent cations (such as Ag + ), are being explored as next-generation candidates due to their non-toxicity, phase stability, and interesting unique advantages.

[0003] The research progress of synthesizing macroscopic single crystals based on chiral silver bismuth (Ag-Bi) double perovskites shows great potential in circularly polarized photodetection and automated force x-ray detection fields. However, the traditional single crystal synthesis method cannot be separated from the energy consumption of long-time heating equipment and the large use of non-environmentally friendly hydrogen halide acid. Furthermore, the macroscopic material specifications to some extent hinder the study of micro-nanocrystalline materials and their performance-structure relationship. Fortunately, perovskite crystal materials with nanoscale can be quickly obtained through a simple ligand-assisted reprecipitation method (LARP), providing a convenient path for the development of more chiral perovskite nanomaterials. However, it is important to note that various factors such as the structure of chiral organic spacer cations, the selection of polar solvents or anti-solvents, and the selection of ligands can significantly affect the morphology, symmetry, and growth of chiral perovskite nanocrystals, as well as the final size and chiral signal expression of the material. However, this has not been explored in chiral double perovskite nanomaterials.

[0004] Several works (Angew. Chem. 2021, 133, 8496-8499, Adv. Optical Mater. 2022, 10, 2102227, Adv. Optical Mater. 2022, 10, 2102227) have reported that the chiral lead-free silver bismuth-based double perovskite crystals formed with chiral ligand R- / S-MPEABr as A-site ions exhibit significant chirality, but most of these reports are based on traditional macroscopic single crystal synthesis and application, and further research or indication of the chiral optical behavior and characteristics exhibited by the microscale size has not been carried out. Nanoscale double perovskite crystal materials can be easily obtained by ligand-assisted reprecipitation (LARP) synthesis (Chem. Commun., 2020, 56, 7917-7920), but this method has not been applied in chiral double perovskite materials. In addition, in ligand-assisted reprecipitation (LARP) synthesis, the use of different solvent and antisolvent combinations or the adjustment of the solvent ratio often leads to changes in the morphology and optical properties of the formed nanocrystals (ACS Appl. Nano Mater. 2019, 2, 12, 7910-7915; Chem. Commun., 2017, 53, 244), and these interesting studies deserve further exploration in the microscale chiral double perovskite system. Furthermore, there are reports (ACS Appl. Mater. Interfaces 2023, 15, 9978-9986) that by comparing the use of different crystallization solvents, the CD response signal of the chiral lead-based perovskite thin film system is regulated, but research based on microscale non-lead double perovskite crystal systems has not been reported. Therefore, the development of microscale chiral lead-free silver bismuth double perovskite nanomaterials by LARP method and the study of the influence of solvent adjustment on the crystal morphology and chiral CD signal of the materials provide a reference for revealing the relationship between the structure and properties of more chiral lead-free perovskite nanomaterials, and have great significance for circularly polarized luminescence and detection, three-dimensional display, biological imaging, quantum computing, quantum communication, memory, and spin transistors. SUMMARY

[0005] In order to overcome the time-consuming and material-consuming synthesis of macroscopic single crystals as mentioned above and to deepen the understanding of the structure and properties of microscale lead-free silver bismuth double perovskite, the present application seeks a simple, fast, economical and environmentally friendly method to prepare a chiral lead-free silver bismuth double perovskite nanobelt with a high CD value, an anisotropy factor g abs and a high CD value, which provides a new strategy for the design of the chiral optical properties of microscale chiral lead-free double perovskite structures.

[0006] The first aspect of the present application is to provide a preparation method of a two-dimensional chiral lead-free silver bismuth-based double perovskite nanobelt, comprising the following steps:

[0007] S1: using chiral ammonium salt, silver halide and bismuth halide as raw materials for perovskite synthesis, long-chain organic amine as surface ligand, and N,N'-dimethylformamide as good solvent to obtain precursor solution S2: using a mixture of toluene and chloroform as anti-solvent, the precursor solution obtained in step S1 is injected into the anti-solvent to synthesize two-dimensional lead-free chiral silver bismuth double perovskite nanobelt with obvious chiral response.

[0008] In step S1, the chiral ammonium salt is any one of R-β-methylphenethylamine bromide, R-β-methylphenethylamine iodide, S-β-methylphenethylamine bromide, and S-β-methylphenethylamine iodide.

[0009] In step S1, the long-chain organic amine is oleylamine or octylamine.

[0010] Further, in step S1, the silver halide is AgBr or AgI, and the bismuth halide is BiBr3 or BiI3.

[0011] Further, in step S1, the feeding ratio of the organic ammonium cation in the precursor solution to the silver halide and the bismuth halide is not more than 4:1:1, and the optimal feeding ratio is 4:1:1.

[0012] Further, in step S1, the volume ratio of the long-chain organic amine to the precursor solution is not more than 1:250, and the optimal volume ratio is 1:416.

[0013] Further, in step S2, the volume ratio of the precursor solution taken to the anti-solvent is not more than 1:1000, and the optimal volume ratio is 1:1000.

[0014] Further, in step S2, the volume ratio of chloroform to toluene in the anti-solvent is any one of 1:4, 2:3, 3:2, and 4:1, and the optimal volume ratio is 2:3.

[0015] Further, in step S2, the volume ratio of dichloromethane to toluene in the anti-solvent is any one of 1:4, 2:3, 2.5:2.5, 3:2, and 4:1, and the optimal volume ratio is 2.5:2.5.

[0016] In addition, the second aspect of the present application provides a two-dimensional chiral lead-free silver bismuth-based double perovskite nanobelt prepared by the preparation method.

[0017] The present application studies the chiral activity of chiral lead-free silver bismuth double perovskite and the influence of the specific properties of the solvent in the crystalline environment on the crystal morphology and structure, and by changing the halogen atom at the X site of the two-dimensional perovskite, a lead-free double perovskite nanobelt with adjustable light emission, narrow emission line width, high quantum yield, and good environmental stability is obtained.

[0018] The innovative mechanism of the application is a method for improving the circular dichroism signal of chiral lead-free silver bismuth perovskite nanomaterials by regulating the properties of solvents, which adopts a double anti-solvent strategy, and uses a ligand-assisted co-deposition method to synthesize chiral-enhanced lead-free silver bismuth-based double perovskite nanobands. abs = -1.43 x 10 -3 , for this phenomenon, a co-blended anti-solvent assisted co-deposition method is used to synthesize chiral double perovskite nanocrystals, the morphology and structure of different volume ratios of mixed anti-solvents and corresponding single solvents are characterized, and the reasons are verified by circular dichroism test results, in addition, the wavelength of the obtained nanocrystals is adjustable, and the stability is good.

[0019] As described above, the application can provide a new way for designing chiral lead-free perovskite with high CD value, anisotropy factor g abs , and promote the development of chiral optical devices. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below, obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings obtained according to these drawings without creative labor still belong to the scope of the application.

[0021] Figure 1 It is a transmission electron microscope graph of chiral lead-free silver bismuth double perovskite nanoband (R-MPEA) 4AgBiBr8 in the embodiment 1 of the application;

[0022] Figure 2 It is an XRD spectrum of chiral lead-free silver bismuth double perovskite nanoband (R-MPEA) 4AgBiBr8 in the embodiment 1 of the application;

[0023] Figure 3 It is a circular dichroism spectrum of chiral lead-free silver bismuth double perovskite material, and ultraviolet absorption spectrum (left) and fluorescence emission spectrum (right) in the embodiment 2 of the application;

[0024] Figure 4 It is a scanning electron microscope graph of chiral lead-free silver bismuth double perovskite C1-m in the embodiment 2 of the application;

[0025] Figure 5 It is an XRD graph of chiral lead-free silver bismuth double perovskite C1-n in the embodiment 2 of the application;

[0026] Figure 6(a) CD and (b) corresponding g abs Trend line graph of change;

[0027] Figure 7 CD spectrum of C3 in Example 4 of the present application;

[0028] Figure 8 XRD spectrum of C3 in Example 4 of the present application;

[0029] Figure 9 (a) UV and (b) CD spectra of C4 series colloidal solution in Example 5 of the present application;

[0030] Figure 10 (a) CD and (b) corresponding g abs Trend column chart of change;

[0031] Figure 11 (a) UV and (b) PL spectra of (R-MPEA)4AgBiBr 8x-8 I 8x colloidal solution in Example 7 of the present application;

[0032] Figure 12 (a) UV and (b) PL spectra of chiral lead-free silver bismuth double perovskite material in Example 2 of the present application;

[0033] Figure 13 PL stability heat map of (R-MPEA)4AgBiBr8 NBs in Example 1 of the present application;

[0034] Figure 14 (a) CD and (b) corresponding g 8x-8 I 8x colloidal solution in Example 7 of the present application; abs Trend line graph of change. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described in detail below through specific examples, but the purpose and function of these example embodiments are only used to exemplify the present application, and do not constitute any form of any limitation on the actual protection scope of the present application, nor limit the protection scope of the present application to this.

[0036] In the following examples, the chiral organic ammonium, long-chain organic amine, and anti-solvent are replaced by abbreviations, specifically:

[0037] R-β-methylphenethylamine bromide ammonium (R-MPEABr), R-β-methylphenethylamine iodide ammonium (R-MPEAI), S-β-methylphenethylamine bromide ammonium (S-MPEABr), S-β-methylphenethylamine iodide ammonium (S-MPEAI), oleylamine (OAM), chloroform (CF), toluene (Tol), dichloromethane (DCM), tetrahydrofuran (THF), ethyl acetate (EA)

[0038] Example 1:

[0039] A preparation of chiral lead-free double perovskite nanobelt (R-MPEA)4AgBiBr8 NBs, the steps are as follows:

[0040] S1: Dissolve the required raw materials R-MPEABr (0.5 mmol) and AgBr (0.125 mmol), BiBr3 (0.125 mmol), oleylamine (1.2 μL) in N,N-dimethylformamide (0.5 mL) to prepare precursor solution 1;

[0041] S2: Take 5 μL of the precursor solution 1 as described in S1, add to chloroform / toluene blend anti-solvent (5 mL) with a volume ratio of 2:3, quickly stir for 2 min to obtain a uniformly dispersed colloidal solution, and the final solution is (R-MPEA)4AgBiBr8 NBs.

[0042] Figure 1 and Figure 2 The corresponding transmission electron microscope images and XRD spectra of (R-MPEA)4AgBiBr8 NBs are given, Figure 3 The CD spectrum of (R-MPEA)4AgBiBr8 NBs is given, which shows that the product has obvious characteristics of two-dimensional chiral lead-free double perovskite nanomaterials.

[0043] Example 2: Investigation of several volume ratios of chloroform / toluene blend anti-solvent of S2 Except that the volume ratio of chloroform / toluene blend anti-solvent described in S2 is replaced by several ratios (see Table 1), the other operations are unchanged, thereby repeating the operation of Example 1, thereby sequentially performing Example 2, obtaining a series of uniformly dispersed colloidal solutions, named C1-n.

[0044] The specific ratio is as follows Table 1:

[0045]

[0046] Figure 4 and Figure 5 The corresponding scanning electron microscope images and XRD spectra of C1-n series of products are given, which show that the prepared products have the characteristics of two-dimensional perovskite nanomaterials.

[0047] Example 3: Investigation of the amount of oleylamine used in Step S1

[0048] The volume of oleylamine in Step S1 was replaced by v OAM (see Table 2, v OAM = 0.5, 1, 1.2, 1.5, 2 μL), and the other operations were unchanged, so that the operation of Example 1 was repeated, and Example 3 was sequentially performed, to obtain a series of colloidal solutions named C2-m.

[0049] The specific amounts and names are as follows in Table 2:

[0050] C2-m v OAM ]]> C2-5 0.5 C2-4 1 (R-MPEA)4AgBiBr8NBs 1.2 C2-2 1.5 C2-1 2

[0051] Figure 6 The corresponding CD and XRD patterns of the C2-m series of materials are given, which reflect the influence of the amount of OAM on the chiral signal of the prepared product. abs The corresponding CD and XRD patterns of the C2-m series of materials are given, which reflect the influence of the amount of OAM on the chiral signal of the prepared product.

[0052] Example 4: Investigation of the absence of AgBr in the raw materials in Step S1

[0053] The AgBr in Step S1 was removed, and the other raw materials were still added in the proportions described in S1, to prepare a hybrid Bi-based metal halide containing no Ag ions, and the other operations were unchanged, so that the operation of Example 1 was repeated, and Example 4 was sequentially performed, to obtain a uniformly dispersed colloidal solution named C3.

[0054] Figure 7 and Figure 8 The corresponding CD and XRD patterns of the product C3 are given, which reflect the influence of the raw materials on the chiral signal of the prepared product.

[0055] Example 5: Investigation of the use of other single anti-solvents in Step S2

[0056] The chloroform / toluene co-blended anti-solvent in Step S2 was replaced by tetrahydrofuran, dichloromethane, ethyl acetate, etc., and the other operations were unchanged, so that the operation of Example 1 was repeated, and Example 5 was sequentially performed, to obtain a uniformly dispersed colloidal solution C4-THF / DCM / EA.

[0057] The specific amounts and names are as follows in Table 3:

[0058] C4-anti-solvent anti-solvent V 反溶剂 ]]> C4-THF tetrahydrofuran 5 mL C4-DCM dichloromethane 5 mL C4-EA ethyl acetate 5 mL

[0059] Figure 9 The corresponding UV and CD patterns of the product C4-THF / DCM / EA are given, which reflect the influence of the appropriate anti-solvent on the chiral signal of the product.

[0060] Example 6: Investigation of several proportions of toluene and dichloromethane co-blended anti-solvents in Step S2

[0061] The operation of Example 2 was repeated by replacing the chloroform anti-solvent in step S2 in Example 2 with dichloromethane DCM in several volume ratios (see Table 3), and the other operations were unchanged, thereby sequentially performing Example 6 to obtain a uniformly dispersed colloidal solution named C5-p.

[0062] The specific ratios and names are as follows in Table 4:

[0063]

[0064]

[0065] Figure 10 The CD and g of the C5-p colloidal solution are given abs The figure shows that the blending anti-solvent with different compositions of anti-solvents can also control the chiral signal of the chiral lead-free double perovskite.

[0066] Example 7:

[0067] S1: A series of chiral lead-free silver bismuth-based double perovskite nanomaterials with different wavelengths of emission were prepared by using a blending anti-solvent strategy, and the steps are as follows: a certain amount of R-MPEABr, AgBr, AgI, BiBr3, BiI3 (see Table 5) and oleylamine (1.2 μL) were dissolved in N,N-dimethylformamide (0.5 mL) to prepare a precursor solution 7;

[0068] S2: 5 μL of the precursor solution 7 was added to a mixed volume ratio of 2:3 of toluene / chloroform anti-solvent (5 mL) under vigorous stirring, and the stirring time was 2 min to obtain a uniformly dispersed colloidal solution. The final solution is (R-MPEA)4AgBiBr 8x- 8I 8x .

[0069] The specific ratios are as follows in Table 5:

[0070]

[0071] Figure 11 The UV and PL spectra of the (R-MPEA)4AgBiBr 8x-8 I 8x nanomaterials are given, which show that the prepared products have different wavelength emission characteristics.

[0072] In order to further verify the optical properties of the prepared chiral perovskite nanosheets, the products obtained in Examples 1, 2 and 7 were respectively tested by emission spectrum test and circular dichroism spectrum test. The specific operations are as follows:

[0073] (I): The prepared chiral perovskite nanosheets were tested by emission spectrum

[0074] 1. Emission spectrum test of chiral perovskite nanomaterials synthesized by blending in proportion of anti-solvent:

[0075] Samples used: (R-MPEA)4AgBiBr8 NBs prepared in Example 1, Example 2, C1-n series solutions.

[0076] Instrument used: Hitachi fluorescence detector 5J1-0004.

[0077] Test steps: Load the colloidal solution into a four-side transparent quartz cuvette, open the cover of the instrument, slowly put the cuvette into the cuvette slot, close the cover, then click the spectrum test software on the computer, select xenon lamp as the excitation light source and set the excitation light wavelength to 375 nm, the size of the slit is 10 nm\10 nm, select the emission spectrum wavelength range 400-700 nm in the test interface, click Start; After a sample is tested, save the data according to the corresponding naming; Repeat the above steps to test other samples. Finally, adjust the slit to the minimum, then take out the cuvette, process the sample, wash the cuvette with ethanol, and then put it into the box.

[0078] Test results: Under the excitation of 375 nm light, the luminescence spectrum of the chiral lead-free silver bismuth double perovskite material prepared in Example 1 and Example 2 is blue emission spectrum at 455-470 nm, and the emission spectrum is shown in Figure 11 .

[0079] 2. Emission spectrum test of chiral lead-free silver bismuth double perovskite nanosheets with different wavelengths

[0080] Samples used: (R-MPEA)4AgBiBr 8x-8 I 8x .

[0081] Instrument used: Hitachi fluorescence detector 5J1-0004.

[0082] Test steps: Put the sample into a four-side transparent quartz cuvette, open the cover of the instrument, put the cuvette into the cuvette slot, close the cover, then open the spectrum test software on the computer, select xenon lamp as the light source, set the excitation wavelength to 375 nm, and finally select the appropriate slit by adjusting the size of the slit. Select the emission spectrum wavelength range 400-750 nm in the test interface, click Start to start measurement; Save the data after the sample is tested, and test other samples according to the above steps. After the test is completed, reduce the slit to the minimum, then take out the cuvette, wash it with ethanol, and put it into the box.

[0083] Test results: The luminescence spectrum of the chiral perovskite nanosheets prepared in Example 7 under 375 nm excitation light is 470-580 nm, which is a blue-green emission spectrum. The emission spectrum is shown in Figure 10 .

[0084] 3. Emission spectrum stability test of chiral lead-free silver bismuth double perovskite nanobelt

[0085] Instrument used: Hitachi fluorescence detector 5J1-0004.

[0086] Test steps: Put the sample into a four-side light-transmitting quartz cuvette, open the instrument cover, put the cuvette into the holder, cover the cover, then open the spectrum test software on the computer, select xenon lamp as the light source, set the excitation wavelength to 375 nm, finally select the appropriate slit by adjusting the size of the slit. Select the emission spectrum wavelength range 400-700 nm in the test interface, click "start"; save the data after the sample test, test the sample every hour according to the above method until 900 min.

[0087] Test results: The (R-MPEA)4AgBiBr8 NBs prepared in Example 1 have good stability under 375 nm excitation light. The stability test is shown in Figure 12 .

[0088] (II) Circular dichroism spectrum and ultraviolet absorption spectrum test of the prepared chiral perovskite nanosheets

[0089] Sample used: A series of chiral lead-free silver bismuth double perovskite nanomaterials prepared in typical examples 1, 2 and 7

[0090] Instrument used: Chirascan of Applied Photophysics

[0091] Test procedure: Turn on the instrument, open the nitrogen cylinder valve, and preheat for 15 minutes. Click on the computer test software and set the parameters: scan range 300-600 nm, scan speed 1 nm / s. First, scan the air sample, then subtract the background, place the sample corresponding to the anti-solvent in a two-sided transparent micro-quartz dish, open the instrument cover, align the front of the quartz dish with the incident light and the detector, then place it in the holder, cover the instrument cover, click the start button to test, and the CD spectrum and UV absorption spectrum will be obtained simultaneously. After the test is completed, save the data and manually subtract the background. Then take out the cuvette, pour out the sample, wash it clean with ethanol, rinse it with toluene, load the next sample, and continue the above test operation. After the last sample test is completed, turn off the instrument, continue to pass nitrogen for 10 minutes, and then turn off the gas valve.

[0092] Test results: The above test results show that the absorption spectrum of a series of chiral lead-free silver bismuth double perovskite nanomaterials prepared by the present application has the same evolution law as the corresponding emission spectrum. And the perovskite nanobelt prepared by R-MPEABr shows circular dichroism absorption near the energy band of the inorganic crystal lattice, indicating that the chirality is transferred to the perovskite material, and the g value can reach 1.43x10 -3 . And by changing the properties of the synthesized blended solvent, the relationship between the structure of the perovskite nanomaterial and the circular dichroism signal can be clearly seen, and by adjusting the halogen, the peak position of the circular dichroism spectrum also moves accordingly. The UV absorption spectrum is shown in Figure 3 , Figure 11 and Figure 12 , and the circular dichroism spectrum is shown in Figure 11 and Figure 14 .

[0093] The present application adopts a ligand-assisted co-deposition method, which is simple and easy to operate, and the synthesized nanobelt has excellent circular dichroism signal. By analyzing single and blended anti-solvents, the influence of the crystalline state on the circular dichroism signal can be obtained. The relationship between the circular dichroism signal and its structure is clear, and the influence of the crystalline morphology on the circular dichroism signal is further verified. The method can prepare a series of chiral lead-free silver bismuth double perovskite nanomaterials with adjustable circular dichroism response. Due to its obvious chirality signal, it can be widely used in the fields of photodetectors and polarized light devices.

[0094] The above disclosure is only a good embodiment of the present application, of course, cannot be used to limit the scope of the rights of the present application, therefore, equivalent changes made according to the claims of the present application still belong to the scope of the present application.

Claims

1. A method for preparing two-dimensional chiral lead-free silver bismuth-based double perovskite nanoribbons, characterized in that: The method comprises the following steps: S1: a precursor solution is obtained by using a chiral ammonium salt, silver halide and bismuth halide as raw materials for perovskite synthesis, a long-chain organic amine as a surface ligand, and N,N'-dimethylformamide as a good solvent; wherein the chiral ammonium salt is any one of R - beta-methylphenethylamine ammonium bromide, R - beta-methylphenethylamine ammonium iodide, S - beta-methylphenethylamine ammonium bromide, S - beta-methylphenethylamine ammonium iodide, and the long-chain organic amine is oleylamine or octylamine; S2: The precursor solution obtained in step S1 is injected into an anti-solvent of a mixed solvent of chloroform and toluene or a mixed solvent of dichloromethane and toluene to synthesize two-dimensional lead-free chiral silver bismuth double perovskite nanobelt; wherein the volume ratio of chloroform and toluene in the anti-solvent is any one of 1:4, 2:3, 3:2, 4:1, and the volume ratio of dichloromethane and toluene is any one of 1:4, 2:3, 2.5:2.5, 3:2, 4:

1.

2. The method for preparing two-dimensional chiral lead-free silver-bismuth-based double perovskite nanoribbons according to claim 1, characterized in that: In step S1, the silver halide is silver bromide or silver iodide, and the bismuth halide is bismuth bromide or bismuth iodide.

3. The method for preparing two-dimensional chiral lead-free silver-bismuth-based double perovskite nanoribbons according to claim 1, characterized in that: In step S1, the feeding ratio of the organic ammonium cation of the precursor solution to the silver halide and the bismuth halide is not more than 4:1:

1.

4. The method for preparing two-dimensional chiral lead-free silver-bismuth-based double perovskite nanoribbons according to claim 1, characterized in that: In step S1, the volume ratio of the long-chain organic amine to the precursor solution is not more than 1:

250.

5. The method for preparing two-dimensional chiral lead-free silver-bismuth-based double perovskite nanoribbons according to claim 1, characterized in that: In step S2, the volume ratio of the precursor solution to the anti-solvent is not more than 1:1000.

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