Preparation method and application of chiral two-dimensional cadmium sulfide nanosheet

Abstract

The application relates to a preparation method and application of chiral two-dimensional cadmium sulfide nanosheets. The application aims to solve the problem that it is difficult to construct non-layered chiral two-dimensional inorganic nanomaterials. The method comprises the following steps: placing a first open reaction container and a second open reaction container in a sealable container, adding a cadmium acetate solution into the first open reaction container, then adding a left-rotational ibuprofen / chloroform solution drop by drop, adding a sodium sulfide aqueous solution into the second open reaction container, then adding a hydrochloric acid solution drop by drop, and finally sealing and standing. The application is used for preparing a circularly polarized light detection device for detecting left-rotational / right-rotational circularly polarized light. The application is used for the preparation and application of chiral two-dimensional cadmium sulfide nanosheets.

Description

Technical Field

[0001] This invention relates to a method for preparing chiral two-dimensional nanosheets and their applications. Background Technology

[0002] Chirality, the property of an object not being superimposed on its mirror image, has wide applications in life sciences, materials science, spintronics, and optoelectronic devices. Exploring chirality in inorganic nanomaterials such as quantum dots, transition metal oxides, and metal nanoparticles paves the way for innovative applications. In this field, two-dimensional (2D) inorganic nanomaterials, especially when their thickness is limited to one or a few atomic layers, exhibit unique physical properties, such as ultra-high conductivity, tunable photoelectric properties, and catalytic properties, which are distinct from their bulk counterparts and other forms of nanostructures. Introducing chirality into 2D inorganic nanomaterials holds promise for providing tailored functional materials for next-generation optically active systems and optoelectronic devices. However, current processes for introducing chiral molecules into 2D inorganic nanostructures are complex, and realizing 2D chiral inorganic nanomaterials with specific functions remains challenging. Currently, obtaining chiral 2D inorganic nanostructures through chemical or mechanical exfoliation is feasible, but its applicability is limited by compounds with layered structures. Exploring chiral 2D nanostructures of non-layered compounds and constructing diverse chiral 2D inorganic nanomaterials to meet practical application needs is crucial. Summary of the Invention

[0003] This invention aims to solve the problem of the difficulty in constructing non-layered chiral two-dimensional inorganic nanomaterials, and thus provides a method for preparing chiral two-dimensional cadmium sulfide nanosheets and their applications.

[0004] A method for preparing chiral two-dimensional cadmium sulfide nanosheets, comprising the following steps:

[0005] The first and second open reaction containers were placed in a sealable container at a temperature of 3℃~5℃. Cadmium acetate solution was added to the first open reaction container, and then levo-ibuprofen / chloroform solution was dropped onto the surface of the cadmium acetate solution. After the chloroform in the first open reaction container had completely evaporated, sodium sulfide aqueous solution was added to the second open reaction container, and then hydrochloric acid solution was dropped onto the surface of the sodium sulfide aqueous solution. The sealable container was then sealed and allowed to stand. After standing, chiral two-dimensional cadmium sulfide nanosheets were obtained at the air-liquid interface of the first open reaction container.

[0006] The molar ratio of cadmium acetate in the cadmium acetate solution to ibuprofen in the levo-ibuprofen / chloroform solution is 1:(1.1×10⁻⁶). -6 ~1.3×10 -6 The molar ratio of levoprofen to the liquid interface area in the levoprofen / chloroform solution is (0.7–0.75) nmol:1cm. 2The molar ratio of sodium sulfide in the sodium sulfide aqueous solution to hydrochloric acid in the hydrochloric acid solution is 1:(2-3); the molar ratio of sodium sulfide in the sodium sulfide aqueous solution to the volume ratio of the sealable container is (1.9-2.1) nmol:1cm³. 3 .

[0007] An application of chiral two-dimensional cadmium sulfide nanosheets for the fabrication of circularly polarized light detection devices to detect left-handed / right-handed circularly polarized light.

[0008] The beneficial effects of this invention are:

[0009] This invention successfully prepared two-dimensional chiral cadmium sulfide nanosheets at the air-liquid interface using ion-layer epitaxy. This method is simple to operate, has mild reaction conditions, and is inexpensive. The obtained chiral cadmium sulfide nanosheets are optically active, and transferring them onto interdigitated electrodes can be used to fabricate circularly polarized light detection devices. The circularly polarized light detection devices prepared using the synthesized chiral cadmium sulfide nanosheets exhibit good photoresponse characteristics and can sensitively detect left-handed and right-handed circularly polarized light.

[0010] Instruction manual illustrations

[0011] Figure 1 Scanning electron microscope image of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1;

[0012] Figure 2 X-ray diffraction pattern of chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1;

[0013] Figure 3 An atomic force microscopy image of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1;

[0014] Figure 4 The circular dichroism chromatogram of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1;

[0015] Figure 5 The current-voltage curve of the circularly polarized light detection device prepared in Example 2 in a dark environment;

[0016] Figure 6 The current-voltage curve of the circularly polarized light detection device prepared in Example 2 under illumination;

[0017] Figure 7 The optical switching characteristic curve of the circularly polarized light detection device prepared in Example 2 under right-hand circularly polarized light irradiation is shown.

[0018] Figure 8 The optical switching characteristic curve of the circularly polarized light detection device prepared in Example 2 under left-handed circularly polarized light irradiation is shown. Detailed Implementation

[0019] Specific Implementation Method 1: This implementation method is a method for preparing chiral two-dimensional cadmium sulfide nanosheets, which is carried out according to the following steps:

[0020] The first and second open reaction containers were placed in a sealable container at a temperature of 3℃~5℃. Cadmium acetate solution was added to the first open reaction container, and then levo-ibuprofen / chloroform solution was dropped onto the surface of the cadmium acetate solution. After the chloroform in the first open reaction container had completely evaporated, sodium sulfide aqueous solution was added to the second open reaction container, and then hydrochloric acid solution was dropped onto the surface of the sodium sulfide aqueous solution. The sealable container was then sealed and allowed to stand. After standing, chiral two-dimensional cadmium sulfide nanosheets were obtained at the air-liquid interface of the first open reaction container.

[0021] The molar ratio of cadmium acetate in the cadmium acetate solution to ibuprofen in the levo-ibuprofen / chloroform solution is 1:(1.1×10⁻⁶). -6 ~1.3×10 -6 The molar ratio of levoprofen to the liquid interface area in the levoprofen / chloroform solution is (0.7–0.75) nmol:1cm. 2 The molar ratio of sodium sulfide in the sodium sulfide aqueous solution to hydrochloric acid in the hydrochloric acid solution is 1:(2-3); the molar ratio of sodium sulfide in the sodium sulfide aqueous solution to the volume ratio of the sealable container is (1.9-2.1) nmol:1cm³. 3 .

[0022] The beneficial effects of this embodiment are:

[0023] This embodiment successfully prepared two-dimensional chiral cadmium sulfide nanosheets at the air-liquid interface using ion-layer epitaxy. This method is simple to operate, has mild reaction conditions, and is inexpensive. The obtained chiral cadmium sulfide nanosheets are optically active, and transferring them onto interdigitated electrodes can fabricate circularly polarized light detection devices. The circularly polarized light detection devices prepared using the synthesized chiral cadmium sulfide nanosheets exhibit good photoresponse characteristics and can sensitively detect left-handed / right-handed circularly polarized light.

[0024] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that: under the condition of a dropping rate of 0.5 μL / s to 1 μL / s, the levo-ibuprofen / chloroform solution is dropped onto the surface of the cadmium acetate solution. Everything else is the same as in Specific Implementation Method One.

[0025] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the hydrochloric acid solution is added dropwise onto the surface of the sodium sulfide solution at a dropping rate of 40 μL / s to 50 μL / s. Everything else is the same as in Specific Implementation Method One or Two.

[0026] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the standing period is specifically 0.5 to 2 hours at a temperature of 3℃ to 5℃. Everything else is the same as Specific Implementation Methods One to Three.

[0027] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the concentration of cadmium acetate in the cadmium acetate solution is 190 mmol / L to 210 mmol / L; and the temperature of the cadmium acetate solution is 3℃ to 5℃. Everything else is the same as in Specific Implementation Methods One to Four.

[0028] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the concentration of cadmium acetate in the cadmium acetate solution is 190 mmol / L to 210 mmol / L; and the temperature of the cadmium acetate solution is 3℃ to 5℃. Everything else is the same as in Specific Implementation Methods One to Five.

[0029] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the concentration of sodium sulfide in the sodium sulfide aqueous solution is 190 mmol / L to 210 mmol / L; and the temperature of the sodium sulfide aqueous solution is room temperature. Everything else is the same as in Specific Implementation Methods One to Six.

[0030] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the concentration of the hydrochloric acid solution is 190 mmol / L to 210 mmol / L; and the temperature of the hydrochloric acid solution is room temperature. Everything else is the same as in Specific Implementation Methods One to Seven.

[0031] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One through Eight in that: the volume of the sealable container is 2.2L to 2.8L; and the opening area of ​​both the first and second open reaction containers is 4.8cm². 2 ~5cm 2 The volume of each sample is 20mL to 22mL. Everything else is the same as in embodiments one through eight.

[0032] Specific Implementation Method 10: This implementation method describes the application of a chiral two-dimensional cadmium sulfide nanosheet, which is used to prepare a circularly polarized light detection device for detecting left-handed / right-handed circularly polarized light.

[0033] The beneficial effects of the present invention are verified using the following embodiments:

[0034] Example 1:

[0035] A method for preparing chiral two-dimensional cadmium sulfide nanosheets, comprising the following steps:

[0036] The first and second open reaction containers were placed in a sealable container at 3°C. 15 mL of cadmium acetate solution was added to the first open reaction container. Then, 2 μL of levo-ibuprofen / chloroform solution was added to the surface of the cadmium acetate solution at a dropping rate of 0.5 μL / s. After the chloroform in the first open reaction container had completely evaporated, 25 μL of sodium sulfide aqueous solution was added to the second open reaction container. Then, 50 μL of hydrochloric acid solution was added to the surface of the sodium sulfide aqueous solution at a dropping rate of 40 μL / s. The sealable container was then sealed and allowed to stand at 3°C ​​for 1 h. After standing, chiral two-dimensional cadmium sulfide nanosheets with a thickness of 15.5 nm were obtained at the air-liquid interface of the first open reaction container.

[0037] The molar ratio of cadmium acetate in the cadmium acetate solution to ibuprofen in the levo-ibuprofen / chloroform solution is 1:1.2×10⁻⁶. -6 The molar ratio of levoprofen to the liquid interface area in the levoprofen / chloroform solution is 0.73 nmol:1 cm⁻¹. 2 The molar ratio of sodium sulfide in the sodium sulfide aqueous solution to hydrochloric acid in the hydrochloric acid solution is 1:2; the molar ratio of sodium sulfide in the sodium sulfide aqueous solution to the volume ratio of the sealable container is 2 nmol:1 cm³. 3 .

[0038] The concentration of cadmium acetate in the cadmium acetate solution is 200 mmol / L; the temperature of the cadmium acetate solution is 3℃.

[0039] The concentration of levoprofen in the levoprofen / chloroform solution is 1.8 mmol / L; the temperature of the levoprofen / chloroform solution is room temperature.

[0040] The concentration of sodium sulfide in the sodium sulfide aqueous solution is 200 mmol / L; the temperature of the sodium sulfide aqueous solution is room temperature.

[0041] The concentration of the hydrochloric acid solution is 200 mmol / L; the temperature of the hydrochloric acid solution is room temperature.

[0042] The volume of the sealable container is 2.5L; the first and second open reaction containers are cylindrical open containers, each with an open area of ​​4.93cm². 2 The volume of each is 20 mL.

[0043] Example 2: Application of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1. These nanosheets are used to prepare a circularly polarized light detection device for detecting left-handed / right-handed circularly polarized light. Preparation of the circularly polarized light detection device: Chiral cadmium sulfide nanosheets were transferred onto interdigitated electrodes based on polyethylene terephthalate (PET) substrates and dried at 50°C for half an hour to obtain the circularly polarized light detection device. The circularly polarized light detection device was connected to a four-probe testing instrument. A 2450 digital source meter was used as the voltage source, and a xenon lamp was used as the light source. The light source was converted into left-handed / right-handed circularly polarized light through left-handed / right-handed circularly polarizers and then irradiated the device. The distance between the left-handed / right-handed circularly polarizers and the light source was 2 cm, and the distance between the left-handed / right-handed circularly polarizers and the device was 1 cm. The photoresponse and circularly polarized light detection capability of the device were verified by detecting the response current of the device.

[0044] Figure 1 The image shows a scanning electron microscope (SEM) image of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1. As can be seen from the image, the chiral cadmium sulfide nanosheets are roughly circular in shape with asymmetrical edges and a size of approximately 10 micrometers, a size that is advantageous for their use in device fabrication.

[0045] Figure 2 The X-ray diffraction pattern of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1 is shown in the figure. As can be seen from the figure, the synthesized nanosheets have obvious diffraction peaks belonging to the (002), (110), and (112) crystal planes of cadmium sulfide crystals, indicating that the synthesized nanosheets are composed of cadmium sulfide crystals.

[0046] Figure 3 The image shows an atomic force microscope (AFM) image of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1. As can be seen from the image, the synthesized chiral cadmium sulfide nanosheets have a thickness of 15.5 nm, demonstrating their two-dimensional structure.

[0047] Figure 4 The image shows a circular dichroism chromatogram of the chiral two-dimensional cadmium sulfide nanosheets prepared in Example 1. As can be seen from the image, the chiral cadmium sulfide exhibits a clear circular dichroism signal, demonstrating its optical activity.

[0048] Figure 5 The figure shows the current-voltage curve of the circularly polarized light detection device prepared in Example 2 in a dark environment. As can be seen from the figure, the chiral cadmium sulfide nanosheets are insulating in the dark and generate virtually no current.

[0049] Figure 6 The image shows the current-voltage curve of the circularly polarized light detection device prepared in Example 2 under illumination. Under illumination, the chiral cadmium sulfide nanosheets become conductive, and the current gradually increases with increasing voltage. Figure 5 of Figure 6 The comparison demonstrates the photoresponse characteristics of devices fabricated using chiral cadmium sulfide.

[0050] Figure 7 The figure shows the optical switching characteristic curve of the circularly polarized light detection device prepared in Example 2 under right-hand circularly polarized light irradiation. As can be seen from the figure, the current changes instantaneously with the presence or absence of light (10s of illumination, 10s of de-illumination). Current is generated when there is light and no current is generated when there is no light, which shows the excellent optical switching characteristics of the device. Furthermore, the current value is approximately 10nA under right-hand circularly polarized light irradiation.

[0051] Figure 8 The figure shows the optical switching characteristic curve of the circularly polarized light detection device prepared in Example 2 under left-handed circularly polarized light illumination. As can be seen from the figure, with the illumination on and off (10s illumination, 10s off), the response current value of the device under left-handed light illumination is about 10.5nA, which is significantly greater than the response current under right-handed light illumination, indicating that the device has sensitive circularly polarized light detection capability.

Claims

1. A method for preparing chiral two-dimensional cadmium sulfide nanosheets, characterized in that It is carried out in the following steps: The first open reaction container and the second open reaction container are placed in a sealed container with a temperature of 3-5℃, cadmium acetate solution is added to the first open reaction container, then the levorotatory ibuprofen / chloroform solution is added dropwise on the surface of the cadmium acetate solution, the first open reaction container is kept still after the chloroform is completely volatilized, sodium sulfide aqueous solution is added to the second open reaction container, then hydrochloric acid solution is added dropwise on the surface of the sodium sulfide aqueous solution, and the sealed container is sealed and kept still, and the chiral two-dimensional cadmium sulfide nanosheet is obtained at the air-liquid interface of the first open reaction container after keeping still; The molar ratio of cadmium acetate in the cadmium acetate solution to ibuprofen in the levo-ibuprofen / chloroform solution is 1:(1.1×10⁻⁶). -6 ~1.3×10 -6 The molar ratio of levoprofen to the surface area of ​​the liquid interface in the levoprofen / chloroform solution is (0.7~0.75) nmol:1cm. 2 The molar ratio of sodium sulfide in the sodium sulfide aqueous solution to hydrochloric acid in the hydrochloric acid solution is 1:(2~3); the molar ratio of sodium sulfide in the sodium sulfide aqueous solution to the volume ratio of the sealed container is (1.9~2.1) nmol:1cm³. 3 .

2. The method of claim 1, wherein the method is characterized by The levorotatory ibuprofen / chloroform solution is added dropwise on the surface of the cadmium acetate solution at a dropwise adding speed of 0.5-1 µL / s.

3. The method of claim 1, wherein the method is characterized by The hydrochloric acid solution is added dropwise on the surface of the sodium sulfide solution at a dropwise adding speed of 40-50 µL / s.

4. The method of claim 1, wherein the method is characterized by The keeping still is specifically keeping still at a temperature of 3-5℃ for 0.5-2h.

5. The method of claim 1, wherein the method is characterized by The concentration of cadmium acetate in the cadmium acetate solution is 190-210 mmol / L, and the temperature of the cadmium acetate solution is 3-5℃.

6. The method of claim 1, wherein the method is characterized by The concentration of levorotatory ibuprofen in the levorotatory ibuprofen / chloroform solution is 1.6-1.9 mmol / L, and the temperature of the levorotatory ibuprofen / chloroform solution is room temperature.

7. The method of claim 1, wherein the method is characterized by The concentration of sodium sulfide in the sodium sulfide aqueous solution is 190-210 mmol / L, and the temperature of the sodium sulfide aqueous solution is room temperature.

8. The method for preparing chiral two-dimensional cadmium sulfide nanosheets according to claim 1, characterized in that... The concentration of the hydrochloric acid solution is 190-210 mmol / L, and the temperature of the hydrochloric acid solution is room temperature.

9. The method of claim 1, wherein the method is characterized by The volume of the closed container is 2.2L~2.8L; the open area of the first open reaction container and the second open reaction container is 4.8cm 2 ~5cm 2 , and the volume is 20mL~22mL.

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