Preparation method and application of carbon nanodot film with Kerr effect

Abstract

The invention relates to the technical field of preparation of carbon nanodot films, in particular to a preparation method and application of a carbon nanodot film with a Kerr effect, and the preparation method comprises the following steps: preparing an MOFs film by a liquid phase epitaxy method; the obtained MOFs thin film is soaked in a phenylenediamine precursor solution; and placing the soaked film under a laser for irradiation to prepare the carbon nanodot film. According to the method, the MOFs film is prepared through a liquid phase epitaxy method, a phenylenediamine precursor is embedded into MOFs pore channels through a soaking method, irradiation is conducted under laser through a post-treatment loading method, the precursor is made to synthesize the carbon nanodots in the MOFs pore channels in a confinement mode, and therefore the carbon nanodot film with the Kerr effect is obtained. The carbon nanodots are high in loading efficiency, uniform in dispersion, short in preparation time and simple to operate, and compared with a traditional optical reaction system, the thin film system has an unexpected optical Kerr effect and a two-photon absorption effect and shows a great nonlinear absorption coefficient, and the performance of the thin film system is far superior to that of a carbon nanodot solution.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing carbon nanodot films, and specifically relates to a preparation method and application of a carbon nanodot film with Kerr effect. Background Art

[0002] Carbon nanodots are generally defined as small carbon nanoparticles with various surface groups. They have attracted much attention due to their wide applications in fields such as catalysis, fluorescence, bioimaging, and drug delivery. As a new type of zero-dimensional carbon nanomaterial, carbon nanodots not only retain the inherent advantages of carbon nanomaterials but also possess unique electronic and optical properties of semiconductor quantum dots, greatly expanding their application potential in the field of nonlinear optical research. Their excellent optical properties, chemical stability, good biocompatibility, low toxicity, and low cost have promoted the trend of carbon nanodots gradually replacing semiconductor quantum dots. In recent years, research in the field of nonlinear optics has shown that semiconductor materials can exhibit various nonlinear optical responses such as Kerr refraction and two-photon absorption, and these properties have wide applications in fields such as optical switches, optical communications, and optical limiters.

[0003] However, carbon nanodots mainly exist as powder materials, and their applications in the optical field are severely restricted by the traditional optical reaction system. Therefore, it is necessary to develop a new optical state system to improve their applications in the optical field. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of a carbon nanodot film with Kerr effect.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] The present invention proposes a preparation method of a carbon nanodot film, including the following steps:

[0007] S1, preparing a MOFs film by liquid phase epitaxy method;

[0008] S2, immersing the obtained MOFs film in a phenylenediamine precursor solution;

[0009] S3, irradiating the immersed film under a laser to obtain a carbon nanodot film.

[0010] Further, the phenylenediamine precursor in step S2 is one or more of o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine.

[0011] Further, the wavelength used for irradiation under the laser in step S3 is one of nanosecond laser wavelength, femtosecond laser wavelength, and picosecond laser wavelength.

[0012] Further, the MOFs thin film described in step S1 is a porous thin film material with a spatial structure formed by coordinating metal ions as the coordination center with organic ligands.

[0013] Further, the MOFs thin film is HKUST-1.

[0014] Further, the MOFs thin film is ZIF-8.

[0015] Further, the MOFs thin film is MOF-2.

[0016] The present invention also includes an application of a carbon nanodot thin film prepared by any of the above preparation methods in the preparation of a nonlinear optical device.

[0017] Compared with the prior art, the present invention prepares the MOFs thin film by liquid phase epitaxy method, embeds the phenylenediamine precursor into the MOFs pore channels by the immersion method, and irradiates under laser by the post-treatment loading method to confine the synthesis of carbon nanodots in the MOFs pore channels, so as to obtain a carbon nanodot thin film with Kerr effect. The carbon nanodot thin film prepared by this method has high carbon nanodot loading efficiency, uniform dispersion, short preparation time and simple operation. Compared with the traditional optical reaction system, this thin film system has unexpected optical Kerr effect and two-photon absorption effect, shows a great nonlinear absorption coefficient, and its performance is far superior to that of the carbon nanodot solution.

[0018] Description of the drawings

[0019] Figure 1 It is the SEM morphology diagram of the o-CDs@HKUST-1 thin film.

[0020] Figure 2 It is the TEM morphology diagram of the carbon nanodots in the o-CDs@HKUST-1 thin film.

[0021] Figure 3 It is the particle size distribution diagram of the carbon nanodots in the o-CDs@HKUST-1 thin film.

[0022] Figure 4 It is the nonlinear absorption curve diagram of the o-CDs@HKUST-1 thin film.

[0023] Figure 5 It is the nonlinear absorption curve diagram of the HKUST-1 thin film.

[0024] Figure 6 It is the TEM morphology diagram of the carbon nanodots in the carbon nanodot ethanol solution.

[0025] Figure 7 It is the particle size distribution diagram of the carbon nanodots in the carbon nanodot ethanol solution.

[0026] Figure 8 It is a non - linear absorption curve graph of a carbon nanodot ethanol solution. Specific implementation manners

[0027] The technical solution of the present invention will be further described below in conjunction with specific embodiments. It should be understood that the following embodiments are only for illustrative explanation of the present invention and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope intended to be protected by the present invention.

[0028] Preparing MOFs thin films by liquid - phase epitaxy method is a conventional method for preparing MOFs thin films. In the following examples, HKUST - 1 is taken as an example, and other MOFs thin films such as ZIF - 8 and MOF - 2 will not be elaborated.

[0029] Example 1

[0030] (1) Preparation of HKUST - 1 thin film: Immerse the functionalized quartz glass into a beaker containing 1 mmol / L Cu(OAc)₂ ethanol solution for 15 min, and wash away the residual Cu(OAc)₂ ethanol solution on the surface with absolute ethanol; then immerse it into a beaker containing ethanol solution of trimesic acid (BTC) for 20 min; then wash away the residual BTC ethanol solution on the surface with absolute ethanol. The above process is a cycle period. After 20 cycles of immersion, a HKUST - 1 thin film with a certain thickness is obtained.

[0031] (2) Preparation of carbon nanodot thin film (o - CDs@HKUST - 1): Immerse the HKUST - 1 thin film into 1 mmol / L o - phenylenediamine ethanol solution for 5 h, and then irradiate the immersed thin film with a 532 - nm laser for 2 h to obtain the o - CDs@HKUST - 1 thin film.

[0032] The SEM morphology diagram of the o - CDs@HKUST - 1 thin film is referred to Figure 1 and the TEM morphology diagram of the loaded carbon nanodots is referred to Figure 2 and the particle size distribution of the loaded carbon nanodots is referred to Figure 3 and the non - linear absorption curve is referred to Figure 4 The non - linear absorption coefficient of the o - CDs@HKUST - 1 thin film can reach 10 -6 m / W.

[0033] Comparative Example 1

[0034] The non - linear absorption curve of the HKUST - 1 thin film prepared in Example 1 is referred to Figure 5 and it does not show non - linear absorption characteristics.

[0035] Comparative Example 2

[0036] The o-phenylenediamine ethanol solution was irradiated under a 532 nm laser for 2 h to obtain a carbon nanodot ethanol solution. Refer to the TEM morphology diagram of the carbon nanodots Figure 6 , and refer to the particle size distribution diagram Figure 7 , and refer to the nonlinear absorption curve of the carbon nanodot ethanol solution Figure 8 , and the nonlinear absorption coefficient is only about 10 -9 m / W.

[0037] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments we described are illustrative rather than used to limit the scope of the present invention. Effective modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be covered by the scope protected by the claims of the present invention.

Claims

1. A preparation method of a carbon nanodot film with Kerr effect, characterized in that: It includes the following steps: S1, preparing the MOFs thin film by liquid phase epitaxy method; S2, soaking the obtained MOFs thin film in the phenylenediamine precursor solution; S3, irradiating the soaked thin film under a laser to obtain the carbon nanodot thin film.

2. The preparation method of a carbon nanodot film according to claim 1, wherein: The phenylenediamine precursor described in step S2 is one or more of o-phenylenediamine, m-phenylenediamine, and p-phenylenediamine.

3. The preparation method of a carbon nanodot film with Kerr effect according to claim 1, characterized in that: The wavelength used for irradiation under the laser in step S3 is one of nanosecond laser wavelength, femtosecond laser wavelength, and picosecond laser wavelength.

4. The preparation method of a carbon nanodot film with Kerr effect according to claim 1, characterized in that: The MOFs thin film described in step S1 is a porous thin film material with a spatial structure formed by coordinating with an organic ligand with a metal ion as a coordination center.

5. The preparation method of a carbon nanodot film with Kerr effect according to claim 3, characterized in that: The MOFs thin film is HKUST-1.

6. The preparation method of a carbon nanodot film with Kerr effect according to claim 3, characterized in that: The MOFs thin film is ZIF-8.

7. The preparation method of a carbon nanodot film with Kerr effect according to claim 3, characterized in that: The MOFs thin film is MOF-2.

8. Application of the carbon nanodot thin film prepared by the preparation method according to any one of claims 1-7 in the preparation of non-linear optical devices.

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