CN105969342A - Method for preparing multicolor and luminous rare earth complex functionalized nano carbon dots - Google Patents

Abstract

The invention discloses a preparation method of rare earth complex-functionalized luminescent carbon dots, which mainly includes the following steps: firstly, nano-carbon dots are synthesized with lysine and deionized water, and then mixed with the synthesized rare earth binary complexes in After reflux reaction in ethanol for several hours, the obtained solution is rotary evaporated and washed to prepare a series of polychromatic luminous rare earth complex functionalized nano-carbon dots. The method of synthesizing pure carbon dots in the present invention is simple, and the rare earth complexes are grafted onto the carbon dots through covalent bonds, and the obtained carbon dots functionalized by the rare earth complexes emit visible light and near-infrared light under the excitation of visible light (the luminous range covers 400 ‑1700 nm), which has potential applications in bioluminescent imaging, laser, optical communication, and organic light-emitting diodes.

Description

Preparation method of multicolor luminescent rare earth complex functionalized nano-carbon dots

technical field

The invention belongs to the technical field of preparation of luminescent nanocomposite materials, and in particular relates to a preparation method of a kind of multicolor luminescent rare earth complex functionalized luminescent carbon dots.

Background technique

Rare earth luminescent materials have been widely used in lighting, display, laser, medicine and other aspects. Because of the special electronic layer structure, rare earth elements have spectral properties that are incomparable to ordinary metals, but the fluorescence of direct excitation of rare earth ions is very weak, which limits their practical applications. However, organic ligands have strong absorption in the ultraviolet-visible region. If rare earth ions are coordinated with ligands to obtain rare earth organic complexes, and the rare earth complexes are compounded in a stable matrix, rare earth host-guest composite materials can be prepared. This not only ensures the thermodynamic stability and luminous efficiency of the rare earth complex, but also overcomes the shortcomings of poor thermal stability and mechanical stability of the organic ligand.

Carbon dots refer to a new type of carbon nanomaterial with a size of less than 10nm, quasi-spherical structure, and stable luminescence. It has the advantages of luminescence dependent on size and excitation wavelength, soluble in water, simple to synthesize, and non-toxic. Under the excitation of visible light, it can emit blue-green light, and the surface of the material often has rich functional groups, such as carboxyl, amino, etc., which can be selectively modified with organic groups. Based on the above advantages, carbon dots have become one of the research hotspots in recent years, and have a wide range of applications in fluorescence sensing and organic photovoltaic devices. The excitation wavelengths of carbon dots and rare earth complexes are both in the ultraviolet and visible light regions, and functional groups such as carboxyl groups on the surface of carbon dots can coordinate with rare earth complexes, but there are few studies on the application of carbon dots to rare earth luminescence. If the characteristic luminescence of rare earth ions is combined with the excellent properties of carbon dots such as water solubility and excitation wavelength dependence, a new type of luminescent carbon dot nanomaterial functionalized with rare earth complexes is prepared, which is expected to be used in biological imaging, laser, optical, etc. Communication and organic light-emitting diodes have potential application prospects.

Contents of the invention

In view of the above problems, one of the objects of the present invention is to provide a kind of polychromatic light-emitting rare earth complex functionalized nano-carbon dots.

The second object of the present invention is to provide a method for preparing the polychromatic light-emitting rare earth complex functionalized nano-carbon dots.

In order to achieve the above object, the present invention provides a method for preparing polychromatic luminescent rare earth complex functionalized nano-carbon dots, which is characterized in that the following preparation steps are included:

(a) Add lysine and deionized water into the beaker at a mass ratio of 1: 8~11, stir well to dissolve completely, and form the first dispersion;

(b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.), freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours to obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs;

(c) Combine the above carbon dots with the rare earth binary complex Ln(tta) ₃ (H ₂ O) ₂ (Ln rare earth metal is any one of Eu europium, Sm samarium, Yb ytterbium, Nd neodymium, Er erbium) or Ln(tfacac) ₃ (H ₂ O) ₂ (Ln rare earth metal is Tb terbium) is added to ethanol at a mass ratio of 1: 4-7, heated and refluxed for 5 hours, and after washing, a multi-colored and luminous rare earth complex is obtained Functionalized nano-carbon dots; tta used is thienoyltrifluoroacetone, and tfacac is 1,1,1-trifluoro-2,4-pentanedione.

Beneficial effects of the present invention:

The present invention functionalizes rare earth complexes on carbon dots through covalent bonds, and obtains rare earth luminescent nano-carbon dots that emit visible and near-infrared light under the excitation of visible light, so that the material has the luminescence of rare earth complexes and nano-carbon dots at the same time characteristic. It has potential practical prospects in biological imaging, laser, optical communication and organic light-emitting diodes.

Description of drawings

Fig. 1 is a transmission electron micrograph of the europium complex-functionalized luminescent nano-carbon dots prepared in Example 1 of the present invention.

Fig. 2 is an emission spectrum diagram of the europium complex functionalized luminescent nano-carbon dots prepared in Example 1 of the present invention.

detailed description

The present invention will be further described in the following examples, but the present invention is not limited thereto.

Example 1 :

This embodiment provides a method for preparing luminescent nano-carbon dots functionalized with europium complexes, which includes the following steps:

(a) 2.33g of lysine is dissolved in a beaker with 25ml of deionized water, fully stirred to make it completely dissolved, forming the first dispersion;

(b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant, and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.); freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours and obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs;

(c) Add 0.82g of rare earth binary complex Eu(tta) ₃ (H ₂ O) ₂ and 0.11~0.27g of carbon dots to 20ml of ethanol, heat to reflux for 5 hours, remove the ethanol solvent by rotary evaporation after cooling, wash and dry The solid obtained after drying is the luminescent nano-carbon dot functionalized by the europium complex.

Example 2 :

The preparation method of a samarium complex-functionalized luminescent nano-carbon dot provided in this example has the same basic steps as in Example 1, except that the following specific steps are different:

(a) 2.33g of lysine is dissolved in a beaker with 25ml of deionized water, fully stirred to make it completely dissolved, forming the first dispersion;

(b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant, and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.); freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours and obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs;

(c) Add 0.72g of rare earth binary complex Sm(tta) ₃ (H ₂ O) ₂ and 0.22g of carbon dots to 20ml of ethanol, heat to reflux for 5 hours, remove the ethanol solvent by rotary evaporation after cooling, wash and dry The obtained solid is the luminescent nano-carbon dot functionalized by the samarium complex.

Example 3 :

A method for preparing luminescent nano-carbon dots functionalized by ytterbium complexes provided in this example has the same basic steps as in Example 1, except that the following specific steps are different:

(a) 2.33g of lysine is dissolved in a beaker with 25ml of deionized water, fully stirred to make it completely dissolved, forming the first dispersion;

(b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant, and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.); freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours and obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs;

(c) Add 0.85g of rare earth binary complex Yb(tta) ₃ (H ₂ O) ₂ and 0.22g of carbon dots to 20ml of ethanol, heat to reflux for 5 hours, and remove the ethanol solvent by rotary evaporation after cooling, wash and dry The obtained solid is the luminescent nano-carbon dot functionalized by the ytterbium complex.

Example 4 :

The preparation method of a neodymium complex-functionalized luminescent nano-carbon dot provided in this example has the same basic steps as in Example 1, except that the following specific steps are different:

(a) 2.33g of lysine is dissolved in a beaker with 25ml of deionized water, fully stirred to make it completely dissolved, forming the first dispersion;

(b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant, and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.); freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours and obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs;

(c) Add 0.77g of rare earth binary complex Nd(tta) ₃ (H ₂ O) ₂ and 0.22g of carbon dots to 20ml of ethanol, heat to reflux for 5 hours, and remove the ethanol solvent by rotary evaporation after cooling, wash and dry The obtained solid is the neodymium complex-functionalized luminescent nano-carbon dot.

Example 5 :

A method for preparing erbium complex-functionalized luminescent nano-carbon dots provided in this example has the same basic steps as in Example 1, except that the following specific steps are different:

(a) 2.33g of lysine is dissolved in a beaker with 25ml of deionized water, fully stirred to make it completely dissolved, forming the first dispersion;

(b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant, and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.); freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours and obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs;

(c) Add 0.85g of rare earth binary complex Er(tta) ₃ (H ₂ O) ₂ and 0.22g of carbon dots to 20ml of ethanol, heat to reflux for 5 hours, and remove the ethanol solvent by rotary evaporation after cooling, wash and dry The obtained solid is the luminescent nano-carbon point functionalized by the erbium complex.

Example 6 :

This example provides a method for preparing terbium complex-functionalized luminescent carbon dots, the basic steps of which are similar to Example 1, except that the following specific steps are different:

(a) 2.33g of lysine is dissolved in a beaker with 25ml of deionized water, fully stirred to make it completely dissolved, forming the first dispersion;

(b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant, and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.); freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours and obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs;

(c) Add 0.82g of rare earth binary complex Tb(tfacac) ₃ (H ₂ O) ₂ and 0.22g of carbon dots to 20ml of ethanol, heat to reflux for 5 hours, remove the ethanol solvent by rotary evaporation after cooling, wash and dry The obtained solid is the luminescent carbon dot functionalized by the terbium complex.

It can be seen from Figure 1 and Figure 2 that:

Figure 1 is a transmission electron microscope image of the luminescent nano-carbon dots functionalized with europium complexes prepared in Example 1 of the present invention. It can be seen that the carbon dots functionalized with rare earth complexes have uniform size and good dispersion.

Fig. 2 is the emission spectrogram of the luminescent nano-carbon dots functionalized with europium complexes prepared in Example 1 of the present invention, and 405nm visible light is selected as the excitation wavelength to obtain the visible light emission of the nanomaterial at 425-800nm, wherein the 420-570nm The broadband emission comes from the carbon dots, with the strongest emission at 613 nm from the luminescence of europium ions.

The invention uses nanometer carbon dots as a substrate, and functionalizes rare earth complexes on the carbon dots through covalent bonds, thereby preparing a new class of nanometer carbon dot composite luminescent materials functionalized by rare earth complexes. The obtained nano-carbon dots functionalized with rare earth complexes have good fluorescence properties, multicolor luminescence and thermal stability, and maintain the morphology and luminescence characteristics of carbon dots. On the one hand, it has potential application value, and it is expected to promote the research of rare earth resources in the high-tech field in my country.

Claims (1)

1. The preparation method of the functionalized nano-carbon point of the rare earth complex of polychromatic light, it is characterized in that, this method has following preparation process steps: (a) Add lysine and deionized water into the beaker at a mass ratio of 1: 8~11, stir well to dissolve completely, and form the first dispersion; (b) Pour the first dispersion liquid into the reaction kettle, heat at 180-210°C for 4-5 hours, then centrifuge the obtained product at 8000-11000 rpm for 10 minutes, take the supernatant and put it into a freeze dryer ( The model is Scientz-N type, produced by Ningbo Xinzhi Biotechnology Co., Ltd.); freeze-drying at a vacuum of 10Pa and -50°C to remove the solvent for 48 hours and obtain a light yellow solid, that is, carbon dot nanomaterials; the reaction formula is C ₆ H ₁₄ N ₂ O ₂ + H ₂ O → CDs; (c) Combine the above carbon dots with the rare earth binary complex Ln(tta) ₃ (H ₂ O) ₂ (Ln rare earth metal is any one of Eu europium, Sm samarium, Yb ytterbium, Nd neodymium, Er erbium) or Ln(tfacac) ₃ (H ₂ O) ₂ (Ln rare earth metal is Tb terbium) is added to ethanol at a mass ratio of 1: 4-7, heated and refluxed for 5 hours, and after washing, a multi-colored and luminous rare earth complex is obtained Functionalized nano-carbon dots; tta used is thienoyltrifluoroacetone, and tfacac is 1,1,1-trifluoro-2,4-pentanedione.