Orange light emitting carbon nano dot, preparation method and applications thereof

Abstract

The invention provides an orange light emitting carbon nano dot, which comprises a nitrogen-enriched carbon based core and a cation passivation layer that wraps the surface of the nitrogen-enriched carbon based core. The provided orange light emitting carbon nano dot has a specific core-shell structure, which improves the light emitting efficiency of the orange light emitting carbon nano dot in the wave band of orange light. The provided orange light emitting carbon nano dot can be used to prepare fluorescent ink, fluorescence powder, and light emitting diode (LED) giving off white light. The fluorescent ink and fluorescence powder prepared from the orange light emitting carbon nano dot both have high fluorescence radiation quantum efficiency. The fluorescence powder can be used to prepare LED giving off white light and the LED can be applied to illumination equipment.

Description

technical field

[0001] The invention belongs to the technical field of carbon nano-dots, and in particular relates to an orange light-emitting carbon nano-dot and its preparation method and application. Background technique

[0002] Carbon nanodots (Carbondots, CDs) are a kind of carbon nanomaterials that can emit light. Compared with semiconductor quantum dots and organic dyes, they have the advantages of good fluorescence stability, no light flicker, good biocompatibility, and low toxicity. Biomolecular labeling, in vivo imaging, sensing, optoelectronics and other fields have broad application prospects.

[0003] At present, carbon nanodots have achieved high-efficiency luminescence in the blue and green light bands, and the fluorescence quantum efficiency has reached more than 50%. However, the luminous efficiency of carbon nanodots in the long wavelength band, especially the orange light band, is still very low. The main reason is the lack of effective preparation of c...

Examples

preparation example Construction

[0047] The present invention also provides a preparation method of orange light-emitting carbon nano-dots, comprising the following steps:

[0048] Dissolving urea and polycarboxylates in high-boiling organic solvents, heating and reacting under airtight conditions to obtain nitrogen-rich carbon-based cores;

[0049] The nitrogen-rich carbon-based inner core is dispersed in an alkaline solution for treatment to obtain orange light-emitting carbon nano-dots.

[0050]In the present invention, firstly, urea and polycarboxy compounds are dissolved in a high-boiling point organic solvent. In the present invention, the polycarboxy compound is preferably citric acid. The high boiling point organic solvent is preferably one or more of N, N'-dimethylformamide (DMF), N, N'-dimethylacetamide (DMAC) and dimethylsulfoxide (DMSO) kind.

[0051] Wherein, the present invention has no special limitation on the sources of the urea, the polycarboxy compound and the high-boiling point organic ...

Embodiment 1

[0088] (1) 2 g of urea and 1 g of citric acid were formulated into 10 mL of dimethylformamide (DMF) solution, placed in a polytetrafluoroethylene autoclave, and reacted at 160 ° C for 4 hours. The resulting solution was removed by rotary evaporation to remove most of the DMF, and a large amount of ethanol was added to obtain a precipitate, which was carbon nanodots with a nitrogen-rich carbon-based core and a large number of carboxyl functional groups on the surface.

[0089] (2) Dissolve the carbon nano-dots obtained in (1) in 20mL NaOH aqueous solution (50mg / mL) and stir for 1min. -1 Centrifuge at high speed for 10min. The solid obtained by centrifugation is washed with water and centrifuged (16000rmin -1 , 10 min) twice to wash off excess alkali and salt impurities, and freeze-dry at -40°C to obtain orange light-emitting carbon nanodots.

[0090] Carry out ultraviolet-visible absorption and fluorescence emission spectroscopic analysis to the carbon nano-dot prepared in emb...

Embodiment 2

[0094] (1) 4 g of urea and 1 g of citric acid were prepared into 10 mL of dimethylformamide (DMF) solution, placed in a polytetrafluoroethylene autoclave, and reacted at 160° C. for 10 hours. The resulting solution was removed by rotary evaporation to remove most of the DMF, and a large amount of ethanol was added to obtain a precipitate, which was carbon nanodots with a nitrogen-rich carbon-based core and a large number of carboxyl functional groups on the surface.

[0095] (2) Dissolve the carbon nano-dots obtained in (1) in 20mL NaOH aqueous solution (50mg / mL) and stir for 1min. -1 Centrifuge at high speed for 10min. The solid obtained by centrifugation is washed with water and centrifuged (16000rmin -1 , 10 min) twice to wash off excess alkali and salt impurities, and freeze-dry at -40°C to obtain orange light-emitting carbon nanodots.

[0096] Carry out ultraviolet-visible absorption and fluorescence emission spectroscopic analysis to the carbon nano-dot prepared in embo...

technical field

[0001] The invention belongs to the technical field of carbon nano-dots, and in particular relates to an orange light-emitting carbon nano-dot and its preparation method and application. Background technique

[0002] Carbon nanodots (Carbondots, CDs) are a kind of carbon nanomaterials that can emit light. Compared with semiconductor quantum dots and organic dyes, they have the advantages of good fluorescence stability, no light flicker, good biocompatibility, and low toxicity. Biomolecular labeling, in vivo imaging, sensing, optoelectronics and other fields have broad application prospects.

[0003] At present, carbon nanodots have achieved high-efficiency luminescence in the blue and green light bands, and the fluorescence quantum efficiency has reached more than 50%. However, the luminous efficiency of carbon nanodots in the long wavelength band, especially the orange light band, is still very low. The main reason is the lack of effective preparation of c...

Examples

preparation example Construction

[0047] The present invention also provides a preparation method of orange light-emitting carbon nano-dots, comprising the following steps:

[0048] Dissolving urea and polycarboxylates in high-boiling organic solvents, heating and reacting under airtight conditions to obtain nitrogen-rich carbon-based cores;

[0049] The nitrogen-rich carbon-based inner core is dispersed in an alkaline solution for treatment to obtain orange light-emitting carbon nano-dots.

[0050]In the present invention, firstly, urea and polycarboxy compounds are dissolved in a high-boiling point organic solvent. In the present invention, the polycarboxy compound is preferably citric acid. The high boiling point organic solvent is preferably one or more of N, N'-dimethylformamide (DMF), N, N'-dimethylacetamide (DMAC) and dimethylsulfoxide (DMSO) kind.

[0051] Wherein, the present invention has no special limitation on the sources of the urea, the polycarboxy compound and the high-boiling point organic ...

Embodiment 1

[0088] (1) 2 g of urea and 1 g of citric acid were formulated into 10 mL of dimethylformamide (DMF) solution, placed in a polytetrafluoroethylene autoclave, and reacted at 160 ° C for 4 hours. The resulting solution was removed by rotary evaporation to remove most of the DMF, and a large amount of ethanol was added to obtain a precipitate, which was carbon nanodots with a nitrogen-rich carbon-based core and a large number of carboxyl functional groups on the surface.

[0089] (2) Dissolve the carbon nano-dots obtained in (1) in 20mL NaOH aqueous solution (50mg / mL) and stir for 1min. -1 Centrifuge at high speed for 10min. The solid obtained by centrifugation is washed with water and centrifuged (16000rmin -1 , 10 min) twice to wash off excess alkali and salt impurities, and freeze-dry at -40°C to obtain orange light-emitting carbon nanodots.

[0090] Carry out ultraviolet-visible absorption and fluorescence emission spectroscopic analysis to the carbon nano-dot prepared in emb...

Embodiment 2

[0094] (1) 4 g of urea and 1 g of citric acid were prepared into 10 mL of dimethylformamide (DMF) solution, placed in a polytetrafluoroethylene autoclave, and reacted at 160° C. for 10 hours. The resulting solution was removed by rotary evaporation to remove most of the DMF, and a large amount of ethanol was added to obtain a precipitate, which was carbon nanodots with a nitrogen-rich carbon-based core and a large number of carboxyl functional groups on the surface.

[0095] (2) Dissolve the carbon nano-dots obtained in (1) in 20mL NaOH aqueous solution (50mg / mL) and stir for 1min. -1 Centrifuge at high speed for 10min. The solid obtained by centrifugation is washed with water and centrifuged (16000rmin -1 , 10 min) twice to wash off excess alkali and salt impurities, and freeze-dry at -40°C to obtain orange light-emitting carbon nanodots.

[0096] Carry out ultraviolet-visible absorption and fluorescence emission spectroscopic analysis to the carbon nano-dot prepared in embo...

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