Method for preparing fluorescent carbon quantum dot by using ozone oxidation photo-reduction technique by taking sulfonated coal as carbon source

Abstract

The invention provides a method for preparing fluorescent carbon quantum dots by using an ozone oxidation photo-reduction technique by taking sulfonated coal as a carbon source. According to the method, sulfonated coal is taken as a carbon source, the carbon quantum dots with fluorescence properties are prepared by using the ozone oxidation-photo-reduction technique, and quantum dot powder is prepared after moisture is removed through rotary evaporation and freeze drying. By adopting the method to prepare the fluorescent carbon quantum dots, sulfonated coal as the carbon source is low in price and simple, convenient and easily available, the ozone oxidation photo-reduction technique is simple in process and short in preparation time, the rotary evaporation and freeze-drying treatment method adopted in later product treatment is simple to operate, no complex later strong acid or surface passivation treatment is needed, popularization and large-scale production can be easily achieved, and the method has good application prospect in technical fields such as the biological industry, the medical industry, the chemical sensor industry and the photocatalysis industry.

Description

technical field [0001] The invention relates to the technical field of nanomaterials, and relates to a method for preparing carbon quantum dots using an ozone oxidation-photoreduction technology, in particular to a simple and rapid preparation method for fluorescent carbon quantum dots. Background technique [0002] Carbon quantum dots are a new type of fluorescent nanomaterial with carbon as the main body. In recent years, carbon quantum dots have attracted widespread attention in the scientific community due to their excellent optical properties, chemical stability, low toxicity, biocompatibility, wide range of preparation materials, various preparation methods, and low cost. , medicine, chemical sensors, photocatalysis and other technical fields have a wide range of application prospects. [0003] The synthesis method of carbon quantum dots includes two kinds: top-down synthesis method and bottom-up synthesis method. The former uses the larger carbon skeleton as the car...

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Problems solved by technology

The top-down synthesis method also includes: laser ablation method / passivation method. This method irradiates the carbon target with a laser beam to peel off the nano-carbon particles from the carbon target to obtain carbon quantum dots. Low yield, poor particle size uniformity, and low purity; electrochemical method, the time required to prepare carbon quantum dots is long, generally 720 hours; arc discharge method, the yield of carbon quantum dots prepared by this method is low, The purification process is complicated and product collection is difficult, so this method is rarely used

The bottom-up synthesis method also includes: chemical oxidation method, which prepares carbon quantum dots by oxidizing carbon materials with oxidants. The disadvantage is that the production yield is low, and the reagents used are mostly strong acids or highly corrosive Liquid, the reaction is violent and does not meet the requirements of environmental friendliness, and is not suitable for the mass preparation of carbon quantum dots; the template method, this method first synthesizes carbon quantum dots on a suitable template, and then removes the template by acid etching and other methods, and applies the template method The prepared carbon quantum dots have more uniform particle size and higher purity, which is convenient for later surface modification, but the disadvantage is that the template needs to be etched during the synthesis process, which is costly, and the residual template prevents the carbon quantum dots from being completely processed. extraction, so its yield is relatively low; microwave-assisted method, which uses microwaves to treat carbon precursors, greatly simplifies the synthesis steps of carbon quantum dots, but the yield is low; thermal decomposition method is to decompose organic carbon sources by high temperature The method of preparing carbon quantum dots, the current research on this method is mainly focused on the selection and trial of different carbon sources, looking for cheap carbon precursors with excellent properties of the synthesized carbon quantum dots, but this method requires constant carbonization during the carbonization process. Adding water, the operation is more cumbersome; the reverse micellar method is a brand-new preparation method for preparing carbon quantum dots, and the carbon quantum dots prepared by this method show great advantages in terms of yield and particle size uniformity , but the reaction conditions of this method are relatively harsh, and argon is expensive, so this method cannot be widely used

[0004] The above-mentioned synthetic carbon quantum dots are cumbersome, expensive raw materials and harsh conditions, not only uneconomical and environmentally friendly, but also due to high synthesis costs, to a large extent limit the large-scale production and practical application of fluorescent carbon quantum dots

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