Methods for synthesizing fluorescent CQDs and nitrogen-phosphorus co-doped fluorescent CQDs and application thereof
View Patent ↗A method for synthesizing fluorescent carbon quantum dots (CQDs) and nitrogen-phosphorus co-doped fluorescent CQDs and applications are provided. Firstly, a mixture of leaf powder and deionized water is subjected to hydrothermal reaction at 200-240° C. to obtain a product A, followed by removing by-products in it and drying to obtain fluorescent CQDs; nitrogen-phosphorus co-doped fluorescent CQDs are obtained by replacing the product A with a product B and treating the product B in a same way as the product A, where product B is obtained as follows: a mixed system of leaf powder, urea phosphate and deionized water is subjected to hydrothermal reaction at 200-240° C. with a mass ratio of urea phosphate to leaf powder as less than or equal to 0.2 to obtain the product B.
1 . A method for synthesizing fluorescent carbon quantum dots (CQDs), comprising:
S1, performing hydrothermal reaction on a mixture containing leaf powder, urea phosphate and deionized water at a temperature in a range of 200-240 degrees Celsius (° C.) to obtain a product, wherein a mass ratio of the urea phosphate to the leaf powder of less than or equal to 0.2; and
S2, removing by-products in the product by filtering the product with an organic filter membrane and an aqueous filter membrane for several times, followed by collecting filtered filtrate, and freeze-drying the filtrate to obtain the fluorescent CQDs,
wherein the fluorescent CQDs are nitrogen-phosphorus co-doped.
2 . The method for synthesizing fluorescent CQDs according to claim 1 , wherein in S1, the mixture is heated from room temperature to the temperature in the range of 200-240° C. at a heating rate in a range of 5-10° C. per minute (° C./min).
3 . The method for synthesizing fluorescent CQDs according to claim 1 , wherein in S1, the mixture is subjected to the hydrothermal reaction at the temperature in the range of 200-240° C. for a duration in a range of 5-6 hours (h) to obtain the product.