Synthesis of Nanocellulose‐Based Nitrogen‐Doped Carbon Quantum Dots with High Fluorescence Quantum Yields for Multifunctional Applications

Abstract

AbstractCarbon quantum dots (CQDs) are one of the most promising luminescent nanomaterials for anti‐counterfeiting due to their excellent optical properties, low toxicity, and environmental friendliness. With the development of green chemistry, biomass carbon sources have attracted attention. Herein, nitrogen‐doped carbon quantum dots (N‐CQDs) are synthesized using waste corn bract nanocellulose as the carbon source and L‐histidine as the nitrogen source in a simple and quick one‐step microwave method. It is found that a raw material mass ratio of 1:4, a temperature of 100 °C, and a preparation time of 5 min are the optimum preparation conditions. The fluorescence quantum yield of N‐CQDs obtained under these conditions is 32.64%. Under the excitation of light at a wavelength of 365 nm, the emission peak of N‐CQDs is located at 430 nm and emits blue light. This study also provides a method to prepare fluorescent anti‐counterfeiting films with excellent performance and fluorescent detection probes solely from waste biomass corn bract leaves and L‐histidine.