物理化学学报2018，Vol.34Issue(1)：92-98,7.DOI:10.3866/PKU.WHXB201706221
微波法制备纳米碳点反应机制与发光机理
Reaction Process and Luminescence Mechanism of Carbon Nanodots Prepared by Microwave Synthesis
摘要
Abstract
In order to explore their luminescence properties, a series of carbon nanodots were prepared by microwave heating by controlling the microwave power, reaction time, and pH value. The luminescence properties of carbon nanodots were characterized by their fluorescence excitation spectrum and emission spectrum. We present the transformation mechanism of glucose into carbon nanodots during the microwave heating process and the corresponding luminescence mechanism together with the analysis of functional group changes during the reaction as monitored with ultraviolet (UV) absorption and Fourier Transform Infrared (FT-IR) spectra. The results show that the optimal luminescence properties of carbon nanodots were obtained when the glucose was heated under a microwave heating power of 560 W for 2.5 min. When the carbon nanodots were excited with UV radiation with a wavelength of 370 nm, the strongest luminescence appeared at 451 nm. The wavelength of the strongest luminescence peak moved from 350 nm to higher wavelengths significantly, when the pH value was modified from acidic to alkaline, and was accompanied with a significant rise in luminescence peak intensity. We show that polycyclic aromatic hydrocarbons form in the reaction process,as evidenced by UV absorption and FTIR monitoring, indicating that microwave synthesis of carbon nanodots proceeds via polymerization and final carbonization of glucose. Carbon nanodots formed under different pH values exhibit a change in the ratio of carbon-to-carbon double bonds to carbon-to- oxygen double bonds. The optical bandgap and exciton binding energy of the carbon nanodots were also investigated co mprehensively.关键词
纳米碳点/荧光发光/葡萄糖/微波合成/碳化反应/光学带隙Key words
Nano carbon dots/Luminescence/Glucose/Microwave synthesis/Carbonation reaction/Optical bandgap分类
化学化工引用本文复制引用
刘金龙,林亮珍,胡锦凤,白明洁,陈良贤,魏俊俊,黑立富,李成明..微波法制备纳米碳点反应机制与发光机理[J].物理化学学报,2018,34(1):92-98,7.基金项目
The project was supported by the National Natural Science Foundation of China (51402013).国家自然科学基金(51402013)资助项目 （51402013）
