石墨相氮化碳量子点的简易水热制备和荧光性能

A Facile Hydrothermal Synthesis and Fluorescent Property of Graphitic Carbon Nitride Quantum Dots

本文以线状石墨相氮化碳(Lg-CN)为原料,在无需强酸加入的情况下,利用简单的纯水中的水热反应成功制得了氮化碳量子点(CN QDs),并利用傅里叶变换红外光谱、X射线粉末衍射、透射电镜、X射线光电子能谱等对所得量子点的形貌和结构进行了表征,进而解释了量子点的形成机理;利用紫外-可见吸收光谱和荧光光谱对其光学性质进行了研究。结果发现,所制备的CN QDs具有良好的光学性能,其荧光光谱不仅与激发波长有关,荧光发射位置和强度还受溶液pH的影响,在pH为7时,荧光强度最大。此外,Fe^(3+)对CN QDs的荧光具有良好的猝灭效果,可用于Fe^(3+)的选择性测定。该工作为CN QDs的制备提供了一种新的方法,既可避免繁琐的操作,也可避免强酸等的使用带来的危害。

In this paper,carbon nitride quantum dots(CN QDs)was successfully prepared by a facile hydrothermal reaction in pure water by using linear graphitic carbon nitride(Lg-CN)as starting material,without the existence of strong acid.The CN QDs were characterized by FT-IR,XRD,TEM,XPS,and its optical properties were determined by UV-Vis absorption and fluorescence spectra.In addition,the formation mechanism of CN QDs was elucidated.The results showed that in accordance with previous reports,on one side,the fluorescence of CN QDs is related to the excitation wavelength.On the other side,the fluorescent intensity and emission wavelength of CN QDs are influenced by the pH of CN QDs aqueous solution.Under pH 7,a maximum intensity was achieved.In addition,the fluorescence of CN QDs can be significantly quenched by Fe^(3+).So it can be used for selective determination of Fe^(3+).This new method for the synthesis of CN QDs provided in this manuscript can avoid both the tedious operations and the hazards caused by using of strong acids.