微波法制备荧光碳点及其荧光性质研究

Microwave-assisted Preparation and Fluorescence Properties of Fluorescent Carbon Dots

本文采用微波辅助法制备荧光碳点,分别以尿素、三羟甲基氨基甲烷、柠檬酸、尿素与柠檬酸混合物为碳源,聚乙二醇(分子量400)作稳定剂,以不同的碳源浓度和微波加热时间,制备了一系列荧光碳材料。利用透射电子显微镜(TEM)、紫外可见光谱与荧光光谱对制备的碳纳米粒子的形貌、尺寸、结构和荧光性能进行了表征。结果表明,以尿素与柠檬酸混合物为碳源制得的碳点单分散性良好,并具有良好的抗盐能力,其平均粒径在2.2 nm左右,在380 nm激发下获得最大荧光强度。

A series of fluorescent carbon dots （CDs） were prepared using microwave-assisted method with urea, tri（hydroxythyl） metylaminomethane, citric acid, the mixture of urea and citric acid as carbon source and ployethylene glycol （molecular weight 400） as the reaction medium, respectively, controlling the microwave heating time and the concentration of each carbon source. The morphology, size, structure and fluorescence properties of the as-prepared CDs were charaterized by TEM, UV-vis spectroscopy and fluorescence spectroscopy, respectively. The results show that the CDs prepared from the mixture of urea and citric acid by microwave-assisted method were well dispersed with an average diameter about 2.2 nm, and had a maximum fluoresence intensity upon a 380 nm excitation.