碳量子点的制备及其上转换性能

Preparation of CQDs and its up conversion ability

以抗坏血酸为碳源,聚乙二醇为表面钝化剂,采用微波消解法一步制备出碳量子点(CQDs)。以X射线衍射仪、傅里叶红外光谱仪、荧光/磷光发光光谱仪和透射电子显微镜等对制备的样品进行表征,考察了合成时间、pH和质量浓度对上转换性能的影响。结果表明,CQDs含有大量的羧基和羟基,亲水性好,在水中具有良好的分散性,粒径尺寸在2nm左右。在合成时间2min、pH 5、质量浓度1mg/mL条件下,CQDs具有最佳的上转换性能。

Carbon quantum dots（CQDs）were prepared by microwave digestion using ascorbic acid as the carbon source and polyethylene glycol as the surface passivator.The samples were characterized by X ray diffraction（XRD）, Fourier transform infrared spectroscopy（FT-IR）,fluorescence/phosphorescence spectrometer（PL）and transmission electron microscopy（TEM）.The effects of preparing time,pH and concentration on upconversion performance of CQDs were evaluated.The results showed that CQDs had a great hydrophilicity due to containing large amounts of carboxyl and hydroxyl groups,and a good dispersion ability in water.The particle size of CQDs was about 2 nm.CQDs had the best up conversion properties at the conditions of 2 min preparing time,pH 5 and CQDs concentration of 1 mg/mL.