溶剂热插层法制备荧光石墨相氮化碳量子点及其在Fe3+检测中的应用

利用溶剂热法, 基于氢氧化钾的插层作用制备了荧光氮化碳量子点(g-C₃N₄ QDs). 所获得的氮化碳量子点具有良好的水溶性和荧光稳定性. 透射电子显微镜(TEM)照片显示, 氮化碳量子点的粒径约为2.3 nm; X射线光电子能谱(XPS)和红外光谱(FTIR)结果表明, 氮化碳量子点表面存在大量的亲水基团; 荧光发射光谱(PL)结果表明, 氮化碳量子点具有激发波长依赖性. 基于三价铁离子(Fe³⁺)对荧光氮化碳量子点荧光的猝灭现象, 构建了一种用于检测Fe³⁺的荧光传感器, 在Fe³⁺浓度为5~100 μmol/L范围内, 检测体系表现出良好的线性关系, 检出限约为0.5 μmol/L, 实现了对Fe³⁺的高效、 灵敏、 选择性检测.

Synthesis of Fluorescent Graphitic Carbon Nitride Quantum Dots by Solvothermal Ions Intercalation Method for Fe(Ⅲ) Detection†

As a new kind of two dimensional nanomaterials, graphitic carbon nitride( g-C3 N4 ) has extensively attracted interests due to the similar performance with grapheme. A solvothermal method of preparing fluorescent graphitic carbon nitride quantum dots ( g-C3N4QDs) in the presence of KOH intercalation was developed in this paper. The obtained g-C3 N4 QDs exhibited excellent water dispersity and fluorescence stabili-ty. Transmission electron microscopy(TEM) image showed the diameter of g-C3N4QDs was about 2. 3 nm. There were large amounts of hydrophilic groups on the surface of g-C3 N4 QDs exhibited by X-ray photoelectron spectroscopy(XPS) and Fourier transform infrared(FTIR) spectrum analysis. Excitation-dependent photolumi-nescence behavior was observed by photoluminescence( PL) spectra. Owing to the phenomenon in which Fe3+ions has great influence on the fluorescence quenching of g-C3N4 QDs, we proposed one fluorescent sensor for the detection of Fe3+ions, and the detection system exhibited excellent liner relationship with the concentration of 5—100 μmol/L Fe3+ ions, the detection limit for Fe3+ ions was about 0. 5 μmol/L, making a highly effi-cient and sensitive selection for Fe3+ ions.