一步法合成枝状NaGdF4∶Yb3+,Er3+荧光材料及碳量子点

One-step synthesis of branched NaGdF4∶Yb3+,Er3+ nanoparticles and carbon quantum dots

以稀土氯化物为前驱体、乙二醇为溶剂,采用一步水热法同时合成枝状形貌的上转换NaGdF4∶Yb^3+,Er^3+纳米粒子和球形碳量子点。利用XRD、TEM、FT-IR和荧光光谱等分析手段对制备样品的结构、形貌和性能进行分析。结果表明,采用水热法制备的溶液经离心后下层固体为具有六方相和立方相混合结构的枝状NaGdF4∶Yb^3+,Er^3+纳米粒子,该纳米粒子具有良好的荧光稳定性,其乙醇分散液放置7 d后,荧光性能未发生明显改变,仍具有良好的上转换发光性能。离心后的上层溶液在365 nm紫外光照射下发出较强的淡蓝色荧光。上层溶液干燥后所得固体经XRD及红外分析确定产物为碳量子点。TEM分析结果表明,该碳量子点的平均粒径为7.46 nm,具有良好的分散性。

Branched up-conversion NaGdF4∶Yb^3+,Er^3+ nanoparticles and sphere carbon quantum dots(CQDs)are prepared by one-step hydrothermal method with rare earth chloride and ethylene glycol as precursor and solvent separately.The structure,morphology and properties of the prepared samples are analyzed by using X-ray power diffraction spectroscopy(XRD),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FT-IR)and fluorescence spectroscopy.The results show that the solid obtained after centrifugation is just the branched NaGdF4∶Yb3+,Er3+nanoparticles with cubic and hexagonal mixed structure,which can emit the strong green light under 980 nm near-infrared motivation.The solution of the branched Na Gd F4∶Yb^3+,Er^3+ nanoparticles in ethyl alcohol has good stability,with a fluorescence performance not changing significantly after 7 days.Meanwhile,the upper solution obtained after centrifugation can emit the strong light blue emission under 365 nm ultra-violet motivation.Through detection by XRD and IR,it is indicated that the solid obtained after drying the upper solution is determined to be carbon quantum dots.TEM analysis verifies that CQDs sample shows uniform sphere and excellent dispersibility,with an average size of 7.46 nm.