Mn∶ZnS胶体纳米晶的结构及光谱性质研究

Structural and spectroscopy properties of colloidal Mn∶ZnS nanocrystals

利用一种绿色的合成工艺,采用巯基乙酸作为配体,在水溶液中成功合成了水溶性的Mn∶ZnS纳米晶,并研究了掺杂浓度对Mn∶ZnS纳米晶的结构及光谱性质的影响。XRD结果表明,合成的Mn∶ZnS纳米晶呈立方闪锌矿结构,通过谢乐公式估算的样品的平均晶粒尺寸约为2.1nm;随着掺杂浓度的增加,产物的晶胞参数逐渐减小,表明Mn离子已经掺入到ZnS纳米晶中,该发现与EDX结果相吻合。FT-IR光谱发现,配体巯基乙酸成功包覆在纳米晶的表面。Raman图谱进一步证实,Mn∶ZnS纳米晶为立方闪锌矿结构。UV-Vis吸收谱表明,不同掺杂浓度Mn∶ZnS纳米晶的吸收峰均随粒径的减小向短波长方向移动,通过吸收峰计算的纳米晶平均粒径为2.3nm。

Water-soluble Mn∶ZnS nanocrystals were successfully synthesized in aqueous solution by agreen synthetic route,using mercaptoacetic acid as the ligand,and the doping concentration was tested to explore the effects on structure and optical properties of Mn∶ZnS nanocrystals.XRD results show that the obtained Mn∶ZnS nanocrystals possess cubic sphalerite structure of ZnS phase and their average grain size was about 2.1nm estimated from Scherrer's formula.With the increase of doping concentration,the lattice parameters of the products gradually decrease,which show that Mn ions have been incorporated to the host of ZnS nanocrystals,which was consistent with the EDX results.FT-IR infrared spectrum demonstrates that thioglycolic acid ligand was successfully coated onto the surface of the nanocrystals.Raman spectrum results further confirm that Mn∶ZnS nanocrystals have the cubic structure.UV-Vis absorption spectra show that the absorption peaks of Mn∶ZnS nanocrystals shift to the short-wave direction with the increase of doping concentrations,indicating the decrease of the particle sizes,the average particle size was 2.3nm with the empirical formula calculation based on the UV-Vis absorption spectroscopy results.