土豆基碳量子点的制备、Mn掺杂及在Ag+检测中的应用

以土豆为碳源采用水热法合成了发光碳量子点(CQDs),向体系中加入碳酸锰,合成了锰掺杂的CQDs(Mn-CQDs)。用透射电镜、X射线衍射仪、X射线光电子能谱、紫外-可见吸收光谱、荧光光谱、红外光谱等对样品进行了表征。结果表明:CQDs和Mn-CQDs为球状,平均粒径3~5 nm;Mn掺杂增强了CQDs的荧光强度及稳定性;CQDs和Mn-CQDs最大激发波长分别为435 nm、395 nm,对应的发射波长分别为525 nm、465 nm。将CQDs、Mn-CQDs用于金属离子检测,它们都对Ag⁺具有很好的选择性,对Ag⁺的检测限分别为0.064 μmol/L、0.027 μmol/L,表明CQDs、Mn-CQDs可应用于水介质中Ag⁺的痕量检测,Mn-CQDs具有更高的灵敏度。

Synthesis of Potato-Based Carbon Quantum Dots,Mn Doping and Their Application in Ag+ Detection

In this study, carbon quantum dots (CQDs) were prepared using potato as carbon source via hydrothermal method, and then Mn-doped CQDs (Mn-CQDs) were prepared by the addition of manganese carbonate as dopant in the reaction system. CQDs and Mn-CQDs were characterized by transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis absorption spectroscopy, photoluminescence (PL) spectroscopy, and infrared spectrometer. The results show that CQDs and Mn-CQDs are spherical with an average particle size of 3 nm to 5 nm. Mn doping enhanced the intensity and stability of photoluminescence of CQDs. The maximum excitation wavelengths of CQDs and Mn-CQDs are 435 nm and 395 nm, and the corresponding emission wavelengths are 525 nm and 465 nm, respectively. In the application of the detection of metal ions, both CQDs and Mn-CQDs exhibit good selectivity to Ag⁺, and the low detection limits of CQDs and Mn-CQDs to Ag⁺ are 0.064 μmol/L and 0.027 μmol/L, respectively, indicating the relatively high sensitivity of Mn-CQDs in the trace detection of Ag⁺compared to CQDs.