Gheorghe Asachi Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, Iasi, 700050, Romania.
Petru Poni Institute of Macromolecular Chemistry, Department of Chemistry, Iasi, 700487, Romania.
Sci Rep. 2019 Dec 11;9(1):18893. doi: 10.1038/s41598-019-55264-x.
The preparation and investigation of Fe(III) doped carbon nanodots (CNDs) with intense green photoluminescence and emission dependence on the dispersion medium are reported. Their unusual photoluminescence is especially highlighted in water where the initial blue emission is gradually shifted to intense deep green, while in other common solvents (chloroform, acetone etc.) this behavior has not been observed. Through embedding in a polymer matrix (e.g., PVA) the color transition becomes reversible and dependent on water content, ranging from a full blue emission, when completely dried, to an intense green emission, when wetted. The preparation path of the Fe(III) doped CNDs undergoes two main stages involving the initial obtaining of Fe(III)-N-Hydroxyphthalimide complex and then a thermal processing through controlled pyrolysis. Morphostructural investigations of the prepared Fe(III) doped CNDs were performed through TG, FT-IR, XPS, DLS, TEM and AFM techniques whereas absolute PLQY, steady state and lifetime fluorescence were used to highlight their luminescence properties. The results issued from structural and fluorescence investigations bring new insights on the particular mechanisms involved in CNDs photoluminescence, a topic still open to debate.
本文报道了具有强绿色磷光发射且发射依赖于分散介质的掺铁（III）碳纳米点（CND）的制备和研究。它们不寻常的磷光特性在水中尤为突出，初始的蓝色发射逐渐移至强烈的深绿色，而在其他常见溶剂（氯仿、丙酮等）中则没有观察到这种行为。通过嵌入聚合物基质（例如 PVA），颜色转变变为可逆的，并且取决于水含量，从完全干燥时的全蓝色发射到润湿时的强烈绿色发射。掺铁（III）的 CND 的制备路径经历了两个主要阶段，包括最初获得 Fe(III)-N-羟基邻苯二甲酰亚胺配合物，然后通过受控热解进行热加工。通过 TG、FT-IR、XPS、DLS、TEM 和 AFM 技术对制备的掺铁（III）的 CNDs 进行了形态结构研究，而绝对 PLQY、稳态和寿命荧光则用于突出其荧光特性。结构和荧光研究的结果为 CNDs 磷光发射所涉及的特定机制提供了新的见解，这一主题仍存在争议。
