Carbon Nanoparticles (C-Dots):Polyol Synthesis, Fluorescence, Screening of Material Properties

碳纳米颗粒（也称为：碳点或C点）-除了富勒烯，碳纳米管（CNT）和石墨烯-代表了碳的另一种形式，由于其强烈的荧光，在过去的2-3年中受到了极大的关注。目前，C点是通过高温处理常规碳源（例如石墨、煤、烟灰）或分解有机碳物质（例如糖、树叶、鸡蛋）来制备的。然而，目前对碳量子点的合成和性质还缺乏基本的了解，本项目的目标是在可控的多元醇合成条件下，以可调的颗粒尺寸和掺杂量合成碳量子点。路易斯酸金属盐用于支持颗粒成核和颗粒生长，考虑到C-点的高度可再现的可用性。通过关联粒度、结晶度、表面钝化和化学组成，旨在对材料特性进行基本了解。特别地，稀土金属改性的（例如，Tb 3+，Eu 3+，Yb 3+）C-点是高度相关的，这是由于在激发C-点时的有效线型发射，因此在水的存在下能量转移的机制和荧光的稳定性既没有被理解也没有被解决。基于C点的受控液相合成，最后，旨在筛选材料性质（例如，聚合物薄膜和电池中的荧光、作为透明导体的C点薄膜、使用C点的气体吸附/气体分离、（光）催化性能、向纳米金刚石的相变）。

Carbon nanoparticles (also named: carbon dots or C-dots) - besides fullerenes, carbon nanotubes (CNTs) and graphene - represent an additional form of carbon that received significant attention during the last 2-3 years due to their intense fluorescence. Currently, C-dots are prepared via high-temperature treatment of conventional carbon sources (e.g. graphite, coal, soot) or decomposition of organic carbon species (e.g. sugar, leaves, eggs). A fundamental understanding of synthesis and properties of C-dots, however, to many regards is missing by now.This project aims at a controlled polyol synthesis of C-dots at adjustable particle size and doping. Lewis-acid metal salts are used to support particle nucleation and particle growth in view of a highly reproducible availability of C-dots. By correlating particle size, crystallinity, surface passivation, and chemical composition, a fundamental understanding of the material properties is intended. Especially, the fluorescence of rare-earth-metal-modified (e.g., Tb3+, Eu3+, Yb3+) C-dots is highly relevant due to the efficient line-type emission upon excitation of the C-dots, whereupon the mechanism of energy transfer and the stability of fluorescence in the presence of water are neither understood nor solved. Based on a controlled liquid-phase synthesis of C-dots, finally, a screening of materials properties is intended (e.g., fluorescence in polymer thin-films and cells, C-dot thin-films as transparent conductors, gas sorption/gas separation with C-dots, (photo)catalytic properties, phase transition to nanodiamonds).