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

• Applicant: Professor Dr. Claus Feldmann
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 281704971

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).

• DFG Programme: Research Grants