Carbon Dots: The Classical Synthesis and Properties

Abstract

Carbon dots (CDots) are generally defined as small carbon nanoparticles with various surface passivation schemes. For the definition, the synthesis with the use of pre-existing small carbon nanoparticles for chemical functionalization obviously eliminates any issues or complications with the structures of carbon cores in the dots, thus “classical.” Results based on amidation chemistry for the functionalization of small carbon nanoparticles are presented and discussed in more detail, and other modes of functionalization for CDots with somewhat different surface structures are highlighted. Also presented and discussed are the optical properties (absorptions and photoluminescence emissions) and photoinduced redox characteristics of CDots from the classical synthesis, which may be considered as references for those of other dot samples, and the mechanistic framework for the photoexcited state properties and processes in CDots.