Unveiling Unconventional Luminescence Behavior of Multicolor Carbon Dots Derived from Phenylenediamine
Yan Fang, Jiurong Li, Xiujian Zhao, Xiao Gong
Abstract
Fluorescence regulation of carbon dots (CDs) during their preparation has become a hot research topic. In this work, multicolor fluorescent CDs with unconventional luminescence behavior are prepared by using o -, m -, or p -phenylenediamine ( o -PD, m -PD, or p -PD, respectively) and 2,3-dihydroxynaphthalene with rich hydroxyl groups as reaction precursors. Tunable multicolor fluorescent CDs with bright blue, yellow, and red colors can be obtained by a solvothermal method under the joint action of ethanol and hydrochloric acid. The fluorescence emission of the synthesized CDs follows a rule of o -PD to m -PD to p -PD from blue to red, which is contrary to most previously reported results (the luminescence from blue to red following an order of m -PD to o -PD to p -PD). Our results reveal that the differences in the polymerization, surface states, functional groups, and graphite N content of CDs might be the main reasons for the unconventional luminescence behavior. In addition, these multicolor CDs have good applications in the fields of light-emitting diode lighting and anticounterfeiting.