Polarization induced dynamic photoluminescence in carbon quantum dot-based ionic fluid

Abstract

We have recently reported the synthesis of water-dispersible, polymer-passivated and redox-active carbon quantum dots (CQDs). The CQDs were converted into a solvent-less conductive fluid through a step-wise surface modification technique. The material has a core-corona-canopy structure with CQD as the core, passivating-polymer as the corona and polyetheramine (Jeffamine®) as the canopy. These materials are unique in characteristics and are designated as nano-ionic materials (NIMs). Structure and properties of CQD-NIMs were determined by dynamic light scattering, thermogravimetry, differential scanning calorimetry, photoluminescence (PL) and cyclic voltammetry (CV). Dynamic changes in extrinsic PL maxima (λem) of the CQDs were observed during and after CV. Such fluctuations in λem helped to understand the sequential ordering and disordering of the Jeffamine® canopy on the CQD surface during polarization during CV. This phenomenon enables us to understand molecular canopy dynamics in NIMs and further showcases redox-active CQDs as a sustainable material for future electrochemical applications.