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 (λ_em) of the CQDs were observed during and after CV. Such fluctuations in λ_em 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.