Electrochemical preparation of quantum dots has attracted much attention recently due to the possibility of tailoring their dimensionality to facilitate a change in their fundamental properties including redox potential, conductivity and electron transfer characteristics in comparison with similar behavior of their bulk analogues. In this talk we describe sequential, single-electron charging of Graphene Quantum Dots (GQDs) encapsulated in a dodecyl amine envelope with a high level of monodispersity, facilitating autofarad charging capacitance(CGQDS). .Average GQDs dimensions, as ascertained from high resolution transmission electron microscopy and Atomic force microscopy 3 ± 0.3 nm, indeed control this unprecedented behavior. Differential pulse Voltammetry and Cyclic Voltammetry for the “as prepared GQDs” revealing 15 evenly spaced (?V) peaks manifesting charge injection to the semiconducting core. These single electron charging peaks with 90 mV width are quite evenly spaced at positive potential and small irregularity at negative potential. The standard heterogeneous electron transfer rate constant and diffusion coefficient of these GQDs are estimated from impedance. Multifunctional properties such as Photoluminescence, Electroluminescence and unique electron transfer behavior of these individual graphene quantum dots might facilitate the fabrication of novel futuristic devices like light emitting, single electron tramsistors
Dr. Vijayamohanan K. Pillai is a leading Electrochemist from India and he has done his Ph.D in Indian Institute of Science, Bangalore. He has authored over 200 publications and 20 patents related to many innovations in both Electrochemistry and Materials Chemistry. He has experience (20 years) in Materials Electrochemistry, fuel cells, investigating new catalyst materials, membranes, optimisation of electrode structures and test procedures for several fuel cell types, batteries and ultracapacitors, funded by many government and multinational organizations. His group at NCL has developed highly sensitive nanostructured platinum electrocatalysts for CO oxidation and PEFCs using Nafion-based composite membranes with functionalized carbon nanotubes. His research interests include Materials Electrochemistry, functionalization of carbon nanotubes and hybrid materials for fuel cells, supercapacitors and rechargeable batteries. He has received many honors and awards like the MRSI Medal, Materials Research Society of India, Bangalore, 1996, Chemical Research Society of India,(CRSI) Bronze Medal, in 2004. He is a Member of the Editorial board of Bulletin of Materials Science, from 2005 onwards and is a Fellow of the Indian Academy of Sciences, Bangalore, from 2008 onwards. He is at present the Acting Director of Central Electrochemical Research Institute, Karaikudi.