Electrochemistry of Metal Nanoparticles and Quantum Dots

Abstract

Metal nanoparticles, with a wide range of applications in catalysis and sensing, have structural and electronic properties that differ from those of their bulk macroscopic counterparts. Electrochemical techniques are of particular interest in the study of metal nanoparticles because electrons may undergo quantum confinement effects which are reflected in their electrochemical behavior, resulting, ultimately, in three distinguishable voltammetric regimes: bulk continuum, quantized double-layer charging, and molecule-like. Similarly, semiconductor nanoparticles (quantum dots, QDs) are receiving considerable attention due to their high fluorescence, which makes them of interest for biological and medical applications, among others. The semiconductor bulk materials possess defect states that originate from impurities, divacancies, or surface reactions as a result of their synthesis. Voltammetric features provide information on bandgap energy, the position of conduction and valence band edges, and the position of defect sites as well as on the interaction with the capping ligand. This chapter is devoted to provide a critical view of the current state of the art in the electrochemistry of such systems.