Electrochemical studies of water-soluble palladium nanoparticles

Aqueous-soluble monolayer-protected palladium nanoparticles were synthesize d by hydrogen reduction of Pd(II) in a water solution. The particles were t hen further functionalized by incorporating multiple copies of mercapto der ivatives of viologen into the particle protecting monolayers. The electroch emistry of the viologen moieties with the particles dissolved in solution o r immobilized onto electrode surfaces was carefully studied using various e lectrochemical techniques. The particle molecular capacitance was evaluated by rotating-disk-electrode voltammetry and the electron-transfer rate cons tant of the particle-bound viologen moieties was estimated by impedance mea surements.