A Study on the Surface Characteristic of the Viologen Self-Assembled Monolayers Using Qca and STM

Abstract

Viologen has been extensively investigated in the paper because their well-behaved electro-chemistry has led to their use in a variety of thesises, including the electron acceptor for the electric charge delivery mediation of the devices. The self-assembled monolayers of alkane derivatives with sulfur containing head groups on gold substrates have been widely examined recently, since the binding between S atoms and Au surface is strong. We could know it was formed monolayer onto quartz crystal microbalance (QCM) surface by self-assembly method from resonant frequency shift using quartz crystal analyzer (QCA). The measured frequency shift were about 408 Hz by VC8SH. From this value, we calculated that the mass adsorbed VC8SH were about 432 ng. The EQCM measurements revealed that anions exit and enter the viologen monolayer during reduction and oxidation, respectively. We also use the scanning tunneling microscopy (STM) for manipulating the surface on a nanometer scale to form nanostructures.