Dynamic behavior of organic thin films attached to carbon surfaces

Abstract

The electrochemical reduction of 4-nitrobenzene diazonium salt has been investigated at carbon electrodes. Glassy carbon and pyrolyzed photoresist films were used as substrates to examine the attached nitrophenyl (NP) thin films using electrochemistry and atomic force microscopy (AFM). NP-films were treated to negative potential excursions in aqueous acidic conditions to electrochemically reduce the NP groups. The voltammetric responses of Fe(CN)63- redox probe were recorded, and the film thicknesses monitored by an AFM mechanical scratching method that involves removing a section of the film with an AFM tip and measuring the depth profile of the trench created. A mechanism is proposed to account for the observed film changes. © 2005 The Surface Science Society of Japan.