Gold electrodes cycling voltammetry

The influence of pH and other factors on the reductive desorption and oxidative reformation of a hexadecanethiol SAM on a gold electrode was studied by reflection-absorption infrared spectroscopy (RAIRS) and cyclic voltammetry. At low pH the lack of solubility of desorbed molecules was problematic however, after three adsorption-desorption cycles the process was reproducible301. The reductive desorption in alkaline solution of an alkanethiol SAM on a single-crystal Au(l 11) electrode involves a one-electron process to yield a thiolate. Oxidative removal is a complicated process, involving up to eleven electrons per alkanethiol molecule302. 

Fig. 9 Cycling voltammetry (5 mV/sec) for gold electrodes of different roughness [28]. SI untreated (as received) surface. S2-S4 surfaces obtained by electrodeposition of gold at currents densities close to the limiting current density. Inset approximate values of the half-width of resonance. Curves S2 and S3 lie between curves SI and S4, in some parts coinciding with them. Arrows P(S1) and P(S4), show the peak currents for reduction of the surface oxide, measured for the surfaces SI and S4, respectively. (From [28])...

The ferrocenyl dendrimers were electrodeposited in their oxidized forms onto the electrode surfaces (platinum, glassy-caibon, and gold) either by controlled potential electrolysis or by repeated cycling between the appropriate anodic and cathodic potential limits therefore the amount of electroactive material electrode-posited can be controlled with the electrolysis time or the number of scans. The electrochemical behavior of films of the polyfeirocenyl dendrimers was studied by cyclic voltammetry in fresh CH2CI2 and CHjCN solutions containing only supporting electrolyte. 

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