Diffusion boundary layer of a rotating disk electrode as a thin-layer spectroelectrochemical cell

A UV-visible rapid scan spectrophotometer (RSS) was coupled to a Au rotating disk electrode (RDE) for monitoring at near-normal incidence the reflection-absorption spectrum of the diffusion boundary layer in Fe(CN)(6)](4)(-) aqueous solutions over a potential region in which Fe(CN)(6)](4-) oxidizes, generating highly absorbing Fe(CN)(6)](3-) (lambda(max) = 420 nm). Measurements were performed under steady-state conditions at rotation rates, omega, in the range 300