Electrochemical Properties of a Conducting Film Derived from Iron(II) Tris(diaminopolypyridyl) Complex in the S(IV) Oxoanions Reduction

A new conducting film derived from the complex [Fe (diaphen)3]2+, (diaphen=5,6-diamino-1,10-phenanthroline) was electropolymerized by cyclic voltammetry onto a glassy carbon electrode. Poly-[FeII (diaphen)3] was studied by cyclic voltammetry, SEM, UV-vis and micro-Raman spectroscopy. Poly-[FeII (diaphen)3] shows electrocatalytic activity in HSO3− reduction in an ethanol/water solution. Electrocatalysis is centered at the π ring of phenanthroline. Rotating disk electrode studies showed a 0.117 V/dec Tafel slope, suggesting an EC process where the electrochemical process is the determining step. The chemical step was studied by UV-vis spectroelectrochemistry. Amperometric behavior showed a linear range between 47.5 µM to 417 µM and the LOD was 19.5 µM.