New observation of near-reversible behaviors for the [Fe(CN)6]3-/4-[Fe(CN)6]3-/4- redox couple in vesicular solution

A typical salt-free zero-charged catanionic system was constructed by mixing C14H29N+(CH3)3OH-C14H29N+(CH3)3OH- (TTAOH) and lauric acid (LA). The electrochemical behaviors of K4[Fe(CN)6] in salt-free TTAOH/LA micelle phase and vesicle phase solutions at glassy carbon (GC) electrode at different scan rate were obtained. A pair of well-defined redox peaks of [Fe(CN)6]3-/4-[Fe(CN)6]3-/4- is observed in TTAOH/LA vesicular solution with ΔEp = 61 mV at the scan rate of 0.001 V/s. Compared to the electrochemistry of K4[Fe(CN)6] in aqueous solution and TTAOH/LA micellar aqueous solution, the reversibility of [Fe(CN)6]3-/4-[Fe(CN)6]3-/4- is significantly improved in TTAOH/LA vesicular aqueous solution.