Cetyltrimethyl ammonium bromide surfactant-assisted morphological and electrochemical changes in electrochemically prepared nanoclustered iron(III) hexacyanoferrate

The iron(III) hexacyanoferrate film (FeHCF) has been deposited on the surface of a glassy carbon (GC) electrode from a pH 1.7 solution (0.02 M HCl + 0.1 M KCl) with a potential cycling procedure in the presence and absence of cationic surfactant, cetyltrimethyl ammonium bromide (CTAB). The unmodified FeHCF is found to be in the form of 50–60 nm dia. nanoclusters as evidenced by STM and AFM. But, the CTAB-modified FeHCF film shows normal-sized nanocrystallites embedded with 10–20 nm sized spherical granules. In addition to this, the presence of CTAB in solution during FeHCF film formation also enhances accumulation of electroactive FeHCF component in the composite film (i.e., higher charge storing capacity). Concerning the electrochemical behavior, the CTAB-modified FeHCF film electrode possesses very high charge retaining capacity (stability), enhanced film permeability for K+ ion ( D K + ) and increased surface electron transfer rate constant (ks).