0A thin film of cobalt hexacyanoferrate (CoHCF), an analogue of mixed-valence
Prussian blue, was deposited electrochemically on the glassy carbon, platinum and
gold electrode surfaces in 0.5M KC1 solution. The electrochemical behavior of these modified electrodes show three couples of redox peaks by CV in a supporting
electrolyte solution of 0.5M NaCl, whereas for Au modified electrode only one
couple of redox peaks is observed because of self-oxidation of gold substrate at more
positive potentials. The effect of various factors such as cations and anions of
supporting electrolyte, solution pH, scan rate and the limit of sweeping potential on
the CV response of modified electrodes was also studied. It was shown that the
electrodeposited CoHCF film is stable for several days, whether stored at open circuit
in a 0.5M KC1 or NaCl supporting electrolyte or in air