In-situ external reflection FTIR spectroelectrochemical and XPS investigations of cobalt-cyanometallates as inorganic polymeric materials on a platinum electrode.
Cobalt-cyanometallate films electrochemically deposited on a platinum electrode were studied by cyclic voltammetry (CV), in-situ FTIR spectroelectrochemistry (FTIRs) and potential resolved XPS measurements. The experimental results reveal that the CoHCF film on Pt electrode exists in two forms. The major form of the inner layer of the film is (M(+))(2)Co(II)Fe(II)(CN)(6) where M(+)denotes a cationic counter ion, in which both the Fe(2+)and Co(2+)centers can be oxidized to Fe(3+)and Co(3+)in the potential range of 0-1.0 V vs. Ag/AgCl in NaCl solution. The major form of the outer layer is Co(II)(2)Fe(II)(CN)(6), in which electrochemical reactions in this potential range are limited by kinetic sluggishness. The FTIR and XPS spectra indicated that the Co centers change from high-spin state to low-spin state accompanying the Co(2+)/Co(3+)oxidation reaction. In addition, the cations' effect on electrochemical reactions of CoHCF is also discussed.
Bo
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AL
Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.
Lin
X Q
XQ