The solid state electrochemistry of samarium (III) hexacyanoferrate (II)

A new electroactive polynuclear inorganic compound of a rare earth metal hexacyanoferrate, samarium hexacyanoferrate (SmHCF), was prepared chemically and characterized using techniques of FTIR spectroscopy, thermogravimetric analysis (TGA), X-ray powder diffraction, UV–Vis spectrometry and X-ray photoelectron spectroscopy (XPS) etc. The cyclic voltammetric behavior of SmHCF mechanically attached to the surface of graphite electrode was well defined and exhibited a pair of redox peaks with the formal potential of 180.5 mV (versus SCE) at a scan rate of 100 mV/s in 0.2-M NaCl solution and the redox peak currents increased linearly with the square root of the scan rates up to as high as 1,000 mV/s. The effects of the concentration of supporting electrolyte on the electrochemical characteristics of SmHCF and the transport behavior of K⁺, Na⁺ and Li⁺ counter-ions through the ion channel of SmHCF were studied by voltammetry.