Preparation And Electrochemical Properties Of Hybrid CoFe Prussian Blue Analogues

The area of inorganic/organic hybrid materials has received considerable interest in recent years, including coordination polymers, supramolecular architectures, surfactant capped inorganic nanoparticles, and lamellar polymer/clay nanocomposites. In the synthetic route for modified hexa-coordinated cyanometallates [(L)M(CN)n]m-units (M=transition metal ions, L=polydentate organic ligands, such as phen, bipy, tacn, pyz, Tp, etc), chelating organic ligands to prepare hybrid compound obtained increasing concerns.Herein, we synthesized different kinds of CoFe PBA (Prussian Blue Analogues) containing six different nitrogen heterocyclic, phen,2,2’-bipy,4,4’-bipy, phmz, quin and pyz, and corresponding PBA with Rb or Cs by hierarchical diffusion method, precipitation titration method or hydrothermal method. The composition and structure of compounds were characterized by Energy dispersive spectroscopy (EDS), CHN elemental analysis, Fourier transform infrared spectroscopy (IR) and X-ray powder diffraction (XRD), respectively. And then, the electrochemical properties of these materials were studied by Cyclic Voltammetry and the influence of the organic ligands and alkali metals to cycle volt-ampere characteristic of the compounds were investigated. It was found that the CoFe PBA containing quin shows great improvement on the electrochemical performance.Otherwise, a cyano-bridged bimetallic compound and three iron-phen compounds with formula Fe(phen)x(CN)6-2x (x=1,2,3) were obtained by changing the ratio of the starting materials and crystallization techniques under180℃.In this formula, the ligand phen is electric neutrality and the cyano have charge of minus one, so iron shows plus two and plus three in different compound to keep intramolecular charge balance. The electrochemical properties of these four materials were characterized by Cyclic Voltammetry and the results indicated different electrochemical behavior. With stronger charge transfer occurs in the electrode, the peak current value of compound Fe(phen)2(CN)2is far higher than others.