Synthesis, characterization and electrochemical behavior of cationic iron porphyrin intercalated into layered niobate

Cationic iron porphyrin 5,10,15,20-tetrakis(N-methylpyridinium-4-yl) porphyrinato iron(III), FeTMPyP, has been intercalated into layered niobate (K4Nb6O17) through a guest–guest exchange method by using propylammonium niobate (PrNH3+–Nb6O17) as a precursor. The microstructure and morphology characterizations for the resulting material FeTMPyP–Nb6O17 have been investigated by means of XRD, FTIR and SEM. The UV–vis spectra results suggest that the incorporation of FeTMPyP in the bidimensional nanostructure produces a red-shift in the Soret absorption band of the cationic metalloporphyrin. By simple dropcoating method, FeTMPyP–Nb6O17 was used as a modifier on the glassy carbon electrode (GCE). The cyclic voltammetry (CV) curves exhibit nearly symmetric anodic and cathodic peaks, corresponding to the Fe(III)/Fe(II) couple. Furthermore, the anodic and cathodic peak currents are linearly dependent on the square root of scan rate, implying a fine diffusion-controlled electrode process.

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► Cationic metalloporphyrin (FeTMPyP) was intercalated into K4Nb6O17·3H2O.
► FeTMPyP–Nb6O17 nanocomposite basically retains the lamellar structure.
► The absorption spectral properties are much affected by the nanocomposite formation.
► FeTMPyP–Nb6O17 nanocomposite exhibits an excellent electrochemical activity.