Approach for Modulation of the Permselective Properties of Ni(II) Porphyrin Polymers

The electropolymerization of Ni(II) Protoporphyrin (polyNiPP) onto glassy carbon electrodes is performed in different experimental conditions, varying the supporting electrolytes, solvent, and oxidative potentials. The AFM images show different average thickness for each polymer, polyNiPP(TBAP) (0.6 μm) and polyNiPP(LiClO₄) (0.1μm). The polyNiPP(LiClO₄) describes a straight line plot of EMF versus log (C) for NO₂^?, with the slope of 37 mV per concentration decade while the same film is not sensitive to the thiocyanate concentration. For polyNiPP(TBAP) the slope for thiocyanate progressively increase when is oxidized in aqueous solution. A sub‐Nernstian response (59 mV /decade) is obtained at 1000 mV. The Nyquist plots confirm that the method of preparation establishes the properties of films related to the movement of the ions.