Tetra-MnIII-containing 30-tungsto-4-phosphate, [MnIII4(H2O)2(P2W15O56)2]12-: Entrapped PEDOT films, surface analysis and electrochemical study

A MnIII-substituted Wells-Dawson-type polyoxoanion, [MnI4II(H2O)2(P2W15O56)2]12- (Mn4(P2W15)2), was surfaceimmobilised within the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) on a glassy carbon electrode (GCE) surface. The resulting immobilised films were characterised by electrochemical techniques and subjected to a compositional and morphological characterization by means of X-ray photoelectron spectroscopy(XPS), field emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM). The redox activity of the entrapped Mn4(P2W15)2 was observed within the polymer phase. The conducting polymer films exhibited a pH-dependant redox activity associated with the polyanion Mn4(P2W15)2 and thin layer behaviour up to 100 mV s-1 with enhanced stability towards redox cycling.