Triple hybrid materials: A novel concept within the field of organic–inorganic hybrids

Abstract

We explored a new approach within the field of hybrid materials, namely, an integration of an electroactive inorganic molecule into a conducting polymer that in turn is intercalated into an extended inorganic oxide. In particular we present the specific material formed by hexacyanoferrate-doped polypyrrole or polyaniline inserted in turn into layered V2O5. This novel kind of hybrid with three components interacting at a molecular level is what we have called, triple hybrid materials (THM). The synthetic approach was based on our earlier work on PAni/V2O5, PAni/HCF and PPy/HCF systems. The materials obtained were characterized by FTIR, XRD, TGA, elemental analyses, and ICP. The electrochemical properties of THMs as insertion cathodes in rechargeable Li cells were also explored. The initial specific charge was high for PPy/HCF/V2O5 system (160 Ah kg−1), giving a greater value than for their corresponding simple hybrids: PPy/HCF (69 Ah kg−1) and PPy/V2O5 (120 Ah kg−1). Repeated charge–discharge cycles showed a poor cyclability, which could be related to the voltage limit values during recharge, overoxidation of the polymer, or to the detrimental effect of structural water from THMs. Nevertheless, the present work showed a novel route towards a more complex and versatile electroactive hybrid design.