Au-V2O5/Polyindole composite: An approach for ORR in different electrolytes

Abstract A nanocomposite of Gold-V2O5/Polyindole (Au-V2O5/PIn), in which V2O5 integrated with nanosized Au encapsulated polyindole has been synthesized through an optimized single-phase chemical polymerization method. Such architecture of Au-V2O5/PIn exhibits a synergism enhanced electrochemical performance over V2O5 and PIn individually. This nanocomposite is well characterized by UV visible, FTIR, XRD, XPS, SEM and TEM techniques for its structural and morphological implications. In Au-V2O5/PIn composite, Au NPs and PIn have been incorporated simultaneously on V2O5 during the polymerization reaction of indole monomer using HAuCl4, as evident by TEM image. Thereafter, as-synthesized composite has been used as an active material for the modification of commercial GC electrode for their ORR applications. In this regard, CV and EIS has been performed in 0.1 M tetrabutylammonium perchlorate in acetonitrile, 0.1 M aqueous KOH and a mixture of 0.1 M KOH + 0.1 M C2H5OH electrolytes. The electrochemical tests reveal that Au-V2O5/PIn delivers superior ORR properties among its parental component in aqueous as well as the non-aqueous electrolytes. In comparison to non-aqueous electrolytes, Au-V2O5/PIn exhibits better ORR performance in aqueous electrolytes having a mixture of 0.1 M KOH + 0.1 M C2H5OH. Such enhancement is expected due to the synergistic effect between V2O5 NPs and Au embedded PIn.