Synthesis, structural, morphological and optical analyses of new Prussian blue, ruthenium oxide and polyindole (PIn-PB-RuO2) nanocomposite

A novel ternary nanocomposite comprising of conducting polymer polyindole (PIn), prussian blue (PB) and ruthenium oxide (RuO 2 ), i.e., PIn-PB-RuO 2 nanocomposite is obtained through chemical method by grinding the as-synthesized PIn, PB and RuO 2 nanoparticles at the stoichiometric ratio of 1:1:1. FTIR, XRD, TGA, FESEM, EDAX, UV–Vis and PL techniques were applied to investigate the structure and optical properties of PIn-PB-RuO 2 nanocomposite. FTIR spectrum shows that the characteristic peaks present in all the unary nanoparticles are also present in the ternary nanocomposite with a small shift in the absorption maximum. The XRD pattern reveals the semicrystalline structure of PIn-PB-RuO 2 nanocomposite with an average crystallite size of 7.27 nm. The value of the intrinsic strain obtained for the ternary material from W–H plot is found to be 0.05466 × 10 –3 . FESEM shows mixed morphological features as the surface of PB nanocubes is covered with a uniform level shagginess due to the presence of PIn and RuO 2 nanoparticles. EDAX reveals the presence of C, N, O, Fe, K and Ru elements in PIn-PB-RuO 2 . Detailed UV–Vis spectroscopic analysis revealed that the ternary material showed an increase of extinction coefficient, refractive index, optical conductivity, Urbach energy and dielectric constant values compared to all the unary materials. The estimated bandgap of PIn-PB-RuO 2 indicates the material’s applicability in optoelectronic devices. Further, the blue emission peak from the PL results confirms that the PIn-PB-RuO 2 composite is highly suitable for visible light based device applications.