Highly electrochemical active composites based on capacitive graphene/aniline oligomer hybrid for high-performance sustainable energy storage devices

Carbon-based nanomaterials have been regarded as an important kind of electrode material for supercapacitors, but suffered from their low energy densities. To achieve high electrochemical performance, here a novel graphene/oligomer polyaniline composite is proposed. We prepare tetraaniline/reduced graphene oxide (RGO) (TAG-2) hybrid nanocomposite from N phenyl-p-phenylenediamine and graphene oxide in acidic media. Based on the high specific surface area, the as-synthesized TAG-2 hybrid composite can be used as a supporting substrate to synthesize Pt nanocatalyst for the methanol oxidation reaction in aqueous media. The TAG-2 hybrid composite and Pt/TAG-2 nanocatalyst are characterized by FT–IR, UV–vis absorption spectroscopy, XRD, XPS, SEM, EDX, TEM, conductivity, and cyclic voltammetry. The electrochemical properties of the TAG-2, tetraaniline (TANI), and RGO materials are thoroughly investigated by using cyclic voltammetry (CV) and charging-discharging techniques in 2 M H₂SO₄ electrolyte solution. TANI and RGO show specific capacitance around 547 F/g and 213.5 F/g @1 A/g, respectively, while the achieved TAG-2 composite shows higher specific capacitance (958.2 F/g @0.1 A/g and 825.5 F/g @1 A/g) and superior rate capability than TANI and RGO. Based on the higher surface area and excellent penetration of ion electrolyte in TAG-2, the Pt/TAG-2 nanocatalyst shows better catalytic activity than commercial Pt/C towards methanol oxidation.