Supercapacitive behaviour of a novel nanocomposite of 3,4,9,10-perylenetetracarboxylic acid incorporated captopril-Ag nanocluster decorated on graphene nanosheets

Abstract

A nanocomposite of PTCA and silver nanocluster incorporated graphene nanosheets were synthesized using a single step facile methodology. The G/PTCA/Capt-AgNC nanocomposites were characterized using UV-Vis, photoluminescence (PL), FTIR, Raman, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy (HRTEM), Scanning electron microscopy (SEM) and X-ray diffraction. The image obtained using an electron microscope revealed a sheet-like nanomaterial decorated with ultra-small (∼2–4 nm) silver nanoclusters. It was found that the synthesized nanocomposite forms a remarkably stable suspension in solvents and exhibits an exceptional fluorescence quantum yield (QY ∼ 0.32) in comparison to the previously reported metal nanoclusters. To test the potential utility of the nanocomposite as a charge storage material, electrochemical capacitance measurements were carried out. A drastic increase in the specific capacitance (C_m) of G/PTCA/Capt-AgNC was observed in comparison to that of PTCA/Capt-AgNC. The as-prepared nanocomposite shows significant charge–discharge reversibility even at a high current density of 137 A g⁻¹. The method for the synthesis of the nanocomposite reported here provides a facile and straightforward approach to decorate graphene sheets with metal nanoparticles and may be readily expanded to other classes of graphene hybrids for flexible electronic, sensor and charge storage applications.