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

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 (similar to 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 similar to 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.

Automated summary

A nanocomposite of PTCA and silver nanocluster incorporated graphene nanosheets was successfully synthesized, showing remarkably stable suspension in solvents and exceptional fluorescence quantum yield compared to previous metal nanoclusters. Electrochemical testing revealed significant charge-discharge reversibility of the nanocomposite even at high current densities.