LAUSR

Abstract A stable aqueous suspension of adenine-functionalized graphene/silver (FG/Ag) nanocomposites was prepared via a hydrothermal-assisted method. The fabricated FG/Ag nanocomposites were characterized by X-ray diffraction (XRD), FTIR, Raman spectroscopy, thermogravimetric analysis (TGA), UV–vis absorption spectroscopy and transmission electron microscopy (TEM). Field emission scanning electron microscopy (FESEM) imaging showed a uniform distribution of Ag nanoparticles on the FG surface, which increased the thermal stability of the material as confirmed via the thermogravimetric analysis (TGA). Upon their use as supercapacitor electrodes, the fabricated nanocomposites containing 20 wt% silver nitrate revealed a remarkable specific capacitance of 567/g at scan rate of 1 mV/s and excellent cycling retention of 100.5% after 1000 cycles at 200 mV/s with high energy density of 82.9Wh kg−1 in a three-electrode system and 37.03 Wh kg−1 when assembled in a symmetric device at 1 A/g, which are higher than those reported in literature for graphene-based materials. The superior electrochemical performance is ascribed to the synergistic effect of adenine functionalization and Ag doping.