Reduced graphene oxide/nano-silica (rGO/n-SiO2) nanocomposite for electrode materials of supercapacitor with a high cycling stability

In this study, a composite of reduced graphene oxide and nano-silica (rGO/n-SiO2) was synthesized via the hydrothermal method, which is a facile technique and green reduction method. Nano-size silica provided a high surface area and more surface-active sites to react, while the modification with rGO improved the silica potential for a supercapacitor electrode. The XRD and Raman results confirmed the success of rGO/n-SiO2 synthesis. The FESEM and TEM showed that the SiO2 nanoparticles are highly distributed on graphene sheets. The rGO/n-SiO2 offers a high energy density value of 23.2 W h kg−1 at a power density of 50.0 W kg−1. After 4000 cycles, the electrode revealed good stability with a high capacitance retention of 95.51%. The rGO/n-SiO2 yields a high specific capacitance of 166.9 F g−1, suggesting that it could be helpful for supercapacitor electrodes.