Synthesis of rGO/nanoclay/PVK nanocomposites, electrochemical performances of supercapacitors

摘要

In this study, graphene oxide (GO) was chemically reacted with sodium borohydride (NaBH4) to form reduced graphene oxide (rGO). rGO, Montmorillonite nanoclay, and polyvinylcarbazole (PVK) were used to form a ternary nanocomposite via chemical reaction. These nanocomposite qualities were described via scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy-attenuated transmission reflectance (FTIR-ATR). In addition, these materials were used in supercapacitor device as an active material to test electrochemical performances via cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The rGO/nanoclay/PVK nanocomposite shows significantly improved specific capacitance (C_(sp) = 168.64 Fg~(-1)) compared to that of rGO (C_(sp) = 63.26 Fg~(-1)) at the scan rate of 10 mVs~(-1) by CV method. The enhanced capacitance results in high power density (P= 5522.6 Wkg~(-1)) and energy density (E = 28.84 Whkg~(-1)) capabilities of the rGO/nanoclay/PVK nanocomposite material. The addition of nanoclay and PVK increased the specific capacitance of rGO material due to a dopant effect for supercapacitor studies. Ragone plots were drawn to observe energy and power density of supercapacitor devices. The C_(sp) of rGO/nanoclay/PVK nanocomposite has only 86.4 of initial capacitance for charge/discharge performances obtained by CV method for 5000 cycles.