Microwave-assisted Reduction of Graphene Oxide Using Artemisia Vulgaris Extract for Supercapacitor Application

The present work has reported a microwave-assisted green reduction approach for reducing graphene oxide (GO) to reduced graphene oxide (rGO) using Artemisia vulgaris plant leaf extract. GO has been synthesised following the modified Hummers method. The reduction of graphene oxide (GO) has been conducted in three sets resulting in six reduced graphene oxide (rGO) samples (R1–R6) with a maximum reduction time of 1 h. Three sets of parameters with changes in microwave input power, reduction reaction time and volume of plant extract have been investigated to acquire an optimised set of reduction conditions. The reported optimised set exhibited the highest specific capacitance (CS) value out of the parameters investigated. The study is based on the comparative analysis of structural, morphological, vibrational, optical, bonding and networks and electrochemical properties of GO and its reduced products (rGO) for supercapacitor application. The potential of this plant extract to reduce GO into rGO has been reported. Furthermore, it was discovered that only a particular volume of Artemisia vulgaris extract might be employed for effective reduction. The rGO samples have been studied for supercapacitor electrode application. Total charge resistance (RCT) analysis through electrochemical impedance spectroscopy (EIS) reveals the decrease in RCT value from 295.51 Ω for GO to as low as 42.09 Ω for R5. The CS of the synthesised GO and all rGO samples have been calculated using CD and CV plots. The highest value recorded for R5 was 111.62 Fg−1 at a scan rate of 0.005 Vs−1 and 94.80 Fg−1 at a current density of Ag−1. The cyclic stability after 5000 cycles at a current density of 3 Ag−1 was recorded as 74.2%.