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Physical properties of graphene-related materials can be tuned by doing chemical modifications in its structure through covalent and non-covalent functionalization. Covalent functionalization of ionic salts on rGO structures changes it’s optical and electronic properties. In this work, pyrrolidone and imidazolium-based ionic liquids namely N-methyl-2-pyrrolidone hydrogensulfate (H-NMP+.HSO4ˉ), 1-butyl-3-methyl imidazoliumtetrafluoroborate (BMIM BF4), 1-butyl-3-methyl imidazoliumtrifluoroacetate (BMIM TFA) and 1-butyl-3-methyl imidazoliummethylsulfate (BMIM MeSO4) were covalently functionalized on reduced graphene oxide through microwave assisted process. Presence of (002) peak in the XRD pattern indicates the reduction of GO and fluorination of rGO prepared by functionalzation with BMIM BF4 was confirmed by a peak (001) appeared at 2θ of 12.73⁰. Red shift of π-π* and blue shift of n-π* transitions in UV-Vis spectrum were due to chemical modification in rGO sheets through IL functionalization. The peaks corresponding to IL were observed in FTIR spectra of synthesized samples. The increase in ID/IG ratio in micro-Raman analysis shows more sp3 bonds were formed during IL functionalization.

Developing a high specific-capacitance, quick charging and long cycle supercapacitor electrodes are essential for the future energy storage devices. In this paper, we report defect induced reduced graphene oxide (dRGO)-MnOx composites, which were prepared through redox reaction of KMnO4 and graphene oxide. The deformation/increasing defects in graphene sheets confirmed through micro-Raman studies. The dRGO-MnOx composite exhibit a high specific-capacitance, 264 Fg−1 at 0.2 Ag−1 in 1 M Na2SO4 neutral electrolyte. Most importantly, the dRGO-MnOx electrode was able to inhibit the outstanding cyclic performance of 153% capacitance retention and 100% Coulombic efficiency after 10,000 cycles at a high current density of 10 Ag−1. It also had 85% capacitance at a very short time (1/10 charging time of 0.2 Ag−1) with a charging current density at 1 Ag−1 and discharge current density of 0.2 Ag−1. The as-prepared dRGO-MnOx composites will find potential use in electrochemical energy storage applications.Developing a high specific-capacitance, quick charging and long cycle supercapacitor electrodes are essential for the future energy storage devices. In this paper, we report defect induced reduced graphene oxide (dRGO)-MnOx composites, which were prepared through redox reaction of KMnO4 and graphene oxide. The deformation/increasing defects in graphene sheets confirmed through micro-Raman studies. The dRGO-MnOx composite exhibit a high specific-capacitance, 264 Fg−1 at 0.2 Ag−1 in 1 M Na2SO4 neutral electrolyte. Most importantly, the dRGO-MnOx electrode was able to inhibit the outstanding cyclic performance of 153% capacitance retention and 100% Coulombic efficiency after 10,000 cycles at a high current density of 10 Ag−1. It also had 85% capacitance at a very short time (1/10 charging time of 0.2 Ag−1) with a charging current density at 1 Ag−1 and discharge current density of 0.2 Ag−1. The as-prepared dRGO-MnOx composites will find potential use in electrochemical energy storage applications.