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Graphene-based nanocomposite materials have drawn the serious attention of researchers due to their remarkable applications in the field of energy storage. Here, in the current work, the authors prepared various composite electrode materials composed of iron oxide and reduced graphene oxide. A simple cost-effective and one-step hydrothermal approach was employed, for the first time, using a combination of two reducing agents, namely urea and starch. The formation of composite materials was characterised using scanning electron microscopy and X-ray diffraction. The electrochemical characteristics of the as-manufactured composite materials were explored using cyclic voltammetry and galvanostatic charge/discharge tests. It was found that the iron oxide–reduced graphene oxide composite prepared by using two reducing agents exhibits higher specific capacitance (286.6 F g− 1) at scan rate of 5 mV s− 1in 1M KOH solution. [ABSTRACT FROM AUTHOR]

In this study, we report the successful reduction of graphene oxide (GO) with cost effective and environment friendly methods. In the first method, we irradiated GO with highly energetic UV laser to obtain reduced GO (rGO). Moreover, Ag and Ni nanoparticles (NPs) were also productively deposited on rGO byin situreduction of metal salts with ultraviolet (UV) laser irradiation. In the second method, we employed neem leaf extract as reducing agent to synthesise rGO decorated with Ag and Ni NPs in a one-step approach. The reduction of GO as well as the deposition of Ag and Ni NPs on rGO was examined by Raman spectroscopy. We also performed ultraviolet–visible (UV-vis) spectroscopy, X-ray diffraction and SEM analysis to observe absorption in UV-vis range, crystallographic orientations and surface morphology of rGO-NPs composites respectively. Both the reducing sources were found efficient for the reduction of GO and successful deposition of metal NPs on the surface of rGO viain situreduction of metal salts. However, UV laser irradiation mediated reduction of GO was better relative to the neem leaf extract. [ABSTRACT FROM AUTHOR]