The sustainable synthesis of high-quality graphene sheets is one of the hottest and most inspiring topics in the fields of science and engineering. While the graphene oxide (GO) chemical reduction method is widely used to synthesize graphene sheets, this route commonly includes highly hazardous reducing agents that are dangerous to both humans and the environment. In this context, here we describe a green, effective, and economical strategy for the synthesis of soluble graphene by using a Eucalyptus polyphenol solution that is obtained from a Eucalyptus bark extract. The reducing ability of polyphenol compounds present in the Eucalyptus bark extract is responsible for the reduction of exfoliated GO to soluble graphene under reflux conditions in an aqueous medium. The XRD, FT-IR, XPS, and UV–vis results demonstrate the effective removal of the oxygen functionalities in GO. TEM and AFM images show straight corroboration for the development of 1–4 layers of graphene. The stable and homogeneous dispersion of the E-graphene in various solvents, both aqueous and nonaqueous, confirms the powerful interactions between Eucalyptus polyphenol compounds and graphene. The electrochemical performances are evaluated by cyclic voltametry (CV) and galvanostatic charge–discharge (GCD). GCD results show that the E-graphene supercapacitor has a high specific capacitance of 239 F g–1 and a high energy density of 71 W h kg–1 at a current density of 2 A g–1. These characteristics demonstrate that this green approach has an excellent prospective not only in the fabrication of high-performance supercapacitors but also in the synthesis of graphene-based materials.

We designed a novel highly robust, graphene-based ZnIn2S4/g-C3N4 ternary nanocomposite for solar-driven H2 evolution (477 μmol h−1 g−1) from water splitting.

Synthesis of high‐quality graphene nanosheets under eco‐friendly strategies is of enormous interest today hence graphene‐based materials offer unique advantages in a wide range of applications including light‐weight supercapacitors. The reduction of graphene oxide (GO) by chemical reagents frequently involves hazardous reductants that are also dangerous to humans. In view of sustainability, we develop a facile and green procedure to synthesize soluble‐graphene by reducing the GO in delphinium root extraction for the first time. The reducing property of organic compounds that exist in the aqueous delphinium root extract may be accountable for the reduction of exfoliated GO to D‐graphene under reflux condition. The efficient elimination of oxygen functionalities from GO was verified by powder X‐ray diffraction (PXRD), UV‐Visible spectroscopy (UV‐Vis), Fourier transform infrared (FT‐IR), and X‐ray photoelectron spectroscopy (XPS) studies. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) studies indicate the successful development of few‐layer graphene. The electrochemical activities are delivered by cyclic voltammetry (CV) and galvanic charge‐discharge (GCD) studies. This uniquely‐synthesized D‐graphene electrode offers superior electrochemical performance at 2 A g−1 with an utmost specific capacitance (Cs) of 158 F g−1 and high energy density (E) of 22 Wh Kg−1. Taking the above remarkable results, the characteristics of eco‐friendly, easy synthesis and cheap endow this green approach as a promising avenue for the exploitation of graphene‐based materials in numerous applications, particularly for graphene‐based light‐weight supercapacitors.