Green reduction of graphene oxide and its applications in band gap calculation and antioxidant activity

Herein, the authors have developed an efficient green method for the reduction of graphene oxide by using seed extract from the easily available and cheap plant Punica granatum L. (pomegranate). Phytochemical constituents present in the extract are responsible for reduction, stabilization and capping of reduced graphene. There are a number of methods reported for the physical and chemical reduction of graphene oxide, but the green reduction approach has become more popular. Utilization of the P. granatum L. seed extract for the reduction of graphene oxide is reported for the first time. The method is essential because the reaction set-up is simple, it takes less time, is non-toxic, uses a mild reducing agent and obtains a very good yield. The reduction of graphene oxide is confirmed by different characterization techniques such as Raman spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, thermogravimetric analysis and morphological study using scanning and transmission electron microscopy. The resultant reduced graphene and graphene oxide nanosheets show stable dispersion in water and other solvents. In the case of graphene materials, the pristine form shows zero band gap; however, the study of new band gap openings for electronics applications is possible using the disperse form. The reduced graphene oxide shows biocompatibility and excellent radical-scavenging activity against 2,2-diphenyl-1-picrylhydrazyl free radicals.