Phyto-reduction of graphene oxide into reduced graphene oxide using centella asiatica extract for downstream applications

Abstract

Green phyto-synthesis represents an environmentally sustainable approach that employs eco-friendly methods and materials to produce various substances, minimizing the use of hazardous chemicals and reducing the overall ecological footprint. The central focus of this research is the utilization of Centella asiatica (C. asiatica) to reduce Graphene Oxide (GO) into reduced Graphene Oxide (rGO). Two rGO samples, designated as rGO1 and rGO2 were synthesized at varying concentrations of C. asiatica extract to investigate the influence of reduction parameters on the desired material. Techniques such as Scanning Electron Microscopy (SEM), High-Power Microscopy (HPM), UV-Vis, Raman, Fourier Transform Infrared Spectroscopy (FTIR) and Four-Point Probes were used to analyze the as-synthesized materials. A mild reduction was occurred under eco-friendly environment where the UV–Vis spectral showed a shift of an absorption peak from 230 nm (GO) to ~241nm (rGO1) and ~250 nm (rGO2), respectively. The microscopy images from HPM and SEM revealed a wavy-like rGO nanoflakes is observed and the restoration of sp² carbon network with minor shifts of G-band indicated by Raman spectral. The reduction and removal of oxygen moieties are further supported by FTIR analyses. Meanwhile, decreased in electrical resistivity from 23.50 Ω·m (GO) to 7.45 Ω·m (rGO2), indicates an improved conductivity, thus supporting the removal of oxygen groups. In summary, the test results confirm the green reduction of GO to produce rGO by C. asiatica is effective and facilitates to produce a structurally stable nanomaterials and conductive that are suitable for electronic and bio-sensing applications. NOTE: The header and footer of this manuscript is not following the provided guideline, please check again.