Fabrication and Characterization of Clinacanthus nutans Mediated Reduced Graphene Oxide Using a Green Approach

The reduction of graphene oxide (rGO) utilizing green methods such as plants has attracted much attention due to its productivity, eco-friendly features, and cost effectiveness. In the present study, the reflux method was employed to synthesize Clinacanthus nutans (C. nutans) leaf extract mediated rGO using a simple approach. The synthesized rGO was characterized using various spectroscopic and microscopic techniques. The UV-Vis spectrum demonstrated the absorption peak of rGO (270 nm) at distinct locations, while the FTIR analysis demonstrated that the amount of oxygen group in rGO was reduced. The Raman analysis confirms the reduction of GO by a slight increase in the D-band to G-band intensity ratio. The XRD spectra demonstrated that rGO was successfully produced based on the illustrated 2 theta angles at a peak of 22.12 degrees with d-spacing of 0.40 nm. FESEM clearly reveals the morphology of rGO that shows crumpled thin sheets, a rougher surface, and a wave-shaped corrugated structure. The reduction of GO was analyzed in the removal of the hydroxyl group and amorphotization of sp(2) carbon structures. The C/O ratio in rGO was higher than GO which indicates the small amount of oxygen-containing functional groups were still presented in the reduced graphene oxide. Furthermore, the cyclic voltammetry behavior of a modified screen-printed carbon electrode (SPCE) was measured. The redox reactivity of rGO-SPCE has been affirmed and compared with GO-SPCE and bare-SPCE. The toxicity using A. salina cysts demonstrated that rGO is less toxic compared to GO. The analysis adequately supports the synthesis of rGO and the effective removal of oxygen-containing functional groups from GO. The findings herein illustrate that C. nutans mediates the synthesis of rGO and is a promising eco-friendly substitute to conventional carbon-based fabrication.