Comparative Analysis of Reduced Graphene Oxide Nanosheets Derived from Microalgal Extract, Thermal Reduction and Chemical Synthesis

Abstract

This thesis aims to thoroughly investigate various methods for synthesizing reduced graphene oxide (rGO), starting with production of graphene oxide (GO) employing Modified Hummer’s Method. My study examines three main reduction techniques, which include green synthesis using microalgae, thermal reduction, and chemical synthesis using hydrazine hydrate. The effectiveness of each strategy is assessed with a specific emphasis on environmental sustainability, cost effectiveness, biocompatibility, and the resulting material quality. Characterizations such as UV visible spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, energy dispersive X-ray analysis (EDS), raman spectroscopy, and thermogravimetric analysis are performed to ensure successful formation of all nanomaterials and their detailed structural or chemical analysis. As an application, the adsorption of methylene blue dye over rGO shows significant promise for wastewater treatment, because to its exceptional efficacy and large surface area. This enhances the progress of ecologically sustainable water treatment techniques. By investigating the adsorption mechanisms and optimizing process parameters, the rGO based adsorbents demonstrate considerable potential for removing dyes and other contaminants from aqueous solutions. The results from UV-visible spectrophotometric analysis reveal that both thermal rGO and algal rGO have considerable adsorption capacity for methylene blue tested over multiple time intervals. The present study concludes with a careful comparative examination of the aforementioned technologies used to produce rGO, providing insights into their advantages and constraints. Comparative evaluation through detailed characterizations may provide a significant reference for researchers to choose the most suitable technique for any specific application. The results not only contribute to the progress of sustainable nano-biotechnological practices but also facilitate the development of more efficient, environmental-friendly, and biocompatible green synthesis of rGO that may be helpful to explore the reduction potential of new microalgal strain dictyosphaerium