Development and Characterization of Advanced Graphene Based Composites for Water Remediation

Abstract

This thesis based on the development and characterization of advanced Graphene based composites for water remediation. The study will involve the synthesis of Graphene oxide (GO), Graphene oxide-montmorillonite (GO-Mt) and Graphene oxide-montmorillonite-chitosan (GO-Mt-Chitosan) composites and used further as an adsorbent for the removal of two commonly used textile dyes: Acid orange 10 (AO10) and Malachite green oxalate (MG oxalate). The primary focus of this study is to investigate the adsorption efficiencies of GO and GO-based composites by varying various parameters like pH, contact time, initial dye concentration, temperature and adsorbent dose. The shifting and broadening of XRD peaks confirmed the structural re-arrangement and effective interaction between dye molecules and GO-based composites. Upon interaction with dye molecules, the significant absorption peaks slightly shifted, indicating successful interaction of dye molecules with functional group of GO-based composites. FE-SEM images revealed rough, irregular layered structures with voids, which became more wrinkled and compact after dye adsorption, reflecting morphological changes. The adsorption efficiency of GO-Mt-Chitosan for MG oxalate dye was 945 mg/g at pH 8 within 20 minutes and 81 mg/g at pH 3 within 80 minutes for AO 10 dye as compared to GO and GO-Mt were better because it provided more sites for dye interaction by adding an extra functional group. The adsorption process followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating monolayer adsorption and chemisorption. Thermodynamic analysis confirmed the process to be exothermic and spontaneous. GO-Mt-Chitosan showed excellent regeneration and reusability, proving to be an efficient and cost-effective adsorbent for removing various organic pollutants. newline