Eco-friendly synthesis and application of NH2-COOH functionalized Fe3O4@graphite carbon microballs in heavy metal removal

Abstract

Heavy metal pollution in wastewater is quite challenging for the environment. This study pioneers the synthesis of a novel adsorbent, amine-acid functionalized Fe3O4 decorated carbon micro-balls (NH2-COOH/Fe3O4@CMBs) via hydrothermal process and controlled thermal treatment under nitrogen atmosphere, utilizing eco-friendly resource glucose as a carbon precursor. The formation of cubic Fe3O4 nanoparticles and crystalline graphite within a carbon core-shell structure is confirmed. NH2-COOH/Fe3O4@CMBs show a porosity conducive to ion exchange in the range of 100–300 nm via FE-SEM, exhibiting a significant surface area of 494 m²/g with optimal pore volume. Within the carbon matrix, H2-TPR affirms the robust integration of Fe3O4, essential for high adsorption rates. In practical applications, NH2-COOH/Fe3O4@CMBs demonstrate exceptional performance, removing ∼ 99 % of Pb2+ ions in 30 min., showcasing an impressive adsorption capacity of 360 mg/g. The rapid and potent adsorption is attributed to the electron-rich graphite layers and the presence of abundant chelating sites. This research introduces NH2-COOH/Fe3O4@CMBs as a commercially viable and environmentally responsible solution for the removal of hazardous heavy metals from wastewater. Scientific understanding of adsorptive material not only advances but also offers a tangible approach to mitigate a pressing public health concern, marking a significant stride towards sustainable water treatment technologies.