Biogenic Synthesis of Magnetic Reduced Graphene Oxide Using Piper chaba Stem Extract for Efficient Pb(II) Removal From Wastewater

ABSTRACT

Lead (Pb(II)) contamination in aquatic environments poses severe risks to human health and ecosystems, necessitating the development of efficient, recoverable, and affordable remediation technologies. This study presents a sustainable, one‐pot hydrothermal approach for synthesizing a magnetic reduced graphene oxide (IONPs@rGO) nanocomposite, utilizing Piper chaba stem extract as a dual green reducing and stabilizing agent. Comprehensive characterization (UV‐Vis, FTIR, XRD, FE‐SEM, TEM, EDX, Raman, VSM, and TGA) confirmed the effective biogenic reduction of graphene oxide and the uniform anchoring of quasi‐spherical Fe ₃ O ₄ nanoparticles (∼40 nm) onto the exfoliated rGO sheets. The resulting IONPs@rGO nanocomposite exhibited robust superparamagnetism, enabling rapid and energy‐efficient solid‐liquid separation. In batch sorption studies, the hybrid material demonstrated excellent efficacy for Pb(II) removal from aqueous solutions, achieving a highly competitive maximum theoretical sorption capacity ( q _max ) of 71.93 mg g ⁻¹ under optimal conditions (pH 5.0, 303 K). The sorption process followed pseudo‐second‐order kinetics and was accurately described by the Langmuir isotherm model, indicating a monolayer chemisorption mechanism driven by electrostatic interactions and inner‐sphere surface complexation. These findings underscore the immense potential of the biogenically synthesized IONPs@rGO nanocomposite as a highly efficient, magnetically recoverable, and eco‐friendly platform for the remediation of metal‐contaminated water.