Phyto-fabricated iron oxide nanoparticles from Phyllanthus acidus: a magnetically recoverable nanoadsorbent for rapid Congo red detoxification

Abstract

This study reports the sustainable synthesis of phyto-fabricated magnetite iron oxide nanoparticles (IONPs) using Phyllanthus acidus leaf extract as a natural reducing and capping agent via a green co-precipitation route. The synthesized IONPs were extensively characterized; X-ray diffraction (XRD) confirmed crystallinity, and Fourier transform infrared spectroscopy (FTIR) identified key functional groups, such as Fe–O. Microscopic analysis (SEM/TEM) revealed polydispersed spherical particles (∼35 nm) capped with phytochemicals, while vibrating sample magnetometer (VSM) analysis demonstrated superparamagnetic behavior with a saturation magnetization of 60 emu per g. The nanoadsorbent exhibited exceptional performance in removing Congo Red (CR) dye, achieving a Langmuir monolayer capacity of 233.21 mg g⁻¹ and over 95% removal efficiency within 80 minutes. Furthermore, the IONPs maintained 76.5% of their initial efficiency after five cycles, showcasing robust stability and reusability. By leveraging the adsorption efficiency of these nanoparticles, this eco-friendly fabrication route offers a scalable and cost-effective strategy for wastewater remediation and dye detoxification.