A facile one-pot synthesis of phyto-conjugate superparamagnetic magnetite nanoparticles for the rapid removal of hexavalent chromium from water bodies

Abstract

Sustainable and economical strategies for producing efficacious adsorbent systems for the rapid removal of hazardous Cr(VI) have recently gained research attention. This study employs the aqueous extract of Chromo laena odorata flowers as a green reductant and capping agent for the synthesis of Chromolaena odorata-derived magnetite nanoparticles (CMNs). The method yielded relatively monodispersed and small superparamagnetic magnetite nanoparticles with an average particle size of 3.14±0.25 nm. At an optimum pH of 2, CMNs enabled rapid removal of Cr(VI) and its subsequent reduction to Cr(III) in under 10 minutes. The maximum adsorption capacity recorded was 173.12 mg g− 1 . The adsorption conformed to Langmuir adsorption isotherm and followed pseudo first order kinetics. The strong magnetic nature of the adsorbent facilitated easy separation and recycling after adsorption. The present work provides insights into the use of aggressive weeds for the phytogenic development of eco-compatible adsorbents for rapid chromium reduction and removal.