One-pot green synthesis of Fe3O4@ZnO core–shell nanocomposites with multifunctional properties
Mahsa Eslamdoust, Fayezeh Samari, Saeed Yousefinejad
Abstract
This study introduces an economical, one-step, and eco-friendly method for synthesizing Fe 3 O 4 @ZnO magnetic core–shell nanocomposites (Fe 3 O 4 @ZnO MNCs) using an aqueous leaf extract of Cordia myxa ( C. myxa ). The effects of zinc salt concentration and calcination temperature were investigated, and the products were characterized using XRD, FE-SEM, TEM, BET, FT-IR, TGA, and VSM techniques. The optimized nanocomposite was spherical, with an average size of 23.01 nm, exhibited superparamagnetic behavior, had a point of zero charge at pH 7.3, and a specific surface area of 18.2 m² g⁻ 1 . It showed moderate antioxidant activity and antibacterial effects against Gram-positive ( Listeria , Micrococcus ) and Gram-negative ( Salmonella ) bacteria. The adsorption performance for Congo red (CR) dye was evaluated and optimized via Central Composite Design (CCD) in Response Surface Methodology (RSM). Under optimal conditions (adsorbent dosage 11.6 mg L⁻ 1 , pH 6.0, contact time 74 min), nearly 100% dye removal was achieved, highlighting the nanocomposite’s strong potential for pollutant removal and environmental remediation.