Recovery of iron from direct reduction iron sludge and biosynthesis of magnetite nanoparticles using green tea extract

Regarding their unique properties, metal and metal oxide nanoparticles such as iron nanoparticles are used in different environmental and engineering aspects. In the field of nanotechnology, a cost-effective and non-hazardous approach is the green synthesis of nanoparticles using plant extracts which can offer additional advantages and subsist environmental sustainability. The present study aims at the synthesis of Magnetite Nano-Particles (MNP) through a green technique using Direct Reduction Iron (DRI) sludge, a waste of steel industry, as the iron source recovered by acid digestion and green tea extract based on its unique antioxidant properties as a non-toxic and eco-friendly reducing agent. In this study, the MNP was synthesized with the co-precipitation method and was subjected to instrumental analyzes to indicate its physicochemical properties such as size, morphology, saturation magnetization, surface area, and thermal decomposition. This study's results were promising, and an average particle size of 8 nm was obtained based on HRTEM analysis, and XRD analysis showed the magnetite nanoparticles are well-crystalline and coordinated well with the standard peaks of Fe3O4. Moreover, the presence of surface functional groups substantiated the green synthesis of nanoparticles using green tea extract. The saturation magnetization and surface area of MNP were determined to be 52.9 emu/g and 84.68 m2/g, respectively. It was found that the synthesized MNP is comparable due to the physical and chemical properties with similar samples which are usually prepared using chemical substances. [Display omitted]