Cost effective, industrially viable production of Fe2O3 nanoparticles from laterites and its adsorption capability

Abstract

Laterite is an iron-rich earth material containing naturally occurring minerals such as hematite (Fe2O3), magnetite (Fe3O4), goethite (Fe3+O(OH)), gibbsite (Al(OH)3) and kaolinite (Al2Si2O5(OH)4). Even though these laterites are negligibly used as a cheap raw material in the brick manufacturing industry, they could be used in the synthesis of advanced materials including iron oxide nanoparticles and nanocomposites for a broad range of applications. Therefore, for the first time, this study focuses on the synthesis of iron oxide nanoparticles using laterites as a cheap raw material. In this method, first, iron and aluminium components of laterites were extracted into hydrochloric acid as their corresponding metallic ions. The extracted solution was then, mixed with sodium dodecyl sulphate (SDS) and the mixture was added dropwise to a basic solution maintaining the pH around 14 while stirring. The obtained ferric hydroxide nanoparticles were calcined to obtain iron oxide nanoparticles. The obtained nanoparticles were spherical shaped particles in the particle size range of 20–50 nm. These nanoparticles are characterized using x-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and inductively coupled plasma mass spectrometry (ICP-MS). Furthermore, these synthesized nanoparticles showed superior adsorption capacity of Cr3+ ions from an aqueous solution, demonstrating its ability to remove heavy metals, which is a crucial factor for water filtration applications.