Obtenção de hemateno a partir de minério de ferro especularítico da região de Caitité-Bahia

Abstract

The progress of science and technological innovations in nanomaterials has driven the study of two-dimensional (2D) materials derived from natural mineral sources, with potential environmental and energy applications. Specularite hematite (also referred to as micaceous or lamellar), found in the Brazilian region of Caetité (Bahia), exhibits a morphology that makes it a strategic precursor for the liquid-phase exfoliation process aimed at producing hematene, a 2D nanomaterial. In this context, hematene was obtained from specularitic iron ore from Caetité-BA through a sonochemical route using dimethyl sulfoxide and sodium citrate. The characterization was carried out by X-ray Diffraction (XRD–Rietveld), X-ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy in the mid-region (FTIR–Middle), Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM–EDS), and Transmission Electron Microscopy (TEM). The results revealed a significant reduction in crystallite size, an increase in microstrain, and the presence of translucent nanosheets with irregular contours, confirming the formation of 2D lamellar structures. A comparison between specularite hematite (MF-E) from Caetité and massive hematite (MF-C) from Carajás demonstrated the role of crystalline anisotropy in the delamination process, reinforcing the choice of raw material. It was concluded that by applying the methodology proposed by Motlagh (2023), with modifications in sonication time—48 hours shorter than previous methods—and using 3 mL of dimethyl sulfoxide (DMSO) for 0.03 g of hematite and 0.06 g of sodium citrate, it was possible to obtain hematene at lower cost and with reduced environmental impact.