KOH-Based Hydrothermal Synthesis of Iron-Rich Titanate Nanosheets Assembled into 3D Hierarchical Architectures from Natural Ilmenite Mineral Sands

The synthesis of titanate nanostructures from low-cost mineral precursors is a topic continuous interest, considering not only their fundamental aspects but also the benefits incorporating such nanomaterials in wide variety applications. In this work, iron-rich nanosheets were synthesized Ecuadorian ilmenite sands (ilmenite–hematite solid solution-IHSS) through an alkaline hydrothermal treatment (AHT) using potassium hydroxide (KOH). effect duration KOH-AHT was assessed at 180 °C for 24, 48, 72, and 96 h. morphology evolution over time plausible formation mechanisms discussed. most significant morphological transformation observed after 72 At interval, assembled into well-defined 3D hierarchical architectures as book-block-like arrangements with open channels. Based on X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), selected area (SAED), scanning coupled energy-dispersive spectroscopy (SEM-EDS) analyses, it determined that these correspond to layered titanates (Fe/Ti mass ratio 7.1). Moreover, evidenced conversion precursor complete, since all tested reaction times presence remaining IHSS identified. Our experiments demonstrated are relatively stable KOH medium.