Cost-effective transformation of rutile to anatase and synthesis of Zn₂Ti₃O₈

This study presents two groundbreaking achievements in materials science with significant implications for advanced technologies. First, we report the successful mechanosynthesis of Zn₂Ti₃O₈ through a solvent-free, solid-state reaction between rutile-type TiO₂ and ZnO, yielding the compound after 8 hours of milling. Second, we demonstrate a novel reverse phase conversion of TiO₂ from rutile to anatase under extreme conditions, involving a highly alkaline (KOH) environment at 160 °C, followed by hydrothermal treatment and calcination at 850 °C. This unprecedented transformation enhances the anatase phase’s morphological, optical, and surface properties, offering substantial advantages for various applications. Comprehensive characterization using X-ray diffraction, UV–Vis, and FT-IR spectroscopy revealed crucial insights into the materials' structural and optical properties. Notably, bandgap energies estimated from Tauc plots showed a systematic decrease with increasing reaction time, ranging from 3.54 to 3.49 eV for 2 to 10 hours, respectively. Our findings contribute significantly to the field by introducing an environmentally friendly Zn₂Ti₃O₈ synthesis route, challenging conventional phase stability understanding, and providing a method for precise bandgap control. This research not only advances fundamental knowledge but also opens new avenues for developing high-performance materials in energy and environmental applications, potentially revolutionizing next-generation technologies.