Mechanical Properties of Multifunctional TiF4 from First-Principles Calculations.

Abstract

Titanium tetrafluoride (TiF4) plays a crucial role in prerestorative dentistry, the synthesis of metal fluorides and titanium silicate thin films, enhancing the photocatalytic activity of TiO2, and hydrogen storage applications. Though TiF4 is touted for superior catalytic activity in deflating the decomposition temperature of metal hydrides, its fundamental properties have not been studied yet. Compressibility is a vital parameter during mechanical milling and hydrogen cycling processes from solid metal hydrides to sustain its stability. Even though many high-pressure studies are available on metal hydrides, a similar study on the TiF4 additive has not yet been conducted by either theoretical or experimental methods. In an effort to identify the compressibility of the TiF4 catalyst, we have performed state-of-the-art density-functional-theory-based calculations for three chemical states of TiFx (x = 4, 3, and 2). The mechanical strength of a material is derived from interatomic interactions, which in turn are influenced by the microstructure and bonding. The results highlight the superior structural, electronic, mechanical, and optical properties of orthorhombic TiF4, which has octahedral columns similar to those of bone tissue material (hydroxyapatite). This article highlights the stable iono-covalent F-Ti-F bonding of the +4 state of titanium fluoride. Materials with Young's moduli close to that of bone (20-30 GPa) have been intensely searched for bone implants. TiF4 can be used for this purpose because its average Young's modulus is 47 GPa. Our detailed analysis of charge density in TiF4 sheds light on its unique bonding characteristics, which result in its extraordinary mechanical properties, making TiF4 a multifunctional material not only for dental fillings but also for orthopedic and catalytic applications.