Fluorine-Modulated Electronic Structure and Atomic Bonding of the Titanium Surface

The fluorine-adsorption-induced local bond relaxation and valence-energy-state evolution of the Ti(0001) surface were examined through density functional theory calculations. The predicted bond–band–barrier (3 B) correlation notation framework for the interaction of the fluorine adsorbate with Ti atoms formed a tetrahedral structure through the creation of four valence density-of-state features, namely bonding electron pairs, nonbonding lone pairs, holes, and antibonding dipoles. The bonding states resulted in the passivation of metal Ti surfaces, the formation of Ti(p) dipoles and Ti(+/p) H-like bonds modulated the work function of the Ti(0001) surface, and the conversion of metallic Ti to semiconducting titanium fluoride by the holes. The findings of this study confirm the universal applicability of the 3 B correlation notation in the dynamics of fluorine chemisorption and the associated valence electrons involved in fluorination.