pH- and Facet-Dependent Surface Chemistry of TiO(2) in Aqueous Environment from First Principles

[Image: see text] TiO(2) is a relevant catalytic material, and its chemistry in aqueous environment is a challenging aspect to address. Also, the morphology of TiO(2) particles at the nanoscale is often complex, spanning from faceted to spherical. In this work, we study the pH- and facet-dependent surface chemistry of TiO(2)/water interfaces by performing ab initio molecular dynamics simulations with the grand canonical formulation of species in solution. We first determined the acid–base equilibrium constants at the interface, which allows us to estimate the pH at the point of zero charge, an important experimental observable. Then, based on simulated equilibrium constants, we predict the amount of H(+), OH(–), and adsorbed H(2)O species present on the surfaces as a function of the pH, a relevant aspect for water splitting semi-reactions. We approximated the complex morphology of TiO(2) particles by considering the rutile (110) and (011), and anatase (101), (001), and (100) surfaces.