Modeling the Water Splitting Activity of a TiO₂ Rutile Nanoparticle

Abstract

We explore, from a theoretical perspective, the effect of particle size on the photocatalytic water splitting activity of TiO₂ rutile (nano)­particles by a combination of explicit quantum chemistry calculations on a hydroxylated rutile nanoparticle in a realistic solvation environment and a comparison with the calculated properties of bulk rutile (surfaces) from the literature. Specifically, we use density functional theory (DFT) and time-dependent DFT to calculate the nanoparticle thermodynamic driving force for the water splitting half-reactions and identify in the process the crucial role of self-trapping of the free charge carriers responsible for proton reduction and water oxidation