Multiscale modeling of solvation effects in the Oxygen Evolution Reaction on TiO₂

Development of sustainable energy generation and storage technologies able to satisfy the needs of modern society represents a major challenge for scientific research. Innovation here essentially rely on hydrogen (H) /oxygen (O) evolution reactions (ER) and /or oxidation of chemical fuels. OER generally represents the bottleneck of (photo)catalytic water splitting, as it requires high overpotentials. This has motivated an impressive search for sustainable high-performance electrocatalysts for OER, which identified TiO₂. Recently the microscopic mechanism of OER at TiO₂–water interface has been deeply studied. In particular, first principles simulations of rutile TiO₂ in explicit water [J. Phys. Chem. C, 123, 18567 (2019)] found the solvent to affect electrostatically the energetics at the interface, rather than to modify the H bond network. Such results pave the way for the use of implicit and hybrid solvation techniques in ab initiosimulations of this system to further elucidate the effect of the solvent on OER, and specifically on its rate limiting step. To this aim, we exploit state-of-the-art implicit solvation schemes for condensed matter simulations, as implemented in the Environ plugin[http://www.quantum-environ.org] for Quantum ESPRESSO[http://www.quantum-espresso.org].