Titania-water interactions: A review of theoretical studies

The interaction between water (H₂O) and titanium dioxide (TiO₂) has a central role in many environment- and energy-related applications, such as the photodecomposition of organic pollutants, solar cells, and solar-hydrogen production. The importance of these applications has motivated strong interest and intensive experimental and theoretical studies of H₂O adsorption on TiO₂ surfaces for decades. This review attempts to summarize the major theoretical outcomes on this topic in the last twenty years, ranging from low coverages of adsorbed water molecules up to water multilayers on various TiO₂ surfaces. Theoretical/computational methods as well as structural models are discussed and a detailed comparison of the results from various computational settings is presented. The interaction of water with photoexcited TiO₂ surfaces is a challenging but very interesting subject for future studies.