1. Proton-Transfer Mechanisms at the Water–ZnO Interface: The Role of Presolvation
- Author
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Matti Hellström, Vanessa Quaranta, and Jörg Behler
- Subjects
Chemistry ,Oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Dissociation (chemistry) ,0104 chemical sciences ,chemistry.chemical_compound ,Molecular dynamics ,Adsorption ,Chemical physics ,Computational chemistry ,Hydroxide ,Molecule ,General Materials Science ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology ,Self-ionization of water - Abstract
The dissociation of water is an important step in many chemical processes at solid surfaces. In particular, water often spontaneously dissociates near metal oxide surfaces, resulting in a mixture of H2O, H+, and OH– at the interface. Ubiquitous proton-transfer (PT) reactions cause these species to dynamically interconvert, but the underlying mechanisms are poorly understood. Here, we develop and use a reactive high-dimensional neural-network potential based on density functional theory data to elucidate the structural and dynamical properties of the interfacial species at the liquid-water–metal-oxide interface, using the nonpolar ZnO(1010) surface as a prototypical case. Molecular dynamics simulations reveal that water dissociation and recombination proceed via two types of PT reactions: (i) to and from surface oxide and hydroxide anions (“surface-PT”) and (ii) to and from neighboring adsorbed hydroxide ions and water molecules (“adlayer-PT”). We find that the adlayer-PT rate is significantly higher than...
- Published
- 2017
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