Effect of Surface Symmetry on the Dissociative Adsorption of Water on Gallium Oxynitride

Abstract

Recently, gallium oxynitride was shown to be a promising material for photoelectrochemical water-splitting applications. Herein, we perform density functional theory (DFT) calculations to study the effect of surface symmetry and chemistry on the adsorption and dissociation processes of water molecules on spinel type gallium oxonitride (Ga3O3N). We found strong dissociative adsorption of water molecules for both N- and O-rich surfaces with different surface symmetries (i.e., (100), (010), (001), and (111)). In addition, DFT molecular dynamics simulations reveal that water molecules undergo dissociation on all considered Ga3O3N surfaces at room temperature. These interesting findings indicate a promising potential of Ga3O3N for water-splitting applications.