DFT Study of H2, H2O, and O2 Adsorption on Ni(111) Surface

Nickel sensor action for analytical detection of hydrogen and oxygen gases is dependent on the adsorption, dissociation, and diffusion of hydrogen and oxygen. These processes and water adsorption was studied by the density functional theory with model Ni(111) slabs. It was found that H atoms were absorbed only by voids in the fcc structure as the Ni surface was filled. The voids in the fcc sites were also preferred for the adsorption of oxygen atoms and oxygen-hydrogen pairs. Two bridge adsorption forms of water were found in addition to the well-known, top-site adsorption form.