A first-principles study of water adsorbed on flat and stepped silver surfaces

The structural, electronic and vibrational properties of a water layer on Ag(100) and Ag(511) have been studied by first-principles calculations and ab initio molecular dynamics simulations. The most stable water structure on the Ag(100) and Ag(511) surfaces have been obtained. The AIMD results showed rather high stability of the water layer on the stepped surface at 140 K, indicating a crystal-like structure with long-range ordering. The calculated vibrational spectra at 140 K showed good agreement with the experimental results. On the Ag(100) surface, a red-shift was observed when the temperature increased from 140 K to 300 K caused by the change in the number of H-bonded (HB) hydrogen. On Ag(511), a three-fold splitting of the O-H stretch mode was observed. This can be explained by the special water structure at the stepped Ag surface: the relatively strong water-metal interaction at the step edge and weak water-terrace interaction/strong water-water interaction at the terrace, which can also explain the high stability of the water layer on the Ag(511) surface.

Automated summary

The structural, electronic, and vibrational properties of water layers on Ag(100) and Ag(511) surfaces have been studied using first-principles calculations and ab initio molecular dynamics simulations. The most stable water structures and their vibrational spectra have been obtained. The results show that the water layer on the stepped Ag surface has high stability and crystal-like structure with long-range ordering at 140 K. The temperature increase from 140 K to 300 K leads to a red-shift in the vibrational spectra on Ag(100) due to changes in the number of H-bonded hydrogen. On Ag(511), a three-fold splitting of the O-H stretch mode is observed, which can be explained by the unique water structure on the stepped Ag surface.