Dissociation and Charge Transfer of H₂O on Cu(110) Probed in Real Time Using Ion Scattering Spectroscopy

Abstract

Water-Cu(110) interaction is of particular importance during the routine use of graphene-based devices. In this work, water adsorption, dissociation, and desorption at elevated temperatures have been well studied using the time-of-flight ion scattering technique. It is found that water adsorption meets the first-order Langmuir adsorption model at room temperature. The variation of the ratio between residual O and H on the surface with temperature has been well determined, which profoundly reveals the dynamical process of surface composition. Furthermore, the change in the surface electronic properties has been probed by measuring negative-ion fractions as a function of the annealing temperature for fast ion scattering. It suggests that charge transfer is a very sensitive method for studying specific electronic processes in real time.

DFT +UStudy of the Adsorption and Dissociation of Water on Clean, Defective, and Oxygen-Covered U3Si2{001}, {110}, and {111} Surfaces

“…The dissociative adsorption structures are characterized by more electrons being transferred from the surface to the dissociating species as evident by the calculated Bader charges of 0.44 e – and 0.17 e – . The charge transfer from the U 3 Si 2 surface to the OH group is a necessary condition for water to bind to the surface, which is consistent with water dissociation on metal surfaces . Furthermore, the above energetics results indicate that the dissociative adsorption of water is notably stronger than the molecular adsorption on the U 3 Si 2 {110} surface.…”

“…The charge transfer from the U 3 Si 2 surface to the OH group is a necessary condition for water to bind to the surface, which is consistent with water dissociation on metal surfaces. 40 Furthermore, the above energetics results indicate that the dissociative adsorption of water is notably stronger than the molecular adsorption on the U 3 Si 2 {110} surface. We also observed the formation of U−H with bond lengths of 2.396 and 2.275 Å in the dissociative configurations, which is required for the H + to achieve stability.…”