| AVS 56th International Symposium & Exhibition | |
| Surface Science | Wednesday Sessions |
| Session SS1-WeM |
| Session: | Water/Surface Interactions & Environmental Chemistry I |
| Presenter: | B.Y. Choi, Lawrence Berkeley National Laboratory |
| Authors: | B.Y. Choi, Lawrence Berkeley National Laboratory Y. Shi, Lawrence Berkeley National Laboratory M. Salmeron, Lawrence Berkeley National Laboratory |
| Correspondent: | Click to Email |
Water dissociation on the surface is the first step in many reactions and wetting processes. A fundamental understanding of this process is necessary and applies to various fields, such as corrosion, catalysis, electrochemistry and hydrogen generation. Thermally dissociated water molecules on an oxygen precovered Cu(110) surface are investigated using scanning tunneling microscopy (STM) at low temperature. Chain structures of elongated molecules are obtained by dosing water on an oxygen precovered Cu(110) at 77K followed by annealing to ~180K. Density functional theory calculations reveal that the elongated molecular shapes are made of two hydrogen bonded OH molecules which form a dimer by tilting one OH to the other1. The weak interaction between dimers gives rise to the changes in shape of the cluster. We propose that this structural variation is the result of molecular fluctuations and from the interaction with atomic hydrogen produced by water dissociation. Switching between the different dimer shapes can be accomplished by exciting the OH-stretch mode with tunneling electrons.
1T. Kumagai et. al Phys. Rev. B 79, 035423 (2009)