Atomic Structure and Bonding of Water Overlayer on Cu(110): The Borderline for Intact and Dissociative Adsorption

By carefully comparing the calculated and measured work function data, energetics, and vibrational spectroscopy, we determine explicitly the water structure in c(2 x 2) periodicity on Cu(110) to be an intact water overlayer with a majority component of H-down bilayer (95%) in low temperature experiments. Water dissociation is accessible by heating or ultraviolet illumination, resulting in a sensitive change in electron density at the surface and could therefore be monitored by work function measurement.