Extending surface-enhanced Raman spectroscopic studies on water at gold electrodes

Surface-enhanced Raman scattering (SERS) of water molecules from gold electrodes is reported for the first time. The metal substrate effect on the SERS active water is investigated by comparison of gold with silver in 3 M KCl. The SERS spectra of water recorded at various electrode potentials are significantly different for the two metals. The SERS active surface structure of gold is much more stable and there may exist two types of the surface structure for gold at 0.3 and −0.3 V, respectively. The results indicate that the electromagnetic (EM) and chemical enhancement mechanisms operate simultaneously.