Spectroscopic observation and structure-insensitivity of hydroxyls on gold.

The O-H stretching vibration of surface hydroxyls remained at 3691 cm -1 for gold structures ranging in size from clusters to nanoparticles, to non-flat bulk surfaces. In contrast, this vibration was not observed on flat gold surfaces. Therefore, this vibration can serve as an indicator of the roughness of the gold surface and associated functional properties, such as catalytic activity.