Investigation on gold corrosion by in situ quartz crystal microbalance and atomic force microscopy in self-assembled processes of alkanethiol monolayers

The corrosion behaviour on gold surface in air-exposed solution induced by alkanethiol molecules such as n-dodecanethiol in self-assembled process has been for the first time investigated in detail by in situ quartz crystal microbalance (QCM). The gold lost from the in situ QCM has been well explained by the observation of atomic force microscopy (AFM), which shows the evident image of corrosive defects or holes produced on the corresponding surface of gold grains. Both alkanethiol assembled monolayer and existing oxygen would be decisive factors for the gold corrosive dissolution on the substrate. The kinetic equation on the corrosion rate of gold dissolved in the air-exposed alkanethiol solution has been obtained. The initial corrosion rate on gold can be estimated to be 5.8 × 1010 Au atoms cm− 2 s− 1.