Initial atmospheric corrosion studies of copper from macroscale to nanoscale in a simulated indoor atmospheric environment

Corrosion effects on copper exposed in a humid atmosphere with formic acid (mimicking indoor corrosion) have been explored through successive increase in surface lateral resolution from macroscale (IRRAS, GIXRD) over microscale (LOM, SEM, IR microscopy) to nanoscale (Nano-FTIR, FIB/SEM/EDS). Initial more uniform growth of Cu2O is followed by more varying topography and thickness until local removal of Cu2O enables the aqueous adlayer to react with the copper substrate. Local formation of Cu(OH)(HCOO) and adjacent Cu2O provide microscopic and spectroscopic evidence of corrosion cells. Nano-FTIR shows that the density of Cu(OH)(HCOO) nuclei, but not their size, increases with exposure time.

Automated summary

The corrosion effects on copper exposed to a humid atmosphere with formic acid were investigated at different scales of surface resolution. The study revealed that initially, there was more uniform growth of Cu2O, followed by varying topography and thickness. Local removal of Cu2O allowed the aqueous adlayer to react with the copper substrate. The formation of Cu(OH)(HCOO) and adjacent Cu2O provided microscopic and spectroscopic evidence of corrosion cells. Additionally, Nano-FTIR analysis showed an increase in the density of Cu(OH)(HCOO) nuclei with exposure time, but not their size.