Induction and pore-formed stages in Al2Au's dealloying process in HCl solutions.

• Two stages can be distinguished in dealloying process of Al 2 Au ribbon. • Multi-resolution analysis on OCP is performed in an innovative way. • The Al 2 Au first undergoes local corrosion and then global corrosion. Two stages, induction stage and pore-formed stage, were distinguished in Al 2 Au's dealloying process in HCl solutions by OCP, SEM and XPS characterization. In induction stage, the Au state with binding energy 85.4 eV (labelled as Al 2 Au (I)) was transformed into the state 84.7 eV (Al 2 Au (II)); in pore-formed stage, nanoporous structure started to be formed, Al 2 Au (II) and residual Al 2 Au (I) were transformed into the state 83.7 eV (pure Au). Multi-resolution analysis on OCP noise revealed that the induction stage and pore-formed stage undergo different corrosion modes: the former is local corrosion and the latter is global corrosion. [ABSTRACT FROM AUTHOR]