Figure 5.

FTIR spectra of a polycrystalline copper electrode in 0.1 M NaClO₄ electrolyte (pH 2.5). The copper film was deposited on the silicon prism by sputtering. The solution was saturated with CO₂ for 30 min, after which the reference spectrum was measured at 0 V. The spectra were measured from −0.4 V to −1.2 V in 0.1 V intervals.