New Aspects of Copper Corrosion in a Neutral NaCl Solution in the Presence of Benzotriazole

The corrosion behavior of copper in neutral NaCl solutions in the presence of benzotriazole (BTAH) was studied by potentiodynamic polarization, Fourier transform infrared spectroscopy (FTIR), and x-ray photoelectron spectroscopy (XPS). The thermodynamic parameter reveals that a decrease in the current density of the dissolution process is mainly controlled by the activation parameters when the BTAH concentration is low, whereas the control changed to the pre-exponential factor with increasing BTAH concentration from 10 mg/L to 40 mg/L from the potentiodynamic polarization results. Cu₂O, CuO, Cu(OH)₂, and Cu(I)BTA were all detected on the copper surface under our experimental conditions. When the BTAH concentration is low, the δ(Cu²⁺) value increases sharply, whereas a gradual increase occurs when the BTAH concentration increases from 10 mg/L to 40 mg/L, which may be ascribed to the competitive reaction of Cu²⁺ and Cu(I)BTA with a preference for Cu(I)BTA film formation.