Rotating disc and hemispherical electrodes for copper dissolution study inhydrochloric solution in the presence of benzotriazole

The effect of benzotriazole (BTAH) on the anodic dissolution of copper in 1 M HCl solution was investigated by using a rotating disc electrode (RDE) a nd a rotating hemispherical electrode (RHSE). It was shown that the presenc e of Cu(I) (CuCl or CuCl2) on the copper surface is necessary to have the i nhibitive effect of BTAH. Just below the current plateau, the effect of BTA H depends on the electrode geometry: for the RDE, the electrode surface rem ained partially active, the protection by BTAH occurred only on a ring at t he edge of the electrode, whereas for the RHSE the surface is uniformly cov ered by a protective BTAH complex. For both electrodes without the presence of BTAH, a surface roughness develops during the copper electrodissolution that can be kinetically interpreted as a porous-like electrode with pores of finite size. In the presence of BTAH and for the RSHE, the size of the p ores becomes semi-infinite. (C) 2001 Elsevier Science Ltd. All rights reser ved.