Atomic force microscopy was used to monitor, in situ, the shape evolution of polycrystalline copper during anodic dissolution in 0.5M H2SO4. During dissolution of the copper surface under a small anodic potential (30 mV), an overlayer of material that resulted from mechanical polishing was removed, exposing the underlying grain boundaries. A chemically etched sample was exposed to the same experimental conditions, and no overlayer was observed. Dissolution of the copper bulk metal was monitored under a higher applied potential (100 mV, 0.5M H2SO4). The overlayer was immediately removed, and the dissolution produced a nonuniform, crystallographically-etched surface. The inhibiting effect of benzotriazole (BTA) on copper dissolution in 0.5M H2SO4/20 mM BTA was observed. Copper dissolution did not proceed at 100 mV or 200 mV applied potential; but at 300 mV, rapid localized dissolution resulted in the formation of pit-like features.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry