Benzotriazole as corrosion inhibitor for type 304 stainless steel in water–ethanol media containing 2M H 2 SO 4

Abstract

The effect of benzotriazole (BTAH) as a corrosion inhibitor for type 304 stainless steel in 2M H₂SO₄ water-ethanol (80: 20) solutions has been studied using weight loss experiments, anodic and cathodic potentiostatic measurements, and analysis by scanning electron microscopy (SEM). BTAH increases the corrosion rate at lower concentrations (≤3·0 × 10⁻⁶M) but it provides complete inhibition when [BTAH]≥1·5 × 10⁻⁴M. The catalytic effect was also observed from anodic potentiostatic curves for [BTAH] ≤ 10⁻⁶M over the entire active potential range. A synergistic effect was observed in the presence of ethanol for higher BTAH concentrations when the system was compared with those in aqueous media. BTAH acts as a cathodic and anodic inhibitor over the entire range of potentials studied.