1-hydroxy Benzotriazole as Corrosion Inhibitor for Mild Steel in 1 mol/L Hydrochloric Acid Solution

Abstract

The inhibition ability of 1-hydroxy benzotriazole (BTAOH) for mild steel in HCL solution (1 mol/L) had been investigated in this manuscript. The inhibition efficiency of BTAOH showed a maximum value around 48% at 303 K, with the concentration 1.5 × 10⁻³ mol/L. The physical adsrobed BTAOH molecules are more stable attached onto the mild steel surface than the corrosion products. The similar free energy of adsorption (Δ G_ads⁰) but much lower IE were ascribed to the thicker but less compact film constructed by the zig-zag H-bond connected BTAOH polymers. According to the effects of concentration and temperature on the adsorption behavior of the BTAOH, we had calculated the Δ G_ads⁰, E_a, Δ H_ads⁰, Δ S_ads⁰ as −26.76, 75.50, −36.14 kJ/mol and −0.0310 kJ/mol/K respectively.