Ziziphus mauritiana leaves extracts as corrosion inhibitor for mild steel in H2SO4 and HCl solutions

Abstract

The inhibition performance of exts. of Ziziphus mauritiana on mild steel corrosion in 0.5 M H2SO4 and 0.5 M HCl was investigated using gravimetric, electrochem. polarization, electrochem. impedance spectroscopy, and SEM studies. The gravimetric results indicate that Ziziphus mauritiana leaves ext. exhibits good inhibition efficiency in both the acids. Furthermore, the inhibition efficiency decreases with increase in temp. Polarization measurements showed that the studied inhibitor is mixed type in both acids with significant redn. of cathodic and anodic current densities. Electrochem. impedance spectroscopy measurements revealed that the charge transfer resistance increases with increase in the concn. of Ziziphus mauritiana exts. Various thermodn. parameters such as activation energy, activation enthalpy,y and activation entropy were evaluated and discussed. Adsorption thermodn. parameters were also computed, and SEM was used to analyze the surface-adsorbed film. [on SciFinder(R)]