4-Hydroxyl-N′-[(3-Hydroxy-4-Methoxyphenyl) Methylidene] Benzohydrazide] as Corrosion Inhibitor for Carbon Steel in Dilute H2SO4

Abstract The effect of an aromatic hydrazide derivative 4-hydroxyl-N′-[(3-hydroxy-4-methoxyphenyl) methylidene] benzohydrazide] (HMBH) as inhibitor for the corrosion carbon steel in 0.5 M H 2 SO 4 solution was investigated temperature range 303 K to 323 using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). concentration HMBH used 0.1 1 mM. Inhibition efficiency (% IE) increased with increase decreased temperature. Maximum % IE obtained around 71 $$\times $$ × 10 -3 at K. Tafel results indicate that acted a mixed type inhibitor. evaluation thermodynamic activation parameters suggest adsorption took place by physisorption, it obeyed Freundlich’s isotherm. Scanning electron microscope (SEM) atomic force (AFM) images were also recorded supplement studies, mechanism inhibition suggested.