Synthesis, electrochemical and theoretical characterization of schiff base as an anticorrosive molecule for mild steel in 0.5 M H2SO4 medium

Herein, the inhibition effect of Schiff base (SB) namely N, N1'-(1,4-phenylene)bis(N4-(4-(dimethylamino)benzylidene)benzene-1,4-diamine) on the corroded mild steel (MS) in 0.5 M H2SO4 was investigated using gravimetric measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Results obtained for the investigated compound exhibited good corrosion inhibition performance for MS in 0.5 M H2SO4. The highest inhibition efficiency of the SB obtained is 98.11% at lower quantity as 200 mgL−1. EIS study displays increase in charge transfer resistance (Rct) which is attributed to the adsorption of inhibitor molecules on MS surface that forms a protective layer between metal and solution interface. Potentiodynamic polarization revealed that the Schiff base acts as mixed-type inhibitor. Surface morphology of mild steel samples was performed by using the SEM and AFM studies which revealed that inhibition of mild steel from the corrosion with different concentrations of SB through adsorption on metal surface. Using different models of adsorptions, it is established that the base got adsorbed on the surface of mild steel obeys Langmuir adsorption isotherm. In addition to experimental observations, the simulation study further supplemented these experimental results.