Non-toxic Schiff bases as efficient corrosion inhibitors for mild steel in 1 M HCl: Electrochemical, AFM, FE-SEM and theoretical studies

Abstract

Two hydrazide derivatives namely N′-(4-Hydroxybezylidene)nicotinic hydrazone (HBNH) and N′-(4-methylybezylidene)nicotinic hydrazone (MBNH) have been investigated as corrosion inhibitors for mild steel in 1M HCl using electrochemical, weight loss, FE-SEM, AFM, quantum chemical calculation and molecular dynamic simulation methods. They show good corrosion inhibition efficiency; with the inhibition efficiency of MBNH being higher than that of HBNH. The polarisation results indicate that both the inhibitors act as mixed type inhibitors. They follow Langmuir adsorption isotherm. Quantum chemical parameters of the inhibitors have been calculated using DFT method. Interaction energies derived from molecular dynamics simulation are in agreement with experimental results.