3-Nitrobenzaldehyde-4-phenylthiosemicarbazone as Active Corrosion Inhibitor for Mild Steel in a Hydrochloric Acid Environment

Natural and synthetic organic compounds were used as corrosion inhibitors to produce coordination complexes with metallic surface utilizing the active sites. These metallic complexes occupy a significant surface area on the metallic surface, therefore coating the metallic surface and shielding the metallic surface from acidic solutions. In the current study, a new Schiff base, namely (3-nitrobenzaldehyde)-4-phenylthiosemicarbazone (3N-4P), was designed and synthesized. The chemical structure of 3N-4P was determined using spectroscopic methods such as infrared (IR) and proton and carbon-13 nuclear magnetic resonance (1H and 13C-NMR) and CHN-analysis. The corrosive inhibitory potential of the 3N-4P was tested on mild steel (MS) coupons in a 1 M HCl utilizing weight loss techniques. The inhibitive efficiency (IE%) of 3N-4P increased with 3N-4P concentration increases and decreased with increasing temperature. The experimental findings revealed that 3N-4P molecules obeyed the Langmuir adsorption isotherm. Scanning by electron microscope (SEM) technology measured the uninhibited and inhibited coupon surface.