The mitigation of mild steel corrosion in 1.0 M H2SO4 solution by trimethoprim drug as a green and commercially available inhibitor was studied at room temperature using weight loss, open circuit potential, and potentiodynamic polarization techniques. The results showed that the investigated compound's inhibition efficiency depended on the concentration and nature of the inhibitor. The inhibition efficiency was found to increase with the concentration of the inhibitor. The polarization result indicated that the compound behaved as mix type inhibitor. The inhibition is assumed to occur via physical adsorption of inhibitor on the metal surface, which obeyed Langmuir adsorption isotherm. The scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDX) results confirmed the formation of a protective layer on the mild steel surface.

The corrosion inhibition study of  1-acetyl-1H-benzotriazole (ABTZ) on mild steel in 1M HCl solution has been investigated using different techniques like weight loss, open circuit potential (OCP), and potentiodynamic polarization. Results showed that ABTZ inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiencies increased with the increase in inhibitor concentration. The polarization curves revealed that the studied compound behaved as a mixed-type of inhibitor. The adsorption of the inhibitor on the surface of mild steel in the corrosive environment followed the Langmuir isotherm. The presence of thin film formed due to adsorption of ABTZ on mild steel surface is further confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX).

The effect of 5-(4-chlorophenyl)-1H-tetrazole (Cl-PTZ) on corrosion inhibition of mild steel in 1M HCl was investigated by weight loss measurement, open circuit potential(OCP), potentiodynamic polarization and surface measurements. Results showed that the inhibition efficiency increased with increase in concentration of inhibitor and attained the maximum value at 500 ppm concentration. Polarization study revealed that 5-(4chlorophenyl)-1H-tetrazole acted as mixed-type inhibitor. Among the several tested isotherms, adsorption of 5-(4-chlorophenyl)-1Htetrazole on the mild steel surface obeyed the Langmuir adsorption isotherm. The adsorption of corrosion inhibitor on mild steel surface is well supported by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) study.