A novel compound, 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine (BPEP), was synthesized and
confirmed by NMR and IR spectroscopy. BPEP was examined as an inhibitor for the corrosion
of zinc electrode in 1.0 M HCl. The inhibition efficiency of BPEP was assessed through various
techniques such as hydrogen evolution, galvanostatic polarization, potentiodynamic
anodic polarization, and electrochemical impedance spectroscopy. The inhibiting action of
BPEP was explained in terms of the formation of a stable complex between zinc ions and
BPEP and then adsorbed onto the zinc surface. The formation of the complex was established
by FT-IR spectroscopy. A conductometric titration indicated that the stoichiometry of
Znþ2:BPEP (metal:ligand) is 1:1. The adsorption follows the Langmuir isotherm. The
Galvanostatic polarization measurements have shown that the BPEP molecule acts as a
mixed-type inhibitor. The pitting potential shifted in the noble direction, indicating that
the inhibition of pitting corrosion of zinc in the presence of BPEP.The activation energy and
themodyanamic parameters of the adsorption process were calculated and have
been explained. |
