Authors :
J. J. O. Ajali; V.E. Ojukwu; O. E. Achugbu; C. C. Ejiofor; C. N. Onyenanu; L.N. Emembolu; J.T. Nwabanne
Volume/Issue :
Volume 8 - 2023, Issue 6 - June
Google Scholar :
https://bit.ly/3TmGbDi
Scribd :
https://tinyurl.com/53sjysv3
DOI :
https://doi.org/10.5281/zenodo.8150009
Abstract :
The corrosion inhibition of Newbouldialeavis
(NL) leaf extract on mild steel in alkaline media was
investigated in this study. The plant leaf extract's
functional groups comprise of oxygen and nitrogen
atoms (O-H, N-H, C-N, C-O, C=O, and CN) as well as
aromatic rings, according to FTIR data.Phytochemical
analysis showed the presence of tannins, saponins,
phytates, phenolics, flavonoids, cardiac glycosides and
alkaloids. The results also showed that mild steel
exhibits a considerable shift to passivation within the
examined potential range. The inhibitors' molecules
created an excellent protective coating on the mild steel,
according to SEM micrographs. Adsorption of plant
extracts on metal surfaces was spontaneous and
occurred via the physical adsorption process.The
measurements of gravimetric, thermometric,
potentiodynamic polarization and electrochemical
impedance spectroscopy results showed that the
inhibition efficiency rose with increasing concentration
of inhibitors and decreased with increasing temperature.
The findings of the potentiodynamic polarization
indicated that the plant leaf extracts were mixed-type
inhibitors because Ecorr value greater than 85mV
confirms that the NL extract is a mixed-type inhibitor.
The findings of electrochemical impedance spectroscopy
demonstrated that adding inhibitors enhanced the
charge-transfer resistance of the corrosion process and
hence the inhibition performance. The inhibition effiency
(IE%) in the presence of 200mg/l and 1000mg/l of NL
inhibitor was gotten to be 71.2% and 87.9% respectively
for 1M KOH medium and 95.6% and 97.1% respectively
for 1M NaOH medium. Quantum chemical parameters
indicated that the inhibitor molecules' active ingredients
slowed the corrosion of mild steel as was confirmed by
density functional theory.
Keywords :
Alkaline corrosion, electrochemical impedance spectroscopy, Density Functional Theory (DFT), potentio dynamic polarization or quantum chemical calculations.
The corrosion inhibition of Newbouldialeavis
(NL) leaf extract on mild steel in alkaline media was
investigated in this study. The plant leaf extract's
functional groups comprise of oxygen and nitrogen
atoms (O-H, N-H, C-N, C-O, C=O, and CN) as well as
aromatic rings, according to FTIR data.Phytochemical
analysis showed the presence of tannins, saponins,
phytates, phenolics, flavonoids, cardiac glycosides and
alkaloids. The results also showed that mild steel
exhibits a considerable shift to passivation within the
examined potential range. The inhibitors' molecules
created an excellent protective coating on the mild steel,
according to SEM micrographs. Adsorption of plant
extracts on metal surfaces was spontaneous and
occurred via the physical adsorption process.The
measurements of gravimetric, thermometric,
potentiodynamic polarization and electrochemical
impedance spectroscopy results showed that the
inhibition efficiency rose with increasing concentration
of inhibitors and decreased with increasing temperature.
The findings of the potentiodynamic polarization
indicated that the plant leaf extracts were mixed-type
inhibitors because Ecorr value greater than 85mV
confirms that the NL extract is a mixed-type inhibitor.
The findings of electrochemical impedance spectroscopy
demonstrated that adding inhibitors enhanced the
charge-transfer resistance of the corrosion process and
hence the inhibition performance. The inhibition effiency
(IE%) in the presence of 200mg/l and 1000mg/l of NL
inhibitor was gotten to be 71.2% and 87.9% respectively
for 1M KOH medium and 95.6% and 97.1% respectively
for 1M NaOH medium. Quantum chemical parameters
indicated that the inhibitor molecules' active ingredients
slowed the corrosion of mild steel as was confirmed by
density functional theory.
Keywords :
Alkaline corrosion, electrochemical impedance spectroscopy, Density Functional Theory (DFT), potentio dynamic polarization or quantum chemical calculations.
