Olawale  Olamide, Adediran  Adeolu, Talabi  Segun Isaac, 
    Corrosion Inhibitory Properties of Vernonia Amygadlina Stem Extract in 0.1 M H<sub>2</sub>SO<sub>4</sub>
Solution,
    Journal of Engineering and Applied Sciences,
    Volume 15,Issue 16,
    2020,
    Pages 3089-3094,
    ISSN 1816-949x,
    jeasci.2020.3089.3094,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2020.3089.3094)
    Abstract: The inhibition potential of Vernonia
Amygdalina Stem Extract (VASE) on the corrosion of
mild Carbon Steel (CS) immersed in 0.1M H<sub>2</sub>SO<sub>4</sub> solution
containing varied concentration of the inhibitor was
reported. Corrosion rate measurements, inhibition
efficiency, FT-IR spectroscopy and Scanning Electron
Microscopic analysis (SEM) were used to assess the
inhibitory properties of the extract. The highest inhibition
efficiency of 97% was attained when 0.8 g L<sup>&#150;1</sup> of VASE
was added to the acidic medium. The inhibitive ability of
the extract was adjudged to be due to the presence of
alkanoids, sapponins, tannins, flavonoids and phytate as
indicated by the functional groups detected with FTIR
analysis. The surface morphology of the corroded samples
as revealed by SEM showed the formation of protective
oxide layer. Furthermore, the adsorption process between
the inhibitor molecules and metal surface obeyed
Langmuir isotherm model and indicate a physisorption
mechanism. Consequently, the extract is recommended as
a safe, cheap and efficient corrosion inhibitor for mild
carbon steel in acidic environment.
    Keywords: Adsorption;inhibition;H2SO4;Vernonia amygdalina;carbon steel;corrosion