TY - JOUR
T1 - Experimental and DFT studies on the ultrasonic energy-assisted extraction of the phytochemicals of
T2 - Catharanthus roseus as green corrosion inhibitors for mild steel in NaCl medium
AU - Palaniappan, N.
AU - Cole, I.
AU - Caballero-Briones, F.
AU - Manickam, S.
AU - Justin Thomas, K. R.
AU - Santos, D.
N1 - Publisher Copyright:
This journal is © The Royal Society of Chemistry.
PY - 2020
Y1 - 2020
N2 - Catharanthus roseus (Apocynaceae family) extract is rich in organic phytochemicals such as alkaloids, polyphenolic compounds, and flavonoids. It contains several functional entities such as fused heterocycles, and hydroxyl and carbonyl groups, which could be useful for corrosion inhibition of mild steel in NaCl environments. In the present work, ultrasonic energy was used to obtain the ethanolic extracts of root and stem which were then tested as corrosion inhibitors for mild steel in the presence of 3.5% NaCl. The corrosion inhibition process was studied by UV-visible spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, weight loss, and electrochemical methods. After immersing in the corrosive medium, the microstructures of mild steel were investigated by scanning electron microscopy, X-ray diffraction, and ellipsometry. The extract of C. roseus showed excellent adsorption on mild steel surface as confirmed by DFT calculations. The results indicate that the extract of C. roseus acts as a mixed type corrosion inhibitor, where the stem extract is the most efficient inhibitor in 3.5% NaCl solution possibly due to the higher active area of stem phytochemicals.
AB - Catharanthus roseus (Apocynaceae family) extract is rich in organic phytochemicals such as alkaloids, polyphenolic compounds, and flavonoids. It contains several functional entities such as fused heterocycles, and hydroxyl and carbonyl groups, which could be useful for corrosion inhibition of mild steel in NaCl environments. In the present work, ultrasonic energy was used to obtain the ethanolic extracts of root and stem which were then tested as corrosion inhibitors for mild steel in the presence of 3.5% NaCl. The corrosion inhibition process was studied by UV-visible spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, weight loss, and electrochemical methods. After immersing in the corrosive medium, the microstructures of mild steel were investigated by scanning electron microscopy, X-ray diffraction, and ellipsometry. The extract of C. roseus showed excellent adsorption on mild steel surface as confirmed by DFT calculations. The results indicate that the extract of C. roseus acts as a mixed type corrosion inhibitor, where the stem extract is the most efficient inhibitor in 3.5% NaCl solution possibly due to the higher active area of stem phytochemicals.
UR - http://www.scopus.com/inward/record.url?scp=85079350997&partnerID=8YFLogxK
U2 - 10.1039/c9ra08971c
DO - 10.1039/c9ra08971c
M3 - Artículo
SN - 2046-2069
VL - 10
SP - 5399
EP - 5411
JO - RSC Advances
JF - RSC Advances
IS - 9
ER -