Kopsia terengganensis ` alkaloids as potential green inhibitors for mild steel corrosion in CO 2-saturated 3.5% NaCl medium
Document Type
Article
Publication Date
8-1-2024
Abstract
The corrosion inhibition potential of alkaloids from Kopsia terengganensis bark extract (KTBE) in mitigating the mild steel corrosion in a CO 2 -saturated 3.5% NaCl medium was evaluated. Standard corrosion evaluation methods, including weight loss test, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PD) were employed, which revealing a concentration -dependent enhancement in KTBE ` s inhibition efficiency. At 500 ppm, the corrosion inhibition efficiency recorded the highest value of 90.63% based on the weight loss study and 87.38% based on electrochemical analysis. Tafel slopes in PD studies affirmed that KTBE functioned as an anodic -type inhibitor. The adsorption of the inhibitor is in accordance with the Langmuir adsorption isotherm with an adsorption free energy ( Delta G degrees ads ) of -26.47 kJ/mol, suggesting the binding of KTBE molecules by means of physisorption. Surface analysis conducted through scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and Fourier transform infrared spectroscopy (FTIR) confirmed the formation of a protective inhibitive layer on the surface of mild steel. The proposed corrosion inhibition mechanism involves electrostatic interactions between KTBE molecules and the mild steel surface. This comprehensive investigation underscores KTBE ` s potential as an effective corrosion inhibitor in corrosive environments.
Keywords
Kopsia terengganensis bark, Alkaloid, Corrosion inhibition, CO2 saturated 3.5% NaCl medium, Mild steel
Divisions
CHEMISTRY
Funders
FRGS Grant from the Ministry of Higher Education Malaysia (FRGS/1/2018/STG01/USM/01/5)
Publication Title
Geoenergy Science and Engineering
Volume
239
Publisher
Elsevier
Publisher Location
RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS