ELECTROCHEMICAL EVALUATION OF LEAF AND BARK EXTRACTS OF Chrozophora Plicata AS GREEN CORROSION INHIBITORS FOR MILD STEEL IN HYDROCHLORICACID:ADSORPTION, THERMODYNAMIC, AND MECHANISTIC STUDIES
Metals and alloys frequently undergo corrosion, a destructive process that reduces their durability, reliability, andservice performance, resulting in significant material and economic losses. This study aims to identify and validatelow-cost, environmentally benign corrosion inhibitors sourced from indigenous plant materials found in Coimbatore, Tamil Nadu, India. Bioactive constituents were extracted using ethanol from the leaf and bark tissues of C. plicata. The extracts were subsequently subjected to phytochemical evaluation, which verified the presence of key secondarymetabolites, including flavonoids and phenolic compounds. Qualitative screening further confirmed the occurrenceof polyphenolic constituents. Electrochemical performance was assessed employing potentiodynamic polarisation, and electrochemical impedance spectroscopy techniques were employed to assess inhibition performance onsteel surfaces. The leaf and bark extracts demonstrated notable protection efficiencies of 87.1% and 69.6%, respectively. PDP measurements uncovered that both extracts act as mixed-type inhibitors, while EIS fallouts indicatedanupsurge in polarisation resistance and confirmed that adsorption on the metal surface adheres to the Langmuir adsorption isotherm, involving a combination of physical and chemical interactions. A insignificant reductionininhibition efficacy with temperature elevation (298–328 K) further substantiated the thermodynamic adsorptiontrend. These outcomes highlight C. plicata as an environmentally benign source of inhibitory compounds, offeringan alternative to synthetic commercial formulations. Future work may involve scaling up formulations, surfacecharacterisation via microscopy techniques, and evaluating long-term performance in industrial conditions.
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