A green tactic for inhibition of corrosion on mild steel in bore well water by aqueous extract of Bauhinia Blakeana leaves

Abstract

The impact of an aqueous extract of <em>Bauhinia Blakeana</em> leaves (AEBBL) in controlling the corrosion of mild steel in bore well water medium has been demonstrated by mass loss method and electrochemical measurements. The extract is characterized by Fourier-Transform Infrared Spectroscopy (FTIR) and the active ingredients present in the AEBBL are identified by Gas Chromatography-Mass Spectrometry (GC-MS). The surface morphology is examined with the help of Scanning electron microscopy (SEM) and the surface roughness analysis is done by Atomic force microscopy (AFM). Weight loss method reveals that of the extract offers a maximum corrosion inhibition efficiency of 96.62 . Potentiodynamic polarization study (PDP) and Electrochemical impedance spectroscopy (EIS) are used to study the mechanistic aspects of corrosion inhibition. Both the double layer capacitance (C_dl) and corrosion current (<i>I</i>_corr) values decreases while the charge transfer resistance (<i>R</i>_ct) value increases with the increase in concentration of AEBBL. The potentiodynamic polarisation reveal that AEBBL acts as mixed type inhibitor with primarily cathodic effectiveness. SEM and AFM documented the development of shielding coating on the mild steel surface.