Multiscale electrochemical analysis of the corrosion control of bronze in simulated acid rain by horse-chestnut (Aesculus hippocastanum L.) extract as green inhibitor

Abstract

Horse-chestnut ethanolic extract was tested as potential corrosion inhibitor of bronze in simulated acid rain. The extract was analysed by FTIR, GC-MS and HPLC-PDA, and its anti corrosion behaviour studied using a multiscale electrochemical approach (polarization curves, EIS and scanning electrochemical microscopy), along with SEM-EDS. 94% inhibition efficiency was attained by developing a surface physisorbed film. A novel methodology for kinetic evaluation of dynamic adsorption of inhibitive species on metal surface is proposed using SECM, achieving good agreement with results from conventional electrochemical techniques. Excellent adsorption-desorption kinetic constants (ka = 0.102 s-1 mol-1 L; kd = 3.33x10-5 s-1) were determined