Electrochemical Study of Interfacial Process in Sensing, Catalysis, and Corrosion Applications

This thesis presents a comprehensive investigation into the application of Electrochemical Impedance Spectroscopy (EIS) as a versatile, non-destructive technique to probe interfacial electrochemical phenomena across three critical domains: biosensing, electrocatalytic water splitting, and corrosion protection. In the biosensing component, gold nanoparticle-modified plastic chip electrodes were functionalized with self-assembled monolayers to enable impedimetric detection of adrenaline and CXCL10 protein with high sensitivity and specificity. A clear structure–property–performance relationship was established, where nanoparticle morphology and immobilization chemistry improved electron transfer kinetics and enhanced sensitivity and selectivity. For electrocatalysis, novel hydrogen and oxygen evolution catalysts—including MOF-derived core–shell structures and nickel–cerium composites—were fabricated and evaluated using EIS, which provided key kinetic parameters such as charge transfer resistance (Rct) and double layer capacitance (Cdl), offering insights into catalytic performance and structure-function relationships. In corrosion studies, natural green inhibitors derived from garlic and onion were applied via rubbing, squeezing, and sublimation methods onto metal substrates. EIS was employed to monitor polarization resistance (Rp), film integrity, and diffusion behavior, revealing superior film performance on copper and the mechanistic role of sulfur-containing species. Across all systems, EIS proved invaluable for real-time analysis of interfacial dynamics, demonstrating its power to guide material design and advance sustainable electrochemical technologies. By systematically linking structure, property, and performance, it highlights the role of EIS in guiding material development, elucidating interfacial phenomena, and advancing sustainable solutions in sensing, catalysis, and corrosion protection.<p></p>