In-Situ Corrosion Monitoring via Gel-Confined Operando Spectro-Electrochemistry

Corrosion causes trillions of dollars in economic loss annually, yet real-time observation of interfacial alloy dissolution remains challenging due to rapid convective mixing, dynamic pH gradients, and post-dissolution side reactions. Here, we present in-situ corrosion monitoring technique (ICMT), a simple spectro-electrochemical approach that transforms buried interfacial corrosion into directly observable optical signals. By confining ionic transport within a transparent, ion-conductive gelatin gel, ICMT suppresses convection while stabilizing dissolved metal species, enabling real-time UV–Vis spectral resolution of Fe, Ni, and Cr dissolution kinetics. Diagnostic absorption features are identified for distinct metal-ion species, with corrosion rates from 0.14 to 14.4 nm s-1 across nearly two orders of magnitude in dissolution flux. By establishing a direct link between Faradaic dissolution, mass transport, and chemical speciation, this platform provides a generalizable framework for operando interrogation of dynamic metal–electrolyte interfaces.