Tracking Photocatalytic Pathways With In Situ Surface‐Enhanced Raman Spectroscopy

ABSTRACT Photocatalytic pathway elucidation is crucial for understanding how light‐driven interfacial reactions convert absorbed photons into selective chemical transformations, yet short‐lived surface intermediates remain difficult to identify directly. Surface‐enhanced Raman spectroscopy (SERS) offers surface‐sensitive molecular fingerprints of reactants, intermediates, and products under working conditions, complementing structural, product, electrochemical, and conventional spectroscopic analyses. This review examines how SERS links catalyst evolution, charge transfer, and molecular transformation into an integrated framework for photocatalytic pathway analysis. Particular attention is given to material platforms that couple Raman enhancement with photocatalytic activation, including noble metal–semiconductor composites, semiconductor/defect‐engineered systems, and porous framework‐confined materials. We also discuss how atomically precise sites, programmable confined microenvironments, and multimodal SERS platforms can improve site specificity, temporal resolution, and intelligent spectral interpretation. By integrating rational material design with rigorous pathway validation, SERS may evolve from a sensitive detection method into a molecular tool for site‐specific photocatalytic pathway analysis.