Nanospectroscopic Imaging of 2D Materials by Tip-Enhanced Raman Spectroscopy

The precise physicochemical and morphological characterization of individual components or heterostructural aggregates at the nanoscale plays a critical role in advancing fundamental research and enabling functional applications, particularly in the field of 2D materials (2DMs). One of its primary objectives is to utilize techniques with exceptional resolution, sensitivity, and specificity to reveal the atomic and molecular structures, nanoscale defects, and interlayer interactions of 2DMs, thereby providing deeper insights into their performance and the underlying mechanisms of their potential applications. Among various analytical methods, tip-enhanced Raman spectroscopy (TERS) stands out due to its high spatial resolution, surface sensitivity, and adherence to surface selection rules, offering unique advantages for the nanospectroscopic imaging of 2DMs. This review begins by contextualizing 2DMs and TERS, highlighting the synergy between TERS capabilities and the characterization needs of 2DMs. We then systematically summarize recent breakthroughs in TERS-based nanoscale mapping of the chemical composition, structural heterogeneities, and interfacial interactions within 2DMs. Finally, we propose future directions for TERS development, emphasizing the integration of advanced probe engineering, hyperspectral imaging modalities, and data-science-driven analysis frameworks. We envision that such advancements will propel TERS toward becoming an indispensable tool for decoding the nanoscopic complexity of 2DMs, ultimately accelerating their translation into next-generation technologies.