Hydrothermal Synthesis and Nanoscale Characterization of Single-Unit-Cell Bi ₂ WO ₆ Nanosheets: Correlation between Morphology, Adhesion, and Surface Potential

High Resolution Image Download MS PowerPoint Slide Single-unit-cell (SUC) Bi 2 WO 6 nanosheets were successfully synthesized via a hydrothermal route and investigated through a comprehensive nanoscale characterization. Structural analyses by powder X-ray diffraction, Raman spectroscopy, and transmission electron microscopy confirmed the formation of a polycrystalline two-dimensional material. Atomic force microscopy revealed uniform nanosheets with an average thickness of ∼1.42 nm, consistent with a single-unit-cell configuration. Nanoscale mechanical analysis demonstrated that increasing PeakForce (1–5 nN) induces irreversible deformation of pre-existing surface pores, while higher oscillation frequencies (2–4 kHz) promote additional topographic modifications, indicating a frequency-dependent surface stability. Kelvin probe force microscopy (KPFM) mapping revealed a pronounced spatial variation in surface potential, with a lower work function at the nanosheet center and higher values at the edges. This edge-center electronic contrast establishes a direct correlation between morphology, adhesion behavior, and local surface potential, providing new insights into charge distribution in SUC-Bi 2 WO 6 . These findings highlight the relevance of nanoscale heterogeneity in governing surface reactivity, reinforcing the potential of Bi 2 WO 6 nanosheets for applications in photocatalysis and nanoelectronics.