Improving Characterization of Nanoparticulate Films Using Surface Specific Vibrational Spectroscopy
Year: 2025
Type: preprint
Abstract: Vibrational sum-frequency generation (vSFG) offers interface-specific spectroscopy under ambient conditions, yet extending it from extended optically flat samples to nanoparticle (NP) ensembles on dielectric supports is hindered by scattering, phase ambiguity, and film inhomogeneity. z-cut $\alpha$-quartz is widely used in vSFG as a convenient standard for both intensity and phase reference. Building on recent work that deposits NPs on z-cut $\alpha$-quartz and employs an internal normalization scheme, we introduce an eight-degree-of-freedom stage that preserves the same micrometer-scale spot during azimuthal rotation. This capability enables phase-contrast measurement across complementary polarization families without changing the probed area. Applied to Mn-doped Co$_3$O$_4$ supported on quartz, the workflow robustly recovers the imaginary spectrum, $\operatorname{Im}\{\chi^{(2)}\}$, of surface-hydroxyl vibrations with internal normalization under different polarization combinations polarization sets. These advances deliver a practical, internally referenced, and phase-resolved vSFG protocol for NP ensembles on dielectric supports, extending \textit{operando} access to catalytic interfaces beyond metallic or plasmonic enhanced architectures.
Source: ChemRxiv
Authors: Furong Yan, Carsten Placke-Yan, Zhipeng Huang, Stephan Schulz, Yujin Tong, R. Kramer Campen
Institution: University of Duisburg-Essen
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W7104031229
Cites:
Cited by:
Related to: