Studying Catalytically Viable Single-Crystalline Metal Oxide Nanorods Using Synchrotron-Based Scanning Hard X-ray Microscopy

Abstract

Synchrotron-based scanning hard X-ray microscopy (SHXM) was used to extract localized chemical and structural information within a system of model alkaline earth-metal tungstate nanorods, characterized by multiple chemical configurations. Specifically, we have highlighted the practical ability of SHXM to probe chemically distinctive nanoscale species, consisting of (i) chemically doped versus (ii) solid solution-state nanorods of comparable dimension, synthesized using a template-directed method under ambient conditions. Indeed, we show that SHXM can be used to map out elemental distributions within individual anisotropic nanorods with nanoscale resolution, coupled with chemical sensitivity and specificity. Complementary electrochemical results suggest the possibility of using these nanorods as support materials for electro-oxidation reactions within an acidic electrolyte medium. Our structural and chemical composition results have been corroborated using parallel lines of inquiry involving scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. These measurements confirmed the relatively even and uniform distribution of the expected, individual elements within all of the nanorod samples tested.

Synchrotron-Based X-ray Analysis: Relating Compressive Lattice Strain with the Photoluminescence Intensity of Li+-Doped β-NaYF4:Yb3+/Ln3+ (Ln3+ = Ho3+/Er3+/Tm3+) Upconversion Crystals

“…High-intensity, tunable X-ray energy present in synchrotron radiation yields superior signal to noise ratio in the diffraction pattern of a crystalline solid in comparison to the conventional X-ray source and thus serves as a reliable and sensitive probe to elucidate the structural intricacy of solid-state materials in great detail. − As a consequence, synchrotron-based X-ray analysis has become an emerging trend in uncovering and adding new insights to crystal lattices, especially where the structural parameters of a lattice govern the optical, electronic, or energy storage properties of a material. − …”

Dose-efficient multimodal microscopy of human tissue at a hard X-ray nanoprobe beamline

“…The performance of the experimental setup presented here is particularly relevant for biological samples, as for these the issue of identifying and optimizing ROIs while minimizing radiation damage is of great concern. This approach could also benefit samples from other fields of research, such as materials science and physical chemistry (Meirer & Weckhuysen, 2018), in which holography and XRF are already in use (Li et al, 2019;Altenbach et al, 2020;Vesely ´et al, 2021).…”

“…XRF measurements are sometimes combined with phasecontrast imaging within the same study, as these techniques return complementary information which can enhance overall results. Within such multimodal studies, phase contrast images can be obtained, for example, through holography (Vesely ´et al, 2021), ptychography (Deng et al, 2018;Stachnik et al, 2020) or scanning transmission X-ray microscopy (STXM) (Li et al, 2019;Pattammattel et al, 2020). This latter approach is often carried out at the same beamline used for the XRF measurements as both techniques rely on a tightly focused X-ray beam.…”