¹⁷O Solid-State NMR Studies of Ta₂O₅ Nanorods

Abstract

17O solid-state NMR spectroscopy was used to study the structure of Ta2O5 nanorods for the first time. Although the observations of oxygen ions in the “bulk” part of the Ta2O5 nanorods can be achieved with conventional high-temperature enrichment with 17O2, low-temperature isotopic labeling with H2 17O generated samples whose surfaces are selectively enriched, leading to surface-only detection of oxygen species. By applying 17O–1H double-resonance NMR techniques and 1H NMR spectroscopy, surface hydroxyl species and adsorbed water can also be studied. The results form the basis for further understanding of the structure–property relationship of Ta2O5 nanomaterials.

Double-resonance17O NMR experiments reveal unique configurational information for surface organometallic complexes

“…21 This procedure is general and can be applied to any oxide support. 22–26 At most, this procedure can lead to an enrichment at half the enrichment level of the water at each step, but in practice, we observe roughly a quarter (Fig. 1b).…”

Emerging Applications of 17O Solid-State NMR Spectroscopy for Catalytic Oxides

“…Many of the above examples achieve very high resolution with single pulse NMR at a relatively low magnetic field (9.4 T) because of small C Q s. For more covalent oxides or surface species with large C Q s (e.g., hydroxyls), significant line broadening from quadrupolar interactions result in poor resolution/sensitivity. , Therefore, it is desired to perform 17 O NMR experiments for oxide nanomaterials at a high external field with a multidimensional NMR approach. , Five distinct bare oxygen species in γ-Al 2 O 3 , one of the most widely used catalysts or catalyst supports, can be detected in 17 O 2D-MQMAS NMR spectra at 18.8 T or higher, while the 17 O 2D-double quantum NMR spectrum obtained at 35.2 T provides the spatial proximity among these sites (Figure a). In combination with 2D 1 H-{ 17 O} J-HMQC and D-HMQC experiments (Figure b), which give through-bond and through-space O–H connectivity information, respectively, detailed structure of the high surface area γ-Al 2 O 3 sample can be mapped …”

Teaching new tricks to old dogs: A review of drug repositioning of disulfiram for cancer nanomedicine

“…A Cu 2+ nanoparticle‐induced DSF capture strategy in the tumor was proposed. [ 95 ] The nanoparticles were prepared by covalently cross‐linking ferritin and albumin, then the copper ions were encapsulated into the ferritin nanocage to form ferritin−albumin−Cu nanoparticle (FHC NP). The i.v.…”