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Using 31P and 13C NMR with DFT calculations we demonstrate the exposed surface of titania nanotubes (TiNTs) is a stable, unterminated anatase (0 0 1)-like surface and is catalytically active under ambient conditions. We find that methanol dissociatively adsorbs on the surface of TiNTs agreeing with the predicted activity of surface dissociation of organic molecules on the crystalline (0 0 1)-anatase surface. We further examined the catalytic activity of anatase power, TiNT, and nanosheets in catalytic hydrolysis of S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX) via 31P NMR and demonstrate that titanate-like nanosheets are inactive in the reaction owing to their hydroxylated (0 0 1) surface.

We constructed a truly nanotubular structure model of titania nanotubes based on delaminated anatase with realistic dimensions replicating those observed in experiments. It is shown that this nanotubular structure based on delaminated anatase produces an XRD pattern in excellent agreement with the observed spectrum and that the tube axis is along the [0 1 0] direction of the anatase structure. Preserving the atomic registry of delaminated anatase between adjacent layers is essential along the tube axis but unnecessary along the circumference. These understandings provide detailed information on the structure and morphology of hydrothermally synthesized titania nanotubes. The findings will help discern the complex surface chemistry of these materials.

Anatase, viewed traditionally as a three-dimensional TiO2 structure, has major applications in solar cells, hydrogen production, and catalysis. Here, we report the synthesis, characterization, and structural simulation of a layered nanosheet material that can be described as delaminated anatase along the [001] direction. Counting the outer and interlayer surfaces, such a nanosheet structure maximizes the areas of surfaces which are similar to anatase (001), believed to be the surface of central importance for the superior efficiency of anatase in various applications. Indeed, the important dissociative adsorption process of water predicted to occur on the anatase (001) surface is observed in such nanosheet material. It is also shown that the structure of titania nanotubes, an issue of debate for nearly a decade, can also be described by delaminated anatase along the [001] direction. Interestingly, the strains in such a curved tubular structure lead to major differences in surface chemistry such as water d...

(1) In abstract, last sentence contains a spelling error of word ‘powder’. Should read ‘. . .further examined the catalytic activity of anatase powder. . .’ (2) Nomenclature errors exist in the article on Page 4, in Section 3.2. ‘Catalytic hydrolysis of VX’ that require correction. The anatase powder used in our VX decontamination experiments is referred to as ‘nanocrystals’ and ‘nanoparticles’ in that section of the article.