Dispersion-corrected DFT (DFT-D2 and DFT-D3) and van der Waals density functional (vdW-DF) calculations are performed on TiO(2), taking in consideration structures common in the nanoscale, viz. two-dimensional lepidocrocite-like (LL) sheets as well as the rutile, brookite, anatase, and B polymorphs. Dispersion effects, which are of marginal importance when comparing 'monolithic' polymorphs, are stronger when the comparison is extended to LL structures. We find that, on one hand, LL sheets are less stable than previously estimated; on the other, stacking interactions in LL multilayers, though significant, are rather weak. Overall, these findings explain the reluctance of LL-TiO(2) to form ordered stacks.
2D vs. 3D titanium dioxide: Role of dispersion interactions
Forrer D;Vittadini A
2011
Abstract
Dispersion-corrected DFT (DFT-D2 and DFT-D3) and van der Waals density functional (vdW-DF) calculations are performed on TiO(2), taking in consideration structures common in the nanoscale, viz. two-dimensional lepidocrocite-like (LL) sheets as well as the rutile, brookite, anatase, and B polymorphs. Dispersion effects, which are of marginal importance when comparing 'monolithic' polymorphs, are stronger when the comparison is extended to LL structures. We find that, on one hand, LL sheets are less stable than previously estimated; on the other, stacking interactions in LL multilayers, though significant, are rather weak. Overall, these findings explain the reluctance of LL-TiO(2) to form ordered stacks.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
