Antiphase Boundaries Accumulation Forming a New C₆₀ Decoupled Crystallographic Phase on the Rutile TiO₂(110)-(1 × 1) Surface

Abstract

C 60 on the rutile TiO 2 (110)-(1×1) surface is known to present a well-ordered p(5×2) surface phase. We have identified another crystallographic phase on this surface characterized by a large unit cell containing four C 60 molecules. This phase, which exhibits four inequivalent C 60 adsorption sites with just two different molecular orientations, is herein explained in terms of an accumulation of the so-called anti-phase boundaries. Among the a priori ten possible anti-phase boundary domains, only three of them can result in possible longrange structures attending to geometrical and energetic considerations. In order to fully characterize the structure and energetics of this new C 60 / TiO 2 (110)-(1×1) phase, an adequate combination of STM and accurate Density Functional Theory-based calculations, including an efficient self-consistent implementation of the vdW interaction, has been used. Results suggest that this new phase is the most stable among all the possible anti-phase boundary domains. On

Energy Level Alignment at the Fullerene/Titanium Oxide Ultrathin Film Interface

“…Here, some point defects can be identified, like the randomly distributed dark features (black encircled), corresponding to missing C 60 molecules. Such missing C 60 molecules are also characteristic for C 60 domains on rutile(110) surfaces and are generated most likely during the island formation process due to the fast growth of the islands. ,, Furthermore, some rare features exhibit a very bright contrast (highlighted by a yellow circle in Figure a) corresponding to an apparent height of 0.30 nm and can be attributed to rare defects in the underlying w′-TiO phase. However, the majority of C 60 molecules displayed in Figure a exhibits a medium contrast.…”

“…The Journal of Physical Chemistry C surfaces and are generated most likely during the island formation process due to the fast growth of the islands. 13,16,17 Furthermore, some rare features exhibit a very bright contrast (highlighted by a yellow circle in Figure 2a) corresponding to an apparent height of 0.30 nm and can be attributed to rare defects in the underlying w′-TiO phase. However, the majority of C 60 molecules displayed in Figure 2a exhibits a medium contrast.…”

“…13 C 60 molecules assemble on the rutile surface in a well-ordered p(5 × 2) as well as in a (5, 2; 2, −3) phase. 16 The molecule/ TMO interface is characterized by a large distance of 0.32−0.33 nm between the carbon atoms of the C 60 and the titanium atoms of the TiO 2 (110) surface. C 60 desorbs completely from the rutile(110) surface for temperatures higher than 600 K, while the sticking temperature is significantly lower, i.e., 420 K and below.…”

“…Rutile­(110) (TiO 2 ) as a prototypical TMO has been tested as a substrate for the assembly of organic molecules and especially fullerenes (C 60 molecules), as prominent components of photovoltaic cells, in a number of studies in the past decade. − It turned out that C 60 molecules are highly mobile on TiO 2 (110) surfaces at room temperature and that nucleation takes place at step edges or substrate defects . C 60 molecules assemble on the rutile surface in a well-ordered p(5 × 2) as well as in a (5, 2; 2, −3) phase . The molecule/TMO interface is characterized by a large distance of 0.32–0.33 nm between the carbon atoms of the C 60 and the titanium atoms of the TiO 2 (110) surface.…”

Self-Sensitized Photocatalytic Degradation of Colorless Organic Pollutants Attached to Rutile Nanorods—Experimental and Theoretical DFT+D Studies

“…Among various wide-band-gap semiconductor materials, rutile TiO 2 ( r -TiO 2 ) is a common substrate for the design of tailored heterointerfaces. − The main exposed (110) facet of the r -TiO 2 crystals is not only very stable but also an excellent template with protruding dangling bonds apt for interacting efficiently with organic compounds such as alcohols (e.g., methanol), phenols (e.g., 4-chlorophenol), or aromatic diols (e.g., catechol). , These organic molecules with different functional groups were used to exploit the site-specific adsorption chemistry of the r -TiO 2 (110) surface …”