Unravelling the atomic structure of cross-linked (1 × 2) TiO2(110)

TY - JOUR

T1 - Unravelling the atomic structure of cross-linked (1 × 2) TiO2(110)

AU - Pieper, Hans Hermann

AU - Venkataramani, Krithika

AU - Torbrügge, Stefan

AU - Bahr, Stephan

AU - Lauritsen, Jeppe V

AU - Besenbacher, Flemming

AU - Kühnle, Angelika

AU - Reichling, Michael

PY - 2010/10/21

Y1 - 2010/10/21

N2 - The cross-linked (1 × 2) reconstruction of TiO(2)(110) is a frequently observed phase reflecting the surface structure of titania in a significantly reduced state. Here we resolve the atomic scale structure of the cross-linked (1 × 2) phase with dynamic scanning force microscopy operated in the non-contact mode (NC-AFM). From an analysis of the atomic-scale contrast patterns of the titanium and oxygen sub-structures obtained by imaging the surface with AFM tips having different tip apex termination, we infer the hitherto most accurate model of the atomic structure of the cross-linked (1 × 2) phase. Our findings suggest that the reconstruction is based on added rows in [001] direction built up of Ti(3)O(6) units with an uninterrupted central string of oxygen atoms accompanied by a regular sequence of cross-links consisting of linear triples of additional oxygen atoms in between the rows. The new insight obtained from NC-AFM solves previous controversy about the cross-linked TiO(2)(110) surface structure, since previously proposed models based on cross-links with a lower O content do not appear to be consistent with the atom-resolved data presented here. Instead, our measurements strongly support the Ti(3)O(6) motif to be the structural base of the cross-linked (1 × 2) reconstruction of TiO(2)(110).

AB - The cross-linked (1 × 2) reconstruction of TiO(2)(110) is a frequently observed phase reflecting the surface structure of titania in a significantly reduced state. Here we resolve the atomic scale structure of the cross-linked (1 × 2) phase with dynamic scanning force microscopy operated in the non-contact mode (NC-AFM). From an analysis of the atomic-scale contrast patterns of the titanium and oxygen sub-structures obtained by imaging the surface with AFM tips having different tip apex termination, we infer the hitherto most accurate model of the atomic structure of the cross-linked (1 × 2) phase. Our findings suggest that the reconstruction is based on added rows in [001] direction built up of Ti(3)O(6) units with an uninterrupted central string of oxygen atoms accompanied by a regular sequence of cross-links consisting of linear triples of additional oxygen atoms in between the rows. The new insight obtained from NC-AFM solves previous controversy about the cross-linked TiO(2)(110) surface structure, since previously proposed models based on cross-links with a lower O content do not appear to be consistent with the atom-resolved data presented here. Instead, our measurements strongly support the Ti(3)O(6) motif to be the structural base of the cross-linked (1 × 2) reconstruction of TiO(2)(110).

U2 - 10.1039/c0cp00160k

DO - 10.1039/c0cp00160k

M3 - Journal article

C2 - 20714579

SN - 1463-9084

VL - 12

SP - 12436

EP - 12441

JO - Physical chemistry chemical physics : PCCP

JF - Physical chemistry chemical physics : PCCP

IS - 39

ER -