Ultrathin films of TiO2 were grown on a W(100)–O(2 × 1) substrate and characterised with a combination of scanning tunneling microscopy (STM) and low energy electron diffraction. In addition to islands of rutile TiO2(110) with (1 × 1) termination that were reported previously, we also observed rutile TiO2(110) islands with a (1 × 2) film termination. A lepidocrocite-like TiO2 nanosheet was also observed on the W(100) surface. High resolution STM images show that the nanosheet grows in the principal orthogonal directions of the W(100) substrate and forms a commensurate (1 × 7) coincident cell.
HenrichV. E. and CoxP. A.: ‘The surface science of metal oxides’, 1994, Cambridge, Cambridge University Press.
2.
KuhlenbeckH., ShaikhutdinovS. and FreundH-J.: ‘Well-ordered transition metal oxide layers in model catalysis—a series of case studies’, Chem. Rev., 2013, 113, 3986–4034. doi: 10.1021/cr300312n
3.
GrinterD. C., YimC. M., PangC. L., SantosB., MentesT. O., LocatelliA. and ThorntonGeoff: ‘Oxidation state imaging of ceria island growth on Re(0001)’, J. Phys. Chem. C, 2013, 117, 16509–16514. doi: 10.1021/jp405887h
4.
FreundH-J. and PacchioniG.: ‘Oxide ultra-thin films on metals: new materials for the design of supported metal catalysts’, Chem. Soc. Rev., 2008, 37, 2224–2242. doi: 10.1039/b718768h
5.
LuchesP., PagliucaF. and ValeriS.: ‘Morphology, stoichiometry, and interface structure of CeO2 ultrathin films on Pt(111)’, J. Phys. Chem. C, 2011, 115, 10718–10726. doi: 10.1021/jp201139y
6.
FranchyR.: ‘Growth of thin, crystalline oxide, nitride and oxynitride films on metal and metal alloy surfaces’, Surf. Sci. Rep., 2000, 38, 195–294. doi: 10.1016/S0167-5729(99)00013-8
7.
GuoQ., OhW. S. and GoodmanD. W.: ‘Titanium oxide films grown on Mo(110)’, Surf. Sci., 1999, 437, 49–60. doi: 10.1016/S0039-6028(99)00678-0
8.
AshworthT. V. and ThorntonG.: ‘Thin film TiO2 on nickel(110): an STM study’, Thin Solid Films, 2001, 400, 43–45. doi: 10.1016/S0040-6090(01)01445-6
9.
XiaY., ZhuK., KasparT. C., DuY., BirminghamB., ParkK. T. and ZhangZ.: ‘Atomic structure of the anatase TiO2(001) surface’, J. Phys. Chem. Lett., 2013, 4, 2958–2963. doi: 10.1021/jz401284u
10.
SillyF. and CastellM. R.: ‘Formation of single-domain anatase TiO2(001)–(1 × 4) islands on SrTiO3(001) after thermal annealing’, Appl. Phys. Lett., 2004, 85, 3223. doi: 10.1063/1.1805177
11.
DuY., KimD. J., KasparT. C., ChamberlinS. E., LyubinetskyI. and ChmabersS. A.: ‘In-situ imaging of the nucleation and growth of epitaxial anatase TiO2(001) films on SrTiO3(001)’, Surf. Sci., 2012, 606, 1443–1449. doi: 10.1016/j.susc.2012.05.010
12.
DieboldU., RuzyckiN., HermanG. S. and SelloniA.: ‘One step towards bridging the materials gap: surface studies of TiO2 anatase’, Catal. Today, 2003, 85, 93–100. doi: 10.1016/S0920-5861(03)00378-X
13.
PangC. L., LindsayR. and ThorntonG.: ‘Structure of clean and adsorbate-covered single-crystal rutile TiO2 surfaces’, Chem. Rev., 2013, 113, 3887–3948. doi: 10.1021/cr300409r
PapageorgiouA. C., CabailhG., ChenQ., RestaA., LundgrenE., AndersonJ. N. and ThorntonG.: ‘Growth and reactivity of titanium oxide ultrathin films on Ni(110)’, J. Phys. Chem. C, 2007, 111, 7704–7710. doi: 10.1021/jp067802m
16.
PapageorgiouA. C., PangC. L., ChenQ. and ThorntonG.: ‘Low-dimensional, reduced phases of ultrathin TiO2’, ACS Nano, 2007, 1, 409–414. doi: 10.1021/nn700158s
17.
AtreiA., CortigianiB. and FerrariA. M.: ‘Epitaxial growth of TiO2 films with the rutile (110) structure on Ag (100)’, J. Phys.: Condens. Mattter, 2012, 24, 445005. doi: 10.1088/0953-8984/24/44/445005
18.
AtreiA., FerrariA. M., SzieberthD., CortigianiB. and RovidaG.: ‘Lepidocrocite-like structure of the TiO2 monolayer grown on Ag (100)’, Phys. Chem. Chem. Phys., 2010, 12, 11587–11595. doi: 10.1039/c0cp00173b
19.
PangC. L., GrinterD. C., MatharuJ. and ThorntonG.: ‘A scanning tunneling microscopy study of ultrathin film rutile TiO2(110) supported on W(100)–O(2 × 1)’, J. Phys. Chem. C, 2013, 117, 25622–25627. doi: 10.1021/jp409948u
20.
BennettR. A., MulleyJ. S., NewtonM. A. and SurmanM.: ‘Spectroscopy of ultrathin epitaxial rutile TiO2(110) films grown on W(100)’, J. Chem. Phys., 2007, 127, 084707. doi: 10.1063/1.2756842
21.
McCavishN. D. and BennettR. A.: ‘Ultra-thin film growth of titanium dioxide on W(100)’, Surf. Sci., 2003, 546, 47–56. doi: 10.1016/j.susc.2003.09.015
22.
BennettR. A. and McCavishN. D.: ‘Non-stoichiometric oxide surfaces and ultra-thin films: characterisation of TiO2’, Top. Catal., 2005, 36, 11–19. doi: 10.1007/s11244-005-7858-2
23.
AshworthT. V., MurynC. A. and ThorntonG.: ‘Nanodots and other low-dimensional structures of titanium oxides’, Nanotechnology, 2005, 16, 3041–3044. doi: 10.1088/0957-4484/16/12/052
24.
HengererR., BolligerB., ErbudakM. and GrätzelM.: ‘Structure and stability of the anatase TiO2 (101) and (001) surfaces’, Surf. Sci., 2000, 460, 162–169. doi: 10.1016/S0039-6028(00)00527-6
25.
ThomasA. G., FlavellW. R., KumarasingheA. R., MallickA. K., TsoutsouD., SmithG. C., StockbauerR., PatelS., GrätzelM. and HengererR.: ‘Resonant photoemission of anatase TiO2 (101) and (001) single crystals’, Phys. Rev. B, 2003, 67, 035110. doi: 10.1103/PhysRevB.67.035110
26.
AtreiA., BardiU. and RovidaG.: ‘Structure and composition of the titanium oxide layers formed by low-pressure oxidation of the Ni94Ti6(110) surface’, Surf. Sci., 1997, 391, 216–225. doi: 10.1016/S0039-6028(97)00485-8
27.
AgnoliS., MentesT. O., NiñoM. A., LocatelliA. and GranozziG.: ‘A LEEM/μ-LEED investigation of phase transformations in TiOx/Pt(111) ultrathin films’, Phys. Chem. Chem. Phys., 2009, 11, 3727–3732. doi: 10.1039/b821339a
28.
BarcaroG., AgnoliS., SedonaF., RizziG. A., FortunelliA. and GranozziG.: ‘Structure of reduced ultrathin TiOx polar films on Pt(111)’, J. Phys. Chem. C, 2009, 113, 5721–5729. doi: 10.1021/jp811020s
29.
DulubO., HebenstreitW. and DieboldU.: ‘Imaging cluster surfaces with atomic resolution: the strong metal-support interaction state of Pt supported on TiO2(110)’, Phys. Rev. Lett., 2000, 84, 3646–3649. doi: 10.1103/PhysRevLett.84.3646
30.
BennettR. A., PangC. L., PerkinsN., SmithR. D., MorrallP., KvonR. I. and BowkerM.: ‘Surface structures in the SMSI state; Pd on (1 × 2) reconstructed TiO2(110)’, J. Phys. Chem. B, 2002, 106, 4688–4696. doi: 10.1021/jp0138328
31.
OrzaliT., CasarinM., GranozziG., SambiM. and VittadiniA.: ‘Bottom-up assembly of single-domain titania nanosheets on (1 × 2)-Pt(110)’, Phys. Rev. Lett., 2006, 97, 156101. doi: 10.1103/PhysRevLett.97.156101
32.
BreinlichC., BuchholzM., MoorsM., Le MoalS., BeckerC. and WandeltK.: ‘Scanning tunneling microscopy investigation of ultrathin titanium oxide films grown on Pt3Ti(111)’, J. Phys. Chem. C, 2014, 118, 6186–6192. doi: 10.1021/jp4105213
33.
ZhukhlistovA. P.: ‘Crystal structure of lepidocrocite FeO(OH) from the electron-diffractometry data’, Cryst. Rep., 2001, 46, 730–733. doi: 10.1134/1.1405857
34.
VittadiniA. and CasarinM.: ‘Ab initio modeling of TiO2 nanosheets’, Theor. Chem. Acc., 2008, 120, 551–556. doi: 10.1007/s00214-008-0425-8
35.
AgnoliS., OrzaliT., SambiM., VittadiniA., CasarinM. and GranozziG.: ‘Ultrathin TiO2 films on (1 × 2)-Pt(110): a LEED, photoemission, STM, and theoretical investigation’, J. Phys. Chem. C, 2008, 112, 20038–20049. doi: 10.1021/jp807694r
36.
WalleL. E., AgnoliS., SvenumI.-H., BorgA., ArtigliaL., KrügerP., SandellA. and GranozziG.: ‘High resolution photoemission and x-ray absorption spectroscopy of a lepidocrocite-like TiO2 nanosheet on Pt (110) (1 × 2).’, J. Chem. Phys., 2011, 135, 054706. doi: 10.1063/1.3623271
PangC. L., HaycockS. A., RazaH., MurrayP. W., ThorntonG., GülserenO., JamesR. and BullettD. W.: ‘Added row model of TiO2(110) 1 × 2’, Phys. Rev. B, 1998, 58, 1586–1589. doi: 10.1103/PhysRevB.58.1586
39.
ElliottS. D. and BatesS. P.: ‘Assigning the (1 × 2) surface reconstruction on reduced rutile by first-principles energetics’, Phys. Rev. B, 2002, 65, 245145. doi: 10.1103/PhysRevB.65.245415
40.
ElliottS. D. and BatesS. P.: ‘Assignment of the (1 × 2) surface of rutile TiO2(110) from first principles’, Phys. Rev. B, 2003, 67, 035421. doi: 10.1103/PhysRevB.67.035421
41.
AsariE. and SoudaR.: ‘Atomic structure of TiO2(110)-p(1 × 2) and p(1 × 3) surfaces studied by impact collision ion-scattering spectroscopy’, Phys. Rev. B, 1999, 60, 10719–10722. doi: 10.1103/PhysRevB.60.10719
42.
OnishiH. and IwasawaY.: ‘Dynamic visualization of a metal-oxide-surface/gas-phase reaction: time-resolved observation by scanning tunneling microscopy at 800 K’, Phys. Rev. Lett., 1996, 76, 791–794. doi: 10.1103/PhysRevLett.76.791
43.
MurrayP. W., CondonN. G. and ThorntonG.: ‘Effect of stoichiometry on the structure of TiO2(110)’, Phys. Rev. B, 1995, 51, 10989–10997. doi: 10.1103/PhysRevB.51.10989
44.
Blanco-ReyM., AbadJ., RogeroC., MéndezJ., LópezM. F., RománE., Martín-GagoJ. A. and de AndrésP. L.: ‘LEED-IV study of the rutile TiO2(110)-1 × 2 surface with a Ti-interstitial added-row reconstruction’, Phys. Rev. B, 2007, 75.
45.
OnishiH. and IwasawaY.: ‘Reconstruction of TiO2(110) surface: STM study with atomic-scale resolution’, Surf. Sci., 1994, 313, L783–L789. doi: 10.1016/0039-6028(94)91146-0
46.
TakakusagiS., FukuiK-I., NariyukiF. and IwasawaY.: ‘STM study on structures of two kinds of wide strands formed on TiO2(110)’, Surf. Sci., 2003, 523, L41–L46. doi: 10.1016/S0039-6028(02)02353-1
47.
Blanco-ReyM., AbadJ., RogeroC., MéndezJ., LópezM. F., Martin-GagoJ. A. and de AndresP. L.: ‘Structure of rutile TiO2(110)–(1 × 2): formation of Ti2O3 quasi-1D metallic chains’, Phys. Rev. Lett., 2006, 96. 055502 doi: 10.1103/PhysRevLett.96.055502
48.
GuoQ., CocksI. and WilliamsE.: ‘Surface Structure of (1 × 2) Reconstructed TiO2(110) studied using electron stimulated desorption ion angular distribution’, Phys. Rev. Lett., 1996, 77, 3851–3854. doi: 10.1103/PhysRevLett.77.3851
49.
BowkerM. and BennettR. A.: ‘The role of Ti3+ interstitials in TiO2(110) reduction and oxidation’, J. Phys.: Condens. Matter, 2009, 21, 474224. doi: 10.1088/0953-8984/22/5/059801
50.
BennettR. A., StoneP., PriceN. J. and BowkerM.: ‘Two (1 × 2) reconstructions of TiO2(110): surface rearrangement and reactivity studied using elevated temperature scanning tunneling microscopy’, Phys. Rev. Lett., 1999, 82, 3831–3834. doi: 10.1103/PhysRevLett.82.3831
51.
PieperH. H., VenkataramaniK., TorbrüggeS., BahrS., LauritsenJ. V., BesenbacherF., KühnleA. and ReichlingM.: ‘Unravelling the atomic structure of cross-linked (1 × 2) TiO2(110)’, Phys. Chem. Chem. Phys., 2010, 12, 12436–12441. doi: 10.1039/c0cp00160k
52.
FukudaK., SasakiT., WatanabeM., NakaiI., InabaK. and OmoteK.: ‘Novel crystal growth from a two-dimensionally bound nanoscopic system. Formation of oriented anatase nanocrystals from titania nanosheets’, Cryst. Growth Des., 2003, 3, 281–283. doi: 10.1021/cg025619m