Adsorption structure of glycine on TiO2(110): A photoelectron diffraction determination

SURFACE SCIENCE

卷:603

Article

Lerotholi, T. J.¹  Kroeger, E. A.²  Knight, M. J.¹  Unterberger, W.²  Hogan, K.³  Jackson, D. C.¹  Lamont, C. L. A.³  Woodruff, D. P.¹ 

[1] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England

[2] Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany

[3] Univ Huddersfield, Dept Chem & Biol Sci, Huddersfield HD1 3DH, W Yorkshire, England

关键词: Surface structure;    Chemisorption;    Photoelectron diffraction;    Titanium dioxide;    Glycine;    Amino acids;   

DOI  :  10.1016/j.susc.2009.05.009

来源: Elsevier

【 摘 要 】

High-resolution core-level photoemission and scanned-energy mode photoelectron diffraction (PhD) of the 0 1s and N 1s states have been used to investigate the interaction of glycine with the rutile TiO2(1 1 0) surface. Whilst there is clear evidence for the presence of the zwitterion NH3+CH2COO- with multilayer deposition, at low coverage only the deprotonated glycinate species, NH2CH2COO is present. Multiple-scattering simulations of the O 1s PhD data show the glycinate is bonded to the surface through the two carboxylate 0 atoms which occupy near-atop sites above the five-fold-coordinated surface Ti atoms, with a Ti-O bondlength of 2.12 +/- 0.06 angstrom. Atomic hydrogen arising from the deprotonation is coadsorbed to form hydroxyl species at the bridging oxygen sites with an associated Ti-O bondlength of 2.01 +/- 0.03 angstrom. Absence of any significant PhD modulations of the N 1s emission is consistent with the amino N atom not being involved in the surface bonding, unlike the case of glycinate on Cu(1 1 0) and Cu(1 0 0). (C) 2009 Elsevier B.V. All rights reserved.

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