Binding of bi-isonicotinic acid to anatase TiO2 (101)

The interaction between dye and semiconductor is a central aspect of dye-se nsitized solar cells. We have in this payer studied the binding of the comm on ligand bi-isonicotinic acid (4,4'-dicarboxy-2,2'-bipyridine) to TiO-2 an atase (101) surfaces by means of quantum chemical calculations. Different a dsorption models were studied with carboxyl oxygens binding to surface Ti a toms, and the acidic protons bonded to surface oxygens. A moderately deform ed surface-binding ligand with two 2 M-bidentate (bridge) dye-surface bonds is found to be more favourable than both the currently prevailing dye-sens itization model of an undeformed 1 M-monodentate tester) binding adsorbate structure, and a 1 M-bidentate surface-binding adsorbate structure, (C) 200 0 Elsevier Science B.V. All rights reserved.