Characterization of Phosphate Species on Hydrated Anatase TiO2 Surfaces

Frederik Tielens (1) , Christel Gervais (1) , Géraldine Deroy (2) , Maguy Jaber (2) , Lorenzo Stievano (3) , Cristina Coelho Diogo (4) , Jean-Francois Lambert (2)

1 LCMCP - Laboratoire de Chimie de la Matière Condensée de Paris
2 LRS - Laboratoire de Réactivité de Surface
3 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
4 IMPC - Institut des matériaux de Paris-Centre

The adsorption/interaction of KH2PO4 with solvated (100) and (101) TiO2 anatase surfaces is investigated using periodic DFT calculations in combination with GIPAW NMR calculations and experimental IR and solid state 17O, and 31P NMR spectroscopies. A complete and realistic model has been used to simulate the solvent by individual water molecules. The most stable adsorption configurations are characterized theoretically at the atomic scale, and experimentally supported by NMR and IR spectroscopies. It is shown that H2PO4– chemisorbs on the (100) and (101) anatase surfaces, preferentially via a bidentate geometry. Dimer (H3P2O7–) and trimer (H4P3O10–) adsorption models are confronted with monomer adsorption models, in order to rationalize their occurrence.

Domaines: Chimie

Frederik Tielens, Christel Gervais, Géraldine Deroy, Maguy Jaber, Lorenzo Stievano, et al.. Characterization of Phosphate Species on Hydrated Anatase TiO2 Surfaces. Langmuir, 2016, 32 (4), pp.997-1008. ⟨10.1021/acs.langmuir.5b03519⟩. ⟨hal-01269687⟩