Interactions of Sn2+ dopant ions located on surface sites of anatase-type TiO2 with adsorbed H2S molecules studied using 119Sn Mössbauer spectroscopic probe

Pavel B. Fabritchnyi (1) , Mikhail I. Afanasov (1) , R. A. Astashkin (1) , Alain Wattiaux (2) , Christine Labrugère (3)

1 Department of Chemistry
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 PLACAMAT - Plateforme Aquitaine de Caractérisation des Matériaux

Information provided by 119Sn2+ Mössbauer probe ions, located on surface sites of anatase-type TiO2 microcrystals exposed, at room temperature, to a H2S/H2 mixture, has permitted to conclude that the interaction of H2S molecules with the substrate surface leads to the dissociation of a fraction of the absorbate molecules. This gives rise to the formation of elemental sulfur which oxidizes the neighboring Sn2+ ions, the produced Sn4+ ions being found coordinated only by S2− anions. Subsequent exposure to ambient air is shown to result in the oxidation of S2− ions, yielding both S0 and SO42−-like species, with concomitant stabilization of Sn4+ ions in coordination polyhedra where they are surrounded by only oxygen anions.

Mots clés: Synthetic anatase; Tin dopant cations; 119Sn Mössbauer probe; Dissociative adsorption of H2S; X-ray photoelectron spectroscopy

Domaines: Matériaux

Pavel B. Fabritchnyi, Mikhail I. Afanasov, R. A. Astashkin, Alain Wattiaux, Christine Labrugère. Interactions of Sn2+ dopant ions located on surface sites of anatase-type TiO2 with adsorbed H2S molecules studied using 119Sn Mössbauer spectroscopic probe. Applied Surface Science, 2014, 320, pp.482-486. ⟨10.1016/j.apsusc.2014.09.005⟩. ⟨hal-01078367⟩