Portal de Periódicos da CAPES

Interaction of NO with Nanosized Ru-, Pd-, and Pt-Doped SnO 2 : Electron Paramagnetic Resonance, Mössbauer, and Electrical Investigation

2005; American Chemical Society; Volume: 109; Issue: 15 Linguagem: Inglês

10.1021/jp040740k

1520-6106

Carmen Canevali, C.M. Mari, M. Mattoni, Franca Morazzoni, Luca Nodari, Riccardo Ruffο, Umberto Russo, Roberto Scotti,

Transition Metal Oxide Nanomaterials

The mechanism of NO interaction with nanosized Ru(Pd,Pt)-doped SnO(2) was studied by electron paramagnetic resonance, Mössbauer, and electric resistance measurements. Three steps were proposed for the reaction between the semiconductor oxide and the gaseous component: (i) the formation of bielectronic oxygen vacancies (V(o)) in SnO(2); (ii) their single-ionization (V(o)(*)) with injection of electrons into the SnO(2) conduction band; (iii) the subsequent transfer of electrons from V(o)(*) to [Ru(Pd,Pt)](4+). The last process induces the formation of further oxygen vacancies which reduce the transition metal centers to lower oxidation states; the redox processes is enhanced and the electrical resistance in transition metal-doped SnO(2) is stronger modified with respect to the undoped material.