Interaction of NO with nanosized Ru-, Pd-, and Pt-Doped SnO2: electron paramagnetic resonance, Mössbauer, and electrical investigation.
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.
Canevali
Carmen
C
Dipartimento di Scienza dei Materiali, INSTM-UdR Milano-Bicocca, Università di Milano-Bicocca, Via Cozzi 53, 20125 Milano, Italy.
Mari
Claudio Maria
CM
Mattoni
Mariachiara
M
Morazzoni
Franca
F
Nodari
Luca
L
Ruffo
Riccardo
R
Russo
Umberto
U
Scotti
Roberto
R