Shape changes of Pt nanoparticles induced by deposition on mesoporous silica.
Polyvinylpyrollidone (PVP)-capped platinum nanoparticles (NPs) are found to change shape from spherical to flat when deposited on mesoporous silica substrates (SBA-15). Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and extended X-ray absorption fine structure (EXAFS) analyses are used in these studies. The SAXS results indicate that, after deposition, the 2 nm NPs have an average gyration radius 22% larger than in solution, while the EXAFS measurements indicate a decrease in first neighbor co-ordination number from 9.3 to 7.4. The deformation of these small capped NPs is attributed to interactions with the surface of the SBA-15 support, as evidenced by X-ray absorption near-edge structure (XANES).
Instituto de Investigaciones Fisicoquıímicas, Teóricas y Aplicadas (INIFTA), FCE, Universidad Nacional de La Plata - CONICET, Sucursal 4 Casilla de Correo 16 (1900), La Plata, Argentina. lisandro@fisica.unlp.edu.ar
Lisandro J
LJ
Giovanetti
José M
JM
Ramallo-López
Michael
M
Foxe
Louis C
LC
Jones
Matthias M
MM
Koebel
Gabor A
GA
Somorjai
Aldo F
AF
Craievich
Miquel B
MB
Salmeron
Félix G
FG
Requejo