ISSN:
1572-879X
Keywords:
model catalysts
;
spin coating
;
Pt colloid
;
AFM
;
XPS
;
Si wafer
;
particle size
;
oxidation
;
reduction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Platinum particles of 2 nm diameter have been immobilised on oxidised silicon wafers by spin coating with colloidal solutions and characterised by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The coverage and dispersion of the Pt colloids on the Si wafer are controlled by varying the concentration and the spin speed. Under optimal conditions mono-dispersed Pt colloids on silicon wafers are prepared. For the Pt colloids immobilised on the Si wafer, the majority of the stabilising ligands are removed through a reduction (with H2 at 200°C) or an oxidation (in air at 300°C) procedure. AFM showed that particle sizes are retained after the reduction procedure, while significant sintering occurs after oxidation. The mechanism of ligand removal was studied using an in situ XPS reaction cell.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1019062901616
Permalink
