RT Journal Article
T1 Assembly, Growth, and Catalytic Activity of Gold Nanoparticles in Hollow Carbon Nanofibers
A1 Giménez López, María del Carmen
A1 La Torre, Alessandro
A1 Fay, Michael W.
A1 Rance, Graham
A1 Solomonsz, William A.
A1 Chamberlain, Thomas W.
A1 Brown, Paul
A1 Khlobystov, Andrei N.
K1 Carbon nanofibres
K1 Gold nanoparticles
K1 Encapsulation
K1 Nanoparticle growth
K1 Nanoparticle assembly
AB Graphitized carbon nanofibers (GNFs) act as efficient templates for the growth of gold nanoparticles (AuNPs) adsorbed on the interior (and exterior) of the tubular nanostructures. Encapsulated AuNPs are stabilized by interactions with the step-edges of the individual graphitic nanocones, of which GNFs are composed, and their size is limited to approximately 6 nm, while AuNPs adsorbed on the atomically flat graphitic surfaces of the GNF exterior continue their growth to 13 nm and beyond under the same heat treatment conditions. The corrugated structure of the GNF interior imposes a significant barrier for the migration of AuNPs, so that their growth mechanism is restricted to Ostwald ripening. Conversely, nanoparticles adsorbed on smooth GNF exterior surfaces are more likely to migrate and coalesce into larger nanoparticles, as revealed by in situ transmission electron microscopy imaging. The presence of alkyl thiol surfactant within the GNF channels changes the dynamics of the AuNP transformations, as surfactant molecules adsorbed on the surface of the AuNPs diminished the stabilization effect of the step-edges, thus allowing nanoparticles to grow until their diameters reach the internal diameter of the host nanofiber. Nanoparticles thermally evolved within the GNF channel exhibit alignment, perpendicular to the GNF axis due to interactions with the step-edges and parallel to the axis because of graphitic facets of the nanocones. Despite their small size, AuNPs in GNF possess high stability and remain unchanged at temperatures up to 300 °C in ambient atmosphere. Nanoparticles immobilized at the step-edges within GNF are shown to act as effective catalysts promoting the transformation of dimethylphenylsilane to bis(dimethylphenyl)disiloxane with a greater than 10-fold enhancement of selectivity as compared to free-standing or surface-adsorbed nanoparticles.
PB American Chemical Society
YR 2012
FD 2012
LK http://hdl.handle.net/10347/32154
UL http://hdl.handle.net/10347/32154
LA eng
NO La Torre, A., Giménez-López, M. C., Fay, M. W., Rance, G. A., Solomonsz, W. A., Chamberlain, T. W., Brown, P. D., Khlobystov, A. N. (2012). Assembly, Growth, and Catalytic Activity of Gold Nanoparticles in Hollow Carbon Nanofibers."ACS Nano". vol 6 (3), 2000-2007
NO The authors thank the European Science Foundation, the Royal Society, Marie CurieFellowship and the University of Nottingham for supporting this research, theNottingham Nanoscience and Nanotechnology Centre for access to TEM facilities andDr Nigel Neate and Keith Dinsdale for technical support.The authors acknowledge the use of the Kratos Axis ULTRA XPS in the School ofChemistry and Emily Smith for running the samples and helpful discussions on datainterpretation.
DS Minerva
RD 24 abr 2026