Influence of thermal treatment on nanostructured gold model catalysts.
We fabricated films of Au onto single crystal alumina (Al(2)O(3)(0001)) and nanostructured the surface using a high resolution focused ion beam (FIB) to remove specific regions of the film. The nanostructures consist of lines and orthogonal lines cut into the film, resulting in one- and two-dimensional islands of gold. When these films are heated above 300 °C, small nanoparticles of gold form due to the dewetting of the Au film from the alumina surface. The dimensions of these islands are dictated by the nature of the nanopatterning. The isolated islands generally have the smallest nanoparticles after heating, while the unpatterned film has much larger particles. Sintering is reduced within the nanostructured metal domains due to isolation of Au islands from each other. The evaporation rate is higher within these islands, due to the smaller size of nanoparticles and hence the higher effective vapor pressure over the surface (the Kelvin effect).
Wolfson Nanoscience Laboratory and Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff CF10 3AT, United Kingdom.
Michael
M
Bowker
Melissa
M
Broughton
Albert
A
Carley
Phil
P
Davies
David
D
Morgan
Jon
J
Crouch
Georgi
G
Lalev
Stefan
S
Dimov
Duc-Truong
DT
Pham
D000537:Aluminum Oxide / Q000737:chemistry*; D002384:Catalysis; D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry*; D008958:Models, Molecular; D010316:Particle Size; D011312:Pressure; D013499:Surface Properties; D013696:Temperature
D008567:Membranes, Artificial; D006046:Gold; D000537:Aluminum Oxide