Raman Spectroscopy Measurements and MP2 Calculations for SOx On Gold Nanocluster Surfaces
Bertina Posada, Samuel Hernandez. Luis Murillo, Roberto Irizarry, Yasuyuki Ishikawa , Julio Briano and Miguel Castro
The University of Puerto Rico at Mayaguez,, US
Keywords: gold nanoparticle, vibrational spectroscopy,Raman, MP2, single particle, adsorption, surface
The reduction of Au3+ with SO3-2 is known to lead to the formation of gold nanoculsters and SO4-2 :
n Au3+ + SO3-2 à + Aun + SO4-2 equation 1
This reaction is fundamental in gold nanocluster synthesis. It has been hypothesized that either SO3-2 or SO4-2 participate in gold particle size control. Particle size control is proposed to occur by the adsorption of SOx species on sub-nanometer sized gold particles. There is however no evidence in the literature for SOx species interacting with gold nanoparticle surfaces. We have performed Raman spectroscopy measurements, in situ, for the reduction of Au3+ with SO3-2 and found direct evidence for the adsorption of both SO3-2 and SO4-2 on gold nanocluster surfaces. The results are consistent with theoretical calculations at the MP2 level.
NSTI Nanotech 2003 Conference Technical Program Abstract