The crystal characteristics of gold particles grown on an amorphous ca
rbon film in a 10(-3)-10(-5)M HAuCl4 solution at different electrode p
otentials have been studied by means of electron microscopy and electr
on diffraction. The results show that the gold particles grown at diff
erent electrode potentials have different shapes, i.e., the particles
formed at negative potential (versus SCE) consist mainly of icosahedra
l and decahedral particles, while at positive potential (versus SCE) f
ee octahedral single crystal particles are dominant. Decahedral partic
les grown to 80 nm and icosahedral particles grown to 32 nm were obser
ved at negative potentials. At positive potentials the icosahedral and
decahedral particles only grew to about 10 nm. From these results it
is clear that at negative potentials the gold particles prefer the gro
wth of decahedral and icosahedral structures, but at positive potentia
ls the fee crystal structure is preferred. The characteristics of the
gold particles depend upon the electrode potential at which the partic
les are grown, but it is not influenced by the concentration of the HA
uCl4 electrolyte. The results will be discussed in relation to the pot
ential-dependent surface reconstruction of Au(111), Au(110) and Au(100
) surfaces.