Highly ordered atomic monolayer of gold for the first time was constructed on the template of polymerized 10,12-pentacosadiynoic acid (poly-PCDA) monolayer and examined by X-ray Photoelectron Spectroscopy (XPS) and Scanning Tunnel Microscopy (STM). An adsorption-and-reduction method was employed for the construction. The resulting two-dimensional array of gold is rather stable within at least 48 hours at room temperature in the air. In contrast to bulk gold and the randomly occurred two-dimensional islands reported previously, the lattice constant of the array is dramatically enlarged with a nearest- and next-nearest-neighbor spacings of 0.41(0.02nm and 0.50(0.01nm. (-A isotherm determination and UV/vis detection were carried out to examine the interaction between carboxyl groups and HAuCl4. According to which, along with the structural interpretations of the STM images, it is most possible that the gold atoms are finally anchored to or pinned into the hydrophilic surface of the poly-PCDA monolayer, which thus leads to the atomic architecture of gold in two dimensions. The new finding threw itself to the lately aroused hot discussion about the non-metallic, monoatomic forms of some transitional elements, and appears as an positive contribution to them.
Professor Long Jiang
Lab. Colloid and Interface
Institute of Photographic Chemistry, Academia Sinica
Beijing 100101, P.R.China
Tel: 86-10-64888171 ; Fax:86-10-64879375