A research team from Sungkyunkwan University synthesized a stable form of gold with different physical properties and a different structure from those of naturally occurring gold. The researchers were able to synthesize gold with a stable hexagonal non-close packed (ncp) structure by fabricating gold nanowires in a closed system of TiO2 nanotubes. The photochemical reduction of gold ions reduced these ions to metallic gold upon ultraviolet illumination. Because of a change in structure, there were corresponding changes in the intrinsic properties of gold, such as its melting point and optical properties.
Gold is one of the most chemically stable metals, and it is known to adopt only a face-centered cubic (fcc) crystal structure. The crystal structure of a material determines its physical and chemical properties. Being able to manipulate this structure allows for the easy modification of materials in order to suit specific requirements.
This study creates numerous implications in theoretical and applied fields. It suggests that nanoscale confined systems follow different theories from those of classical thermodynamics, and the method used to modify the gold nanostructure may be applicable to other noble metals as well.