Noncrystallographic atomic arrangement driven enhancement of the catalytic activity of Au nanoparticles

Determining the atomic-scale structure of nanosized particles remains a challenge and crucial goal for today's science and technology. We investigate the atomic-scale structure of 3-8 nm Au particles obtained by a fast solution reaction and find it to be of a noncrystallographic icosahedral type, in particular, close to the particles' surface. This noncrystallographic structure may well explain the previously observed but poorly understood enhancement of the particles' catalytic properties. Our finding demonstrates that together with size the structure type of nanosized particles can be used as a tunable parameter for achieving improved functionality.