June 11, 2009

Interconnected carbon nanostructures made

U.S. scientists have formed interconnected carbon nanostructures on graphene substrates in a study that might lead to new carbon-based devices.

The researchers from the University of Pennsylvania, Sandia National Laboratories and Rice University said the simple assembly process involves heating few-layer graphene sheets to sublimation using electric current.

Curvy nanostructures such as carbon nanotubes and fullerenes have extraordinary properties, the scientists said, but are extremely challenging to pick up, handle and assemble into devices after synthesis.

Penn Associate Professor Ju Li and Sandia scientist Jianyu Huang, the study's co-leaders, developed an idea to construct curvy nanostructures directly integrated on graphene, since the atomically thin two-dimensional sheet bends easily with open edges that can then permanently fuse with other open edges.

The experiments were performed inside an electron microscope using electrical current generating up to 2000 degrees Celsius heat.

This study demonstrates it is possible to make and integrate curved nanostructures directly on flat graphene, which is extended and electrically conducting, said Li. Furthermore, it demonstrates that multiple graphene sheets can be intentionally interconnected.

The research that included Liang Qi at the University of Pennsylvania, Ping Lu at Sandia and Feng Ding and Boris Yakobson at Rice is reported in the Proceedings of the National Academy of Sciences.