Fibrous nanostructures formation using helium plasma and their applications as functional materials

Growth of fibrous nanostructures by helium plasma irradiation has been found on the surface of transition metals such as tungsten and molybdenum. These fibrous nanostructured surfaces are expected to be applied as functional materials because of their increased surface area and high photon absorption rates.

The fibrous nanostructures have been observed on a variety of metals, and there are differences in the formation conditions and shapes of the nanostructures depending on the metals. Based on these experimental findings, models of the formation mechanism will be discussed in the beginning of the presentation.

Recent studies show improved sensitivities of this fibrous nanostructures in trace gas sensing tests. Sensors having the fibrous nanostructured surface were prepared and tested for ethanol, hydrogen, and ethylene gases. Sensitivity improvements of up to 300% have been confirmed by a comparison between a flat surface and the fibrous surface. Further improvements can be achieved if we optimize the plasma irradiation conditions.

As well as the gas sensor, the fibrous nanostructure can also be applied to electrodes. Performance of the fibrous nanostructure surface as photo-catalysis, thermal-catalysis and lithium-ion battery electrode will also be presented.

In summary, remaining open questions for the formation mechanism of the nanostructure and the prospects of this material’s applications will be discussed.