17 May 2018
Clean fuel, smart devices thanks to versatile nanotubes
Published online 4 June 2016
Scientists present a new way to harvest sunlight and generate hydrogen fuel.
Porous and hollow nanotubes made of titanium dioxide can harness solar energy and split water, providing a cheap way to generate hydrogen fuel for cars1.
These nanotubes can also be integrated with metal-oxide semiconductor field-effect transistors, making them potentially useful for fabricating smart electronic devices, as per a new study by a research team led by Nageh Allam from the American University in Cairo, Egypt.
The scientists created nanotubes using a cost-effective method known as galvanostatic anodization process. The tubes possess high surface area and the ability to induce directional charge transfer.
When heated to 400 °C, the nanotubes exhibited maximum solar-light-induced current which was almost three times higher than those of conventional nanotubes.
Heating helped increase the current by reducing bulk defects in addition to increasing crystallinity and the active surface sites of the nanotubes. In addition, the photons absorbed by the nanotubes also enhanced the current.
Because of their ability to convert solar energy into electrical energy, the nanotubes need smaller voltage to split water than their conventional counterparts.
“In the future, the nanotubes could potentially be used to make electrochrome devices that can control the transmission of light and solar energy passing through them,” says Allam.
- Samir, M., et al. Sub-100 nm TiO2 tubular architectures for efficient solar energy conversion. J. Mater. Chem. A http://dx.doi.org/10.1039/C6TA03156K (2016).