Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanostructure boosts efficiency in energy transport

05.03.2009
Complimentary semiconductors enhance 'water-splitting' technique

Overcoming a critical conductivity challenge to clean energy technologies, Boston College researchers have developed a titanium nanostructure that provides an expanded surface area and demonstrates significantly greater efficiency in the transport of electrons.

The challenge has vexed researchers pursuing solar panels thick enough to absorb sunlight, yet thin enough to collect and transport electrons with minimal energy loss. Similarly, the relatively new science of water splitting requires capturing energy within semiconductor materials and then efficiently transporting charges ultimately used to generate hydrogen.

Boston College Asst. Prof of Chemistry Dunwei Wang and members of his lab found that incorporating two titanium-based semiconductors into a nano-scale structure improved the efficiency of power-collecting efforts by approximately 33 percent, the team reported in the online edition of the Journal of the American Chemical Society.

The team achieved a peak conversion efficiency of 16.7 percent under ultraviolet light, reported Wang and his co-authors, BC graduate students Yongjing Lin and Sa Zhou, post doctoral researcher Xiaohua Liu and undergraduate Stafford Sheehan. That compared to an efficiency of 12 percent from a structure composed only of titanium dioxide (TiO2).

Wang said the efficiency gains within the novel material can serve so-called water-splitting, where semiconductor catalysts have been shown to separate and store hydrogen and oxygen gases.

"The current challenge in splitting water involves how best to capture photons within the semiconductor material and then grab and transport them to produce hydrogen," Wang says. "For practical water splitting, you want to generate oxygen and hydrogen separately. For this, good electrical conductivity is of great importance because it allows you to collect electrons in the oxygen-generation region and transport them to the hydrogen-generation chamber for hydrogen production."

By using two crystalline semiconductors – materials critical to the processes of energy capture and transport – Wang says the researchers discovered a new and successful transfer mechanism in an engineered structure nearly invisible to the human eye.

Titanium dioxide has played a key role in early water-splitting research because of its prowess as a catalyst. However, its light absorption is confined to ultraviolet rays only and the material is also a relatively poor conductor.

Wang and his researchers started by growing a nanostructure made of titanium disilicide (TiSi2), a semiconductor capable of absorbing solar light and a material able to provide a sturdy structure with expanded surface area critical to absorbing photons. Still in need of its catalytic capabilities, titanium dioxide was used to coat the structure, Wang said.

The resulting net-like nanostructure effectively separated charges, collecting the electrons in the titanium disilicide core and transporting them away. The structure transferred positive charges to the titanium dioxide region of the material for chemical reactions. In water-splitting, these charges could potentially be used to generate hydrogen.

Ed Hayward | EurekAlert!
Further information:
http://www.bc.edu
http://pubs.acs.org/doi/abs/10.1021/ja808426h

More articles from Life Sciences:

nachricht Molecular Force Sensors
20.09.2017 | Max-Planck-Institut für Biochemie

nachricht Foster tadpoles trigger parental instinct in poison frogs
20.09.2017 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>