Navigation Links
Tiny tubes and rods show promise as catalysts, sunscreen
Date:9/10/2007

UPTON, NY - Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have developed new ways to make or modify nanorods and nanotubes of titanium oxide, a material used in a variety of industrial and medical applications. The methods and new titanium oxide materials may lead to improved catalysts for hydrogen production, more efficient solar cells, and more protective sunscreens. The research is published in two papers now available online, one in Advanced Materials (August 22, 2007), and the other in the Journal of Physical Chemistry (September 8, 2007).

In the first study, the scientists enhanced the ability of titanium oxide to absorb light.

"Titanium dioxide's ability to absorb light is one the main reasons it is so useful in industrial and medical applications," said Wei-Qiang Han, a scientist at Brookhaven's Center for Functional Nanomaterials (CFN) and lead author on both papers. It is used as a photocatalyst for converting sunlight to electricity in solar cells and also has applications in the production of hydrogen, in gas sensors, in batteries, and in using sunlight to degrade some environmental contaminants. It is also a common ingredient in sunscreen.

Many scientists have explored ways to improve the light-absorbing capability of titanium oxide, for example, by "doping" the material with added metals. Han and his coworkers took a new approach. They enhanced the material's light-absorption capability by simply introducing nanocavities, completely enclosed pockets measuring billionths of a meter within the 100-nanometer-diameter solid titanium oxide rods.

The resulting nanocavity-filled titanium oxide nanorods were 25 percent more efficient at absorbing certain wavelengths of ultraviolet A (UVA) and ultraviolet B (UVB) solar radiation than titanium oxide without nanocavities.

"Our research demonstrates that titanium oxide nanorods with nanocavities can dramatically improve the absorption of UVA and UVB solar radiation, and thus are ideal new materials for sunscreen," Han said.

The cavity-filled nanorods could also improve the efficiency of photovoltaic solar cells and be used as catalysts for splitting water and also in the water-gas-shift reaction to produce pure hydrogen gas from carbon monoxide and water.

The method for making the cavity-filled rods is simple, says Han. "We simply heat titanate nanorods in air. This process evaporates water, transforming titanate to titanium oxide, leaving very densely spaced, regular, polyhedral nanoholes inside the titanium oxide."

In the second paper, Han and his collaborators describe a new synthesis method to make iron-doped titanate nanotubes, hollow tubes measuring approximately 10 nanometers in diameter and up to one micrometer (one millionth of a meter) long. These experiments were also aimed at improving the material's photoreactivity. The scientists demonstrated that the resulting nanotubes exhibited noticeable reactivity in the water-gas-shift reaction.

"Although the activity of the iron-doped nanotubes was not as good as that of titanium oxide loaded with metals such as platinum and palladium, the activity we observed is still remarkable considering that iron is a much less expensive metal and its concentration in our samples was less than one percent," Han said.

The scientists also observed interesting magnetic properties in the iron-doped nanotubes, and will follow up with future studies aimed at understanding this phenomenon.

Materials developed in these studies were analyzed using several of Brookhaven Lab's unique tools and methods for the characterization of nanostructures, including transmission electron microscopy and various techniques using x-ray and infrared beams at the Lab's National Synchrotron Light Source (NSLS).


'/>"/>

Contact: Karen McNulty Walsh
kmcnulty@bnl.gov
631-344-8350
DOE/Brookhaven National Laboratory
Source:Eurekalert

Related biology news :

1. Nanoparticles, nanoshells, nanotubes: How tiny specks may provide powerful tools against cancer
2. Motorola researchers develop selective sensors based on carbon nanotubes
3. Gadonanotubes greatly outperform existing MRI contrast agents
4. Nanotubes inspire new technique for healing broken bones
5. Modifications render carbon nanotubes nontoxic
6. Carbon nanotubes that detect disease-causing mutations developed by Pitt researcher
7. Detection of DNA on nanotubes offers new sensing, sequencing technologies
8. Stable polymer nanotubes may have a biotech future
9. Nanotubes used for first time to send signals to nerve cells
10. Pure carbon nanotubes pass first in vivo test
11. Neural networking nanotubes
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2016)... 2016   EyeLock LLC , a market leader ... of an IoT Center of Excellence in ... development of embedded iris biometric applications. EyeLock,s ... and security with unmatched biometric accuracy, making it the ... DNA. EyeLock,s platform uses video technology to deliver a ...
(Date:4/28/2016)... April 28, 2016 First quarter 2016:   ... 966% compared with the first quarter of 2015 The ... 589.1 M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) ... guidance is unchanged, SEK 7,000-8,500 M. The operating margin ...
(Date:4/15/2016)... April 15, 2016 Research ... Gait Biometrics Market 2016-2020,"  report to their offering.  ... ) , ,The global gait biometrics market is ... during the period 2016-2020. Gait analysis ... can be used to compute factors that are ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Mass. , June 23, 2016   ... development of novel compounds designed to target cancer ... napabucasin, has been granted Orphan Drug Designation from ... the treatment of gastric cancer, including gastroesophageal junction ... stemness inhibitor designed to inhibit cancer stemness pathways ...
(Date:6/23/2016)... , June 23, 2016 Houston ... with the Cy-Fair Sports Association to serve as ... the agreement, Houston Methodist Willowbrook will provide sponsorship ... and connectivity with association coaches, volunteers, athletes and ... with the Cy-Fair Sports Association and to bring ...
(Date:6/23/2016)... -- The Biodesign Challenge (BDC), a university competition that asks ... systems and biotechnology, announced its winning teams at the ... York City . The teams, chosen ... MoMA,s Celeste Bartos Theater during the daylong summit. Keynote ... of architecture and design, and Suzanne Lee , ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the sample tracking software company, ... Crime Laboratory, has joined STACS DNA as a Field Application Specialist. , “I ... President and COO of STACS DNA. “In further expanding our capacity as a scientific ...
Breaking Biology Technology: