 |
|
Tiny Tubes and Rods Show Promise as Catalysts, Sunscreen
September 11, 2007Scientists 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).
This research, which has clear connections to improved energy technologies, was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science.
Collaborators on the Advanced Materials paper include Lijun Wu, Robert F. Klie, and Yimei Zhu, all of Brookhaven's Center for Functional Nanomaterials (CFN). For the Journal of Physical Chemistry paper, collaborators include Brookhaven chemists Wen Wen and Jonathan Hanson; Ding Yi, Mathew Maye, and Oleg Gang of the CFN; Zhenxian Liu of the Carnegie Institution of Washington; and Laura Lewis, formerly at the CFN and now at Northeastern University.
Brookhaven National Laboratory
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).
This research, which has clear connections to improved energy technologies, was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science.
Collaborators on the Advanced Materials paper include Lijun Wu, Robert F. Klie, and Yimei Zhu, all of Brookhaven's Center for Functional Nanomaterials (CFN). For the Journal of Physical Chemistry paper, collaborators include Brookhaven chemists Wen Wen and Jonathan Hanson; Ding Yi, Mathew Maye, and Oleg Gang of the CFN; Zhenxian Liu of the Carnegie Institution of Washington; and Laura Lewis, formerly at the CFN and now at Northeastern University.
Brookhaven National Laboratory
Titanium Oxide Current Events and Titanium Oxide News RSSDomain Walls that Conduct Electricity
The logic and memory functions of future electronic devices could shrink dramatically - to one or two nanometers (billionths of a meter) instead of the many tens of nanometers that characterize today's most advanced elements - if a way can be found to control domain walls, the ultrathin transition zones that separate regions of a material having different magnetic, electric, or other properties.
Photonic crystal biosensors detect protein-DNA interactions
Scientists at the University of Illinois have developed a new class of disposable, microplate-based optical biosensors capable of detecting protein-DNA interactions. Based on the properties of photonic crystals, the biosensors are suitable for the rapid identification of inhibitors of protein-nucleic acid and protein-protein interactions.
NIST and partners identify tiny gold clusters as top-notch catalysts
For most of us, gold is only valuable if we possess it in large-sized pieces. However, the "bigger is better" rule isn't the case for those interested in exploiting gold's exceptional ability to catalyze a wide variety of chemical reactions, including the oxidation of poisonous carbon monoxide (CO) into harmless carbon dioxide at room temperatures.
Popcorn-ball design doubles efficiency of dye-sensitized solar cells
A new approach is able to create a dramatic improvement in cheap solar cells now being developed in laboratories.
'Hot' oxygen atoms on titanium dioxide motivated by more than just temperature
Like two ballroom dancers waltzing together, the two atoms of an oxygen molecule severed by a metal catalyst usually behave identically. But new research reveals that on a particular catalyst, split oxygen atoms act like a couple dancing the tango: one oxygen atom plants itself while the other shimmies away, probably with energy partially stolen from the stationary one.
Nanowire coating for bone implants, stents
University of Arkansas researchers have found a simple, inexpensive way to create a nanowire coating on the surface of biocompatible titanium that can be used to create more effective surfaces for hip replacement, dental reconstruction and vascular stenting.
Researchers think pink to produce 'green' solar energy
When it comes to producing earth-friendly solar energy, pink may be the new green, according to Ohio State University researchers. Scientists here have developed new dye-sensitized solar cells, that get their pink color from a mixture of red dye and white metal oxide powder in materials that capture light.
Nature's secrets yield new adhesive material
Scientists report they have merged two of nature's most elegant strategies for wet and dry adhesion to produce a synthetic material that one day could lead to more durable and longer-lasting bandages, patches, and surgical materials.
Higher efficiency organic solar cell created by UCSB Nobel Laureate and research team
Using plastics to harvest the energy of the sun just got a significant boost in efficiency thanks to a discovery made at the Center for Polymers and Organic Solids at the University of California, Santa Barbara.
Solar energy: Charged for the future
Once regarded as costly and impractical, solar technology is now poised to play a larger role in the future, thanks to new developments that could result in lower costs and improved efficiency.
More Titanium Oxide Current Events and Titanium Oxide News Articles
![Study of adsorption of phenol on titanium oxide (TiO"2) [An article from: Desalination]](http://ecx.images-amazon.com/images/I/51W2ZTSE75L._SL160_.jpg) |
Study of adsorption of phenol on titanium oxide (TiO"2) [An article from: Desalination] by S. Bekkouche (Author), M. Bouhelassa (Author), N.H. Salah (Author), Meghlaoui (Author) This digital document is a journal article from Desalination, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The application of photocatalysis in the treatment of organic micropollutants in wastewater is an interesting alternative and is the object of a great interest over the last years by many researchers. The stage of adsorption of the micropollutant on the photocatalyst, mainly the titanium oxide anatase form, is a determining stage in the process of photodegradation. We present an experimental study of the adsorption of phenol, chosen as the model pollutant, on a photocatalyst, titanium oxide anatase (Degussa P25). The... |
 |
Sponix Sunscreen Spf 38, Zinc Oxide And Titanium Dioxide, 4-Ounce Boxes (Pack of 2) by Sponix Sponix- Sunscreen Lotion SPF 38 |
 |
Irwin Industrial Tools 314018 Black Oxide Drill Bit Set, 18-Piece by IRWIN The bits in this handy 18-piece set are coated with black oxide for added corrosion resistance and smoother drilling operations. High Speed Steel means smoother, faster drilling. This set comes in a durable rubber-sided case for added impact resistance. The case's sliding latch keeps the bits from spilling out into the dirt. This set includes 18 commonly used bits including: 1/16"(2), 5/64", 3/32"(2), 7/64", 1/8"(2), 9/64", 5/32", 11/16", 3/16", 13/64", 7/32", 1/4", 5/16", 3/8" and 1/2". |
 |
Kershaw Scallion Knife with Stainless-Steel Titanium-Oxide Multi-Colored Coating by Kershaw The Scallion is ideal for knife users who prefer a slightly larger knife than the Chive, but one that's still compact, features great styling, and performs like a champ. It's 3 1/2 inch folded size makes it perfect for everyday pocket carry. What's more, it offers high-performance styling, plus the convenience of SpeedSafe ambidextrous manually assisted opening. Just pull back on the blade protrusion or use the thumb-stud for easy SpeedSafe opening. As with all Kershaw SpeedSafe knives, the torsion bar holds the blade safely in the handle until the user releases it. And it won't allow the blade to fall back into the handle until the user pushes it into place. For additional safety, the Safety Tip Lock keeps the blade secure even when carried in a pocket. For good edge retention and... |
 |
Windchaser MDHTi-W Personal Dehumidifier with UV / Titanium Oxide Filter (TiO2) by WindChaser Products, Inc. The Windchaser Personal Dehumidifier with UV/Titanium Oxide Filter and Continuous Drain Option has a modern design with a warm air outlet at the top for drying purposes. The Titanium Oxide Filter is a photocatalyst filterwhich works under natural UVlight to kill more than 90% of bacteria, mold and other volatileorganic compounds and to remove odor. Ideal for use in small areas such as a closet, storage room, kitchen cabinet or baby's room. Moisture removal : 1.26 pts. (6000 ml) per day at 86 degrees farenheit. Water tank capacity 2.11pts (1 liter). Power consumption : 65watts. |
|
Kids by Baby Blanket Sunscreen Lotion, SPF 50, with Cherry Lip Block, SPF 30 (Pack of 3) by Kids by Baby Blanket Kids by Baby Blanket Sunscreen Lotion, SPF 45, with Cherry Lip Block, SPF 30 | |
 |
Killer GT Red Mirror Titanium Oxide Coated Lenses Sunglasses Motorcycle Glasses by SPITS MOTORCYCLE SUNGLASSES |
 |
X-Fiber Car Air Cleaner by Compact-Impact.com This is the perfect solution for air in the car! Just by utilizing light, it constantly cleans and sanitizes the air inside your car. It even reduces Formaldehyde in the air! The effects last about 1 year. No smells or chemicals, it is perfect for family with children. The Titanium DiOxide Photo Catalyst is the most environmental invention of 21st century. Size : 4" x 3.5" x 5/8" Weight : 9oz |
|
Environmentally Benign Photocatalysts: Applications of Titanium Oxide-based Materials (Nanostructure Science and Technology) by Masakazu Anpo (Editor), Prashant Kamat (Editor) Titanium oxide-based catalysts are especially promising as one of the most stable, non toxic, easily available photofunctional materials known today. Previously, the successful development of second-generation titanium oxide photocatalysts using an advanced metal ion-implantation technique led to reactions that could be induced not only with UV but also visible light. Since then, not only has efficiency been improved but new materials and synthesis methods have also been developed. This book will cover the various approaches in the design of efficient titanium oxide-based photocatalysts by such methods as sol-gel, precipitation, dip-coating, metal implantation and sputtering deposition. It will cover the most recent advances in TiO2 research and their potential applications as well as... | |
 |
The 2009 Import and Export Market for Titanium Oxides in Latin America by Icon Group International (Author) On the demand side, exporters and strategic planners approaching the market in Latin America face a number of questions. Which countries are supplying titanium oxides to Latin America? What is the dollar value of these imports? How much do the imports of titanium oxides vary from one country to another in Latin America? Do exporters serving the market in Latin America have similar market shares across the importing countries? On the supply side, Latin America also sells to the international market of titanium oxides. Which countries in Latin America supply the most exports of titanium oxides? Which countries are buying their exports? What is the value of these exports and which countries are the largest buyers? This report was created for strategic planners, international marketing... |
| © 2009 BrightSurf.com |