Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Revolution in Solar Hydrogen on the Horizon

Abstract:
A cheap and easily scalable technique to produce hydrogen from visible light is close to being a reality.

Revolution in Solar Hydrogen on the Horizon

University Park, PA | Posted on August 15th, 2007

The prospect for the wide spread use of hydrogen as a portable energy carrier is dependent on finding a clean, renewable method of production. At Penn State University, a research group headed by professor of electrical engineering Craig Grimes in the Materials Research Institute is "only a couple of problems away" from developing an inexpensive and easily scalable technique for water photoelectrolysis - the splitting of water into hydrogen and oxygen using light energy - that could help power the proposed hydrogen economy.

Most current methods of hydrogen production split hydrogen from natural gas in a process that produces climate changing greenhouse gas while consuming a nonrenewable resource. A more environmentally friendly approach would produce hydrogen from water using the renewable energy of sunlight.

In a paper published online in Nano Letters on July 3, 2007, lead author Gopal K. Mor, along with Haripriya E. Prakasam, Oomman K. Varghese, Kathik Shankar, and Grimes, describe the fabrication of thin films made of self-aligned, vertically oriented titanium iron oxide (Ti-Fe-O) nanotube arrays that demonstrate the ability to split water under natural sunlight.

Previously, the Penn State scientists had reported the development of titania nanotube arrays with a photoconversion efficiency of 16.5% under ultraviolet light. Titanium oxide (TiO2), which is commonly used in white paints and sunscreens, has excellent charge-transfer properties and corrosion stability, making it a likely candidate for cheap and long lasting solar cells. However, as ultraviolet light contains only about 5% of the solar spectrum energy, the researchers needed to finds a means to move the materials band gap into the visible spectrum.

They speculated that by doping the TiO2 film with a form of iron called hematite, a low band gap semiconductor material, they could capture a much larger portion of the solar spectrum. The researchers created Ti-Fe metal films by sputtered titanium and iron targets on fluorine-doped tin oxide coated glass substrates. The films were anodized in an ethylene glycol solution and then crystallized by oxygen annealing for 2 hours. They studied a variety of films of differing thicknesses and varying iron content. In this paper they report a photocurrent of 2 mA/cm2, and a photoconversion rate of 1.5%, the second highest rate achieved with an iron oxide related material.

The team is now looking into optimizing the nanotube architecture to overcome the low electron-hole mobility of iron. By reducing the wall thickness of the Ti-Fe-O nanotubes to correspond to the hole diffusion length of iron which is around 4nm, the researchers hope to reach an efficiency closer to the 12.9% theoretical maximum for materials with the band gap of hematite.

"As I see it, we are a couple of problems away from having something that will revolutionize the field of hydrogen generation by use of solar energy," Grimes says.

####

About The Pennsylvania State University 108 Materials Research Laboratory
The Materials Research Institute supports interdisciplinary materials research at Penn State, with more than 200 faculty, 800 graduate students, and 200 post doctoral researchers engaged in ground-breaking research in advanced materials.

For more information, please click here

Contacts:
The Pennsylvania State University
108 Materials Research Laboratory
University Park, PA 16802
United States
814-865-0285

Mr. Walter Mills
Associate Editor Publications
814-865-0285

Craig Grimes
(814) 865-9142

Copyright © Newswise

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Announcements

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Nanotechnology and math deliver two-in-one punch for cancer therapy resistance June 24th, 2016

Researchers discover new chemical sensing technique: Technique allows sharper detail -- and more information -- with near infrared light June 24th, 2016

Soft decoupling of organic molecules on metal June 23rd, 2016

Energy

Researchers discover new chemical sensing technique: Technique allows sharper detail -- and more information -- with near infrared light June 24th, 2016

FEI and University of Liverpool Announce QEMSCAN Research Initiative: University of Liverpool will utilize FEIís QEMSCAN technology to gain a better insight into oil and gas reserves & potentially change the approach to evaluating them June 22nd, 2016

Titan shines light on high-temperature superconductor pathway: Simulation demonstrates how superconductivity arises in cuprates' pseudogap phase June 22nd, 2016

New generation of high-efficiency solar thermal absorbers developed June 20th, 2016

Solar/Photovoltaic

New generation of high-efficiency solar thermal absorbers developed June 20th, 2016

Novel capping strategy improves stability of perovskite nanocrystals: Study addresses instability issues with organometal-halide perovskites, a promising class of materials for solar cells, LEDs, and other applications June 13th, 2016

Perovskite solar cells surpass 20 percent efficiency: EPFL researchers are pushing the limits of perovskite solar cell performance by exploring the best way to grow these crystals June 13th, 2016

A type of nanostructure increases the efficiency of electricity-producing photovoltaic June 10th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic