Thursday, August 2 , 2007Volume 7, Issue 4
Materials Research Group Highly Cited
For the second year in a row, a team of Penn State researchers led by Prof. Craig Grimes has landed a paper among the top 5 most cited articles in the premier journal in the field of nanotechnology, Nano Letters.
Their article, "Enhanced Photocleavage of Water Using Titania Nanotube Arrays," was ranked #5 on the 2005 list. Titanium dioxide (also known as titania) is a common material with characteristics that make it of interest to researchers in the fields of energy, biomedicine, optics, and electronics. Titania is also used in the manufacture of sunscreens and paint. The 2005 paper describes a method of controlling the architecture of titania at the nanoscale, using a simple and easily scalable anodization process from a starting titanium film. This study suggests that controlling the nanoscale architecture of titania can greatly increase the photocleavage of water into hydrogen and oxygen gas under ultraviolet light. The ability to create hydrogen by cheap and nonpolluting methods is one of the cornerstones of the proposed hydrogen economy.
Grimes Group
In 2006, a second article by the Grimes group, also describing a new development in titania nanotube arrays, reached the #2 spot on the Nano Letters highly cited list. "Use of Highly-Ordered TiO2 Nanotube Arrays in Dye-Sensitized Solar Cells" describes the first use of transparent, highly ordered titania nanotube arrays as the negative electrode in dye solar cells for the direct conversion of light to electricity. This study indicated that the ability to align the nanotubes so that electrons would have a free path to the electrode could achieve much higher photoconversion efficiency than using nanoparticles or disordered nanotubes.
The co-authors on the two studies are postdoctoral researchers Gopal K. Mor, Maggie Paulose, Oomman K. Varghese, former graduate student now postdoc Karthik Shankar in the Materials Research Institute, and team leader Craig Grimes, professor of electrical engineering and materials science and engineering. Their research is supported by the Department of Energy, DARPA, and the Pennsylvania Energy Development Authority.
