Nanowebs may lead to energy solution

The key to solving the energy crisis may lie in a tiny, webbed structure, less than one one-hundreth the width of a human hair.

Nanowebs, the latest scientific creation spearheaded by Dunwei Wang, a professor in the chemistry department, are microscopic, interlocked titanium and silicon nano-scale wires with potential for alternate energy applications, particularly through solar cells. The flexible, superconductive nanowebs have the ability to split hydrogen from water using sunlight.

Wang and a select number of undergraduate, graduate, and postdoctoral students, dubbed "The Wang Group," began working on the project in January. The technology was developed in just six months, and was conceived only last October, after Wang read a study about the development of nanowires, which limited the growth of the material to one direction. Wang wanted to control the growth of the substance so it grew on one thin, complex plane, large enough to transfer electricity.

"It is actually surprising in a number of ways - it has a better performance in splitting water and better conductivity," Wang said. Typically, smaller materials don't conduct electricity as well. "We are truly actually surprised, in a very good way."

This promising material has a number of potential uses, and is a particularly valuable discovery because it is made from materials that are relatively available on earth: titanium and silicon. This is an important component in solving the "terawatt challenge," or the task of finding a source of energy that can power all of the world's energy-needs. Whatever the solution to the energy crisis might be, the materials have to be largely and readily available.

"For electronics, you can use a tiny bit of the material," Wang said. "For energy, you would want to power an entire house, street, city. You have to use something abundant on earth."

In addition to being abundant, the components need to be easily assembled so the nanowebs can be produced in large quantities. While Wang's nanowebs were originally difficult to conceive, the process of creating the material, once discovered by Wang, is relatively easy to replicate.

"It is very reproducible once you learn all the tricks and find all the secrets. We are making this every day," Wang said.

The energy that would be produced by nanowebs would be a cleaner alternative to fossil fuels. Powered by solar energy, the material splits hydrogen from the oxygen in water, resulting in potential energy that produces no pollution, with zero carbon-emissions.

All of these factors, combined with their physical properties, make nanowebs a discovery with commercial potential down the road. Wang said that while he didn't know when the nanowebs would eventually be applied in wide-spread commercial use, they had numerous possible applications. "For commercialism it's hard to predict - my conservative estimate is 5 to 10 years, but as a scientist, I can't predict markets," Wang said.

The technology of nanowebs solve only a very small part of the energy problem, Wang said. "What we are doing right now is try to reduce the price and increase efficiency. At the end of the day, all the consumer cares about is how much each kilowatt per hour costs."

Wang said it would take a concerted effort by researchers from a number of fields to break down the barriers that prevent alternative energy technology from being widely used. "The whole picture is beyond what I can paint," Wang said.

Soon, Wang said, the scarcity of traditional energy sources will force the development and commercialization of these technologies. "I don't think it will take too long. Soon there won't be a choice."

The Wang Group has been working on a number of other projects involving new uses for nanotechnology and nanowebs. This group, which has already made significant contributions to the scientific community, was only assembled last August after Wang joined Boston College as a professor in the chemistry department.

Wang, who had been working at a post-doctoral scholar at California Technical Institute, said BC was the ideal environment for developing his project.

"Boston College is a very attractive university. A lot of research is going on here and they are very supportive financially," Wang said.

The University also had a brand new nanofabrication facility on Newton Campus that was essential to Wang's research, and a strong science program that supported the undergraduate students who would help him in his work.

"Undergraduate students here at BC are very good. I'm very happy and impressed by their performance," Wang said.

Zainul Hasanali, A&S '09, who has worked under Wang since last August, said that unlike many professors, Wang permitted his students to play a significant role in developing the experiments.

"He is fantastic - a great professor, one of the smartest people I know," Hasanali said. He said that both he and the other undergraduate student, Stafford Sheehan, A&S '11, were given the freedom to take active roles in all the projects the students work on. "He believes that we're smart enough to handle main roles in the projects, which is really refreshing," Hasanali said.

Hasanali said he himself had been recently working to create a nanotube using nanowires, which could also be potentially used as a possible alternative energy source.

"This excellent material is going to have a wide range of applications," Wang said. "It is useful for making many things - some things I can't even imagine yet."

Wang hinted at some of the revolutionary potential applications, but said the findings had yet to be published.

"This is just a start, but it's been a good start," he said.