Source: The Watchers - 2/02/13, By Nix
Hydrogen is a zero-emission fuel and arguably an excellent candidate of alternative energy. Use of hydrogen extracted from water to generate electricity is a topic of an ongoing debate. Recent experiments by University at Buffalo researchers revealed how silicon can be used to produce energy efficiently. They created spherical silicon nano particles that react with water to form silicic acid (a nontoxic byproduct) and hydrogen. What’s more, this process doesn’t require light, heat or electricity and produce hydrogen instantaneously. Hydrogen produced during experiments was relatively pure as researchers tested it successfully in a small fuel cell that powered a fan.
Researcher Mark T. Swihart, UB professor of chemical and biological engineering and director of the university’s Strategic Strength in Integrated Nanostructured Systems said,
“When it comes to splitting water to produce hydrogen, nanosized silicon may be better than more obvious choices that people have studied for a while, such as aluminum.”
Research team found that 10-nonometer particles created by them produced hydrogen about 150 times faster than similar reactions using silicon particles 100 nanometers wide, and 1,000 times faster than bulk silicon. Also, these nano particles had amazing speed of reaction with water – they produced more hydrogen in a minute than 100-nanometer particles produced in 45 minutes. Furthermore, Maximum rate of reaction of 10-nanometer particles was about 150 times faster. Researcher Paras Prasad, executive director of UB’s Institute for Lasers, Photonics and Biophotonics (ILPB) and a SUNY Distinguished Professor in UB’s Departments of Chemistry, Physics, Electrical Engineering and Medicine said,
“With further development, this technology could form the basis of a ‘just add water’ approach to generating hydrogen on demand. The most practical application would be for portable energy sources.”
In the three images above, transmission electron microscopy images show spherical silicon nanoparticles about 10 nanometers in diameter. Credit: Swihart Research Group, University at Buffalo.
According to Swihart, geometry of particles led to this great variance. As they react, the larger particles form nonspherical structures whose surfaces react with water less readily and less uniformly than the surfaces of the smaller, spherical particles. Though it takes significant energy and resources to produce the super-small silicon balls, the nanoparticles could help power portable devices in situations where water is available and portability is more important than low-cost. Military operations and camping trips are two examples of such scenarios. Talking about applications of these nanoparticles, first author of the study, Folarin Erogbogbo, a research assistant professor in UB’s ILPB and a UB PhD graduate said,
“It was previously unknown that we could generate hydrogen this rapidly from silicon, one of Earth’s most abundant elements. Safe storage of hydrogen has been a difficult problem even though hydrogen is an excellent candidate for alternative energy, and one of the practical applications of our work would be supplying hydrogen for fuel cell power. It could be military vehicles or other portable applications that are near water.”
Swihart further added,
“Perhaps instead of taking a gasoline or diesel generator and fuel tanks or large battery packs with me to the campsite (civilian or military) where water is available, I take a hydrogen fuel cell (much smaller and lighter than the generator) and some plastic cartridges of silicon nanopowder mixed with an activator. Then I can power my satellite radio and telephone, GPS, laptop, lighting, etc. If I time things right, I might even be able to use excess heat generated from the reaction to warm up some water and make tea.”
These findings appeared online in Nano Letters on January 14, 2013.
Source: University at Buffalo
Featured image: Swihart Research Group, University at Buffalo
A close-up of spherical silicon nanoparticles about 10 nanometers in diameter. In Nano Letters, UB scientists report that these particles could form the basis of new technologies that generate hydrogen for portable power applications.
