- Category: Technology
10 Feb 2011
- Published on Thursday, 10 February 2011 05:36
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By Nuel Navarrete
Rust may serve a role other than common nuisance in the future as researchers from Boston College have developed an economical and efficient platform for harvesting hydrogen from water by applying rust on a mesh of tiny wires known as nanonets.
Dunwei Wang, an assistant professor of chemistry at the college, led a team of chemists in developing nanonets in 2008. Nanonets are a flexible network of nano-scale wires capable of multiplying surface areas to improve efficiency in electronics and energy applications.
They grew wires of titanium and silicon into a two-dimensional mesh of branches to create a flat, rectangular netting. While each wire mesh only measures about 1/400th the size of a human hair, they are highly conductive and provide considerable surface area.
Now, the scientists discovered applying a layer of mineral called hematite on the material could allow it to absorb light efficiently without using an oxygen-evolving catalyst for enhancements.
Hematite is the mineral form of iron oxide, otherwise known as rust. By itself, the mineral’s use in electrical processes is hampered by the intrinsic limit in its ability to carry a charge. By applying it on a conductive framework like nanonets, the mineral increases its charge transport abilities.
“By using this unique Nanonet structure, we have shed new light on the fundamental performance capabilities of hematite in water-splitting," said Mr. Wang.
Water-splitting is a chemical process where water is divided into oxygen and hydrogen gas by running an electric current through the water. The hydrogen components can be used as fuel for hydrogen fuel cells.
"The result highlights the importance of charge transport in semiconductor-based water-splitting, particularly for materials whose performance is limited by poor charge diffusion," the researchers said in the recent report.
"Our design introduces material components to provide a dedicated charge transport pathway, alleviates the reliance on the materials' intrinsic properties, and therefore has the potential to greatly broaden where and how various existing materials can be used in energy-related applications," the researchers concluded.
Water-splitting to produce hydrogen from water tends to be an expensive process, so any gains in efficiency and conductivity are required to make it an economically viable source of clean energy.