Creating hydrogen from rust and sun

Diagram of the iron oxide device in actionHydrogen—whether or not you know it—is the fuel of today, and more so the fuel of tomorrow. It’s the explosive component behind the hydrocarbons in coal, gas and diesel, but when you free carbon from hydrogen and use it as a fuel you don’t get the pollution from hydrocarbons. But the problem is is that though hydrogen is the most abundant element in the universe it’s also the simplest and most likely to combine with other elements into things like oil or water. Now scientists are developing a method of using rust and sunlight to extract hydrogen from water.

Today most pure hydrogen is reformed from natural gas through steam reformation, which needs high temperatures and fuels like natural gas. Water’s also a significant potential source for hydrogen, but the H2O bond is stronger than the bond in natural gas, and generally has required more energy to break the bond than what you get back. 

Scientists across the world have been tackling the issue of how produce cheaper hydrogen for decades. Enter research a research team led by Tenure-Track Assistant Professor Kevin Sivula at the Swiss university Ecole polytechnique fédérale de Lausanne’s (EPFL’s) Laboratory for Molecular Engineering of Optoelectronic Nanomaterials. There Sivula and his colleagues have developed an inexpensive method of splitting hydrogen from water. “We’ve used very inexpensive materials like rust or iron oxide to put it together,” Sivula said in a video explaining the device. The group published their research in the journal Nature Photonics.

The most expensive part of the device, according to Sivula, is the glass that would cover device, since from the onset, the chief concern was making the device inexpensive. The team thinks that with the help of nano-enhanced rust with silicon oxide, aluminum oxide and cobalt oxide it can reach a conversion efficiency of 10 percent within a few years, making a device that costs less than $80 per square meter. Sivula said at the price point it would be competitive with other commercial forms of hydrogen production.

That’s still a bit in the future though. “Right now the efficiency of our device is very modest. We’re only able to convert about 1.2 percent of the solar light into hydrogen. But the fact that we’re using inexpensive materials like rust, which can potentially convert up to 16 percent of solar energy into hydrogen gives us hope that soon we’ll be able to, and in a very economical way, to create chemical energy from sunlight,” Sivula said.