Nanocrystals split water molecules making hydrogen fuel.
Technology is always looking for ways to make it easier to be green. Now, researchers in New York state report creating a new long-lived catalyst that uses the energy in sunlight to generate hydrogen gas, a carbon-free fuel. With further improvements, the advance could lead to systems that use sunlight to split water molecules, generating a fuel that can power cars and trucks without emitting any greenhouse gases.
The idea of using sunlight to convert water into a fuel may sound fanciful. But plants do it: They capture photons of sunlight and use that energy to split water molecules into their constituents of hydrogen and oxygen ions. Pairs of hydrogen ions are then knitted together with a pair of electrons (swiped from the oxygen ions) to make hydrogen molecules (H2).
Researchers have actually mimicked this same reaction for many years, but the catalysts they use to do so have been either too expensive or too quick to break down. So the search has been on for cheaper, more rugged catalysts.
To do the job, researchers usually look for two key ingredients: a good light absorber and a good catalyst. The light absorber captures photons of sunlight and then harnesses the energy to generate the energetic electrons. Those energized electrons are then passed to the catalyst, which knits the hydrogen ions into H2.