Artificial leaf produces clean gas

Researchers at the University of Cambridge developed an ‘artificial leaf’, which uses only sunlight to produce a type of gas that is currently produces from fossil fuels, and which could eventually be used as a sustainable liquid fuel.

The artificial leaf is used to produce syngas, which is currently made from a mixture of hydrogen and carbon monoxide. While the name may not sound familiar, many every-day products are created using it. The gas is used in a range of commodities, ranging from fuels and pharmaceuticals, plastics and fertilisers.

The device is inspired by photosynthesis, a natural process by which plants use solar energy to turn carbon dioxide into food and oxygen. On the artificial leaf, two light absorbers are combined with a catalyst made from the naturally abundant element cobalt. When immersed in water, one light absorber uses the catalyst to produce oxygen. The other carries out the chemical reaction that reduces carbon dioxide and water into carbon monoxide and hydrogen, forming the syngas mixture.

As an added bonus, the researchers discovered that their light absorbers work even under the low levels of sunlight on a rainy or overcast day.

The team is now looking at ways to use their technology to produce a sustainable liquid fuel alternative to petrol.

Photo: University of Cambridge