Floating artificial leaf converts energy from sunlight into fuel

Alex Wilkins is a writer.

An artificial leaf that is light enough to float on water can be used to address the shortage of land for capturing solar energy.

The difference between solar fuel cells and photovoltaic cells is that solar fuel cells use energy from the sun to power chemical reactions that make fuels. Synthetic processes that produce fuel from carbon dioxide, water and sunlight have been sought after by researchers. Existing technology is so heavy that it is limited to land, where there is not enough space.

A group of people at the University of Cambridge developed a solar fuel cell that can capture energy from light. A fuel called syngas can be made from bubbles of hydrogen and carbon monoxide.

It is the first of its kind. There are a lot of developments for photovoltaics where people look at floating photovoltaic farms, and we thought that the same could be done for solar fuels.

The prototype device is about 10 centimetres wide. It produced hydrogen with an efficiency of 0.58 per cent and carbon monoxide with an efficiency of 0.0053 per cent. It is similar to current solar fuel technologies when compared on a gram basis.

There are some problems with the fabrication process, but it is easy to do. The materials used in the prototype could be toxic to waterways, even though they are contained in the device, because the efficiency needs to be closer to 10 per cent.

The leaf is a proof of concept for a method to collect gas bubbles from a device.

The journal's title is " Nature."