Harnessing sunlight to convert carbon dioxide into fuel

Using waste carbon dioxide and easily obtainable machined parts, researchers have devised an efficient method for harnessing sunlight to convert carbon dioxide into a potential alternative fuel known as formic acid.

"This approach offers a promising route to a renewable fuel," said Andrew Bocarsly, a professor of chemistry at the Princeton University in the US.

The transformation from carbon dioxide and water to formic acid was powered by a commercial solar panel.

The process takes place inside an electrochemical cell, which consists of metal plates the size of rectangular lunch-boxes that enclose liquid-carrying channels.

To maximise the efficiency of the system, the amount of power produced by the solar panel must match the amount of power the electrochemical cell can handle, Bocarsly added.

This optimisation process is called impedance matching. By stacking three electrochemical cells together, the research team was able to reach almost two percent energy efficiency, which is twice the efficiency of natural photosynthesis.

It is also the best energy efficiency reported to date using a man-made device, the researchers claimed.

The study appeared in the Journal of CO2 Utilisation.