Science http://dx.doi.org/10.1126/science.1209786 and http://dx.doi.org/10.1126/science.1209816 (2011)

Credit: © ISTOCKPHOTO.COM/ALXPINA

Researchers have long struggled to recreate photosynthesis in an industrial setting. Now, one group has found a method of reducing carbon dioxide (CO2) to carbon monoxide (CO) using an electrical potential difference of less than 1.5 V, and another has managed to generate hydrogen gas by using light to split water molecules.

The first, led by Richard Masel, of Dioxide Materials in Champaign, Illinois, USA, employs a silver cathode to catalyse the formation of CO from an intermediate, (CO2)−, which reacts with H+ ions in water. A number of improvements are required before this process can be copied on a large scale, however, including speeding up the reaction rate.

The second group has made cells containing a silicon-based photovoltaic and an alloy made of abundantly available metals, with cobalt borate catalysts. Steven Reece of Sun Catalytix, a firm in Cambridge, Massachusetts, USA, and his co-workers report that this system could be developed into a means of generating cheap fuel from sunlight, because, unlike similar devices that have been created in the past, this one operates in benign conditions, without wires and expensive noble metal catalysts.