Graphene – hailed as the first “wonder material” of the 21st century because of its strength, lightness, flexibility and electrical conductivity – has just gained another remarkable attribute that could give it an important role in energy production.
The unexpected finding, published online by the journal Nature, could revolutionise the technology of fuel cells, which generate power through the electrochemical oxidation of hydrogen. A graphene membrane between electrodes – a carbon sheet just one atom thick and extending indefinitely in two dimensions – would let through protons but not hydrogen atoms.
As a result the cell would be more stable and produce more power, says Gareth Hinds, a fuel cell chemist at the National Physical Laboratory. “This would have major implications for an environmentally friendly technology on the brink of commercialisation.”
A longer-term possibility is to design graphene membranes to “sieve” hydrogen gas out of the atmosphere, where it exists in tiny traces. It would then generate power in a fuel cell – in effect making electricity from the air.
“It is a very simple set-up,” says Marcelo Lozada-Hidalgo, one of the Manchester team. “You put a hydrogen-containing gas on one side, apply a small electric current and collect pure hydrogen on the other side. This hydrogen can then be burnt in a fuel cell.”