Highly read on pubs.acs.org in July

Flowing acidic water over a few layers of graphene — atom-thick sheets of carbon — generates ten times the energy previously achieved by running acidic water over carbon nanotubes.

Water flowing over carbon nanotubes can produce only a small electric current in the direction of the flow. Nikhil Koratkar at Rensselaer Polytechnic Institute in Troy, New York, and his team added hydrochloric acid to water and streamed it over flat sheets of graphene, generating 85 nanowatts of power using a few hundred square micrometres of graphene film.

The group's simulations suggest that the voltage is generated by chloride ions that hop along the surface of graphene, interacting with and dragging the material's electrons along. The authors say that the graphene sheets boosted power generation because of their high electron mobility and continuous surface for efficient ion gliding.

Nano Lett. 11, 3123–3127 (2011)