Air-based photoelectrochemical cell capturing water molecules from ambient air for hydrogen production

A system is demonstrated that autonomously produces hydrogen gas using sunlight and outside air as the only inputs. Oxygen and hydrogen formation reactions occur on either side of a monolithic “solar membrane” inserted in a two-compartment photoelectrochemical cell. A surface film of Nafion® serves as a solid electrolyte. This proof of concept invites further development of air-based cells.