title: Photoelectrochemical water splitting in separate oxygen and hydrogen cells.
abstract: Solar water splitting provides a promising path for sustainable hydrogen production and solar energy storage. One of the greatest challenges towards large-scale utilization of this technology is reducing the hydrogen production cost. The conventional electrolyser architecture, where hydrogen and oxygen are co-produced in the same cell, gives rise to critical challenges in photoelectrochemical water splitting cells that directly convert solar energy and water to hydrogen. Here we overcome these challenges by separating the hydrogen and oxygen cells. The ion exchange in our cells is mediated by auxiliary electrodes, and the cells are connected to each other only by metal wires, enabling centralized hydrogen production. We demonstrate hydrogen generation in separate cells with solar-to-hydrogen conversion efficiency of 7.5%, which can readily surpass 10% using standard commercial components. A basic cost comparison shows that our approach is competitive with conventional photoelectrochemical systems, enabling safe and potentially affordable solar hydrogen production.
authors.affiliation: The Nancy &Stephen Grand Technion Energy Program (GTEP), Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Avigail
authors.initials: A
authors.lastname: Landman
authors.affiliation: Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Hen
authors.initials: H
authors.lastname: Dotan
authors.affiliation: Department of Chemical Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Gennady E
authors.initials: GE
authors.lastname: Shter
authors.affiliation: Institute of Solar Research, German Aerospace Center (DLR), Cologne 51147, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Wullenkord
authors.affiliation: Institute of Solar Research, German Aerospace Center (DLR), Cologne 51147, Germany.
authors.forename: Anis
authors.initials: A
authors.lastname: Houaijia
authors.affiliation: Evonik Creavis GmbH, Marl 45772, Germany.
authors.forename: Artjom
authors.initials: A
authors.lastname: Maljusch
authors.affiliation: Department of Chemical Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Gideon S
authors.identifier: 0000-0003-4371-4575
authors.initials: GS
authors.lastname: Grader
authors.affiliation: Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Avner
authors.initials: A
authors.lastname: Rothschild