title: Water photolysis at 12.3% efficiency via perovskite photovoltaics and Earth-abundant catalysts.
abstract: Although sunlight-driven water splitting is a promising route to sustainable hydrogen fuel production, widespread implementation is hampered by the expense of the necessary photovoltaic and photoelectrochemical apparatus. Here, we describe a highly efficient and low-cost water-splitting cell combining a state-of-the-art solution-processed perovskite tandem solar cell and a bifunctional Earth-abundant catalyst. The catalyst electrode, a NiFe layered double hydroxide, exhibits high activity toward both the oxygen and hydrogen evolution reactions in alkaline electrolyte. The combination of the two yields a water-splitting photocurrent density of around 10 milliamperes per square centimeter, corresponding to a solar-to-hydrogen efficiency of 12.3%. Currently, the perovskite instability limits the cell lifetime.
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland. Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University (NTU), 637371 Singapore.
authors.forename: Jingshan
authors.initials: J
authors.lastname: Luo
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland. School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 440-746, Korea.
authors.forename: Jeong-Hyeok
authors.initials: JH
authors.lastname: Im
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Mayer
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Marcel
authors.initials: M
authors.lastname: Schreier
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Mohammad Khaja
authors.initials: MK
authors.lastname: Nazeeruddin
authors.affiliation: School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University (SKKU), Suwon 440-746, Korea.
authors.forename: Nam-Gyu
authors.initials: NG
authors.lastname: Park
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: S David
authors.initials: SD
authors.lastname: Tilley
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University (NTU), 637371 Singapore.
authors.forename: Hong Jin
authors.initials: HJ
authors.lastname: Fan
authors.affiliation: Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland. michael.graetzel@epfl.ch.
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel