title: Strategies for stable water splitting via protected photoelectrodes.
abstract: Photoelectrochemical (PEC) solar-fuel conversion is a promising approach to provide clean and storable fuel (e.g., hydrogen and methanol) directly from sunlight, water and CO2. However, major challenges still have to be overcome before commercialization can be achieved. One of the largest barriers to overcome is to achieve a stable PEC reaction in either strongly basic or acidic electrolytes without degradation of the semiconductor photoelectrodes. In this work, we discuss fundamental aspects of protection strategies for achieving stable solid/liquid interfaces. We then analyse the charge transfer mechanism through the protection layers for both photoanodes and photocathodes. In addition, we review protection layer approaches and their stabilities for a wide variety of experimental photoelectrodes for water reduction. Finally, we discuss key aspects which should be addressed in continued work on realizing stable and practical PEC solar water splitting systems.
authors.affiliation: Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark. ibchork@fysik.dtu.dk.
authors.forename: Dowon
authors.initials: D
authors.lastname: Bae
authors.affiliation: Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark. ibchork@fysik.dtu.dk.
authors.forename: Brian
authors.initials: B
authors.lastname: Seger
authors.affiliation: Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark. ibchork@fysik.dtu.dk.
authors.forename: Peter C K
authors.identifier: http://orcid.org/0000-0002-3761-4212
authors.initials: PC
authors.lastname: Vesborg
authors.affiliation: Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Hansen
authors.affiliation: Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark. ibchork@fysik.dtu.dk.
authors.forename: Ib
authors.identifier: http://orcid.org/0000-0002-2832-1338
authors.initials: I
authors.lastname: Chorkendorff