title: Identifying champion nanostructures for solar water-splitting.
abstract: Charge transport in nanoparticle-based materials underlies many emerging energy-conversion technologies, yet assessing the impact of nanometre-scale structure on charge transport across micrometre-scale distances remains a challenge. Here we develop an approach for correlating the spatial distribution of crystalline and current-carrying domains in entire nanoparticle aggregates. We apply this approach to nanoparticle-based α-Fe₂O₃ electrodes that are of interest in solar-to-hydrogen energy conversion. In correlating structure and charge transport with nanometre resolution across micrometre-scale distances, we have identified the existence of champion nanoparticle aggregates that are most responsible for the high photoelectrochemical activity of the present electrodes. Indeed, when electrodes are fabricated with a high proportion of these champion nanostructures, the electrodes achieve the highest photocurrent of any metal oxide photoanode for photoelectrochemical water-splitting under 100 mW cm(-2) air mass 1.5 global sunlight.
authors.affiliation: 1] Laboratory of Photonics and Interfaces, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland [2].
authors.forename: Scott C
authors.initials: SC
authors.lastname: Warren
authors.forename: Kislon
authors.initials: K
authors.lastname: Voïtchovsky
authors.forename: Hen
authors.initials: H
authors.lastname: Dotan
authors.forename: Celine M
authors.initials: CM
authors.lastname: Leroy
authors.forename: Maurin
authors.initials: M
authors.lastname: Cornuz
authors.forename: Francesco
authors.initials: F
authors.lastname: Stellacci
authors.forename: Cécile
authors.initials: C
authors.lastname: Hébert
authors.forename: Avner
authors.initials: A
authors.lastname: Rothschild
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
mesh_terms: D004566:Electrodes; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D012993:Solar Energy; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water