title: Nanostructured WO3 /BiVO4 photoanodes for efficient photoelectrochemical water splitting.
abstract: Nanostructured photoanodes based on well-separated and vertically oriented WO3 nanorods capped with extremely thin BiVO4 absorber layers are fabricated by the combination of Glancing Angle Deposition and normal physical sputtering techniques. The optimized WO3 -NRs/BiVO4 photoanode modified with Co-Pi oxygen evolution co-catalyst shows remarkably stable photocurrents of 3.2 and 5.1 mA/cm(2) at 1.23 V versus a reversible hydrogen electrode in a stable Na2 SO4 electrolyte under simulated solar light at the standard 1 Sun and concentrated 2 Suns illumination, respectively. The photocurrent enhancement is attributed to the faster charge separation in the electronically thin BiVO4 layer and significantly reduced charge recombination. The enhanced light trapping in the nanostructured WO3 -NRs/BiVO4 photoanode effectively increases the optical thickness of the BiVO4 layer and results in efficient absorption of the incident light.
authors.affiliation: Department of Applied Chemistry School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan.
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Pihosh
authors.forename: Ivan
authors.initials: I
authors.lastname: Turkevych
authors.forename: Kazuma
authors.initials: K
authors.lastname: Mawatari
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Asai
authors.forename: Takashi
authors.initials: T
authors.lastname: Hisatomi
authors.forename: Jin
authors.initials: J
authors.lastname: Uemura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tosa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Shimamura
authors.forename: Jun
authors.initials: J
authors.lastname: Kubota
authors.forename: Kazunari
authors.initials: K
authors.lastname: Domen
authors.forename: Takehiko
authors.initials: T
authors.lastname: Kitamori
keywords: BiVO4; WO3; glancing angle deposition; nanorods; photocatalytic water splitting