title: Triple-layered nanostructured WO₃ photoanodes with enhanced photocurrent generation and superior stability for photoelectrochemical solar energy conversion.
abstract: Unique nanorods/nanoparticles/nanoflakes (NRs/NPs/NFs) WO3 triple-layers are grown on a metallic W foil by a simple one-step anodization method. The triple-layered structure is formed through a self-organization process, the film thickness (up to 3 μm) being controlled by the anodization time. A first layer made of an array of WO3 densely-packed vertically-aligned NRs (1.2-1.4 μm in height) grow atop the tungsten foil, followed by a second layer of small NPs (50-80 nm) and finally a third layer made of rectangular NFs (200-300 nm). When irradiated by white light in a photoelectrochemical cell these WO3 triple-layers generate a photocurrent as high as 0.9 mA cm(-2) at 1.2 V/RHE. Moreover, we show that the stability of the triple-layered WO3 photoanodes can be considerably enhanced by adding an ultrathin (10 nm) TiO2 protective overlayer.
authors.affiliation: School of Materials Science Engineering, Nanyang Technological University, Singapore 639798, Singapore. aszchen@ntu.edu.sg.
authors.forename: Huan
authors.initials: H
authors.lastname: Qi
authors.forename: Jonathan
authors.initials: J
authors.lastname: Wolfe
authors.forename: Danping
authors.initials: D
authors.lastname: Wang
authors.forename: Hong Jin
authors.initials: HJ
authors.lastname: Fan
authors.forename: Denis
authors.initials: D
authors.lastname: Fichou
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen