title: Novel ZnO/Fe₂O₃ Core-Shell Nanowires for Photoelectrochemical Water Splitting.
abstract: A facile and simple fabrication of Fe2O3 as a shell layer on the surface of ZnO nanowires (NW) as a core-shell nanoelectrode is applied for the photoelectrochemical (PEC) splitting of water. An ZnO NW array of core diameter ∼80 nm was grown on a fluorine-doped tin-oxide (FTO) substrate with a hydrothermal method; subsequent deposition and annealing achieved a shell structure of the Fe2O3 layer of thickness a few nm. Fe2O3 in the α phase and ZnO in the wurtzite phase were identified as the structures of the shell and core, respectively, through analysis with X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The ZnO/Fe2O3 core-shell NW showed an excellent PEC response to the oxidation of water, and also benefited from a negative shift of onset potential because of an n/n heterojunction structure. A detailed energy diagram of the ZnO/Fe2O3 core-shell NW was investigated with a Mott-Schottky analysis. This novel core-shell nanostructure can hence not only exhibit a great potential for the solar generation of hydrogen, but also offer a blueprint for the future design of photocatalysts.
authors.affiliation: †Department of Optoelectronic Engineering, National Dong Hwa University, Hualien 97401, Taiwan.
authors.forename: Yu-Kuei
authors.initials: YK
authors.lastname: Hsu
authors.affiliation: ‡Karlsruhe Institute of Technology (KIT), Institut für Anorganische Chemie, Engesserstraße 15, Karlsruhe D-76131, Germany.
authors.forename: Ying-Chu
authors.initials: YC
authors.lastname: Chen
authors.affiliation: §National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
authors.forename: Yan-Gu
authors.initials: YG
authors.lastname: Lin
keywords: core−shell nanowires; iron oxide; photoelectrochemical; solar hydrogen; zinc oxide