title: Quantum dot-sensitized hierarchical micro/nanowire architecture for photoelectrochemical water splitting.
abstract: We report the fabrication of quantum dot-sensitized hierarchical structure and the application of the structure as a photoanode for photoelectrochemical water splitting. The structure is synthesized by hydrothermally growing ZnO nanowires on silicon microwires grown with the vapor-liquid-solid method. Then the hierarchical structure is further sensitized with CdS and CdSe quantum dots and modified with IrOx quantum dots. As a result, the silicon microwires, ZnO nanowires, and the quantum dot/ZnO core/shell structure form a multiple-level hierarchical heterostructure, which is remarkably beneficial for light absorption and charge carrier separation. Our experimental results reveal that the photocurrent density of our multiple-level hierarchical structure achieves a surprising 171 times enhancement compared to that from simple ZnO nanowires on a planar substrate. In addition, the photoanode shows high stability during the water-splitting experiment. These results prove that the quantum dot-sensitized hierarchical structure is an ideal candidate for a photoanode in solar water splitting applications. Importantly, the modular design approach we take to produce the photoanode allows for the integration of future discoveries for further improvement of its performance.
authors.affiliation: State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Sheng
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.forename: Tielin
authors.initials: T
authors.lastname: Shi
authors.forename: Xianhua
authors.initials: X
authors.lastname: Tan
authors.forename: Zhengchun
authors.initials: Z
authors.lastname: Peng
authors.forename: Guanglan
authors.initials: G
authors.lastname: Liao