title: CuWO4 Nanoflake Array-Based Single-Junction and Heterojunction Photoanodes for Photoelectrochemical Water Oxidation.
abstract: Over recent years, tremendous efforts have been invested in the search and development of active and durable semiconductor materials for photoelectrochemical (PEC) water splitting, particularly for photoanodes operating under a highly oxidizing environment. CuWO4 is an emerging candidate with suitable band gap and high chemical stability. Nevertheless, its overall solar-to-electricity remains low because of the inefficient charge separation process. In this work, we demonstrate that this problem can be partly alleviated through designing three-dimensional hierarchical nanostructures. CuWO4 nanoflake arrays on conducting glass are prepared from the chemical conversion of WO3 templates. Resulting electrode materials possess large surface areas, abundant porosity and small thickness. Under illumination, our CuWO4 nanoflake array photoanodes exhibit an anodic current density of ∼0.4 mA/cm(2) at the thermodynamic potential of water splitting in pH 9.5 potassium borate buffer--the largest value among all available CuWO4-based photoanodes. In addition, we demonstrate that their performance can be further boosted to >2 mA/cm(2) by coupling with a solution-cast BiVO4 film in a heterojunction configuration. Our study unveils the great potential of nanostructured CuWO4 as the photoanode material for PEC water oxidation.
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University , Suzhou 215123, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Ye
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University , Suzhou 215123, China.
authors.forename: Fengjiao
authors.initials: F
authors.lastname: Chen
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University , Suzhou 215123, China.
authors.forename: Feipeng
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University , Suzhou 215123, China.
authors.forename: Na
authors.initials: N
authors.lastname: Han
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University , Suzhou 215123, China.
authors.forename: Yanguang
authors.initials: Y
authors.lastname: Li
keywords: CuWO4; charge separation; heterojunction; nanoflakes; photoelectrochemical water oxidation