CuWO4 Nanoflake Array-Based Single-Junction and Heterojunction Photoanodes for Photoelectrochemical Water Oxidation

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• 作者：Wen Ye ; Fengjiao Chen ; Feipeng Zhao ; Na Han ; Yanguang Li
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 13, 2016
• 年：2016
• 卷：8
• 期：14
• 页码：9211-9217
• 全文大小：549K
• 年卷期：0
• ISSN：1944-8252

文摘

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/cm² 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/cm² 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.