Enhanced Photoelectrochemical Performance from Rationally Designed Anatase/Rutile TiO2 Heterostructures

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• 作者：Fengren Cao ; Jie Xiong ; Fangli Wu ; Qiong Liu ; Zhiwei Shi ; Yanhao Yu ; Xudong Wang ; Liang Li
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：May 18, 2016
• 年：2016
• 卷：8
• 期：19
• 页码：12239-12245
• 全文大小：465K
• 年卷期：0
• ISSN：1944-8252

文摘

In a photoelectrochemical (PEC) cell for water splitting, the critical issue is charge separation and transport, which is usually completed by designing semiconductor heterojunctions. TiO₂ anatase–rutile mixed junctions could largely improve photocatalytic properties, but impairs PEC water splitting performance. We designed and prepared two types of TiO₂ heterostructures with the anatase thin film and rutile nanowire phases organized in different sequences. The two types of heterostructures were used as PEC photoanodes for water splitting and demonstrated completely opposite results. Rutile nanowires on anatase film demonstrated enhanced photocurrent density and onset potential, whereas strong negative performance was obtained from anatase film on rutile nanowire structures. The mechanism was investigated by photoresponse, light absorption and reflectance, and electrochemical impedance spectra. This work revealed the significant role of phase sequence in performance gain of anatase–rutile TiO₂ heterostructured PEC photoanodes.