title: Enhanced Photoelectrochemical Performance from Rationally Designed Anatase/Rutile TiO2 Heterostructures.
abstract: 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.
authors.affiliation: College of Physics, Optoelectronics and Energy, Center for Energy Conversion Materials & Physics (CECMP), Jiangsu Key Laboratory of Thin Films, Soochow University , Suzhou 215006, People's Republic of China.
authors.forename: Fengren
authors.initials: F
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China , Chengdu 610054, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xiong
authors.affiliation: College of Physics, Optoelectronics and Energy, Center for Energy Conversion Materials & Physics (CECMP), Jiangsu Key Laboratory of Thin Films, Soochow University , Suzhou 215006, People's Republic of China.
authors.forename: Fangli
authors.initials: F
authors.lastname: Wu
authors.affiliation: College of Physics, Optoelectronics and Energy, Center for Energy Conversion Materials & Physics (CECMP), Jiangsu Key Laboratory of Thin Films, Soochow University , Suzhou 215006, People's Republic of China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Liu
authors.affiliation: College of Physics, Optoelectronics and Energy, Center for Energy Conversion Materials & Physics (CECMP), Jiangsu Key Laboratory of Thin Films, Soochow University , Suzhou 215006, People's Republic of China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Yanhao
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Xudong
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Physics, Optoelectronics and Energy, Center for Energy Conversion Materials & Physics (CECMP), Jiangsu Key Laboratory of Thin Films, Soochow University , Suzhou 215006, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
keywords: TiO2; atomic layer deposition; heterostructure; photoelectrochemical; water splitting