title: Facile fabrication of organic/inorganic nanotube heterojunction arrays for enhanced photoelectrochemical water splitting.
abstract: Organic/inorganic heterojunction photoanodes are appealing for making concurrent use of the highly photoactive organic semiconductors, and the efficient dielectric screening provided by their inorganic counterparts. In the present work, organic/inorganic nanotube heterojunction arrays composed of TiO2 nanotube arrays and a semiconducting N,N-(dicyclohexyl) perylene-3,4,9,10-tetracarboxylic diimide (PDi) layer were fabricated for photoelectrochemical water splitting. In this arrayed architecture, a PDi layer with a tunable thickness was coated on anodic TiO2 nanotube arrays by physical vapor deposition, which is advantageous for the formation of a uniform layer and an adequate interface contact between PDi and TiO2. The obtained PDi/TiO2 junction exhibited broadened visible light absorption, and an effective interface for enhanced photogenerated electron-hole separation, which is supported by the reduced charge transfer resistance and prolonged excitation lifetime via impedance spectroscopy analysis and fluorescence emission decay investigations. Consequently, such a heterojunction photoanode was photoresponsive to a wide visible light region of 400-600 nm, and thus demonstrated a highly enhanced photocurrent density at 1.23 V vs. a reversible hydrogen electrode. Additionally, the durability of such a photoanode can be guaranteed after long-time illumination because of the geometrical restraint imposed by the PDi aggregates. These results pave the way to discover new organic/inorganic assemblies for high-performance photoelectric applications and device integration.
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China. luning.wang@ustb.edu.cn.
authors.forename: Yingzhi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China. luning.wang@ustb.edu.cn.
authors.forename: Aoxiang
authors.initials: A
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China. luning.wang@ustb.edu.cn.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Yue
authors.affiliation: School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China. luning.wang@ustb.edu.cn.
authors.forename: Lu-Ning
authors.initials: LN
authors.lastname: Wang
authors.affiliation: Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. zhhuang@mail.tsinghua.edu.cn.
authors.forename: Zheng-Hong
authors.initials: ZH
authors.lastname: Huang
authors.affiliation: Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. zhhuang@mail.tsinghua.edu.cn.
authors.forename: Feiyu
authors.initials: F
authors.lastname: Kang
authors.affiliation: Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620, USA.
authors.forename: Alex A
authors.initials: AA
authors.lastname: Volinsky