Epitaxial hetero-structure of CdSe/TiO2 nanotube arrays with PEDOT as a hole transfer layer for photoelectrochemical hydrogen evolution

Chong, Baohe; Zhu, Wen; Hou, Xianghui

Abstract

© 2017 The Royal Society of Chemistry. The photocatalytic decomposition of water is believed to be able to help mitigate the crisis of fossil fuel depletion. However, obtaining high and stable photoconversion efficiency remains a challenge in photocatalytic hydrogen production. Here we report an epitaxial hetero-structure of CdSe/TiO2 nanotube arrays as efficient photo-anodes via simple, room-temperature, low-cost electrochemical deposition. With the help of a similar d spacing to TiO2, the CdSe sensitizing layer is epitaxially grown on the tube wall of the TiO2 nanotubes, resulting in an ideal coherent grain boundary and single crystal growth. The resultant photo-anode produces 30% more photocurrent than those samples without a coherent grain boundary. Notably, the especial epitaxial hetero-structure is beneficial to decrease the recombination site and accelerate the separation of photogenerated electron-hole pairs. Furthermore, an ultrathin PEDOT surface layer was developed on the epitaxial hetero-structure of CdSe/TiO2 nano-tube arrays in which it functions as both a physical passivation barrier and a hole transfer layer. As a result, significantly enhanced photocurrent density and substantially better stability have been achieved. This methodology may provide a new pathway of epitaxial growth for preparing heterogeneous junction materials which have similar d spacing.

Citation

Chong, B., Zhu, W., & Hou, X. (2017). Epitaxial hetero-structure of CdSe/TiO2 nanotube arrays with PEDOT as a hole transfer layer for photoelectrochemical hydrogen evolution. Journal of Materials Chemistry A, 5(13), 6233-6244. https://doi.org/10.1039/c6ta10202f

• Journal Article Type: Article
• Acceptance Date: Feb 21, 2017
• Online Publication Date: Feb 22, 2017
• Publication Date: 2017
• Deposit Date: Mar 6, 2017
• Publicly Available Date: Feb 23, 2018
• Journal: Journal of Materials Chemistry A
• Print ISSN: 2050-7488
• Electronic ISSN: 2050-7496
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 13
• Pages: 6233-6244
• DOI: https://doi.org/10.1039/c6ta10202f
• Public URL: https://nottingham-repository.worktribe.com/output/844733
• Publisher URL: http://pubs.rsc.org/en/Content/ArticleLanding/2017/TA/C6TA10202F#!divAbstract