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Wang X, Mayrhofer L, Keunecke M, Estrade S, Lopez-Conesa L, Moseler M, Waag A, Schaefer L, Shi W, Meng X, Chu J, Fan Z, Shen H. Low-Energy Hydrogen Ions Enable Efficient Room-Temperature and Rapid Plasma Hydrogenation of TiO 2 Nanorods for Enhanced Photoelectrochemical Activity. Small 2022; 18:e2204136. [PMID: 36192163 DOI: 10.1002/smll.202204136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/01/2022] [Indexed: 06/16/2023]
Abstract
Hydrogenation is a promising technique to prepare black TiO2 (H-TiO2 ) for solar water splitting, however, there remain limitations such as severe preparation conditions and underexplored hydrogenation mechanisms to inefficient hydrogenation and poor photoelectrochemical (PEC) performance to be overcome for practical applications. Here, a room-temperature and rapid plasma hydrogenation (RRPH) strategy that realizes low-energy hydrogen ions of below 250 eV to fabricate H-TiO2 nanorods with controllable disordered shell, outperforming incumbent hydrogenations, is reported. The mechanisms of efficient RRPH and enhanced PEC activity are experimentally and theoretically unraveled. It is discovered that low-energy hydrogen ions with fast subsurface transport kinetics and shallow penetration depth features, enable them to directly penetrate TiO2 via unique multiple penetration pathways to form controllable disordered shell and suppress bulk defects, ultimately leading to improved PEC performance. Furthermore, the hydrogenation-property experiments reveal that the enhanced PEC activity is mainly ascribed to increasing band bending and bulk defect suppression, compared to reported H-TiO2 , a superior photocurrent density of 2.55 mA cm-2 at 1.23 VRHE is achieved. These findings demonstrate a sustainable strategy which offers great promise of TiO2 and other oxides to achieve further-improved material properties for broad practical applications.
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Affiliation(s)
- Xiaodan Wang
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
| | - Leonhard Mayrhofer
- Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstraße 11, 79108, Freiburg, Germany
| | - Martin Keunecke
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
| | - Sonia Estrade
- Department d'Electrònica, Universitat de Barcelona, c/Martí Franquès 1, Barcelona, 08028, Spain
| | - Lluis Lopez-Conesa
- Department d'Electrònica, Universitat de Barcelona, c/Martí Franquès 1, Barcelona, 08028, Spain
| | - Michael Moseler
- Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstraße 11, 79108, Freiburg, Germany
| | - Andreas Waag
- Institute for Semiconductor Technology, TU Braunschweig, Hans-Sommer-Strasse 66, 38106, Braunschweig, Germany
| | - Lothar Schaefer
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
| | - Weidong Shi
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, China
| | - Xiangjian Meng
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Yu Tian Road 500, Shanghai, 200083, China
| | - Junhao Chu
- Institute of Optoelectronics, Fudan University, Song Hu Road 2005, Shanghai, 200438, China
| | - Zhiyong Fan
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Hao Shen
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
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