Paving the road toward the use of β-Fe2O3 in solar water splitting: Raman identification, phase transformation and strategies for phase stabilization

• 作者: Huiting Huang Jianyong Feng Ninasi Zhana Xin Wang Yongsheng Guo Zhaosheng Li Zhigang ZOU
• 来源期刊: 国家科学评论（英文版）
• 关键词: solar energy conversion metastable phase phase transformation iron oxide photoelectrochemical water splitting
• 年，卷（期）: 2020,（6）
• 页码范围: 1059-1067
• 页数: 9页
• 语种: 英文
• DOI: 10.1093/nsr/nwaa039

摘要

Although β-Fe2O3 has a high theoretical solar-to-hydrogen efficiency because of its narrow band gap,the study ofβ-Fe2O3 photoanodes for water splitting is elusive as a result of their metastable nature.Raman identification ofβ-Fe2O3 is theoretically and experimentally investigated in this study for the first time,thus clarifying the debate about its Raman spectrum in the literature.Phase transformation ofβ-Fe2O3 to α-Fe2O3 was found to potentially take place under laser and electron irradiation as well as annealing.Herein,phase transformation ofβ-Fe2O3 to α-Fe2O3 was inhibited by introduction of Zr doping,and β-Fe2O3 was found to withstand a higher annealing temperature without any phase transformation.T-he solar water splitting photocurrent of the Zr-doped β-Fe2O3 photoanode was increased by 500％ compared to that of the pure β-Fe2O3 photoanode.Additionally,Zr-dopedβ-Fe2O3 exhibited very good stability during the process of solar water splitting.TThese results indicate that by improving its thermal stability,metastable β-Fe2O3 film is a promising photoanode for solar water splitting.