Long-term durability of metastable β-Fe2O3 photoanodes in highly corrosive seawater

Changhao Liu; Ningsi Zhang; Yang Li; Rongli Fan; Wenjing Wang; Jianyong Feng; Chen Liu; Jiaou Wang; Weichang Hao; Zhaosheng Li; Zhigang Zou

doi:10.1038/s41467-023-40010-9

Long-term durability of metastable β-Fe₂O₃ photoanodes in highly corrosive seawater

Nat Commun. 2023 Jul 17;14(1):4266. doi: 10.1038/s41467-023-40010-9.

Authors

Changhao Liu^{1

2}, Ningsi Zhang^{1

2}, Yang Li¹, Rongli Fan¹, Wenjing Wang¹, Jianyong Feng³, Chen Liu⁴, Jiaou Wang⁴, Weichang Hao⁵, Zhaosheng Li^{6

7}, Zhigang Zou^{1

2}

Affiliations

¹ Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, 210093, China.
² Jiangsu Key Laboratory for Nano Technology, Nanjing University, 22 Hankou Road, Nanjing, 210093, China.
³ Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, 210093, China. fengjianyong@nju.edu.cn.
⁴ Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
⁵ School of Physics and Centre of Quantum and Matter Sciences, International Research Institute for Multidisciplinary Science, Beihang University, Beijing, 100191, China.
⁶ Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing, 210093, China. zsli@nju.edu.cn.
⁷ Jiangsu Key Laboratory for Nano Technology, Nanjing University, 22 Hankou Road, Nanjing, 210093, China. zsli@nju.edu.cn.

Abstract

Durability is one prerequisite for material application. Photoelectrochemical decomposition of seawater is a promising approach to produce clean hydrogen by using solar energy, but it always faces the problem of serious Cl^- corrosion. We find that the main deactivation mechanism of the photoanode is oxide surface reconstruction accompanied by the coordination of Cl^- during seawater splitting, and the stability of the photoanode can be effectively improved by enhancing the metal-oxygen interaction. Taking the metastable β-Fe₂O₃ photoanode as an example, Sn added to the lattice can enhance the M-O bonding energy and hinder the transfer of protons to lattice oxygen, thereby inhibiting excessive surface hydration and Cl^- coordination. Therefore, the bare Sn/β-Fe₂O₃ photoanode delivers a record durability for photoelectrochemical seawater splitting over 3000 h.