The rapid self-reconstruction of Fe-modified Ni hydroxysulfide for efficient and stable large-current-density water/seawater oxidation

• Published in: Energy & environmental science Vol. 15; no. 11; pp. 4647 - 4658
• Main Authors: Huang, Chuqiang, Zhou, Qiancheng, Duan, Dingshuo, Yu, Luo, Zhang, Wei, Wang, Zhouzhou, Liu, Jin, Peng, Bowen, An, Pengfei, Zhang, Jing, Li, Liping, Yu, Jiaguo, Yu, Ying
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 09.11.2022
• Subjects: Alkaline water; Catalysts; Chemical analysis; Chemical properties; Corrosion resistance; Current density; Electrocatalysts; Free energy; Heat of formation; In situ leaching; Iron; Leaching; Metal foams; Nickel; Oxidation; Oxidation resistance; Oxygen evolution reactions; Reconstruction; Seawater; Theoretical analysis; Water analysis
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d2ee01478e

The reasonable design of electrocatalysts with rapid self-reconstruction for an efficient oxygen evolution reaction (OER) at commercially required current densities is highly desirable but very challenging. Herein, ultrathin Fe-modified Ni hydroxysulfide (Fe-NiSOH) nanosheet arrays were grown in situ on Ni foam via a simple two-step oxidation strategy for efficient and stable large-current-density water/seawater oxidation. Systematic insights, including experimental and theoretical analysis, reveal that in situ S leaching from the electrode boosts its self-reconstruction and results in the more-ready generation of highly active Ni 4+ species, which benefits from a reduced formation energy. Owing to its excellent physical and chemical properties, the Fe-NiSOH catalyst requires only low overpotentials of 207, 240, and 268 mV in alkaline water to deliver current densities of 10, 100, and 500 mA cm −2 , respectively, and it can work stably for 1100 hours at the commercially required current density of 500 mA cm −2 . Furthermore, it also exhibits excellent seawater oxidation activity and superior resistance to Cl − corrosion, since it can run stably at 500 mA cm −2 for over 900 hours. This work offers an efficient strategy to build rapidly self-reconstructing electrocatalysts to promote the formation of highly oxidized metal species for efficient and stable water/seawater oxidation. S leaching induces rapid self-reconstruction and the ready formation of Ni 4+ in an Fe-NiSOH electrode, supporting high-efficiency and stable alkaline large-current-density water/seawater oxidation.