Journal Article

A self-healing catalyst for electrocatalytic and photoelectrochemical oxygen evolution in highly alkaline conditions

Qianbao Wu, Chunhua Cui, Mamiko Nakabayashi, Ian D. Sharp, Naoya Shibata, Chao Feng, Qiugui Zeng, Kazunari Domen, Yi-Fan Han, Zhi Liu, Jie Fu, Yanbo Li, Yequan Xiao, Faze Wang

2021

Overview

While self-healing is considered a promising strategy to achieve long-term stability for oxygen evolution reaction (OER) catalysts, this strategy remains a challenge for OER catalysts working in highly alkaline conditions. The self-healing of the OER-active nickel iron layered double hydroxides (NiFe-LDH) has not been successful due to irreversible leaching of Fe catalytic centers. Here, we investigate the introduction of cobalt (Co) into the NiFe-LDH as a promoter for in situ Fe redeposition. An active borate-intercalated NiCoFe-LDH catalyst is synthesized using electrodeposition and shows no degradation after OER tests at 10 mA cm −2 at pH 14 for 1000 h, demonstrating its self-healing ability under harsh OER conditions. Importantly, the presence of both ferrous ions and borate ions in the electrolyte is found to be crucial to the catalyst’s self-healing. Furthermore, the implementation of this catalyst in photoelectrochemical devices is demonstrated with an integrated silicon photoanode. The self-healing mechanism leads to a self-limiting catalyst thickness, which is ideal for integration with photoelectrodes since redeposition is not accompanied by increased parasitic light absorption. While self-healing catalysts may survive the harsh environments used for oxygen evolution, understanding how to develop such electrocatalysts remains a challenge. Here, authors find cobalt to promote the self-healing of leached iron centers in borate-intercalated nickel-iron-cobalt oxyhydroxides.

• Publisher: Springer Science and Business Media LLC,Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 140/146 / 147/135 / 147/137 / 147/143 / 639/301/299/886 / 639/301/299/890 / 639/4077/909 / 639/638/77/885 / Adsorption / Affordable and Clean Energy / Article ; Catalytic mechanisms ; Electrocatalysis ; Photocatalysis ; Renewable energy / Carbon dioxide / Catalysts / Chemical synthesis / Cobalt / Electrocatalysts / Electrolytes / Electromagnetic absorption / Evolution / Ferrous ions / Glass substrates / Harsh environments / Humanities and Social Sciences / Hydroxides / In situ leaching / Intermetallic compounds / Investigations / Ions / Iron / Iron compounds / Leaching / multidisciplinary / Nickel / Nickel compounds / Nickel iron / Oxygen / Oxygen evolution reactions / Photoelectrochemical devices / Q / Science / Science (multidisciplinary)