Zhang-Rice singlets state formed by two-step oxidation for triggering water oxidation under operando conditions

• Published in: Nature communications Vol. 14; no. 1; p. 529
• Main Authors: Peng, Chun-Kuo, Lin, Yu-Chang, Chiang, Chao‐Lung, Qian, Zhengxin, Huang, Yu-Cheng, Dong, Chung-Li, Li, Jian‐Feng, Chen, Chien-Te, Hu, Zhiwei, Chen, San-Yuan, Lin, Yan-Gu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-02-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166/898; 639/301/299/886; Catalysts; Catalytic activity; Copper; Copper oxides; Electrochemistry; Evolution; High temperature; High temperature superconductors; Humanities and Social Sciences; Hydrogen; multidisciplinary; Oxidation; Oxygen; Oxygen evolution reactions; Rice; Science; Science (multidisciplinary); Splitting; Superconductivity; Transition metals; Water splitting
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-36317-2

The production of ecologically compatible fuels by electrochemical water splitting is highly desirable for modern industry. The Zhang-Rice singlet is well known for the superconductivity of high-temperature superconductors cuprate, but is rarely known for an electrochemical catalyst. Herein, we observe two steps of surface reconstruction from initial catalytic inactive Cu
1+
in hydrogen treated Cu
2
O to Cu
2+
state and further to catalytic active Zhang-Rice singlet state during the oxygen evolution reaction for water splitting. The hydrogen treated Cu
2
O catalyst exhibits a superior catalytic activity and stability for water splitting and is an efficient rival of other 3
d
-transition-metal catalysts. Multiple
operando
spectroscopies indicate that Zhang-Rice singlet is real active species, since it appears only under oxygen evolution reaction condition. This work provides an insight in developing an electrochemical catalyst from catalytically inactive materials and improves understanding of the mechanism of a Cu-based catalyst for water oxidation.
The Zhang-Rice singlet is known for the superconductivity of high-temperature superconductors cuprate but is rarely studied for an electrochemical catalyst. Here, the authors use
operando
spectroscopic tools and observe Cu active site evolves into high-valent CuO
4
geometry with Cu
3+
active species, so-called Zhang-Rice singlet state, during oxygen evolution reaction.