Self-Assembly of Ir-Based Nanosheets with Ordered Interlayer Space for Enhanced Electrocatalytic Water Oxidation

Lianhai Zu; Xingyue Qian; Shenlong Zhao; Qinghua Liang; Yu Emily Chen; Min Liu; Bing-Jian Su; Kuang-Hsu Wu; Longbing Qu; Linlin Duan; Hualin Zhan; Jun-Ye Zhang; Can Li; Wei Li; Jenh Yih Juang; Junwu Zhu; Dan Li; Aibing Yu; Dongyuan Zhao

doi:10.1021/jacs.1c11241

Self-Assembly of Ir-Based Nanosheets with Ordered Interlayer Space for Enhanced Electrocatalytic Water Oxidation

J Am Chem Soc. 2022 Feb 9;144(5):2208-2217. doi: 10.1021/jacs.1c11241. Epub 2022 Jan 31.

Authors

Lianhai Zu^{1

2

3}, Xingyue Qian^{4

5}, Shenlong Zhao⁶, Qinghua Liang³, Yu Emily Chen⁷, Min Liu³, Bing-Jian Su⁸, Kuang-Hsu Wu⁸, Longbing Qu³, Linlin Duan¹, Hualin Zhan³, Jun-Ye Zhang¹, Can Li⁹, Wei Li¹, Jenh Yih Juang⁸, Junwu Zhu⁴, Dan Li³, Aibing Yu^{2

10}, Dongyuan Zhao^{1

2}

Affiliations

¹ Department of Chemistry, Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, iChEM, and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, China.
² ARC Hub for Computational Particle Technology, Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia.
³ Department of Chemical Engineering, The University of Melbourne, Parkville, VIC 3010, Australia.
⁴ Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education, Nanjing University of Science and Technology, Nanjing 210094, China.
⁵ Key Laboratory of Advanced Catalytic Materials and Technology, Advanced Catalysis and Green Manufacturing Collaborative Innovation Center, Changzhou University, Changzhou, Jiangsu 213164, China.
⁶ School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
⁷ Monash Centre for Electron Microscopy (MCEM), Monash University, Clayton, VIC 3800, Australia.
⁸ Department of Electrophysics, National Chiao Tung University, Hsinchu 30076, Taiwan.
⁹ Institute of Optoelectronic Materials and Devices, China Jiliang University, Hangzhou 310018, China.
¹⁰ Southeast University-Monash University Joint Research Institute, Suzhou 215123, China.

PMID: 35099956
DOI: 10.1021/jacs.1c11241

Abstract

Iridium (Ir)-based electrocatalysts are widely explored as benchmarks for acidic oxygen evolution reactions (OERs). However, further enhancing their catalytic activity remains challenging due to the difficulty in identifying active species and unfavorable architectures. In this work, we synthesized ultrathin Ir-IrO_x/C nanosheets with ordered interlayer space for enhanced OER by a nanoconfined self-assembly strategy, employing block copolymer formed stable end-merged lamellar micelles. The interlayer distance of the prepared Ir-IrO_x/C nanosheets was well controlled at ∼20 nm and Ir-IrO_x nanoparticles (∼2 nm) were uniformly distributed within the nanosheets. Importantly, the fabricated Ir-IrO_x/C electrocatalysts display one of the lowest overpotential (η) of 198 mV at 10 mA cm^-2_geo during OER in an acid medium, benefiting from their features of mixed-valence states, rich electrophilic oxygen species (O^(II-δ)-), and favorable mesostructured architectures. Both experimental and computational results reveal that the mixed valence and O^(II-δ)- moieties of the 2D mesoporous Ir-IrO_x/C catalysts with a shortened Ir-O^(II-δ)- bond (1.91 Å) is the key active species for the enhancement of OER by balancing the adsorption free energy of oxygen-containing intermediates. This strategy thus opens an avenue for designing high performance 2D ordered mesoporous electrocatalysts through a nanoconfined self-assembly strategy for water oxidation and beyond.