Ex Situ Reconstruction-Shaped Ir/CoO/Perovskite Heterojunction for Boosted Water Oxidation Reaction

Guo, Hongquan, Yang, Yanling, Yang, Guangming, Cao, Xiaojuan, Yan, Ning, Li, Zhishan, Chen, Emily, Tang, Lina, Peng, Meilan, Shi, Lei
et al (show 11 more authors) (2023) Ex Situ Reconstruction-Shaped Ir/CoO/Perovskite Heterojunction for Boosted Water Oxidation Reaction. ACS CATALYSIS, 13 (7). pp. 5007-5019.

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The oxygen evolution reaction (OER) is the performance-limiting step in the process of water splitting. In situ electrochemical conditioning could induce surface reconstruction of various OER electrocatalysts, forming reactive sites dynamically but at the expense of fast cation leaching. Therefore, achieving simultaneous improvement in catalytic activity and stability remains a significant challenge. Herein, we used a scalable cation deficiency-driven exsolution approach to ex situ reconstruct a homogeneous-doped cobaltate precursor into an Ir/CoO/perovskite heterojunction (SCI-350), which served as an active and stable OER electrode. The SCI-350 catalyst exhibited a low overpotential of 240 mV at 10 mA cm<sup>-2</sup> in 1 M KOH and superior durability in practical electrolysis for over 150 h. The outstanding activity is preliminarily attributed to the exponentially enlarged electrochemical surface area for charge accumulation, increasing from 3.3 to 175.5 mF cm<sup>-2</sup>. Moreover, density functional theory calculations combined with advanced spectroscopy and <sup>18</sup>O isotope-labeling experiments evidenced the tripled oxygen exchange kinetics, strengthened metal-oxygen hybridization, and engaged lattice oxygen oxidation for O-O coupling on SCI-350. This work presents a promising and feasible strategy for constructing highly active oxide OER electrocatalysts without sacrificing durability.

Item Type: Article
Uncontrolled Keywords: ex situ reconstruction, heterojunction, oxygen evolution, lattice oxygen mechanism, charge accumulation
Divisions: Faculty of Science and Engineering > School of Electrical Engineering, Electronics and Computer Science
Depositing User: Symplectic Admin
Date Deposited: 04 Apr 2023 14:52
Last Modified: 03 May 2023 16:34
DOI: 10.1021/acscatal.2c05684
Open Access URL: https://pubs.acs.org/doi/full/10.1021/acscatal.2c0...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3169419