In-situ reconstructed hollow iridium-cobalt oxide nanosphere for boosting electrocatalytic oxygen evolution in acid. (10th November 2022)

• Record Type: Journal Article
• Authors: Sun, Jiuyi; Zhao, Rong; Niu, Xiaopo; Xu, Meng; Xu, Zhihong; Qin, Yue; Zhao, Wenli; Yang, Xinyue; Han, Yunxi; Wang, Qingfa
• Is Part Of: Electrochimica acta. Volume 432(2022)
• Publication Date: 2022-11-10
• Subjects: In-situ reconstruction -- Hollow nanospheres -- Crystalline/amorphous iridium oxides -- Heterostructure -- OER; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.141199
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: Hollow IrCoOx structure is fabricated via a sample in-situ reconstruction strategy. The unique hollow structure exposes more active sites and increases the active area. The IrOx -rich shell is enriched in crystalline/amorphous and atomic heterointerface. Hollow structure and heterointerface are beneficial to improve OER performance. Hollow Ir0.16 Co0.84 Ox presents excellent mass activity of 1032.16 A gIr -1 . Abstract: Iridium oxide (IrOx )-based materials perform high efficiency and durability for oxygen evolution reaction (OER) in acidic environment. Developing highly efficient OER electrocatalysts with low Ir-loading in acid is still a great challenge. Herein, we fabricated a hollow IrCoOx nanosphere via in-situ electrochemistry reconstruction strategy. The developed hollow Ir0.16 Co0.84 Ox electrocatalyst with low Ir-loading (51.91 μg cm −2 ) exhibits 71-fold and 42-fold improvement in OER mass activity and TOF value compared with commercial IrO2 (1032.16 vs 14.44 A gIr −1, 0.754 vs 0.018 s −1 ) in 0.1M HClO4, respectively. Combining with the analysis of the IrCoOx structure, the electrochemical performance reveals that the superior activity ascribes to the favorable hollow structure, the abundant crystalline/amorphous heterostructure in the IrOx -enriched shell and the atomic heterointerfaces between Co and Ir oxides, which increase the electrochemical active area, accelerate the OER kinetics and lower the charge transfer resistance (2.8 Ω cm 2 ). This work is anticipated to aid the design of novel low Ir-loading electrocatalysts with outstanding catalytic activity for water splitting in acidic environments. Graphical abstract: Image, graphical abstract