Co0.7Fe0.3 NPs confined in yolk–shell N-doped carbon: engineering multi-beaded fibers as an efficient bifunctional electrocatalyst for Zn–air batteries. Issue 4 (25th January 2021)

• Record Type: Journal Article
• Authors: Long, Ling; Liu, Haohui; Jia, Jianbo; Zhang, Yelong; Dong, Shaojun
• Is Part Of: Nanoscale. Volume 13:Issue 4(2021)
• Page Start: 2609
• Page End: 2617
• Publication Date: 2021-01-25
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d0nr08781e
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : A bifunctional electrocatalyst, Co0.7 Fe0.3 @NC X : Y - T with a unique and porous confinement structure was synthesized for assembling efficient Zn–air batteries. Abstract : The development of bifunctional catalysts with a delicate structure, high efficiency, and good durability for the oxygen evolution reaction (ORR) and oxygen evolution reaction (OER) is crucial to renewable Zn–air batteries. In this work, Co0.7 Fe0.3 alloy nanoparticles (NPs) confined in N-doped carbon with a yolk–shell structure in multi-beaded fibers were prepared as a bifunctional electrocatalyst. The confinement structure was composed of an N-doped graphitized carbon shell and a core formed by numerous Co0.7 Fe0.3 NPs, and was evenly threaded into a one-dimensional fiber. Moreover, this distinctive hierarchical structure featured abundant mesopores, a high BET surface area of 743.8 m 2 g −1, good electronic conductivity, and uniformly distributed Co0.7 Fe0.3 /Co(Fe)–N x coupling active sites. Therefore, the experimentally optimized Co0.7 Fe0.3 @NC 2:1 - 800 showed excellent OER performance (overpotential reached 314 mV at 10 mA cm −2 ) that far exceeded RuO2 (353 mV), and good ORR catalytic performance (half-wave potential of 0.827 V) comparable to Pt/C (0.818 V). Impressively, the Co0.7 Fe0.3 @NC 2:1 - 800 Zn–air battery delivered a higher open circuit voltage of 1.449 V, large power density of 85.7 mW cm −2, and outstanding charge–discharge cycling stability compared with the commercial RuO2 + 20 wt% Pt/C catalyst. This work provides new ideas for the structural design of electrocatalysts and energy conversion systems.