Stone-Wales defect-rich carbon-supported dual-metal single atom sites for Zn-air batteries. (December 2021)

• Record Type: Journal Article
• Authors: Khan, Kishwar; Yan, Xingxu; Yu, Qiangmin; Bae, Sang-Hoon; White, Jessica Jein; Liu, Junxian; Liu, Tangchao; Sun, Chengjun; Kim, Jeehwan; Cheng, Hui-Ming; Wang, Yun; Liu, Bilu; Amine, Khalil; Pan, Xiaoqing; Luo, Zhengtang
• Is Part Of: Nano energy. Volume 90(2021)Part A
• Publication Date: 2021-12
• Subjects: Stone-wales defects -- Nanocarbons -- Dual metal single atom sites -- Electrocatalyst; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2021.106488
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: This work aims to obtain a fundamental understanding of active sites near stone-wales (SW) defects rich nitrogen-doped graphene (DG) with specific coordination of carbon atom rings. It reveals that the SW rich defects ( e.g., pentagon (5), pentagon—octagon—pentagon ( i.e . 585), or pentagon-heptagon-heptagon-pentagon (5775) rings, appears correspondingly with carbon rings that brought active sites during catalytic reactions. Moreover, we anchored dual isolated metallic atoms (Ni/Fe) on DG support via linkers (O/N) called NiFe-DG. X-ray absorption spectroscopy indicates Ni/Fe metal single atoms are embedded via Fe-N4 and Ni-N4 coordination on DG surfaces. It exhibits high catalytic activity for oxygen reduction reaction (ORR) with an onset potential of 0.97 V, a half-wave potential of 0.86 V, and diffusion current density of 5.7 mA cm − 2, which is at par with commercial Pt/C. The catalyst shows superior stability, retained 82% of the initial current density even after 12 h under an applied potential of 0.86 V. Similarly, the oxygen evolution reaction (OER) overpotential of 358 mV was achieved at 10 mA cm − 2 with a lower Tafel slope value (76 mV/dec) than commercial Pt/C. It maintains 85% stability for 12 h at a constant potential of 1.588 V, shows better stability than commercial Pt/C. Graphical Abstract: Stone-Wales (SW) defects-rich nanocarbon support composed of 585 and 5775 structures, anchored with dual metal (Ni/Fe) single-atom catalyst towards bifunctional oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and Zn-air batteries (ZAB). ga1 Highlights: Defects engineering in nanocarbon support. Stone-Wales (SW) defects-rich structure. Dual metal single-atom catalyst. Bifunctional electrocatalyst exhibits excellent activity towards ORR and OER. High-performance Zn-air batteries achieving good stability and durability.