MOF-derived CoNi, CoO, NiO@N–C bifunctional oxygen electrocatalysts for liquid and all-solid-state Zn–air batteries. Issue 41 (20th October 2021)

• Record Type: Journal Article
• Authors: Duan, Xinde; Ren, Shuangshuang; Ge, Fayuan; Zhu, Xukun; Zhang, Mingdao; Zheng, Hegen
• Is Part Of: Nanoscale. Volume 13:Issue 41(2021)
• Page Start: 17655
• Page End: 17662
• Publication Date: 2021-10-20
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d1nr04537g
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : MOF-derived CoNi, CoO, NiO@NC bifunctional electrocatalysts for the ORR and OER have been prepared via pyrolysis, exhibiting ultra-high catalytic activity and promising performance in liquid- and all-solid-state Zn–air batteries. Abstract : Metal–organic framework (MOF)-derived carbon composites with embedded metal alloy/metal oxides have attracted much attention due to their low-cost and excellent electrochemical reactivity. However, the drawback of this concept is the severe carbon evaporation during their synthesis, resulting in a reduction of active sites and catalytic durability. To solve this problem, this study proposes the possibility of using Ketjen black (KB) to replenish the carbon content. Impressively, MOF-derived bimetal and oxide N-doped porous carbon (CoNi-CoO-NiO@NC-800) exhibits extremely high catalytic activity with an oxygen reduction reaction (half-wave potential: 0.83 V) and oxygen evolution reaction (overpotential: 352 mV @ 10 mA cm −2 ) potential gap of 0.75 V due to the virtue of the hierarchically porous structure and sufficient active sites. By combining theoretical studies, a strong synergetic coupling of the CoNi dual metal is proposed in decreasing the overall reaction barriers and promoting the reversible oxygen reactions. Moreover, the assembled liquid- and all-solid-state Zn–air batteries (ZABs) with the bifunctional catalyst as the air cathode demonstrate superior discharging (223 mW cm −2 at 310 mA cm −2 ) and charging–discharging performance and long lifetime (450 cycles, 75 h). This work will provide guidance for the rational design of metal/carbon hybrid catalysts and cut-price reproducible energy systems.