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3D hierarchically macro-/mesoporous graphene frameworks enriched with pyridinic-nitrogen-cobalt active sites as efficient reversible oxygen electrocatalysts for rechargeable zinc-air batteries
- Source :
- Chinese Journal of Catalysis. 42:571-582
- Publication Year :
- 2021
- Publisher :
- Elsevier BV, 2021.
-
Abstract
- Efficient and affordable electrocatalysts for reversible oxygen reduction and oxygen evolution reactions (ORR and OER, respectively) are highly sought-after for use in rechargeable metal-air batteries. However, the construction of high-performance electrocatalysts that possess both largely accessible active sites and superior ORR/OER intrinsic activities is challenging. Herein, we report the design and successful preparation of a 3D hierarchically porous graphene framework with interconnected interlayer macropores and in-plane mesopores, enriched with pyridinic-nitrogen-cobalt (pyri-N-Co) active sites, namely, CoFe/3D-NLG. The pyri-N-Co bonding significantly accelerates sluggish oxygen electrocatalysis kinetics, in turn substantially improving the intrinsic ORR/OER activities per active site, while copious interlayer macropores and in-plane mesopores enable ultra-efficient mass transfer throughout the graphene architecture, thus ensuring sufficient exposure of accessible pyri-N-Co active sites to the reagents. Such a robust catalyst structure endows CoFe/3D-NLG with a remarkably enhanced reversible oxygen electrocatalysis performance, with the ORR half-wave potential identical to that of the benchmark Pt/C catalyst, and OER activity far surpassing that of the noble-metal-based RuO2 catalyst. Moreover, when employed as an air electrode for a rechargeable Zn-air battery, CoFe/3D-NLG manifests an exceedingly high open-circuit voltage (1.56 V), high peak power density (213 mW cm−2), ultra-low charge/discharge voltage (0.63 V), and excellent charge/discharge cycling stability, outperforming state-of-the-art noble-metal electrocatalysts.
- Subjects :
- Battery (electricity)
Materials science
Graphene
Oxygen evolution
chemistry.chemical_element
02 engineering and technology
General Medicine
010402 general chemistry
021001 nanoscience & nanotechnology
Electrocatalyst
01 natural sciences
0104 chemical sciences
law.invention
Catalysis
chemistry
Chemical engineering
law
Electrode
0210 nano-technology
Mesoporous material
Cobalt
Subjects
Details
- ISSN :
- 18722067
- Volume :
- 42
- Database :
- OpenAIRE
- Journal :
- Chinese Journal of Catalysis
- Accession number :
- edsair.doi...........25a7e115ec3a142ed43babfb56b39a83