Metal-organic framework-derived carbon nanotubes with multi-active Fe-N/Fe sites as a bifunctional electrocatalyst for zinc-air battery

作者：Yang, Chao; Shang, Shanshan; Gu, Qinfen; Shang, Jin; Li, Xiao-yan^*

来源：Journal of Energy Chemistry, 2022, 66: 306-313.

DOI：10.1016/j.jechem.2021.08.019

• Bifunctional electrocatalyst
• Oxygen reduction reaction
• Oxygen evolution reaction
• Single-atom iron
• Encapsulated iron nanoparticles

Sustainable metal-air batteries demand high-efficiency, environmentally-friendly, and non-precious metal-based electrocatalysts with bifunctionality for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In this research, novel functional carbon nanotubes with multi-active sites including well-dispersed single-atom iron throughout the walls and encapsulated ultrafine iron nanoparticles were synthesized as an electrocatalyst (Fe-NP@Fe-N-C) through one-step pyrolysis of metal-organic frameworks. High-resolution synchrotron powder X-ray diffraction and X-ray absorption spectroscopy were applied to characterize the unique structure of the electrocatalyst. In comparison to the commercial Pt/C and RuO2 electrodes, the newly prepared Fe-NP@Fe-N-C presented a superb bifunctional performance with its narrow potential difference (E-gap) of 0.73 V, which is ascribed to the metallic Fe nanoparticles that boosts the adsorption and activation of oxygen on the active sites with an enhanced O-2 adsorption capacity of 7.88 cm(3) g(-1) and synergistically functionalizes the iron atoms dispersed on the nanotubes. A rechargeable zinc-air battery based on Fe-NP@Fe-N-C exhibited a superior open-circuit voltage (1.45 V), power density (106.5 mW cm(-2)), and stable cycling performance. The green technique developed in this work for the fabrication of functional nanotubes raises the prospect of making more efficient electrocatalysts for sustainable energy cells.

• 单位
  清华大学