3 years ago

Amorphous Bimetallic Oxide–Graphene Hybrids as Bifunctional Oxygen Electrocatalysts for Rechargeable Zn–Air Batteries

Amorphous Bimetallic Oxide–Graphene Hybrids as Bifunctional Oxygen Electrocatalysts for Rechargeable Zn–Air Batteries
Hongwei Liu, Li Wei, Yuan Chen, Zongwen Liu, Xuncai Chen, H. Enis Karahan, Yaojie Lei, Shengli Zhai, Zheng Zhou
Metal oxides of earth-abundant elements are promising electrocatalysts to overcome the sluggish oxygen evolution and oxygen reduction reaction (OER/ORR) in many electrochemical energy-conversion devices. However, it is difficult to control their catalytic activity precisely. Here, a general three-stage synthesis strategy is described to produce a family of hybrid materials comprising amorphous bimetallic oxide nanoparticles anchored on N-doped reduced graphene oxide with simultaneous control of nanoparticle elemental composition, size, and crystallinity. Amorphous Fe0.5Co0.5Ox is obtained from Prussian blue analog nanocrystals, showing excellent OER activity with a Tafel slope of 30.1 mV dec−1 and an overpotential of 257 mV for 10 mA cm−2 and superior ORR activity with a large limiting current density of −5.25 mA cm−2 at 0.6 V. A fabricated Zn–air battery delivers a specific capacity of 756 mA h gZn−1 (corresponding to an energy density of 904 W h kgZn−1), a peak power density of 86 mW cm−2 and can be cycled over 120 h at 10 mA cm−2. Other two amorphous bimetallic, Ni0.4Fe0.6Ox and Ni0.33Co0.67Ox, are also produced to demonstrate the general applicability of this method for synthesizing binary metal oxides with controllable structures as electrocatalysts for energy conversion. Simultaneous control of bimetallic oxide nanoparticle elemental composition, size, and crystallinity yields a high-performance bifunctional oxygen evolution and reduction electrocatalyst for rechargeable Zn–air batteries. This method has general applicability toward various binary, tertiary, or even quadruple metal systems.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adma.201701410

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.