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Metal (Ni, Co)-Metal Oxides/Graphene Nanocomposites as Multifunctional Electrocatalysts.
- Source :
- Advanced Functional Materials; Sep2015, Vol. 25 Issue 36, p5799-5808, 10p
- Publication Year :
- 2015
-
Abstract
- Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) along with hydrogen evolution reaction (HER) have been considered critical processes for electrochemical energy conversion and storage through metal-air battery, fuel cell, and water electrolyzer technologies. Here, a new class of multifunctional electrocatalysts consisting of dominant metallic Ni or Co with small fraction of their oxides anchored onto nitrogen-doped reduced graphene oxide (rGO) including Co-CoO/N-rGO and Ni-NiO/N-rGO are prepared via a pyrolysis of graphene oxide and cobalt or nickel salts. Ni-NiO/N-rGO shows the higher electrocatalytic activity for the OER in 0.1 m KOH with a low overpotential of 0.24 V at a current density of 10 mA cm<superscript>−2</superscript>, which is superior to that of the commercial IrO<subscript>2</subscript>. In addition, it exhibits remarkable activity for the HER, demonstrating a low overpotential of 0.16 V at a current density of 20 mA cm<superscript>−2</superscript> in 1.0 m KOH. Apart from similar HER activity to the Ni-based catalyst, Co-CoO/N-rGO displays the higher activity for the ORR, comparable to Pt/C in zinc-air batteries. This work provides a new avenue for the development of multifunctional electrocatalysts with optimal catalytic activity by varying transition metals (Ni or Co) for these highly demanded electrochemical energy technologies. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 1616301X
- Volume :
- 25
- Issue :
- 36
- Database :
- Complementary Index
- Journal :
- Advanced Functional Materials
- Publication Type :
- Academic Journal
- Accession number :
- 109556434
- Full Text :
- https://doi.org/10.1002/adfm.201502217