Abstract
Durable electrocatalysts with high catalytic activity toward oxygen reduction reaction (ORR) are crucial to high-performance primary zinc-air batteries (ZnABs) and direct methanol fuel cells (DMFCs). An efficient composite electrocatalyst, Co@Co3O4 core@shell nanoparticles (NPs) embedded in pyrolyzed polydopamine (PPD) is reported, i.e., in Co@Co3O4@PPD core@bishell structure, obtained via a three-step sequential process involving hydrothermal synthesis, high temperature calcination under nitrogen atmosphere, and gentle heating in air. With Co@Co3O4 NPs encapsulated by ultrathin highly graphitized N-doped carbon, the catalyst exhibits excellent stability in aqueous alkaline solution over extended period and good tolerance to methanol crossover effect. The integration of N-doped graphitic carbon outer shell and ultrathin nanocrystalline Co3O4 inner shell enable high ORR activity of the core@bishell NPs, as evidenced by ZnABs using catalyst of Co@Co3O4@PPD in air-cathode which delivers a stable voltage profile over 40 h at a discharge current density of as high as 20 mA cm-2. Co@Co3O4 core@shell nanoparticles (NPs) embedded in N-doped graphitic carbon matrix of pyrolyzed polydopamine (PPD), i.e., Co@Co3O4@PPD core@bishell structure are obtained. This material shows high oxygen reduction reaction activity. Consequently, it is used as a cathode catalyst in zinc-air batteries and delivers stable voltage profile over an extended period at a discharge current density of as high as 20 mA cm-2.
Original language | English |
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Pages (from-to) | 2580-2587 |
Number of pages | 8 |
Journal | Small |
Volume | 12 |
Issue number | 19 |
DOIs | |
Publication status | Published - 18 May 2016 |
Externally published | Yes |
Keywords
- cobalt oxide
- dopamine
- nitrogen-doped carbon
- oxygen reduction reaction
- zinc-air batteries
ASJC Scopus subject areas
- Biotechnology
- Biomaterials
- General Chemistry
- General Materials Science