1. Core/shell Ni@C particle-supported N-doped carbon with hollow capsules for efficient electrocatalytic reduction of oxygen.
- Author
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Gao, Jian, Meng, Lingxin, Ma, Na, Tan, Xiaoyao, Li, Yuan, Wang, Hong, and Zhang, Peng
- Subjects
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CARBON-based materials , *METAL-air batteries , *NANOPARTICLES , *METAL catalysts , *PRECIOUS metals , *OXYGEN reduction - Abstract
To replace the noble metal catalysts for oxygen reduction reaction (ORR), a Ni@C-supported N-doped carbon material (Ni@C/NC) is in-situ prepared via one-step pyrolyzing the polymerizable ionic liquid of vinyl imidazole combined with Ni(NO 3) 2. Systemic investigations demonstrate that these nanosized Ni particles are tightly wrapped with a thin carbon layer to form the core/shell structure, meanwhile carbon capsules are synchronously yielded on the carbon matrix. As a result, both the carbon shell and the carbon capsule jointly increase the active sites of the Ni@C/NC, while the carbon shell also contributes the fast electron-transfer from Ni particle. Compared with the normal Ni-supported carbon catalyst, the Ni@C/NC shows the respectable ORR performance with the onset and half-wave potentials of 0.96 and 0.84 V RHE. After the long-term electrocatalysis (10 h), the Ni@C/NC is found to possess the great structural and electrocatalytic stabilities, which maintains 93 % of the initial current density and the well-dispersed and uniform Ni@C particles. Subsequently, a Zn-Air battery with the Ni@C/NC cathode is assembled and exhibits a peak power density of 200 mW cm−2. Therefore, the as-obtained Ni@C/NC with the high electroactivity and stability can be expected as an ideal candidate to apply in the metal-air batteries and fuel cells in the future. Ni particles wrapped with a thin carbon layer is in-situ formed and supported on a N-doped carbon with many capsules, fabricating the Ni@C/NC catalyst, which exhibit the superior catalytic performance for oxygen reduction. [Display omitted] • A Ni@C-supported N-doped carbon material is in-situ prepared. • Nanosized Ni particles are wrapped with a thin carbon layer. • Carbon capsules are synchronously yielded on the carbon matrix. • The Ni@C/NC shows the respectable ORR performance. • The Ni@C/NC possesses the great structural and electrocatalytic stabilities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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