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Preparation of CoP/Co@NPC@rGO nanocomposites with an efficient bifunctional electrocatalyst for hydrogen evolution and oxygen evolution reaction
- Source :
- 工程科学学报, Vol 42, Iss 1, Pp 91-98 (2020)
- Publication Year :
- 2020
- Publisher :
- Science Press, 2020.
-
Abstract
- The construction of the highly active transition-metal phosphide/carbon-based electrocatalyst from metal-organic frameworks (MOFs) precursors is considered as an efficient approach. In this work, ZIF-67/GO precursors were firstly obtained by the in situ controllable growth of ZIF-67 nanocrystals on both surfaces of GO sheets. Then, a highly efficient bifunctional electrocatalyst CoP/Co@NPC@rGO nanocomposite was derived by the thermal pyrolysis of ZIF-67/GO precursors under N2 atmosphere and a subsequent phosphatization process. The structure and elemental composition of the ZIF-67/GO, Co@NPC@rGO, and CoP/Co@NPC@rGO nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and N2 ad-/desorption isotherms analysis. The Co@NPC@rGO‒800 nanocomposite exhibits a high Brunauer-Emmett-Teller (BET) surface area of 186.27 m2·g‒1, indicating that both micropores and mesopores existed. Subsequently, the electrocatalytic properties of the CoP/Co@NPC@rGO nanocomposites for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were investigated by electrochemical measurements. The results suggest that the obtained CoP/Co@NPC@rGO‒350 nanocomposite only requires an overpotential of 127 mV to reach a current density of 10 mA·cm‒2 for HER in 1.0 mol·L–1 KOH solution. For OER, CoP/Co@NPC@rGO‒350 nanocomposite can reach a current density of 10 mA·cm‒2 at an overpotential of 276 mV, with a Tafel slope of 42 mV·dec−1, in the same alkaline aqueous solution, which is superior to RuO2. In addition, for both HER and OER, CoP/Co@NPC@rGO‒350 nanocomposite also shows impressive strong durability in alkaline aqueous solution. The outstanding performance can be attributed to the synergistic effect of coupled highly graphitized N-doped porous carbon and N-doped graphene. The as-prepared CoP/Co@NPC@rGO‒350 electrocatalyst is a promising candidate for overall water splitting in the alkaline solution. This development offers an attractive catalyst material based on MOF/GO composites. It is expected that the presented strategy can be extended to the fabrication of other composites electrode materials for more efficient water splitting.
Details
- Language :
- Chinese
- ISSN :
- 20959389
- Volume :
- 42
- Issue :
- 1
- Database :
- Directory of Open Access Journals
- Journal :
- 工程科学学报
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.8abae441cf94e798da1041e870bd1b5
- Document Type :
- article
- Full Text :
- https://doi.org/10.13374/j.issn2095-9389.2019.07.26.002