In:
Angewandte Chemie, Wiley, Vol. 127, No. 41 ( 2015-10-05), p. 12172-12176
Kurzfassung:
The bottleneck in water electrolysis lies in the kinetically sluggish oxygen evolution reaction (OER). Herein, conceptually new metallic non‐metal atomic layers are proposed to overcome this drawback. Metallic single‐unit‐cell CoSe 2 sheets with an orthorhombic phase are synthesized by thermally exfoliating a lamellar CoSe 2 ‐DETA hybrid. The metallic character of orthorhombic CoSe 2 atomic layers, verified by DFT calculations and temperature‐dependent resistivities, allows fast oxygen evolution kinetics with a lowered overpotential of 0.27 V. The single‐unit‐cell thickness means 66.7 % of the Co 2+ ions are exposed on the surface and serve as the catalytically active sites. The lowered Co 2+ coordination number down to 1.3 and 2.6, gives a lower Tafel slope of 64 mV dec −1 and higher turnover frequency of 745 h −1 . Thus, the single‐unit‐cell CoSe 2 sheets have around 2 and 4.5 times higher catalytic activity compared with the lamellar CoSe 2 ‐DETA hybrid and bulk CoSe 2 .
Materialart:
Online-Ressource
ISSN:
0044-8249
,
1521-3757
DOI:
10.1002/ange.v127.41
DOI:
10.1002/ange.201505245
Sprache:
Deutsch
Verlag:
Wiley
Publikationsdatum:
2015
ZDB Id:
506609-8
ZDB Id:
1479266-7
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