Tuning the Activity of Carbon for Electrocatalytic Hydrogen Evolution via an Iridium-Cobalt Alloy Core Encapsulated in Nitrogen-Doped Carbon Cages

Bibliographische Detailangaben
Veröffentlicht in:	Advanced materials (Deerfield Beach, Fla.). - 1998. - 30(2018), 9 vom: 20. März
1. Verfasser:	Jiang, Peng (VerfasserIn)
Weitere Verfasser:	Chen, Jitang, Wang, Changlai, Yang, Kang, Gong, Shipeng, Liu, Shuai, Lin, Zhiyu, Li, Mengsi, Xia, Guoliang, Yang, Yang, Su, Jianwei, Chen, Qianwang
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2018
Zugriff auf das übergeordnete Werk:	Advanced materials (Deerfield Beach, Fla.)
Schlagworte:	Journal Article alloys charge-density difference graphene shells metal-organic frameworks

Beschreibung
Zusammenfassung:	© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Graphene, a 2D material consisting of a single layer of sp2 -hybridized carbon, exhibits inert activity as an electrocatalyst, while the incorporation of heteroatoms (such as N) into the framework can tune its electronic properties. Because of the different electronegativity between N and C atoms, electrons will transfer from C to N in N-doped graphene nanosheets, changing inert C atoms adjacent to the N-dopants into active sites. Notwithstanding the achieved progress, its intrinsic activity in acidic media is still far from Pt/C. Here, a facile annealing strategy is adopted for Ir-doped metal-organic frameworks to synthesize IrCo nanoalloys encapsulated in N-doped graphene layers. The highly active electrocatalyst, with remarkably reduced Ir loading (1.56 wt%), achieves an ultralow Tafel slope of 23 mV dec-1 and an overpotential of only 24 mV at a current density of 10 mA cm-2 in 0.5 m sulfuric acid solution. Such superior performance is even superior to the noble-metal catalyst Pt. Surface structural and computational studies reveal that the superior behavior originates from the decreased ΔGH* for HER induced by the electrons transferred from the alloy core to the graphene layers, which is beneficial for enhancing CH binding
Beschreibung:	Date Completed 01.08.2018 Date Revised 30.09.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE
ISSN:	1521-4095
DOI:	10.1002/adma.201705324