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Self-reconstruction mechanism in NiSe2 nanoparticles/carbon fiber paper bifunctional electrocatalysts for water splitting.
- Source :
-
Electrochimica Acta . May2019, Vol. 305, p37-46. 10p. - Publication Year :
- 2019
-
Abstract
- Abstract Developing efficient bifunctional electrocatalysts and gaining fundamental understanding of reaction mechanisms are crucial for practical water splitting. Herein, a bifunctional NiSe 2 nanoparticles/carbon fiber paper (NSN/CFP) electrode is fabricated by the pyrolysis of Ni(NO 3) 2 on CFP, followed by a selenization step. The as-prepared electrocatalysts exhibit superior overall water splitting behavior in 1 M KOH with low overpotentials of 145 mV and 280 mV at current densities of 10 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) respectively, comparable to the performance of 20% Pt/C and RuO 2. Detailed compositional and morphological studies reveal that the NiSe 2 gradually transforms into an amorphous Ni(OH) 2 /NiOOH heterojunction during both HER and OER in alkaline medium. Based on these experimental results, an oxidation-induced self-reconstruction mechanism is proposed. Owing to the highly-oxidized Ni(OH) 2 /NiOOH active species, the self-reconstructed structure enhances the water splitting under fixed potentials for a prolonged time of 96 h with negligible current degradation. This work not only provides a facile route to fabricate efficient and stable electrocatalysts for large-scale water splitting but also reveals an underlying structural evolution mechanism, which guides the rational design of heterogeneous catalysts. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00134686
- Volume :
- 305
- Database :
- Academic Search Index
- Journal :
- Electrochimica Acta
- Publication Type :
- Academic Journal
- Accession number :
- 135642148
- Full Text :
- https://doi.org/10.1016/j.electacta.2019.03.031