A Heterostructure Coupling of Exfoliated Ni–Fe Hydroxide Nanosheet and Defective Graphene as a Bifunctional Electrocatalyst for Overall Water Splitting

Jia, Yi and Zhang, Longzhou and Gao, Guoping and Chen, Hua and Wang, Bei and Zhou, Jizhi and Soo, Mun Teng and Hong, Min ORCID: https://orcid.org/0000-0002-6469-9194 and Yan, Xuecheng and Qian, Guangren and Zou, Jin and Du, Aijun and Yao, Xiangdong (2017) A Heterostructure Coupling of Exfoliated Ni–Fe Hydroxide Nanosheet and Defective Graphene as a Bifunctional Electrocatalyst for Overall Water Splitting. Advanced Materials, 29 (17):1700017. pp. 1-8. ISSN 0935-9648


Abstract

Herein, the authors demonstrate a heterostructured NiFe LDH-NS@DG10 hybrid catalyst by coupling of exfoliated Ni–Fe layered double hydroxide (LDH) nanosheet (NS) and defective graphene (DG). The catalyst has exhibited extremely high electrocatalytic activity for oxygen evolution reaction (OER) in an alkaline solution with an overpotential of 0.21 V at a current density of 10 mA cm−2, which is comparable to the current record (≈0.20 V in Fe–Co–Ni metal-oxide-film system) and superior to all other non-noble metal catalysts. Also, it possesses outstanding kinetics (Tafel slope of 52 mV dec−1) for the reaction. Interestingly, the NiFe LDH-NS@DG10 hybrid has also exhibited the high hydrogen evolution reaction (HER) performance in an alkaline solution (with an overpotential of 115 mV by 2 mg cm−2 loading at a current density of 20 mA cm−2) in contrast to barely HER activity for NiFe LDH-NS itself. As a result, the bifunctional catalyst the authors developed can achieve a current density of 20 mA cm−2 by a voltage of only 1.5 V, which is also a record for the overall water splitting. Density functional theory calculation reveals that the synergetic effects of highly exposed 3d transition metal atoms and carbon defects are essential for the bifunctional activity for OER and HER.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 14 Jun 2022 00:02
Last Modified: 14 Jun 2022 01:32
Uncontrolled Keywords: defects; graphene; heteroassembly; layered double hydroxide; nonprecious electrocatalysts
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
40 ENGINEERING > 4004 Chemical engineering > 400403 Chemical engineering design
Identification Number or DOI: https://doi.org/10.1002/adma.201700017
URI: http://eprints.usq.edu.au/id/eprint/49050

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