ZIF-67-Derived NiCo-Layered Double Hydroxide@Carbon Nanotube Architectures with Hollow Nanocage Structures as Enhanced Electrocatalysts for Ethanol Oxidation Reaction

Yixuan Li; Yanqi Xu; Cunjun Li; Wenfeng Zhu; Wei Chen; Yufei Zhao; Ruping Liu; Linjiang Wang

doi:10.3390/molecules28031173

ZIF-67-Derived NiCo-Layered Double Hydroxide@Carbon Nanotube Architectures with Hollow Nanocage Structures as Enhanced Electrocatalysts for Ethanol Oxidation Reaction

Molecules. 2023 Jan 25;28(3):1173. doi: 10.3390/molecules28031173.

Authors

Yixuan Li¹, Yanqi Xu^{1

2}, Cunjun Li^{1

2}, Wenfeng Zhu^{1

2}, Wei Chen³, Yufei Zhao³, Ruping Liu⁴, Linjiang Wang^{1

2}

Affiliations

¹ College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China.
² Key Laboratory of New Technology for Processing Nonferrous Metals and Materials, Ministry of Education, Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of Resources in Guangxi, Guilin University of Technology, Guilin 541004, China.
³ State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
⁴ Beijing Institute of Graphic Communication, Beijing 102600, China.

Abstract

The rational design of efficient Earth-abundant electrocatalysts for the ethanol oxidation reaction (EOR) is the key to developing direct ethanol fuel cells (DEFCs). Among these, the smart structure is highly demanded for highly efficient and stable non-precious electrocatalysts based on transition metals (such as Ni, Co, and Fe). In this work, high-performance NiCo-layered double hydroxide@carbon nanotube (NiCo-LDH@CNT) architectures with hollow nanocage structures as electrocatalysts for EOR were prepared via sacrificial ZIF-67 templates on CNTs. Comprehensive structural characterizations revealed that the as-synthesized NiCo-LDH@CNTs architecture displayed 3D hollow nanocages of NiCo-LDH and abundant interfacial structure between NiCo-LDH and CNTs, which could not only completely expose active sites by increasing the surface area but also facilitate the electron transfer during the electrocatalytic process, thus, improving EOR activity. Benefiting from the 3D hollow nanocages and interfacial structure fabricated by the sacrificial ZIF-67-templated method, the NiCo-LDH@CNTs-2.5% architecture exhibited enhanced electrocatalytic activity for ethanol oxidation compared to single-component NiCo-LDH, where the peak current density was 11.5 mA·cm^-2, and the j_f/j_b value representing the resistance to catalyst poisoning was 1.72 in an alkaline environment. These results provide a new perspective on the fabrication of non-precious metal electrocatalysts for EOR in DEFCs.

Keywords: carbon nanotubes; electrocatalytic ethanol oxidation reaction; hollow nanocage structure; layered double hydroxide; sacrificial ZIF-67 template.

Abstract

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