Assembled 3D MOF on 2D Nanosheets for Self-boosting Catalytic Synthesis of N-doped Carbon Nanotube Encapsulated Metallic Co Electrocatalysts for Overall Water Splitting

• Published in: Applied catalysis. B, Environmental Vol. 271; p. 118939
• Main Authors: Yang, Lijun, Li, Hui, Yu, Yang, Wu, Yang, Zhang, Lei
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.08.2020; Elsevier BV
• Subjects: Bimetals; Carbon nanotubes; Chemical composition; Chemical synthesis; Cobalt-based composites; Composition effects; Density functional theory; Density functional theory calculation; Electrical conductivity; Electrical resistivity; Electrocatalyst; Electrocatalysts; Electrochemical analysis; Electrochemistry; Encapsulation; Melamine; N-doped carbon nanotubes; Nanosheets; Overall water splitting; Pyrolysis; Splitting; Structural hierarchy; Structural stability; Synergistic effect; Water splitting; N-doped carbon nanotubes; Density functional theory calculation; Electrocatalyst; Overall water splitting; Cobalt-based composites
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.118939

[Display omitted] •A binder-free electrode with Co embedded in uniform N-doped carbon nanotubes array was fabricated.•Co@N-CNT/NF was obtained via an electrodeposition, stereoscopic assembly and self-boosting catalytic pyrolysis.•The bifunctional electrocatalyst exhibited better performance in both HER and OER.•Require only 1.58V@30 mA cm−2 in alkaline solution with robust durability for overall water splitting.•The method can be extensively applied to fabricate well-defined monometal or bimetal encapsulated into N-CNTs. A binder-free electrode with metallic Co embedded in N-doped carbon nanotube array (Co@N-CNT) was fabricated via an electrodeposition, stereoscopic assembly and self-boosting catalytic pyrolysis. Specifically, directed-eletrodeposition vertical growth of Co(OH)2-nanosheet serves as the structure inducer to offer abundant sites for ZIF-67 growth, and melamine is selected as an initiator for orientated growth of N-CNTs. As an integrative non-noble electrocatalyst for water splitting, it requires only 1.58 V to achieve 30 mA cm−2 in an alkali-electrolyzer. The remarkable electrochemical performance is mainly attributed to the unique 3D hierarchical tubular structure and the synergistic effect of each chemical compositions, which provide amount of accessible active sites, accelerate the diffusion of electron/electrolyte, and improve the electrical conductivity, hydrophilicity and structural stability. The electro-catalytic splitting water mechanism was further explored by density functional theory. This universal method can be extensively applied to fabricate well-defined monometal or bimetal encapsulated into N-CNTs for various electrochemical applications.