Enhancing One‐Dimensional Charge Transport in Metal‐organic Framework Hexagonal Nanorods for Electrocatalytic Oxygen Evolution

• Published in: ChemSusChem 2021-04, Vol.14 (8), p.1830-1834
• Main Authors: Lai, Yulian, Xiao, Longhui, Tao, Yuan, Gao, Zhi, Zhang, Liuxin, Su, Xuemin, Dai, Ying
• Format: Article
• Language: English
• Subjects: Bimetals; Chains; Charge efficiency; Charge transport; Chemical reactions; Current carriers; electrocatalysis; Intermetallic compounds; Iron compounds; Ligands; Low conductivity; Metal-organic frameworks; Morphology; Nanorods; nanostructures; Nickel compounds; oxygen evolution reaction; Oxygen evolution reactions
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.202100179

Metal‐organic frameworks (MOFs) have exhibited huge potential in electrocatalytic fields. However, the intrinsic low conductivity and the blockage of metal active sites by organic linkers still seriously hinder their large‐scale application. In this study, as a proof of principle, constructing cofacial π–π stacking in the terminal ligand (4,4′‐bipyridine) of a Ni/Fe‐chain‐based MOF to fabricate strong π–π interaction, in combination with unique hexagonal nanorod (HXR) structure, is found to be an effective strategy to enhance one‐dimensional charge carrier efficiency and thus achieve excellent activity in the oxygen evolution reaction (OER). The approach yields a high turnover frequency (4.54 s−1) in well‐designed bimetallic chain‐based MOFs (NiFe‐HXR) at an overpotential of 350 mV, which is about 8.7 and 34.9 times higher than those in Ni‐HXR (0.52 s−1) and IrO2 (0.13 s−1), respectively. This work effectively combines “through‐bond” channel in chain‐based structure of NiFe‐HXR and “through‐space” transport between face‐to‐face terminal ligands, thus resulting in outstanding OER activity. This strategy of modulating the structure chemistry and morphology of MOFs to promote the OER may open a new perspective to synthesize MOFs for energy‐relevant electrochemical reactions. One for the rod: This work effectively combines a “through‐bond” channel in the chain‐based structure of NiFe metal‐organic framework hexagonal nanorods and “through‐space” transport between face‐to‐face terminal ligands, thus resulting in outstanding oxygen evolution activity.