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

Abstract

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.

Tentacle-like core–shell CoNi2S4/C3N4 bifunctional electrocatalysts for efficient overall alkaline water splitting

“…10,11 Moreover, most reported non-precious metal electrocatalysts only exhibit high activity in the single HER or OER. [12][13][14][15] Therefore, the development of inexpensive and efficient nonnoble metal-based bifunctional catalysts is important for electrochemical water splitting.…”

Robust High-performance Bifunctional Porous Cobalt MOF-Based Catalysts for Overall Water Splitting

“…Nevertheless, the two Co centers in Co-MOF 4 exhibit distinct coordination environments, yet both conform to an unsaturated four-coordination mode. Structural analysis reveals that Co-MOF 4 exhibits synergistic catalysis between Co 1 and Co 2 ions, while the metal center with an unsaturated coordination mode offers vacant orbitals that facilitate the binding of water molecules, thereby reducing activation energy and improving catalytic activity. , In addition, the interwoven structure of Co-MOF 4 depicted in Figure c enables efficient electron conduction across two rectangular networks, which is more advantageous for electron transfer compared to the double layers of Co-MOFs 1–3 . − Combined with BET results, Co-MOF 4 has the largest specific surface area, which leads to a higher ECSA and exposes more catalytically active sites. As a result, Co-MOF 4 becomes a truly stable and efficient bifunctional electrocatalyst for water splitting.…”

Borate Anion Dopant Inducing Oxygen Vacancies over Co3O4 Nanocages for Enhanced Oxygen Evolution

“…Metal-organic frameworks (MOFs), consisting of inorganic metal ions/clusters coordinated with organic ligands, are distinctive organic-inorganic hybrid porous materials with controllable porous structures, high specific surface areas and well-tunable structures [34,35]. Because of these unique structural merits, MOFs and their derivatives have been widely applied in energy storage and conversion [36,37], gas adsorption and separation [38,39] and other research fields.…”