High Electrical Conductivity in a 2D MOF with Intrinsic Superprotonic Conduction and Interfacial Pseudo-capacitance

Abstract

Two-dimensional (2D) conductive metal-organic frameworks (MOFs), whose advanced electrical properties accompany their intrinsic structural characteristics, represent an exciting new class of 2D atomic crystals for the van der Waals integration of novel heterostructures and the development of novel nano/ quantum devices. Guided by topology, we report two 2D MOFs (1 and 2) constructed via combination of [In(COO) 4 ] À metal nodes and tetratopic tetrathiafulvalene (TTF)-based linkers, with ultrahigh proton conductivity (6.66 3 10 À4 and 1.30 3 10 À2 S cm À1 for 1 and 2, respectively). Additionally, high electrical conductivity was simultaneously achieved with the pure protonic nature of the 2D MOF 2. The electrical conduction at the MOF-metal interface is enabled by the redox-switchable behavior of the TTF-based ligands. This unique charge-transport mechanism, protonic/pseudo-capacitance coupling, offers a new strategy for utilizing the ionic conductivity from MOFs to construct functional electronic devices.

Interlayer Engineering of α‐MoO3 Modulates Selective Hydronium Intercalation in Neutral Aqueous Electrolyte

“…Moreover, WP-MoO 3 -c also shows an activation energy (E a ) of 0.28 eV, which suggests the Grotthuss conduction mechanism (E a < 0.4 eV). [23] H 2 O molecules between the interlayers serve as the proton transport intermedia, providing a hydrogen-bonding network for the high-kinetics charge carrier diffusion. [24] Moreover, the charge transfer from H 3 O + to WP-MoO 3 -c can be also through Grotthuss mechanism without breaking the hydrogen bonding interaction between H 2 O and the terminal O of [MoO 6 ] bilayers ( Figure 5 c).…”

Persistent Radical Tetrathiafulvalene‐Based 2D Metal‐Organic Frameworks and Their Application in Efficient Photothermal Conversion

“…The Zn 2 (TTFTB) framework has shown a rare stacked structure and high intrinsic charge mobility [18a] . With consideration for the low‐dimensional structure and molecular assembly of the TTF SBU, a new ligand, m ‐H 4 TTFTB, similar to H 4 TTFTB was recently synthesized [10a] . Herein, a series of two‐dimensional radical MOFs, named Tb‐2D , Dy‐2D , and Er‐2D ([RE 6 ( m ‐TTFTB) 2.5 (μ 3 ‐OH) 8 (H 2 O) 2 (HCOO) 2 ]⋅1.5 (NH 2 (CH 3 ) 2 )⋅5 DMF⋅8 H 2 O), have been successfully assembled from the rare earth metal ions and the m ‐H 4 TTFTB ligand.…”

Cationic Covalent‐Organic Framework as Efficient Redox Motor for High‐Performance Lithium–Sulfur Batteries

“…[ 28–34 ] However, even the carbon materials with good electrical conductivity could facilitate the transformation of the electrons and power the redox reaction in Li–S batteries, the vast majority of common carbon materials are amorphous and structurally uncertain, resulting in uneven characters of the materials and unclear mechanism of the interaction between host materials and sulfur. Nowadays, crystalline metal–organic frameworks (MOFs) with precise structure, [ 35,36 ] diverse species, [ 37–41 ] and adjustable aperture size [ 42 ] have been utilized as the potential cathode host for Li–S batteries. [ 17,43 ] MOFs with open metal sites can anchor the soluble PSs and thus suppress the shuttle effects, endowing the MOF‐based Li–S batteries with high specific capacity and satisfactory cycling stability.…”