2D conductive metal–organic frameworks (2D c‐MOFs) feature promising applications as chemiresistive sensors, electrode materials, electrocatalysts, and electronic devices. However, exploration of the spin‐polarized transport in this emerging materials and development of the relevant spintronics have not yet been implemented. In this work, layer‐by‐layer assembly was applied to fabricate highly crystalline and oriented thin films of a 2D c‐MOF, Cu3(HHTP)2, (HHTP: 2,3,6,7,10,11‐hexahydroxytriphenylene), with tunable thicknesses on the La0.67Sr0.33MnO3 (LSMO) ferromagnetic electrode. The magnetoresistance (MR) of the LSMO/Cu3(HHTP)2/Co organic spin valves (OSVs) reaches up to 25 % at 10 K. The MR can be retained with good film thickness adaptability varied from 30 to 100 nm and also at high temperatures (up to 200 K). This work demonstrates the first potential applications of 2D c‐MOFs in spintronics.

Two‐dimensional conductive metal–organic frameworks (2D c‐MOFs) as an emerging class of multifunctional materials have attracted extensive attention due to their predictable and diverse structures, intrinsic permanent porosity, high charge mobility, and excellent electrical conductivity. Such unique characteristics render them as a promising new platform for electrical related devices. This Minireview highlights the recent key progress of 2D c‐MOFs with emphasis on the design strategies, unique electrical properties, and potential applications in electrochemical energy storage. The thorough elucidation of structure–function correlations may offer a guidance for the development of 2D c‐MOFs based next‐generation energy storage devices.

We report a new H x CrS 2 -based crystalline/amorphous layered material synthesized by soft chemical methods. We study the structural nature and composition of this material with atomic resolution scanning transmission electron microscopy (STEM), revealing a complex structure consisting of alternating layers of amorphous and crystalline lamellae. Furthermore, the magnetic properties show evidence for increased magnetic frustration compared to the parent compound NaCrS 2 . Finally, we show that this material can be exfoliated, thus providing a facile synthesis method for chromium-sulfide-based ultrathin layers. The material reported herein can not only be a source of new thin TMD-related sheets for potential application in catalysis but also be of interest for realizing new 2D magnetic materials.

Two-dimensional (2D) covalent organic frameworks (COFs) are an emerging class of promising 2D materials with high crystallinity and tunable structures. However, the low electrical conductivity impedes their applications in electronics and optoelectronics. Integrating large π-conjugated building blocks into 2D lattices to enhance efficient π-stacking and chemical doping is an effective way to improve the conductivity of 2D COFs. Herein, two nonplanar 2D COFs with kagome (DHP-COF) and rhombus (c-HBC-COF) lattices have been designed and synthesized from distorted aromatics with different π-conjugated structures (flexible and rigid structure, respectively). DHP-COF shows a highly distorted 2D lattice that hampers stacking, consequently limiting its charge carrier transport properties. Conversely, c-HBC-COF, with distorted although concave–convex self-complementary nodes, shows a less distorted 2D lattice that does not interfere with interlayer π-stacking. Employing time- and frequency-resolved terahertz spectroscopy, we unveil a high charge-carrier mobility up to 44 cm2 V–1 s–1, among the highest reported for 2D COFs.

the other hand, transition metal oxides, [8] conductive polymers, [9] and redox-active porous organic materials [10] are promising candidates as pseudocapacitive electrodes. These materials typically exhibit large capacities and high energy densities, resulting from the reversible faradic redox processes between the electrolytes and the redox-active electrodes.Covalent organic frameworks (COFs) are an emerging class of porous crystalline polymer networks connected by stable covalent linkages possessing unique characteristics, such as light weight, high porosity, diverse topologies, designable open channels, and functional tunability. [11] These advantages endow COFs with a wide range of applications in gas storage and separation, [12] catalysis, [13] drug delivery, [14] optoelectronics, [15] sensing, [16] etc. The open channels and designable structures based on various building blocks provide substantial possibilities for the construction of novel redox-active porous skeletons, where rapid mass transfer can be realized. Compared with other carbon (or metal)-based SC electrodes, crystalline redox-active COFs showcase unique physicochemical features, and thus featuring huge potentials for the construction of promising SC devices. First of all, redox-active COFs are crystalline polymers with extended and rigid skeletons connected by stable covalent bonds. Therefore, the rigid framework structures can be maintained under harsh conditions and exhibit superior electrochemical stability in various electrolytes.Secondly, ordered open channels of redox-active COFs facilitate the adsorption and migration of electrolyte ions. Thirdly, various redox-active moieties can be readily introduced into the COF skeletons and the density of active sites can be facilely controlled by the pore-wall engineering strategy. [17] Last but not least, 2D redox-active COFs can be easily grown as thin films at different interfaces, [18] which facilitate the integration of COFs into electric devices. Most reported redox-active COFs involve carbonyl-containing structures, N/S-rich moieties, free radical species, etc. The chemical stability is a mandatory requirement for 2D redox-active COF based SC electrodes, which is directly related to their eventual electrochemical performance. High crystallinity COFs were usually prepared by the highly thermodynamic reversible reactions, which might lead to the inferior stability of COFs. [19a] Nonetheless, many COF materials, such as CTFs and imine COFs, have been demonstrated with excellent chemical stability even under harsh conditions like strong acid/alkali solutions, which enables the application potentials under extreme conditions. Furthermore, many effective strategies have been developed to enhance the chemical stability Due to the tunable skeletons, variable pore environments, and predesignable structures, covalent organic frameworks (COFs) can be served as a versatile platform to tailor redox activities for efficient energy storage. Redox-active COFs with specific functional groups can not only...

Highly crystalline and oriented 2D Py-COF thin films were readily fabricated via an elaborately designed A2B2 monomer, and served as stable acidichromism sensors with rapid response, low detection limit and good repeatability.

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Two‐dimensional conductive metal–organic frameworks (2D c‐MOFs) as an emerging class of multifunctional materials have attracted extensive attention due to their predictable and diverse structures, intrinsic permanent porosity, high charge mobility, and excellent electrical conductivity. Such unique characteristics render them as a promising new platform for electrical related devices. This Minireview highlights the recent key progress of 2D c‐MOFs with emphasis on the design strategies, unique electrical properties, and potential applications in electrochemical energy storage. The thorough elucidation of structure–function correlations may offer a guidance for the development of 2D c‐MOFs based next‐generation energy storage devices.