Zhongyue Zhang 교수

By adopting a facile synthetic strategy, we obtained a microporous redox-active metal-organic framework (MOF), namely, Cu(2,7-AQDC) (2,7-H2AQDC = 2,7-anthraquinonedicarboxylic acid) (1), and utilized it as a cathode active material in lithium batteries. With a voltage window of 4.0-1.7 V, both metal clusters and anthraquinone groups in the ligands exhibited reversible redox activity. The valence change of copper cations was clearly evidenced by in situ XANES analysis. By controlling the voltage

Two-dimensional metal-organic frameworks (2D MOFs) have attracted much attention, as they are the crystalline materials that exhibit both conductivity and microporosity. Numerous efforts have been made to advance their application as chemiresistive sensors or electrochemical capacitors. However, the intrinsic physical properties and spin states of these materials remain poorly understood. Most of these 2D MOFs possess a honeycomb lattice, with a Kagomé lattice arrangement of metal cations. These

Metal–organic frameworks (MOFs) are well-known for their application to various types of energy storage; nevertheless, their potential in electron storage has scarcely been investigated. Indeed, the synthetic strategy of MOFs toward the pseudocapactive materials is still absent due to the lack of a detailed insight into the solid-state redox process of MOFs. In this manuscript, we reported the discovery of a new electrochemical mechanism, namely, “bipolar charging” mechanism by analyzing the sol

A spontaneous entrapment of electron-donating small guest molecules, including tetrathiafulvalene (TTF) and <i>N</i>,<i>N</i>,<i>N</i>',<i>N</i>'-tetramethyl-1,3-propanediamine (TMPDA), was realized in a structurally flexible metal-organic framework, {Mn₇(2,7-AQDC)₆(2,6-AQDC)(DMA)₆}_∞ (AQDC = anthraquinone dicarboxylates, DMA = <i>N</i>,<i>N</i>-dimethylacetamide), with electron-accepting anthraquinone groups, generating two MOF guest charge transfer co

Quasi-two-dimensional (2D) fully π-d conjugated metal-organic frameworks (MOFs) have been widely employed as active materials of secondary batteries; however, the origin of their high charge storage capacity is still unknown. Some reports have proposed a mechanism by assuming the formation of multiple radicals on one organic ligand, although there is no firm evidence for such a mechanism, which would run counter to the resonance theory. In this work, we utilized various magnetometric techniques

Abstract Reactions of the main‐group cation Tl I with anions of 2,5‐derivatives of TCNQ (TCNQ=7,7,8,8‐tetracyanoquinodimethane) have led to the isolation of a family of unprecedented semiconducting main‐group‐metal–organic frameworks, namely, [Tl(TCNQX 2 )], (X=H, Cl, Br, I). A comparison of single‐crystal and powder X‐ray diffraction data revealed the existence of a third polymorph of the previously reported material Tl(TCNQ)] and two distinct polymorphs of [Tl(TCNQCl 2 )], whereas only one pha

MFM-722(Pb)-DMA undergoes a single-crystal-to-single-crystal (SCSC) transformation to give MFM-722(Pb)-H2O via ligand substitution upon exposure to water vapour. In situ single crystal impedance spectroscopy reveals an increase in proton conductivity due to this structural transition, with MFM-722(Pb)-H2O showing a proton conductivity of 6.61 × 10-4 S cm-1 at 50 °C and 98% RH. The low activation energy (Ea = 0.21 eV) indicates that the proton conduction follows a Grotthuss mechanism.

Two new silver containing materials with TCNQ derivatives were prepared by electrocrystallization. Synchrotron radiation diffraction studies were conducted to determine the structures of the new phases which exhibit unprecedented high room temperature conductivity. The I–V characteristics reveal a room-temperature switching behaviour and memory effect based on intrinsic negative differential resistance (NDR). EPR spectroscopic measurements performed under an applied electric field indicate a g-t

Abstract The tuning of the chemical composition of polyoxometalate (POM)‐based open framework materials with the same structure, leading to a property change of the materials, is interesting. Here, we report the synthesis of a series of vanadium‐incorporated, ϵ‐Keggin polyoxometalate‐based open framework materials by using a hydrothermal method. The resulting materials were characterized by powder X‐ray diffraction, FTIR spectroscopy, scanning electron microscopy, energy dispersive X‐ray spectro

Abstract In investigating the relationship between the particle size of the dispersed phase in a polymer blend and the physical properties of the resulting product, the effects of conditions of blending, viscosity difference, and volume fraction, etc., are usually observed and studied. This approach is uncertain since blending is a complex process. From a theoretical background similar to that of N. Tokita's, but using a different mathematical and experimental treatment, a complex factor compose

Precise tuning of the magnetic states of geometrically frustrated materials remains a critical challenge, as this process will not only promote understanding of fundamental magnetism but also accelerate the discovery of new materials with unprecedented magnetic behaviors. In this article, we present a study of the tuning magnetic properties of spinel LiMn2O4 by electrochemical oxidation/reduction in a lithium battery. The ex-situ magnetic susceptibility and specific heat measurements were perfor

Recent advances in two-dimensional (2D) π-d conjugated conductive metal-organic frameworks (2D cMOFs) have highlighted their potential as sophisticated, active materials in electrochemical energy storage devices, electrocatalysis, and sensors. However, a lack of high-quality structural characterization severely limits our understanding of their physical properties. Specifically, rapid and irreversible nucleation and aggregation, induced by strong interlayer π-π interactions, have hindered crysta

The focus on dark matter search has expanded to include low-mass particles such as axions or axion-like particles, and novel theoretical schemes extending the phenomenological landscape, within QCD and beyond, also garnered additional interest in recent decades. Assuming dark matter is composed of axions, in presence of a solenoidal magnetic field, they induce a displacement current that gives rise to a toroidal magnetic field. The Weakly Interacting Slender Particle detection with LC circuit (W

The field of molecular electronics has been under investigation by materials scientists for the last two decades, activity that has increased in recent years as their potential to be components in modern quantum computing devices began to be discussed in a more sophisticated manner. In this field, the challenge is to obtain stable highly conducting materials and to manipulate their properties with external stimuli. As one of the most stable organic radicals, the singly reduced form of TCNQ (7,7,