Suppressing Dielectric Loss in MXene/Polymer Nanocomposites through Interfacial Interactions.

Although numerous polymer-based composites exhibit excellent dielectric permittivity, their dielectric performance in various applications is severely hampered by high dielectric loss induced by interfacial space charging and a leakage current. Herein, we demonstrate that embedding molten salt etched MXene into a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE))/poly(methyl methacrylate) (PMMA) hybrid matrix induces strong interfacial interactions, forming a close-packed inner polymer layer and leading to significantly suppressed dielectric loss and markedly increased dielectric permittivity over a broad frequency range. The intensive molecular interaction caused by the dense electronegative functional terminations (-O and -Cl) in MXene results in restricted polymer chain movement and dense molecular arrangement, which reduce the transportation of the mobile charge carriers.

High-performance van der Waals antiferroelectric CuCrPS-based memristors.

Layered thio- and seleno-phosphate ferroelectrics, such as CuInPS, are promising building blocks for next-generation nonvolatile memory devices. However, because of the low Curie point, the CuInPS-based memory devices suffer from poor thermal stability (<42 °C). Here, exploiting the electric field-driven phase transition in the rarely studied antiferroelectric CuCrPS crystals, we develop a nonvolatile memristor showing a sizable resistive-switching ratio of ~ 1000, high switching endurance up to 20,000 cycles, low cycle-to-cycle variation, and robust thermal stability up to 120 °C.

NbCT MXene Cathode for High-Capacity Rechargeable Aluminum Batteries with Prolonged Cycle Lifetime.

Aluminum-ion batteries have garnered significant interest as a potentially safer and cheaper replacement for conventional lithium-ion batteries, offering a shorter charging time and denser storage capacity. Nonetheless, the progress in this field is considerably hampered by the limited availability of suitable cathode materials that can sustain the reversible intercalation of Al/[AlCl] ions, particularly after long cycles. Herein, we demonstrate that rechargeable Al batteries embedded with two-dimensional (2D) NbCT MXene as a cathode material exhibit excellent capacity and exceptional long cyclic performance.

H -H Pairs in Partially Oxidized MAX Phases for Bifunctional Catalytic Conversion of Furfurals into Linear Ketones.

Currently, less favorable C=O hydrogenation and weak concerted acid catalysis cause unsatisfactory catalytic performance in the upgrading of biomass-derived furfurals (i.e., furfural, 5-methyl furfural, and 5-hydroxymethyl furfural) to ketones (i.

Enhancement of Dielectric Permittivity of TiCT MXene/Polymer Composites by Controlling Flake Size and Surface Termination.

We report a strong effect of the MXene flake size and surface termination on the dielectric permittivity of MXene polymer composites. Specifically, poly(vinylidene fluoride-trifluoro-ethylene-chlorofluoroehylene) or P(VDF-TrFE-CFE) polymer embedded with large (ca. 4.

MXene-Derived Ferroelectric Crystals.

This study demonstrates the first synthesis of MXene-derived ferroelectric crystals. Specifically, high-aspect-ratio potassium niobate (KNbO ) ferroelectric crystals is successfully synthesized using 2D Nb C, MXene, and potassium hydroxide (KOH) as the niobium and potassium source, respectively. Material analysis confirms that a KNbO orthorhombic phase with Amm2 symmetry is obtained.

Large Dielectric Constant Enhancement in MXene Percolative Polymer Composites.

We demonstrate that poly(vinylidene fluoride) (PVDF)-based percolative composites using two-dimensional (2D) MXene nanosheets as fillers exhibit significantly enhanced dielectric permittivity. The poly(vinylidene fluoride-trifluoro-ethylene-chlorofluoroehylene) (P[VDF-TrFE-CFE]) polymer embedded with 2D TiCT nanosheets reaches a dielectric permittivity as high as 10 near the percolation limit of about 15.0 wt % MXene loading, which surpasses all previously reported composites made of carbon-based fillers in the same polymer.