MoS<inf>2</inf>-on-MXene Heterostructures as Highly Reversible Anode Materials for Lithium-Ion Batteries

© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Two-dimensional (2D) heterostructured materials, combining the collective advantages of individual building blocks and synergistic properties, have spurred great interest as a new paradigm in materials science. The family of 2D transition-metal carbides and nitrides, MXenes, has emerged as an attractive platform to construct functional materials with enhanced performance for diverse applications. Here, we synthesized 2D MoS2-on-MXene heterostructures through in situ sulfidation of Mo2TiC2Tx MXene. The computational results show that MoS2-on-MXene heterostructures have metallic properties. Moreover, the presence of MXene leads to enhanced Li and Li2S adsorption during the intercalation and conversion reactions. These characteristics render the as-prepared MoS2-on-MXene heterostructures stable Li-ion storage performance. This work paves the way to use MXene to construct 2D heterostructures for energy storage applications

Two-Dimensional Arrays of Transition Metal Nitride Nanocrystals

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The synthesis of low-dimensional transition metal nitride (TMN) nanomaterials is developing rapidly, as their fundamental properties, such as high electrical conductivity, lead to many important applications. However, TMN nanostructures synthesized by traditional strategies do not allow for maximum conductivity and accessibility of active sites simultaneously, which is a crucial factor for many applications in plasmonics, energy storage, sensing, and so on. Unique interconnected two-dimensional (2D) arrays of few-nanometer TMN nanocrystals not only having electronic conductivity in-plane, but also allowing transport of ions and electrolyte through the porous nanosheets, which are obtained by topochemical synthesis on the surface of a salt template, are reported. As a demonstration of their application in a lithium–sulfur battery, it is shown that 2D arrays of several nitrides can achieve a high initial capacity of >1000 mAh g−1 at 0.2 C and only about 13% degradation over 1000 cycles at 1 C under a high areal sulfur loading (>5 mg cm−2)