Borophene as Conductive Additive to Boost the Performance of MoS₂‑Based Anode Materials

Carbon-based materials, including graphene, porous carbon, and nanotubes, have been widely used as conductive additives to reduce the resistance in semiconductive anode materials of lithium-ion batteries (LIBs) toward better performance and the alleviated battery overheat problem. However, these additives are usually denounced for their low lithium-ion capacity. Moreover, emergence of vacant defect and heteroatom incorporation would open a sizable energy gap accompanied by reduced conductance. Here, by selecting MoS₂ as a prototype system, we proclaim the utilization of emerging borophene as the conductive additive in terms of its low ion-transport barrier and robust metallic conductivity against defects and external doping in addition to its high Li-storage capacity. We found that substantial electrons transfer from MoS₂ to borophene, producing strong electronic coupling that conduces to favorable interface bonding in combination with improved Li affinity. Incorporation of borophene also compensates the poor mechanical property of MoS₂ with increased elastic modulus, ensuring the electrode integrity against pulverization. Furthermore, B/MoS₂ can achieve a maximum Li-storage capacity of 539 mAh/g along with low ion-hopping barriers inherited from its counterparts. Our work brings new opportunities to boost the electrochemical performance of semiconductive anode materials with borophene for LIBs

First-Principles Study on the Mechanism of Hydrogen Decomposition and Spillover on Borophene

Borophane, a derivate of borophene, has been shown to eliminate the phonon imaginary frequency of borophene entirely with enhanced structural stability and be a 2D Dirac material with many appealing properties similar to its counterpart graphene. However, the mechanisms involved in borophene hydrogenation are still unclear, which are essential to borophane fabrication in experimental studies and which benefit our understanding of borophene functionalization. In this work, we investigate H₂ adsorption and dissociation with (without) an external field and the subsequent spillover of H atoms on borophene based on density functional theory (DFT) to shed light on the procedure of borophene hydrogenation. We find that the incorporation of positive electric fields could facilitate the borophane formation with shallower energy barriers for H₂ decomposition and H atoms present ultrahigh mobility on borophene under positive field. The origin of the field modulated energy barriers has been discussed. Our work provides an alternative method to hydrogenate borophene, which contributes to the application of borophane in ultrahigh speed electronic devices

Internal B ← O Bond Facilitated Photo/Thermal Isomerization of Tetra-Coordinated Boranes

A new series of O∧C-chelate tetra-coordinated boranes with naphtha-aldehyde as the chelate backbone have been synthesized. Their photophysical and photochemical properties have been examined, which show that all of the compounds can undergo both photo and thermal transformations, generating aryl-migrated [1,2]oxaborinine derivatives as the major products. 1,3-Sigmatropic shifts and an intramolecular nucleophilic addition mechanism are proposed for the photochemical and thermal conversion pathways, respectively