Although ultrahigh theoretical capacity has long been predicted for boron-based lithium-ion battery anodes, experimentally, boron has exhibited only limited performance and its lithiation process remains elusive. The two-dimensional (2D) form of boron is believed to be an ideal model system to investigate the lithiation behavior of boron; however, unfortunately, most reported 2D boron structures are prone to oxidation under ambient conditions. In this contribution, through a simultaneous etching and in situ functionalization process, we synthesized for the first time methyl-functionalized boron nanosheets, which remain stable up to 250 °C. Combining experiments and theoretical calculations, we found that lithiation of boron is realized through the formation of alloys such as LiB3 and Li3B14, while alloys with higher Li content such as Li5B are thermodynamically less favored. In addition, detailed electrochemical analysis reveals that side reactions on the boron surface may also contribute to the unsatisfactory performance of boron-based electrodes. Our findings suggest that reducing the enthalpy of formation of high Li content alloys and the choice of a less nucleophilic electrolyte are key to developing high-performance anodes based on novel boron materials. Our demonstration of stable 2D boron structures also paves the way for their fundamental study and practical applications.

Combining polymeric materials and conductive one-dimensional metal nanostructures is able to achieve enhanced chemical and electrical properties, but the control over their morphology and spatial arrangement remains a big challenge. Herein, by replacing benzenedicarboxylate (BDC) in ZnBDC nanoplates with oleylamine (OAM) in the presence of HAuCl 4 , Zn-OAM nanobelts with a highly ordered laminar structure were obtained, on which ultrathin Au nanowires (Au NWs) were deposited and aligned along the long axes of the nanobelts. The resulting Zn-OAM/Au NW hybrid further underwent an OAM-to-2-methylimidazole ligand exchange, resulting in the formation of porous nanobelts composed of ZIF-8 nanocrystals interwound with aligned Au NWs. Due to the synergistic effect between the polymeric and metallic structures, the Zn-OAM/Au NW hybrid nanobelts and ZIF-8/Au NW porous nanobelts demonstrated fast and selective gas sensing at ambient conditions, in sharp contrast to the nonresponsive Au NWs or Zn-based polymers alone.

The mechanistic investigation of the coprecipitation formation of iron oxides has been a long-standing challenge due to the rapid reaction kinetics and high complexity of iron hydrolysis reactions. Although few...

Two-dimensional (2D) boron nanomaterials have received considerable attention due to their distinct physicochemical properties in contrast to bulk boron. However, the susceptibility to oxidation in air has limited their practical...