During the synthesis of ultra-thin materials with hexagonal lattice structure Stone-Wales (SW) type of defects are quite likely to be formed and the existence of such topological defects in the graphene-like structures results in dramatical changes of their electronic and mechanical properties. Here we investigate the formation and reactivity of such SW defects in silicene. We report the energy barrier for the formation of SW defects in freestanding (∼2.4 eV) and Ag(111)-supported (∼2.8 eV) silicene and found it to be significantly lower than in graphene (∼9.2 eV). Moreover, the buckled nature of silicene provides a large energy barrier for the healing of the SW defect and therefore defective silicene is stable even at high temperatures. Silicene with SW defects is semiconducting with a direct bandgap of 0.02 eV and this value depends on the concentration of defects. Furthermore, nitrogen substitution in SW defected silicene shows that the defect lattice sites are the least preferable substitution locations for the N atoms. Our findings show the easy formation of SW defects in silicene and also provide a guideline for bandgap engineering in silicenebased materials through such defects.

Anion storage in cathode of dual-ion batteries provides leeway for new battery chemistries. For high energy density and better safety, it is desirable but challenging to reversibly intercalate chloride in a graphite cathode because either the oxygen or chlorine evolution reaction can prevail over chloride insertion. The primary barrier is the lack of suitable aqueous electrolytes that suppress these parasitic reactions. Herein, we report an aqueous deep eutectic solvent gel electrolyte that allows reversible chloride storage for graphite based on a chloride-based electrolyte via the formation of iodine–chloride interhalogens. The results suggest three reversible steps: iodine plating on the host surface, oxidation to form I-Cl interhalides, and then intercalation into graphite. As a result, the graphite cathode delivers a high reversible capacity of 291 mAh g–1 with stable cycling performance. Facilitated by the same mechanism, a porous graphenic carbon delivered a record-high capacity of over 1100 mAh g–1.

The energy barrier for hydrogenation of silicene decreases as the strains increase, and the barrier reduces from 1.71 to 0.24 eV when the strain reaches the critical value of 12%. In this way, the reaction time for the hydrogenation of silicene can accelerate significantly from 8.06 × 1016 to 1.68 × 10−8 s.

Influence of the uniaxial strain on the electronic structures of ZnO nanowires (NWs) and nanotubes (NTs) has been studied using the density functional theory. It was found that the uniaxial compress strain can lead to a band gap transition from direct to indirect band for both ZnO NWs and NTs. Under the same strain, the phase transition of the thick NW is easier than that of the thin one, and the phase transition of NWs seems easier than that of NTs. These results suggested the uniaxial strain can be used to tune the band structures of ZnO nanostructures, which may be help for design of ZnO-based nanodevices.