Domain Engineering in ReS₂ by Coupling Strain during Electrochemical Exfoliation

Abstract

Chemical exfoliation has been used for the fast and large‐scale production of 2D nanosheets from graphene and transition metal dichalcogenides; however, it is rarely used for domain engineering of exfoliated nanosheets. Herein, it is found that the use of large sized molecular intercalants during electrochemical intercalation induce atomic row dislocation and parallel mirror twin boundaries (MTBs) on an otherwise pristine rhenium disulfide (ReS2) crystal, such that the exfoliated flakes possess a parallel, multi‐domain structure. These domains can be distinguished under a polarized microscope owing to the intrinsic in‐plane optical dichroic properties of ReS2, thereby affording a way to track the number of domains introduced versus the size of the molecular intercalant during electrochemical exfoliation. Ferromagnetism is detected on the intercalated sample using large sized molecular intercalants. Density function theory suggests that these may be due to the coupled effects of lattice strain and S vacancies in the MTBs.

Facile Production of Phosphorene Nanoribbons towards Application in Lithium Metal Battery

“…[ 30 ] By using organic molecules as the intercalants, strain can be coupled to the crystal during electrochemical intercalation, and the exfoliation yield can be optimized by changing the size of the molecules. [ 31 ] In our case, smaller sized TPA gives enhanced PNR yield compared with THA, and using a lower intercalation voltage can further increase the ribbon yields (Figure 1c). As molecules intercalate into BP, the strain may create a fissure along the ZZ direction that opens up like a zip as more molecules are intercalated.…”

Ferroelastic–Ferroelectric Multiferroicity in van der Waals Rhenium Dichalcogenides

“…Recent studies on the reconstruction of ReS 2 and ReSe 2 using various methods, e.g., electron beam irradiation, [13,17] crack generation, [18] and intercalation of molecules, [19] suggest the possibility of domain switching by strain, but the direct relation between external stress and domain reconstruction is still obscure. Here, we report intrinsic ferroelastic-ferroelectric multiferroicity in single-crystalline van der Waals rhenium dichalcogenides (ReX 2 ).…”

Structure Engineering of 2D Materials toward Magnetism Modulation

“…Loh and coworkers demonstrated that thin-layer ReS 2 with mirror twin boundaries (MTBs) and S vacancies exhibited ferromagnetism with T C of 60 K. [86] The monolayer ReS 2 was prepared via electrochemical exfoliation methods by the intercalation of tetraheptylammonium (THA). The volume of ReS 2 expanded after THA intercalation driven by electric field.…”

“…d,e) Reproduced with permission. [86] Copyright 2020, Wiley-VCH. f ) STEM and simulated images of the DT edges, Mo-Klein edges, S-ZZ edges, and Mo-ZZ edges.…”

“…e) Magnetization versus magnetic field curves of THA-intercalated ReS 2 at 10, 50, and 60 K, respectively. d,e) Reproduced with permission [86]. Copyright 2020, Wiley-VCH.…”