Highly thermal-stable paramagnetism by rolling up MoS₂nanosheets

Abstract

Controlling phase transitions through local strain engineering is an exciting avenue for tailoring the electronic and magnetic properties of materials at the nanoscale. Herein, we demonstrate a tunable semiconducting to metallic phase transition of two-dimensional transition metal dichalcogenides using strain engineering through rolled up MoS sheets (named as MoS scrolls). A phase incorporated structure for MoS nanoscrolls containing the maximum concentration of 1T phase (∼58%) with high thermal stability up to 473 K can be produced by a gliding-rolling process for the S plane. These phase transitions are irreversible by virtue of the van der Waals interaction between the layers of the nanoscrolls, which is relatively stronger than the bending strain. A high concentration of the 1T phase can tune the bandgap through temperature, and also the magnetic property from nonmagnetic to paramagnetic MoS. This study, which is able to control phase transitions by strain engineering in the field of 2D materials, proves an exciting avenue for tailoring the novel functional properties of low-dimensional materials.

Topological structures of transition metal dichalcogenides: A review on fabrication, effects, applications, and potential

“…Recently, there have been studies exploring controllable methods for the fabrication of wrinkles, folds, and scrolls on TMD materials 56‐58,69‐73 . The preparation of wrinkled TMD structures often involves the transfer of the TMDs to a pre‐stretched polymer or rigid substrates with pre‐defined microstructures and thermally induced polystyrene (PS) substrate 56‐58,74‐84 .…”

“…The preparation of folded TMDs also occurs during sample exfoliation and transfer 69,86‐88 . Limited by the sample size, mechanical property, and chemical stability, 89 the self‐assembly of scrolls requires an external medium, such as a weak argon plasma and treatment with a drop of alcohol 70‐73 . Such topological TMD structures greatly affect the optical properties of the material.…”

Atomically Thin Transition‐Metal Dichalcogenides for Electrocatalysis and Energy Storage

“…Recently, another finding revealed that 1T‐MoS 2 nanotubes could be prepared through a rolling process with the gliding of 2H‐MoS 2 nanosheets by its inner atomic plane . As shown in Figure b, the S‐plane during the rolling up of the 2H‐MoS 2 nanosheets is glided over a distance equivalent to a = 3.16 Å.…”

“…b) Schematic presentation of synthesis of the 1T metallic phase. Reproduced with permission . Copyright 2017, The Royal Society of Chemistry.…”

A facile and general approach for production of nanoscrolls with high-yield from two-dimensional nanosheets

“…Only a few previously published articles involved fabricating the NSs. Moreover, the reported processes are complicated, and the conversion yield is tiny limiting their application 16 – 23 . Up to date, there is no general and efficient method to enable assembling the NSs with high-yield.…”