Etching anisotropy in two-dimensional SnS layered crystals using a thiol-amine solvent mixture as an etchant

Inorganic–Organic Hybrid Layered Semiconductor AgSePh: Quasi-Solution Synthesis, Optical Properties, and Thermolysis Behavior

“…The relatively weak interlayer vdWs force arising from phenyl rings drives the superposed stacking of monolayers parallel to the ab plane, resulting in a certain thickness for the 2D AgSePh microcrystals. This anisotropic growth habit has broadly been demonstrated in vdWs-stacked layered 2D materials, such as MOCs and all-inorganic crystals (e.g., graphite, TMDs, SnS), and 2D layered hybrid halide perovskites . When the physical thickness is scaled down to the molecularly thin limit (Figure c,d), like graphene from graphite, the AgSePh monolayers could be named “mithrene”. − , …”

Oxidation-enabled SnS conversion to two-dimensional porous SnO2 flakes towards NO2 gas sensing

“…This discrepancy is mainly a result of the sluggish, incomplete conversion of SnS to SnS 2 and SnO 2 . The relatively large size of SnS flakes (∼1–10 micrometers in edge lengths and tens to hundreds of nanometers in thickness, 31 see Fig. 4 and Fig.…”

“…However, it is observed that after oxidation at high temperatures (≥600 °C), single-crystal SnS flakes with smooth surfaces (Fig. S1†) 31 would transform into polycrystalline SnS 2 –SnO 2 or SnO 2 flakes composed of rough surfaces and nanoscale particles (Fig. 4).…”

“…2D SnS flakes were first synthesized by a simple solution method that we reported recently. 31 In a typical procedure, SnCl 2 ·2H 2 O (0.452 g, 2 mmol) and dodecylamine (1 g) were mixed with oleylamine (10 mL) and 1-dodecanethiol (2 mL) in a 50 mL three-necked flask, and then the flask was heated to 230 °C in a heating jacket under magnetic stirring. After maintaining the flask at 230 °C for 1 hour, it was cooled to room temperature naturally.…”

“…, SnS 2 and SnSe) have been used as self-sacrificial templates to prepare porous SnO 2 materials through thermal annealing or oxidation to remove chalcogen elements. 29,30 In particular, the two-dimensional (2D) morphology of tin chalcogenides due to their intrinsic layered structures 30,31 can be inherited to produce 2D SnO 2 with a flake- or sheet-like morphology, which was found to exhibit superior porosity and gas sensing capability ( e.g. , ethanol 29 and NO 2 30 ).…”