Shape-Engineered Synthesis of Atomically Thin 1T-SnS₂ Catalyzed by Potassium Halides

Abstract

Shape engineering plays a crucial role in the application of two-dimensional (2D) layered metal dichalcogenide (LMD) crystalline materials in terms of physical and chemical property modulation. However, controllable growth of 1T phase tin disulfide (SnS2) with multifarious morphologies has rarely been reported and remains challenging. Herein, we report a direct synthesis of large-size, uniform, and atomically thin 1T-SnS2 with multiple morphologies by adding potassium halides via a facile chemical vapor deposition process. A variety of morphologies, i.e., from hexagon, triangle, windmill, and dendritic to coralloid, corresponding to fractal dimensions from 1.01 to 1.81 are accurately controlled by growth conditions. Moreover, the Sn concentration controls the morphology change of SnS2. The edge length of the SnS2 dendritic flake can grow larger than 500 μm in 5 min. Potassium halides can significantly reduce the surface migration barrier of the SnS2 cluster and enhance the SnS2 adhesion force with substrate to facilitate efficient high in-plane growth of monolayer SnS2 compared to sodium halides by density functional theory calculations. More branched SnS2 with higher fractal dimension provides more active sites for enhancing hydrogen evolution reactions. Importantly, we prove that potassium halides are preferable for 1T-phase LMDs structures, while sodium halides are more suitable for 2H-phase materials. The growth mechanism proposed here provides a general approach for controllable-phase synthesis of 2D LMD crystals and related heterostructures. Shape engineering of 2D materials also provides a strategy to tune LMD properties for demanding applications.

Semimetal 1H‐SnS2 Enables High‐Efficiency Electroreduction of CO2 to CO

“…Additionally, the energy‐dispersive X‐ray spectroscopy (EDS) elemental mapping in Figure 1e revealed the existence of Sn and S elements in 1H‐SnS 2 , and the ratio of Sn/S was found to be ≈1:1.95 (Figure S5, Supporting Information), suggesting a reasonable stoichiometric composition of SnS 2 . [ 41 ]…”

“…In addition, as shown in the survey XPS spectra and the high‐resolution XPS spectra of 1H‐SnS 2 and 1T‐SnS 2 (Figures S7 and S8, Supporting Information), the Sn 3d 5/2 (at 486.67 eV) and 3d 3/2 (at 495.09 eV) peaks are in line with Sn 4+ , and S 2p 3/2 (at 161.74 eV) and 2p 1/2 (at 162.94 eV) peaks are assigned to S 2− , also suggesting that the 1T‐SnS 2 was synthesized with high purity. [ 41 ] However, the Sn 3d peaks of 1H‐SnS 2 are located at 486.06 eV (3d 5/2 ) and 494.48 eV (3d 3/2 ), and the S 2p peaks of 1H‐SnS 2 are located at 161.17 eV (2p 3/2 ) and 162.37 eV (2p 1/2 ), respectively. Compared with 1T‐SnS 2 , all the peak positions of Sn 3d and the S 2p regions in 1H‐SnS 2 were lower binding energy shifted.…”

“…The 1T‐SnS 2 spectrum shows only one characteristic peak at 311 cm −1 , corresponding to the A 1g phonon mode. [ 41 ] Compared with 1T‐SnS 2 , the 1H‐SnS 2 has additional two new peaks at 135 cm −1 ( J 1 ) and 231 cm −1 ( J 2 ) in the Raman spectrum. The PL spectrum, recorded with a 325 nm laser, was used to study the intrinsic optical properties of 1H‐SnS 2 and 1T‐SnS 2 , and the result is depicted in Figure S13 (Supporting Information).…”

Template‐Assisted Synthesis of Metallic 1T′‐Sn0.3W0.7S2 Nanosheets for Hydrogen Evolution Reaction

“…As a representative post‐transition metal dichalcogenide semiconductor material, tin disulfide (SnS 2 ), which has a stable T‐phase, is an abundant earth material with an appropriate Gibbs free energy that adsorbs hydrogen atoms . In addition to being nontoxic, low‐cost, and chemically stable in acidic or neutral aqueous solutions, SnS 2 provides a favorable catalytic activity and relatively high surface electronegativity.…”

2D Materials Based on Main Group Element Compounds: Phases, Synthesis, Characterization, and Applications

“…[ 124 ] Recently, various shapes (hexagonal, triangular, windmill, dendritic, and coralloid) of SnS 2 nanosheets were prepared by controlling the growth conditions and substrate surfaces. [ 125 ] Importantly, selective phase growth of 2H or 1T was observed with the help of different salts. Herein, sodium halides favored the growth of the 2H phase, and potassium halides helped the growth of the 1T phase.…”