Synthesis and Characterization of Solid‐Solution ReS2−xTex (0 ≤ x ≤ 1) Nanosheets

ReS2 nanosheets have recently attracted attention because of their excellent electrocatalytic properties. It has also been reported that the electrocatalytic activity of solid‐solution ReS2−xSex nanosheets is improved by tuning the bandgap structure through a solid solution with Se. However, Se has application limitations in that it is highly toxic. Thus, herein, solid‐solution ReS2−xTex nanosheets are focused. Solid‐solution ReS2−xTex (x = 0, 0.5, and 1.0) bulk is synthesized by solid‐state reactions. The optical bandgaps of ReS2, ReS1.5Te0.5, and ReSTe are measured to be 1.29, 1.07, and 0.99 eV, respectively. Solid‐solution ReS2−xTex (x = 0, 0.5, and 1.0) nanosheets are obtained by the ultrasonic exfoliation and Li‐intercalation exfoliation of the ReS2−xTex bulks. The typical lateral sizes and thicknesses of the ReS2, ReS1.5Te0.5, and ReSTe nanosheets by ultrasonic exfoliation are 200 and 6 nm, 160 and 3 nm, and 600 and 2 nm, respectively. The typical lateral sizes and thicknesses of ReS2, ReS1.5Te0.5, and ReSTe nanosheets using the Li‐intercalation exfoliation method are 150 and 2 nm, 100 and 1 nm, and 100 and 1 nm, respectively. In the nanosheets obtained from both exfoliation methods, the lateral size is not composition‐dependent, and the thickness decreases with increasing x in ReS2−xTex.