Herein we report superior dye-adsorption performance for flower-like nanostructure composed of two dimensional (2D) MoS₂ nanosheets by a facile hydrothermal method, more prominent adsorption of cationic dye compared with anodic dye indicates the dye adsorption performance strongly depends on surface charge of MoS₂ nanosheets. The adsorption mechanism of dye is analyzed, the kinetic data of dye adsorption fit well with the pseudo-second-order model, meanwhile adsorption capability at different equilibrium concentrations follows Langmuir model, indicating the favorability and feasibility of dye adsorption. The regenerable property for MoS₂ with full adsorption of dye molecules by using alkaline solution were demonstrated, showing the feasibility of reuse for the MoS₂, which is promising in its practical water treatment application.

The mid-wave single-crystal HgCdTe (211) films were successfully grown on GaAs (211) B substrates by molecular beam epitaxy (MBE). Microstructure and optical properties of the MBE growth HgCdTe films grown at different temperatures were characterized by X-ray diffraction, scanning transmission electron microscopy, Raman and photoluminescence. The effects of growth temperature on the crystal quality of HgCdTe/CdTe have been studied in detail. The HgCdTe film grown at the lower temperature of 151 °C has high crystal quality, the interface is flat and there are no micro twins. While the crystal quality of the HgCdTe grown at higher temperature of 155 °C is poor, and there are defects and micro twins at the HgCdTe/CdTe interface. The research results demonstrate that the growth temperature significantly affects the crystal quality and optical properties of HgCdTe films.