Removal of Cd (II) from water by using nano-scale molybdenum disulphide sheets as adsorbents

Nano-scale molybdenum disulphide sheets with large sulphur-rich surfaces could function as excellent scavengers for cadmium ions, based on the affinity of S to heavy metals. In this work, nano-scale molybdenum disulphide sheets were applied for cadmium uptake from aqueous solution. Transmission Electron Microscope (TEM) and Atomic Force Microscopy (AFM) studies demonstrated that as-prepared molybdenum disulphide nanosheets maintained the 2H-phase of the structure, with most of the sheets having less than five S-Mo-S layers. The adsorption results showed that nano-scale molybdenum disulphide sheets have an extremely high adsorption capacity (477 mg/g) for Cd2+, demonstrating that molybdenum disulphide nanosheets were excellent Cd2+ scavengers. Strong complexation between Cd2+ and the intrinsic S planes was proposed for the high adsorption of Cd2+ on molybdenum disulphide nanosheets, based on the results of XPS.