AFM study on the adsorption of Hg on natural molybdenum disulfide in aqueous solutions.

The adsorption of Hg on natural molybdenum disulfide has been studied using atomic force microscope (AFM). The AFM imaging clearly illustrated the adsorption of Hg on the surface of molybdenum disulfide, and also hydration layers on the surfaces. It was found that the presence of a hydration layer on molybdenum disulfide surfaces hindered the Hg adsorption. Also, it was observed that the Hg adsorbed appeared in the form of multilayers. The first adsorbed Hg layer might be mainly attributed to the complexation of Hg with S atoms exposed on molybdenum disulfide surfaces, while the second one might be due to the electrostatic interaction between negatively charged molybdenum disulfide and the cation Hg.