Chemisorption of metallic radionuclides on a monolayer MoS₂ nanosheet

In the process of developing nuclear energy, removing radioactive waste in the environment is a challenging problem that human beings have to face. The main work of this paper is to investigate the mechanism of the interaction between metallic radionuclides (Cs, Sr, and Ba) and a monolayer MoS₂ nanosheet, and the work is completed by using the first principles calculation method. The results show that all of the three kinds of metallic radionuclides can be chemisorbed on the monolayer MoS₂ nanosheet. The optimum adsorption site for the metallic radionuclides adsorbed on the monolayer MoS₂ is T_Mo (top of the Mo atom), because the metallic radionuclides can interact with the three nearest S atoms when the metallic radionuclides are at the T_Mo site. The chemisorption strength of the metallic radionuclides on the monolayer MoS₂ is Ba > Sr > Cs. The mechanism of the chemisorption is explored by using the total charge transfer, density of states, and electron density difference. The final analysis shows that the s orbital of S atoms plays an important role in the chemisorption.