First-principles Study of Catalytic Oxygen Reduction Reaction on Si Doped MoS2 Monolayer for Li-air Battery

The mechanism of oxygen reduction reaction (ORR) in alkaline solution on the surface of Si-doped MoS2 monolayer was studied to provide instructive suggestions for designing hybrid Li-air battery ORR catalysts with high performance. The catalysis performance of ORR on surface of n (n=1-3) Si doped MoS2 was determined by the first-principles calculation. The results indicated that the embedded Si atoms remained stable and fixed to the defects, the Si substitutional atoms introduced impurity state in the forbidden region and enhanced its surface activity. Si doped MoS2 greatly enhanced the reduction ability to O2, compared with the original MoS2 monolayer. Meanwhile, on the single and double Si doped MoS2, the maximum dissociation energy barrier of H2O molecule (0.85 eV, 0.75 eV) revealed that the reaction could take place at room temperature. On the triple Si atoms doped surface, the reaction would occur spontaneously without any barrier. However, single Si doped MoS2 had a strong adsorption ability to OH group, which is not conducive to the continuous ORR. With the increase of the number of doped atoms, the adsorption energy of OH group adsorbed on the triple Si doped MoS2 surface was greatly reduced. The results have shown that triple Si doped MoS2 monolayer is expected to be novel materials for ORR. © 2021, Materials Review Magazine. All right reserved.