O Adsorption Associated with Sulfur Vacancies on MoS Microspheres.

MoS is well-known for its catalytic properties, mainly to adsorb hydrogenous or carbonaceous materials. However, the effect of MoS on the oxygen adsorption has been investigated only a few times thus far. In this work, we first studied the adsorbability of O by MoS through the analysis of LiO growth on the surface of flower-like MoS microspheres with different concentrations of sulfur vacancies, which can be applied as the highly active electrocatalysts for Li-O batteries. The enhancement of battery performance for the Def-MoS@CTs (CTs = carbon textile substrates) with a larger concentration of sulfur vacancies (S/Mo = 1.61) can be achieved. The experimental and theoretical results confirm that the sulfur vacancies play a crucial role in the adsorption process and thus affect the morphology and nucleation of LiO. In addition, a fundamental catalytic mechanism for this adsorption process is also proposed. These results provide a new insight into the development of a highly active electrocatalyst by introducing a large concentration of defects for Li-O batteries.