Incorporated oxygen in MoS2 ultrathin nanosheets for efficient ORR catalysis

Abstract

Controllable engineering of high-electronegativity oxygen (O)-heteroatoms into MoS₂ ultrathin nanosheets is realized via a facile post-modification process. The incorporated oxygen atoms impart a dramatically enhanced ORR activity to the pristine nanosheets, with a 7.8-fold current increase as well as 180 mV and 160 mV positive shifts in both onset and half-wave potentials that are almost comparable with the commercial Pt/C catalyst. Furthermore, oxygen incorporation also triggers a transformation of the process from two-electron to a four-electron process. The improved topical conductivity, as well as the preferential adsorption of oxygen molecules originating from the heteroatoms engineering is supposed to be responsible for the efficient ORR. The prospect of controllably engineering heteroatoms into MoS₂ ultrathin nanosheets with versatile applications is also highlighted in this work.