In Situ Architecting Endogenous Heterojunction of MoS2 Coupling with Mo2 CTx MXenes for Optimized Li+ Storage.

ABSTRACT

Endogenous heterojunction of 2D MXenes with unique structure shows inspiring potential in energy applications, which is impeded by complex synthesis method and finite MAX materials. Herein, an in situ hydrothermal strategy is implemented to successfully synthesize unique endogenous hetero-MXenes of amorphous MoS2 coupling with fluoride-free Mo2 CTx (hetero-Mo2 C) directly from Mo2 Ga2 C MAX. The distinctive morphology and heterojunction structure caused by the introduction of MoS2 endow the hetero-MXenes with extraordinary structural stability and optimized Li+ storage mechanism with improved charge transport and lithium ion adsorption capabilities. As a result, hetero-Mo2 C exhibits excellent electrochemical performance with a high discharge specific capacity of 1242 mAh g-1 at 0.1 A g-1 and long cycle stability of 683.9 mAh g-1 after 1200 cycling. This work provides new insights into rational design of novel MXenes heterojunctions, practically important for the development of MXenes and their applications in high-performance energy storage systems.