Mixed‐phase MoS 2 decorated reduced graphene oxide hybrid composites for efficient symmetric supercapacitors

Abstract
In this work, we demonstrated the phase‐tuned MoS2 layers (2H‐ MoS2, 1 T‐ MoS2, and 2H/1 T‐MoS2) using a one‐pot reaction, scientifically significant due to their impermeable characteristics. Strongly‐bonded, vertically‐aligned layers were perceived by transmission electron microscopy (TEM) for 2H/1 T‐MoS2 layers. The spacing between the two layers was expanded to 0.67 nm, which is favorable for intercalation process. Further, mixed‐phase MoS2 sheets were successively blended with reduced graphene oxide (rGO) to form 2H/1 T‐MoS2@rGO hybrid. Spectroscopic studies verified the formation of phase‐tuned MoS2 and 2H/1 T‐MoS2@rGO hybrid. The resulting 2H/1 T‐MoS2@rGO hybrid TEM micrograph shows the layered MoS2 lattices decorated rGO nano‐structure. Symmetric supercapacitors constructed from 2H/1 T‐MoS2@rGO hybrid electrodes demonstrated improved storage capacity with solid pseudo‐capacitive behavior compared to the pure phases. Surface‐modified 2H/1 T‐MoS2@rGO nanostructures exhibited a high energy density of 55 Wh·kg−1 at a power density of 3 kW·kg−1 with a symmetric capacitance of 275 F·g−1 at a current density of 1 A·g−1, along with an excellent cyclic constancy (~97% capacity after 5000 cycles).
Funding Information
  • Dongguk University (S‐2020‐G0001‐00023)
  • National Research Foundation of Korea (2019R1A2C2086747)