Nitrogen-doped reduced graphene oxide/MoS2 'nanoflower' composites for high-performance supercapacitors

Mixed-phase (MP) metal disulfides have interesting electrochemical properties which originate from the generation of the abundance of electrochemically active sites and a higher structural stability as compared with crystalline materials. However, there is less exploration in the design and performance of the MP materials for supercapacitors application. Herein, nitrogen-doped reduced graphene oxide (N-rGO) with MP molybdenum disulfide (MoS2) nanoflower (NGM) nanocomposite was self-assembled in a one-pot hydrothermal synthesis. The NGM nanocomposites featured a high surface area and electrical conductivity governed by the uniform growth of nanoflowers on the conductive N-rGO sheets. Coupled with an interconnected network of charge transport channels, the robust ion transport and lowered charge transfer resistance at the electrode-electrolyte interphase significantly boost the electrochemical activity enabling the electrodes to deliver a high specific capacitance (539.5 F g(-1)), exceptional energy and power densities (P-max = 25.4 kW kg(-1), and E-max = 71.5 Wh kg(-1)) and excellent capacitance retention of 95.3 % during long-term cycling.

Automated summary

This study synthesized a nanocomposite of nitrogen-doped reduced graphene oxide and mixed-phase molybdenum disulfide nanoflowers using a one-pot hydrothermal synthesis. The nanocomposite exhibited high surface area and electrical conductivity, and the interconnected charge transport channels facilitated robust ion transport and minimized charge transfer resistance. As a result, the electrodes showed excellent electrochemical activity, high specific capacitance, and exceptional energy and power densities, with excellent capacitance retention during long-term cycling.