Hydrothermal synthesis of Co₃O₄ nanoparticles decorated three dimensional MoS₂ nanoflower for exceptionally stable supercapacitor electrode with improved capacitive performance

In this study, a novel, Co₃O₄ nanoparticle decorated MoS₂ nanoflower (MoS₂/Co₃O₄) has been fabricated via a facile hydrothermal method by taking different concentrations of Co₃O₄ (0, 1, 2, 4, and 6%). The FE-SEM images represent a three-dimensional flower-like structure for MoS₂ and MoS₂/Co₃O₄. The different structural parameters of the nanoflowers were estimated from the XRD analysis. TEM analysis revealed that the inter-planar spacing of the nanostructure varied with the concentration of the Co₃O₄ nanoparticles. The Raman spectroscopy of MoS₂/Co₃O₄ nanoflower showed a distinct low-shift of the first-order Raman peaks suggesting n-type doping due to the incorporation of Co₃O₄. The specific capacitance as high as 220.72 mFcm^-2 at 0.14 mAcm^-2 together with high energy density and superior cycling stability (87% capacitance retention after 10,000 charge/discharge cycles) were obtained for the MoS₂/Co₃O₄ (4%) nanocomposite from the electrochemical analysis. This improved specific capacitance of MoS₂/Co₃O₄ can be attributed to the higher surface area, defect-rich structure, and lower charge transfer resistance of the prepared sample. The MoS₂/Co₃O₄ nanostructure with improved specific capacitance and higher stability synthesized from a simple, low-cost process will pave the way to the production of efficient and economic energy storage devices.