Hydrothermal synthesis of novel Mn1/3Ni1/3Co1/3MoO4 on reduced graphene oxide with a high electrochemical performance for supercapacitors

The novel chemical composition of pristine Mn1/3Ni1/3Co1/3MoO4 (MNC) and Mn1/3Ni1/3Co1/3MoO4 dispersed in various percentages of reduced graphene oxide (MNC/rGO) composites were prepared via the one-step hydrothermal method. X-ray diffraction (XRD) patterns showed pure crystalline phase CoMoO4 for the heat treated powder at 350 °C. Fourier Transform Infrared (FT-IR) spectra showed that the chemical band structure of Mn1/3Ni1/3Co1/3MoO4 corresponds to the strong vibrational bands of Mo O, Mo O and Mo O Mo bonds. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of Mn, Ni, Co, Mo, C and O elements and its valance in the MNC/rGO powder. Field Emission Scanning Electron Microscope (FE-SEM) images displayed the nanorods morphology of the MNC/rGO powders. High-resolution Transmission Electron Microscopy (HR-TEM) images showed the morphology of MNC nanorods wrapped with the reduced graphene oxide of the MNC/rGO composite. The MNC/rGO composite displayed the highest specific capacitances of 1750 F g−1 at 1 A g−1 in 3 M KOH. The MNC/rGO composite demonstrated a better cycling stability with a cycling efficiency of 85.5% after 5000 cycles at 10 A g−1. The high rate performances, good reversibility and capacity retention at a range of current densities were demonstrated the structural stability of the MNC/rGO composite. The high energy density of 38.8 W h kg−1 at a constant power density of 200 W kg−1was achieved for the MNC/rGO composite.