Cu–Mo–S Mixed Chalcogenide Nanostructures for Pseudocapacitive Applications

The present work reports the synthesis of a Cu–Mo–S mixed chalcogenide by wet chemical synthesis. The compound exhibited morphology similar to nanocubes with size in the range of 30–50 nm. The phase formation and pseudocapacitive properties of the compound were investigated. X-ray diffraction analyses demonstrated the presence of CuS and a ternary phase that do not match with any reported structure. The ternary phase exhibited cube-like structures with a size in the range of 60–80 nm. Extensive electron diffraction analysis using high-resolution transmission electron microscopy established that the compound belongs to the tetragonal phase (space group: P4/mmm), exhibiting a structure similar to the Cu4RbS3 phase. The scanning transmission electron microscopy─energy-dispersive X-ray spectroscopy established the chemical composition and confirmed the presence of a ternary Cu–Mo–S (Cu21Mo5S14) phase. The compound exhibited a maximum specific capacitance of 159 F g–1 at a scan rate of 5 mV s–1 in 1 M Na2SO4 electrolyte.