Electrochemical performance and energy storage capacity of copper sulphide (CuS) nanoparticles obtained by the co-precipitation method

This study employs a chemical co-precipitation method in sulphur-rich and sulphur-deficient environments to synthesize and characterize copper sulphide (CuS) nanoparticles. The structural, morphological, optical, and electrical properties of the synthesized CuS nanoparticles were systematically investigated. X-ray diffraction analysis predominantly suggests the formation of hexagonal covellite CuS, though additional peaks indicate the presence of secondary phases, particularly in sulfur-deficient conditions. Scanning electron microscopy revealed significant morphological differences, while energy-dispersive X-ray spectroscopy indicated higher purity in sulphur-enriched samples. Optical characterization, including bandgap determination via UV-Vis spectroscopy, highlighted the potential of CuS nanoparticles for optoelectronic applications. Electrochemical performance, assessed through cyclic voltammetry, demonstrated the superior specific capacitance of CuS-based capacitors in a Cu-CuS-Cu configuration. This work underscores the critical role of sulphur in optimizing CuS nanoparticle properties and provides a foundation for exploring their applications in energy storage, optoelectronics, and catalysis. The findings encourage further research into synthesis optimization and expanding functional applications of CuS nanoparticles across various technological domains. • SEM revealed morphological variations and size differences in sulfur-rich samples. • CuS nanoparticles showed a 2.26 eV band-gap for optoelectronic applications. • CuS capacitors achieved 9398.5 F/kg, ideal for advanced energy storage systems.