Photocatalytic degradation of dye pollutants under solar, visible and UV lights using green synthesised CuS nanoparticles

A green method for the solvothermal synthesis of copper sulphide nanoparticles (CuS NPs) using xanthan gum as a capping agent was developed. The CuS NPs were characterised by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, Brunauer-Emment-Teller, zeta analysis, thermal gravimetric- differential thermal analysis, Fourier transform infrared and UV-visible absorption spectra. These characterisations together determine the composition, structural, thermal and optical properties. The UV-visible spectrum had a broad absorption in the visible range. The particle size of the products was observed by TEM in the range of 8-20 nm. The photocatalytic performance of the CuS NPs was evaluated for the degradation of organic dyes (methylene blue, rhodamine B, eosin Y and congo red) under irradiation of solar, visible and UV lights. The CuS NPs showed good photocatalytic activity. Kinetic analyses indicate that the photodegradation rates of dyes usually follow pseudo-first-order kinetics for degradation mechanisms.