Simple preparation and properties of surface-modified mechanochemically synthesised copper sulphide semiconductor

Nanostructured semiconductor, copper sulphide, CuS prepared by a mechanochemical synthesis in a large-scale operation industrial mill was modified by surfactant-assisted milling in a planetary mill. Surface modified CuS with cetrimonium bromide, and sodium dodecyl sulphate surfactants were characterised by particle size distribution and compared to mechanochemically synthesised CuS. X-ray diffraction, Fourier-transform infrared spectroscopy and elemental analysis confirmed the binding of surfactants to the CuS structure. Transmission electron microscopy has revealed that the particles composed of nanocrystallites are embedded in the surfactant matrix. Their optical properties were studied using ultraviolet-visible and photoluminescence spectroscopies. The optical band gap energies were determined to be 1.70 and 1.63 eV for CuS modified with cetrimonium bromide and sodium dodecyl sulphate.