Nanocomposites and nanomaterials

Simple preparation and study of surface-modified mechanochemically synthesized CuS

Achimovičová M.1, Tóthová E.1, Daneu N.2, Dutková E.1, Zubrík T.1, Fabián M.1
1 Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 040 01 Košice, Slovakia. E-mail: achimovic@saske.sk
2 Jožef Stefan Institute, Advanced Materials Department, Jamova 39, SI-1000 Ljubljana, Slovenia.

Copper sulphide, covellite, CuS is IB-VIA transition metal chalcogenide and p-type semiconductor with multifunctional utilization which depends on high crystallinity, shape and size of particles [1], colloidal stability and miscibility of dispersed nanoparticles by wet applications or technologies [2]. CuS prepared by mechanochemical synthesis in a large-scale operation industrial mill from copper and sulfur powders was modified by surfactant-assisted ball milling in a planetary ball mill. Surface modified CuS particles with cetrimonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactants were characterized by particle size analysis and compared to as-received mechanochemically synthesized CuS particles. As a results, the average particle size values, d50 drastically decreased.  X-ray diffraction analysis, FTIR spectroscopy and CHNS analysis confirmed the binding of used surfactants to the structure and surface of CuS particles. The scanning electron microscopy analysis has revealed that the particles are embedded in the surfactant matrix and the larger particles are composed of tightly packed, randomly oriented nanocrystallites. The optical properties of surface modified CuS were studied using UV-Vis and photoluminescence spectroscopy. The optical band gap was determined to be 1.70 eV for CuS modified with CTAB and 1.63 eV for CuS modified with SDS surfactant. The observed photoluminescence emissions had higher intensities in both cases of surface-modified CuS in comparison with the emission peak of original CuS.

1.	Wu Ch., Zhou G., Mao D., Zhang Z., Wu Y., Wang W., Luo L., Wang L., Yu Y., Hu J., Zhu Z., Zhang Y., Jie J. CTAB assisted synthesis of CuS microcrystals: Synthesis, mechanism, and electrical properties // Mater Sci Technol.-2013.-29.-P. 1047-1052.
2.	Gao L., Wang E., Lian S., Kang Z., Lan Y., Wu D. Microemulsion-directed synthesis of different CuS nanocrystals // Solid State Commun.-2004.-130.-P. 309-312.