In the present study, a quick and environmentally friendly approach has been developed for the synthesis of CuS nanocrystals of different shape with antibacterial activity. The process is completed in 5 min. The presence of copper sulfide in the final products was confirmed by XRD, Raman spectroscopy, XPS, and TEM. The morphology of the product is dependent on whether or not the reaction providing sulfur was realized. When sulfur was included, the CuS particles developed an elongated shape with a thickness in the range between 6 and 8 nm and lengths up to 60 nm. It was found that sulfur plays a role of a nucleation agent in this case and then is removed during the washing process. On the other hand, if just precursors for copper sulfide were used, the morphology was spherical and the crystallite size was around 20 nm. Finally, the antibacterial activity of the products was evaluated. The activity was less selective in the case of CuS prepared by the assistance of sulfur.

An effort to prepare different non-stoichiometric CuxSy compounds starting from elemental precursors using mechanochemistry was made in this study. However, out of 7 stoichiometries tested, it was only possible to...

CdS nanoparticles were successfully synthesized using cadmium acetate and sodium sulfide as Cd and S precursors, respectively. The effect of using sodium thiosulfate as an additional sulfur precursor was also investigated (combined milling). The samples were characterized by XRD, Raman spectroscopy, XPS, UV-Vis spectroscopy, PL spectroscopy, DLS, and TEM. Photocatalytic activities of both CdS samples were compared. The photocatalytic activity of CdS, which is produced by combined milling, was superior to that of CdS, and was obtained by an acetate route in the degradation of Orange II under visible light irradiation. Better results for CdS prepared using a combined approach were also evidenced in photocatalytic experiments on hydrogen generation. The antibacterial potential of mechanochemically prepared CdS nanocrystals was also tested on reference strains of E. coli and S. aureus. Susceptibility tests included a 24-h toxicity test, a disk diffusion assay, and respiration monitoring. Bacterial growth was not completely inhibited by the presence of neither nanomaterial in the growth environment. However, the experiments have confirmed that the nanoparticles have some capability to inhibit bacterial growth during the logarithmic growth phase, with a more substantial effect coming from CdS nanoparticles prepared in the absence of sodium thiosulfate. The present research demonstrated the solvent-free, facile, and sustainable character of mechanochemical synthesis to produce semiconductor nanocrystals with multidisciplinary application.

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