Abstract:
Nanoparticles of the metal sulfides (ZnS, CdS and NiS) were prepared by precipitation method from the
aqueous solution of Na2S. 9H2O using aqueous solutions of their soluble salts Zn (NO3)2.6H2O,
Cd(NO3)2.4H2O, Ni(NO3)2.4H2O, respectively. Likewise the binary nanocomposites ZnS/CdS and ZnS/NiS
were prepared by the same method, by mixing equimolar solutions of their precursors used for the
preparation of ZnS and CdS as well as ZnS and NiS, respectively. Similarly, the ternary nanocomposite
ZnS/CdS/NiS was prepared by mixing aqueous solution of their precursors used for the preparation of ZnS,
CdS and NiS. All these as-synthesized nanomaterials were characterized using Uv-Vis Spectrophotometer
and X-ray diffractometer. The band gap energy were obtained using Tauc plot. XRD patterns were recorded
using a diffractometer equipped with a Cu target Kα radiation (λ=1.5401 A0
) source. Accordingly, the
average crystallite size of ZnS/CdS/NiS nanocomposite was calculated based on the primary peak on its
XRD patterns and found to be in the range of 2.5 and 9 nm. Finally antimicrobial activities of all the
synthesized nanomaterials were studied against Gram positive (Staphylococcus aureus and
Streptocococcus) and Gram negative (Escherichia coli and Pseudomonas aeuruginosa) bacteria using
paper disc diffusion technique. Accordingly, ZnS/CdS/NiS nanocomposite exhibited a much better
cumulative effect than the other as-synthesized nanoparticles and this value was almost comparable with
that of, Chloramphnicol, a commercially available antibiotics. The binary nanocomposites ZnS/CdS and
ZnS/NiS also showed significant antimicrobial activities better than their corresponding single components
