Phase transition in ZnS nanoparticles: electrical, thermal, structural, optical, morphological, antibacterial and photocatalytic properties

Abstract

Zinc Sulphide nanoparticles (ZnS-NPs) are synthesized by microwave assisted chemical precipitation method. The as-synthesized nanoparticles are identified by X ray diffraction and electrical studies to examine the structural transition. The HT-XRD at 1000 C (373 K) and 2000 C (473 K) of ZnS-NPs also confirms structural transition of cubic to hexagonal phase. Thermal properties of the ZnS sample is also studied using thermo gravimetricdifferential thermal analysis (TG-DTA). From D.C. electrical resistance, a discontinuity occurs in the temperature resistance curve of the ZnS-NPs due to phase transition around 450 K. The energy dispersed x-ray analysis and Raman spectra of the ZnS-NPs confirm the presence of zinc and sulphur. The optical studies of the prepared ZnS-NPs are confirmed by its UV-vis and PL spectra. The TEM image of cubic ZnS-NPs reveals the well distribution of spherical shaped particles with mean size of 12.52 nm with standard deviation of 9.326 nm. According to the photocatalytic results of ZnS-NPs for the degradation of methylene blue (MB) have the highest degradation efficiency of 93.24% under UV irradiation within 80 min. Antibacterial effects of ZnS-NPs nanoparticles against some pathogens, like gram-negative, gram-positive, E. coli (Escherichia coli), S. aureus (Staphylococcus aureus) bacteria.

Structural, Electrical and Optical Studies of ZnxCu1-xS (x = 0.8, 0.6, 0.4 and 0.2) Nanoparticles

“…4a, 4b, 4c and 4d respectively. A discontinuity is observed in all the samples at a particular temperature due to phase transition [33]. The electrical properties of all the samples also change at this particular temperature.…”

“…Phase transition in Zinc Sulphide nanoparticles were already studied by varying annealing temperature and pressure, from resistance measurements [29][30][31][32][33]. Phase transition in Copper Sulphide nanoparticles have been studied by previous works [34][35].…”