Effect of Size and pH Variation on Antibacterial Activities of ZnS-ZnO Nanocomposite Towards Application in Water Treatment.

Stable and rapid zinc oxide and zinc sulphide nanocomposite with high antimicrobial efficiency was investigated by chemical route. The composite ZnS-ZnO has much importance because of their various application in different filed and as it shows enhanced and wide band gap with tunable size. The synthesized nanocomposite shows excellent antimicrobial activity in with sun light. The structural and size was estimated by various instrument like XRD, UV- Visible spectrometer, HRTEM, HRSEM and bonding was analyzed by FTIR analysis. Surface was studied through AFM. The sample in PL spectra shows the defect states and it was red shifted. The size of the particles were decreases when more photon induced in the samples. The size and band gap of the prepared samples depends mainly the parameters like ZnS and ZnO ratio, reaction time and pH of the composite. The optimizing ZnS-ZnO nanocomposite exhibits promising antibacterial effects in pathogens Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae and Escherichia coli. The energy band of nanocomposite is higher compared to individual bulk value of ZnS and ZnO. Due to the high chemical affinity and active antimicrobial activity, it has large possible application in water purification. In our attempt it is found that the optimum condition for smaller particle size and high efficient antimicrobial activity the composite ratio of ZnS and ZnO is 5:3 and pH 0.7.