Synthesis of ZnO-Ag Nanocomposites by Thermal Decomposition Method and Studies on their Antibacterial Activity Against E. coli and S. aureus

Twelve different types of ZnO-Ag nanocomposites were prepared in the present work using thermal decomposition method. Three different types of ZnO nanoparticles were first synthesized using three different methods. Then, Ag nanoparticles were decorated on the surface of ZnO nanoparticles by thermal decomposition of silver acetate (Agac) in diphenyl ether. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray analysis (EDXA), transmission electron microscopy (TEM), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and UV-visible diffuse reflectance spectroscopy (DRS) were used to characterize the synthesized ZnO-Ag nanocomposites. XRD results confirm the presence of silver nanoparticles in all the ZnO-Ag nanocomposites. FE-SEM and TEM images demonstrate the presence of Ag on the surface of ZnO nanoparticles in the ZnO-Ag nanocomposites. DRS results show characteristic surface plasmon resonance (SPR) absorption due to Ag nanoparticles in the ZnO-Ag nanocomposites. The synthesized ZnO-Ag nanocomposites were explored for antibacterial activity against Escherichia coli and Staphylococcus aureus. The originality of the present study is that the antibacterial activity of ZnO-Ag nanocomposites, prepared by the thermal decomposition method, has not been reported.