Antibacterial property of silica-supported Zinc Oxide prepared by molten salt

The aim of this study was to introduce a new method for producing ZnO/silica gel nanocomposites ZnO/silica gel. Nanocomposites were synthesized by inserting silica gels in a molten bath of zinc sulfate (at 560 °C) for different contact times. Except for zinc sulfate, no reduction agent or chemical material was used for the preparation of nanocomposite. In this method, synthesis of nanoparticles and their immobilization on the substrate were carried out in a period of time less than 60 minutes. The ZnO/silica gel nanocomposites were studied by scanning electron microscopy (SEM) and UV–visible diffusive reflectance spectrometer (UV–Vis DRS). The SEM micrograph showed that the contact of silica gel with molten salt resulted in the formation of nanoparticles on the silica gel surface. On the other hand, by increasing the contact time, ZnO nanoparticles loading was increased. The antibacterial test against E. coli revealed that nanocomposites produced by 60 min contact duration, reached a mortality rate of 99.85%. The leaching test demonstrated the stability of the nanocomposites, and the delivery of zinc in water was less than 1.5% for all samples.