Study On The Preparation Of Molybdenum Oxide And Silver Nanomaterials And Their Antibacterial Properties

Herein,two nano-antibacterial materials were synthesized and antibacterial properties of them were studied.One was the one-step stirring method for facile synthesis of highly photoluminescent molybdenum oxide quantum dots?MoO_x QDs?at room temperature,in which molybdenum trioxide?MoO₃?powder was used as precursor and dimethyl sulfoxide?DMSO?as both solvent and exfoliation agents,respectively.The other was using C₃N₄nanosheets as both stabilizing and reducing agents to prepare the silver/g-C₃N₄?Ag-g-C₃N₄?nano-composite materials with efficient antibacterial activity.1.MoO_x QDs were prepared via the room-temperature stirring method using MoO₃ as precursor and dimethyl sulfoxide?DMSO?as both solvent and exfoliation agents.The as-prepared MoO_x QDs were with average diameter of 3.9±0.8 nm,fluorescence quantum yield of 15.01%,and good dispersivity.The obtained MoO_x QDs was a uniform and stable colorless transparent suspension.The as-prepared MoO_x QDs were characterized by transmission electron microscopy?TEM?,high resolution transmission electron microscopy?HRTEM?,infrared spectrum ultraviolet visible?UV-Vis?absorption spectra,fluorescence spectroscopy?FL?,atomic force microscopy?AFM?,X-ray diffraction?XRD?,X ray photoelectron spectroscopy?XPS?and Fourier infrared spectroscopy?FTIR?to analyze the morphology and functional groups on the surface of MoO_x QDs.In addition,the generated MoO_x QDs could be applied to the quantitative detection of iron ions and pyrophosphate anions,respectively.Both the low detection limit was 3.3?M?S/N?3?.More importantly,antibacterial activity of the obtained MoO_x QDs was investigated.Through the Oxford cup method,the growth curve measurement and the transmission electron microscope characterization,it was obtained that the MoO_x could induce the damage of cell membrane and inhibit the bacterial reproduction of Escherichia coli?E.coli?and Staphylococcus aureus?S.aureus?,respectively.The lethality rates for E.coli and S.aureus were 58.1%and 53.3%,respectively.2.Using C₃N₄ nanosheets as both stabilizing and reducing agents,the silver/g-C₃N₄?Ag-g-C₃N₄?nano-composite with efficient antibacterial activity was prepared.After mixing the C₃N₄ nanosheets with the silver nitrate solution,the silver ions were rapidly reduced and aggregated to the surface of C₃N₄,and Ag-g-C₃N₄ nano-composite materials were obtained.Transmission electron microscopy?TEM?,energy dispersive spectroscopy?EDS?,scanning electron microscopy?SEM?,and other characterization techniques were used to study the composition and functional groups of the nano-composite.Antibacterial activity of the obtained nano-composite was investigated via measuring the growth curve of E.coli and S.aureus,respectively.As a result,the efficient antibacterial activity of the Ag-g-C₃N₄nano-composite can be confirmed.