Synthesis And Antibacterial Activity Of Copper Based Nanocomposites

With the population explosion over the world,the water pollution is becoming more and more serious.In spite of the efficiency,traditional physicochemical methods have the limitations of producing toxic by-products and development of resistance strains.In recent years,inorganic nano-materials have attracted widespread attention because of avoiding the above shortcomings.Among them,Ag nanoparticles（NPs）and Ti O₂NPs were the most widely used in spite of high cost and complex operation.Here,copper-based antimicrobial materials with high antimicrobial activity and low price were selected and the antimicrobial activity were studied.First,cocklebur-shaped Cu₄O₃was synthesized by microwave-assisted hydrothermal reduction.The products obtained under microwave heating at low power for five min had a typical Xanthium-like morphology of1.0μm×1.5μm.The tetragonal crystalline and mixed valence of copper were confirmed by X-ray diffraction（XRD）and X-ray photoelectron spectroscopy（XPS）.The high antibacterial activity was validated by shake-flask inactivation experiments and minimum inhibitory concentration test(156.25mg·L^-1for Escherichia coli,78.12mg·L^-1for Staphylococcus aureus).The results of free radical quenching test coupled with reactive oxygen species detection with electron spin resonance trapping proved that the antibacterial activity of the material is mainly from¹O₂.Next,flower-like ZnO,Cu₂O NPs and composites with different ratios of ZnO and Cu₂O were prepared.The ratio of ZnO:Cu₂O were optimized from the results of SEM,the elemental composition and valence of the materials were obtained by XRD and XPS analysis,and the antibacterial activity of the Cu₂O/ZnO（ZnO:Cu₂O of 1:1）was investigated.The antibacterial test results showed that the material had excellent antibacterial activity under both light and dark conditions.Inactivation efficiency of 86.79%and 93.59%for E.coli and S.aureus were achieved within 480min when treated with 250mg·L^-1of the disinfectant under light and 85.37%and 91.78%of E.coli and S.aureus were killed in dark.Figure 25;Table 9;Reference 126...