Preparation Of Modified TiO₂ And WO₃ Nanomaterials And Study On The Anti-Escherichia Coli K12

In the detection results of food microbial contamination,mainly coliform bacteria and E.coli exceeded the standard.Therefore,the sterilization measures for E.coli are conducive to the development of the food industry and reduce the risk of food contamination.Nowadays,a new sterilization technology is playing a great role:semiconductor photocatalytic sterilization technology.As soon as the nano-semiconductor photocatalytic sterilization materials come out,they attracted the attention of many researchers.Nano-semiconductor photocatalytic sterilization technology has unique advantages,it can directly use light energy to kill pathogenic microorganisms without causing secondary pollution to the environment.In this study,silver-modified titanium carbide/titanium dioxide hetero composites,palladium-modified boron-doped titanium dioxide nanomaterials and palladium-modified tungsten trioxide composites were prepared by chemical synthesis.E.coli K12 was used as the target strain to study the bactericidal performance.The details are as follows:1?Ag-TiC/TiO₂ hetero composites with photocatalytic antibacterial properties were prepared by calcination and photo-deposition.Through the materialistic characterization,the prepared materials have significant light absorption properties for visible light.As the results show that 10%Ag-TiC/TiO₂ showed significant photocatalytic sterilization ability,which could reduce E.coli by 7orders of magnitude within 3 hours.2?The precursor B/TiO₂ was prepared by solvothermal method.The palladium on the surface of the material is palladium chloride reduced by sodium borohydride.Finally,Pd-B/TiO₂ nano-photocatalytic composite was formed.Through material characterization,the results show that the synthesized material has a light response to visible light.After 2 hours of visible light irradiation,2×10⁷ E.coli was completely killed by 7%Pd-B/TiO₂.3?PdO/WO₃ materials with excellent sterilization performance under visible light were synthesized by solvothermal method and calcination method.Through XRD,TEM and XPS characterization analysis,the experimental results show that due to the SPR effect of PdO,the light response range of the material is enhanced.For 1%PdO/WO₃ materials,E.coli was reduced by 7orders of magnitude after 25 minutes of visible light exposure.The capture agent experiments showed that h⁺played a leading role in the photocatalytic sterilization process,followed by the redox effects of·O₂^-and·OH.Preliminary biosafety assessment tests have shown that the material is safe and non-toxic to mammalian cells.