Preparation Of Silver-based Nanocomposite And Its Antibacterial And Photocatalytic Degradation Of Antibiotics

In recent years,due to the massive abuse of antibiotics,the antibiotic content in the environment has exceeded the standard.This induces the development of drug-resistant bacteria or genes.This phenomenon will pose a potential threat to the ecological environment and public health security.Therefore,research and development of new materials with broad-spectrum antibacterial,environmental protection,low toxicity and photocatalytic activity are particularly important.Among these materials,most of the silver-based nanocomposites have both antibacterial properties and photocatalytic activity,which has become a research hotspot in the field of inorganic materials.The main contents and results of this paper are as follows:?1?The nano silver is coated with polypyrrole?PPy?with good biocompatibility and supported on reduced graphene oxide.PPy@Ag/rGO ternary nanocomposite was successfully synthesized by one-pot hydrothermal method.The morphology and structure of the ternary nanocomposite were characterized by scanning electron microscope?SEM?and transmission electron microscope?TEM?.The antibacterial effect and photocatalytic activity of the composite material were investigated.The results show that PPy@Ag NPs?NPs = Nanoparticles?are well distributed on the reduced graphene oxide nanosheets.Compared with the same concentration of Ag NPs,PPy@Ag/rGO has enhanced antibacterial activity against Gram-negative bacteria?E.coli?.The addition of polypyrrole helps to improve the stability of nano-silver and can reduce the loss of nano-silver during the antibacterial process.After several cycles,the antibacterial rate of PPy@Ag/rGO nanomaterials can still be maintained above 90%.Under visible light irradiation,the photocatalytic degradation efficiency of the ternary composite material to tetracycline?TC?reached 80.88%.The results of cycling experiments show that the composite material has good photocatalytic stability.?2?Using carbon nanotubes?CNT?as a carrier,a silver chloride/carbon nanotube/graphite phase carbon nitride?AgCl/CNT/g-C₃N₄?composite with photocatalytic and antibacterial properties was constructed by chemical deposition material.Material characterization test results show that AgCl nanoparticles are deposited on CNTs,and two-dimensional g-C₃N₄?CN?is conducive to the uniform dispersion of AgCl/CNTs.The photocatalytic performance of the composite was investigated by photocatalytic degradation of TC in water under visible light irradiation.The results show that the photocatalytic degradation efficiency of AgCl/CNTs/CN for TC in water can reach 86.44% after 100 minutes of visible light irradiation.It is three times the photocatalytic degradation efficiency of pure CN and AgCl/CN.In addition,AgCl/CNTs/CN composites have a strong inhibitory effect on E.coli.?3?The magnetically recoverable AgCrO₂/?-Fe₂O₃/HNTs nanocomposites were synthesized by hydrothermal method.Characterization test results show that AgCrO₂ and ?-Fe₂O₃ nanoparticles can grow well on halloysite nanotubes.Under visible light irradiation,the prepared AgCrO₂/?-Fe₂O₃/HNTs composite material exhibited excellent photocatalytic degradation performance for the antibiotic ciprofloxacin?CIP?with a degradation efficiency of 76%.Holes and superoxide radicals are the main active species in the photocatalytic degradation CIP reaction system and play an important role.The compound has excellent antibacterial activity against E.coli,and the antibacterial rate reaches 98% within 24 hours.