Preparation Of Modified Ti-MOFs For Photocatalytic Inactivation Of Microorganisms In Water

Metal-organic frameworks（MOFs）are a unique class of porous crystalline materials formed by assembling metal ions or clusters with organic ligands through coordination bonds.MOFs have found extensive applications in gas storage,adsorption,separation and catalysis.However,research on the photocatalytic inactivation of microorganisms using MOFs is still limited.In this study,we focused on the development of novel Ti-MOFs and prepared three composite photocatalysts by incorporating Ag nanoparticles to induce surface plasmon resonance（SPR）effects.These composite materials were investigated for their efficacy in inactivating water microorganisms,including bacteria,cyanobacteria,and viruses.The main conclusions of this study are as follows:（1）Bacterial inactivation:Ag/Ti-MOFs composite photocatalysts were synthesized using an in-situ reduction method.Our results demonstrated that Ag nanoparticles possess inherent inactivation capabilities in the absence of light,and they significantly enhanced the photocatalytic performance of Ti-MOFs.Under visible light irradiation,the synthesized Ag/NH₂-MIL-125（Ti）composite achieved a remarkable 7.2-log reduction in Escherichia coli within 25 min.Compared to pure NH₂-MIL-125（Ti）,the composite photocatalyst exhibited excellent antibacterial efficacy,regardless of the presence or absence of light.（2）Cyanobacterial inactivation:We designed and synthesized Ag/Ti-MOFs/g-C₃N₄composite photocatalysts with Z-scheme heterojunctions using in-situ reduction and solvent-thermal methods.The incorporation of Ag nanoparticles as electron transfer mediators in the composite photocatalyst significantly enhanced its photocatalytic performance.Under visible light irradiation,the composite photocatalyst achieved an impressive 99.5%removal of chlorophyll-a within 240 min.The cyanobacterial cells employed enzymatic defense mechanisms to counteract the·O₂^-and H₂O₂ species generated by the photocatalyst.（3）Viral inactivation:Ag@AgCl/Ti-MOFs composite photocatalysts were synthesized through an in-situ reduction approach.The presence of Ag nanoparticles facilitated the electron transfer from Ti-MOFs to AgCl,thereby enhancing the charge carrier recombination efficiency of the composite photocatalyst.We investigated the influence of environmental factors,including initial solution p H,humic acid concentration and catalyst dosage,on the inactivation of MS2 bacteriophage.Our results revealed that Ag@AgCl/NH₂-MIL-125 exhibited outstanding photocatalytic performance under visible light irradiation,achieving a substantial5.8-log reduction in MS2 bacteriophage within a mere 120 min.In summary,the incorporation of Ag nanoparticles inducing SPR effects proved to be an effective strategy for enhancing the photocatalytic and catalytic properties of Ti-MOFs.Our study establishes the feasibility of utilizing Ti-MOFs derivatives for the photocatalytic disinfection of waterborne microorganisms,thereby offering valuable insights for the advancement of photocatalytic technologies in water treatment applications.Figure[41]Table[9]Reference[114]...