Iodine-modified Titania For Photocatalytic Antibacterial Application Under Visible Light Illumination

Semiconductor photocatalyst TiO₂ is attracting more and more attention in water treatment,air purification and medical applications and more,for its highly active,low toxicity,chemical stability,biocompatibility and inexpensiveness.However,TiO₂ can only be excited by UV Light,which greatly limits its biomedical application under visible-light or normal room light illumination.iodine-modified not only alters the surface charge and bulk band gap of TiO₂,which causes the photo-response of TiO₂ to enlarge from UV to VL region,but also sufficiently reduces the recombination of photogenerated electron-hole?e-=h+?by trapping the photogenerated electrons and enhanced visible-light photocatalytic activities.In the research,Iodine-modified TiO₂ powder?denoted I-TiO₂?were prepared by sol-solvothermal method.And I-TiO₂ was deposited on medical-care material PVC surface by combination of sol-solvothermal and liquid deposition method.The photocatalytic and antibacterial activities and stability were investigated by photocatalytic degradation of Rhodamine B and anti-bactericidal of Escherichia coli under visible light.The as-prepared samples were characterized by XRD,SEM,TEM,EDS,XPS,UV-Vis diffuse reflectance spectra?DRS?,and ESR.The results indicated that:I-TiO₂:?1?The as-prepared I-TiO₂ that pretreated with furfurals bigger specific surface area,better photocatalytic activity and atability than that without furfural.?2?After modified by different iodine?potassium periodate,hydroidic acid,potassium iodide,iodine?,the modified iodine on TiO₂ surface existed in the form of I2 and all these catalysts exhibit good activity.?3?The amount of Iodine has great effect on the visible photocatalytic and anti-bactericidal activities of Iodine modified TiO₂,in which the 0.8 I-TiO₂ catalyst shows the best photocatalytic activity.?4?In addition,an interesting post-illumination catalytic memory of I-TiO₂ that continues to inhibit the growth of E.coli in dark after the visible light was shut off was also observed.?5?Strong circumstantial evidence suggests that the reactive oxygen species?ROS??·OH or ·O₂-?produced by photogenerated electron-hole play a crucial role in the photocatlytic killing bacteria.I-TiO₂/PVC?1?:A combination of sol-solvothermal and liquid deposition method was used to deposition I modified TiO₂ sol particles on the biocompatible Medical-Grade PVC material to form a no toxicity and reusability functional thin film?I-TiO₂/PVC?for photokilling applications.?2?The results of contact angle measurement revealed that I-TiO₂/PVC has photoinduced hydrophilicity via visible light irradiation,AFM measurement revealed that the surface roughness of I-TiO₂/PVC film increases after TiO₂ were modified by I.?3?I-TiO₂/PVC film eshibit excellent antibacterial activity and stability under visible light irradiation.The E.coli has informed evident inhibition zone under the irradiation of VL light,1×107cfu/mL can be photocatalytically killed within 30 min VL irradiation.