Effects Of The Structure And Morphology Of TiO₂ Nanotube Films On Its Photocatalytic Activity And Antibacterial Property

Nano-TiO2 as a photocatalytic material with attractive characteristics of high photocatalytic property, nontoxicity and long-term stability has been given more and more attention in the fields of pollutant degradation and antibacterial. TiO2 nanotube array film not only possesses high specific surface area and high photocatalytic property which the traditional TiO2 nano-powder has, but also has good immobilization on the substrate. Besides, it is easy to recycle, and can be reused.In this article, TiO2 nanotube array film was fabricated on Ti substrate through electrochemical anodization, and the effects of its morphology and structure on its photocatalytic activity and antibacterial property were researched.Through controlling the anodizing voltage, anodizing time of electrochemical anodization, and heat treatment, TiO2 nanotube arrays with morphology and structure were fabricated. TiO2 porous film was fabricated by micro-arc oxidation. The morphology and the structure of TiO2 films were characterized respectively by means of SEM, XRD. The results indicate that nanotube arrays with different tubediameter, tubulength and crystallites are formed on Ti substrate through anodization. TiO2 porous film is formed through micro-arc oxidation.The effects of morphology and structure of nanotube arrays on its photocatalytic activity were researched by decolorization of methyl orange in aqueous solution. The reusability of catalyst was investigated by repeated photocatalytic reaction expenriment. The catalyst's selectivity on pollutants was evalued by comparison of degradations of phenol and methyl orange. The degradation of pollutants was characterized respectively by the mean of uv-vis spectrophotometer. The results indicate that the TiO2 nanotube films with the diameter of 100nm and with structure of anatase exhibits the best photocatalytic activity, and the length of nanotube has little effect on the photocatalytic activity. TiO2 nanotube film has excellent resuability as photocatalyst. The nanotube film in some degree shows selectivity on pollutants. The photocatalytic activity of nanotube arrays is much higher than that of TiO2 porous film, but close with that of nano-powder.The effects of morphology and structure of nanotube arrays on its antibacterial were investigated by antibacterial experiment. The results indicate that the TiO2 nanotube film with the diameter of 100nm of 50nm and with structure of anatase exhibits the best antibacterial property. The length of nanotube has little effect on the antibacterial property. The nanotube film has higher antibacterial property than TiO2 porous film.The antibacterial property of nanotube film which was coated with silver particles through a disturbed silver-mirror reaction was investigated. The results indicate that Ag deposited nanotube film shows excellent antibacterial property, and the removal rate of colon bacillus reaches nearly 100% after 4h antibacterial experiment.