Research On Preparation And Properties Of Composite TiO₂ Nanotubes Film By Anodic Oxidation

The problem of environmental pollution caused by industrial modernization is serious,the photocatalyst,especially TiO₂,have been extensive used in the field of photo-catalysis.Anodic oxidation becomes one of the main methods due to its merits of easy preparation and high orderly structure.However,the narrow light abstraction width and high recombination rate of the photoelectron/hole confine the application of TiO₂.In order to solve the problems exist in the TiO₂ and enhance the practicability of material,the modification should be taken.Numerous studies have recently been performed,which include narrow-bandgap semiconductor doping,ion doping,sensitization and noble metal deposition.Therefore the research on preparation and properties of composite TiO₂ nanotubes film by anodic oxidation method has siginificance in science and great value in practical application.In this paper,the NH₄F,ethylene glycol and H2O were used as electrolyte to prepare TiO₂ nanotubes film.After that,Ag/TNS was prepared by using reverse voltage pulsed power in the electrolyte added AgNO₃ aqueous solution.The morphology,structure,wettability and photocatalytic performance of samples were studied by means of SEM,EDS,TEM,XRD,UV-VIS and contact angle measurement.The results show that:The TiO₂ nanotubes film with thickness of 2.86?m and inner diameter of 191nm was prepared under the constant voltage power.The experimental parameters were:the electrolyte contained 0.3wt%NH₄F,95vol%EQ 5vol%deionized water;anodic temperature of 25?;time of 1h;voltage of 60V.The structure of film after 450?annealing treatment is anatase,and the morphology of nanotube is integrated.The film after 450? performs well wettability,the contact angle is 9.74°.The 2-10mmo/L AgNO₃ aqueous solution was added into EG electrolyte,and the TiO₂ nanotubes film deposited Ag nanoparticles was prepared.The spherical Ag nanoparticles have a widely distribution on the edge of nanotube hole,the interior of nanotube hole and side wall of nanotubes.The composition of Ag can enhance the absorption of TiO₂ in the visible spectral range,and the contact angle of film which has the best hydrophilia is 5.6° when the addition of AgNO₃ is 2mmol/L.When the addition of AgNO₃ is 10mmol/L,the MO degradation of Ag/TNS reaches 63.63%from 38.31%.Ag plays a role in decreasing the recombination of photoelectron/hole,and the MO degradation of Ag/TiO₂ composite nanotube performs well under UV-light irradiation.