Preparation And Performance Of Branched Structure TiO₂/VO_x Composite Nanofibers

It is a hot research in improved photocatalytic activity,which is by doping form a compound semiconductor and organic dye photosensitization of TiO₂ are modified to improve the activity of TiO₂ and preparation of powder,porous,branched structure to improve the specific surface area of TiO₂.Vanadium oxide get the attention of people because of the narrow bandgap,and superior catalytic activity in the partial oxidation.By electrospinning,melt-quenching,dipping and annealing treatment was prepared branched TiO₂/VO_x composite nanofibers.Formation?structure and valence state of branched TiO₂/VO_x nanofiber have been characterized by using thermogravimetry-differential scanning calorimetry?TG-DSC?,scanning electron microscope?SEM?,X-ray photoelectron spectroscopy?XPS?,ultraviolet-visible spectra?UV-vis?and surface contact angle measurement.Discusses the annealing environment,temperature and holding time are influence of vanadium valence state?branched structure?photocatalysis and hydrophilic.The main conclusions are as follows:?1?TiO₂ nanofibers are prepared by electrospinning,under 550? calcination,the fiber is shrinked because of polymer are decomposited,after calcination TiO₂ fibers diameter between 118 nm to 500 nm.TiO₂ nanometer fiber coating stability of V sol then dry obtain the composite fiber.?2?Under the different environment can get TiO₂/VO_x branched fiber,and with higher processing temperature,longer holding time,the size is increased.V³⁺? V⁴⁺andTi³⁺can be obtained in vacuum with 100%N₂;V⁴⁺and Ti³⁺can be obtained in vacuum with 10%H₂;annealing in the air,no V⁴⁺ and Ti³⁺ produced.?3?Increases the annealing temperature,rise diameter is influence photocataytic activity of TiO₂/VO_x composite fiber first increases then decreases.In a vacuum with 100% N₂ TiO₂/VO_x composite nanofibers photocatalytic activity is 78.52%,which is increased by38.41% than pure TiO₂ nanofibers.?4?With the increase of annealing temperature and rise diameter,the light to hydrophilic is improved.Under the 90 min uv-irradiation branched structure TiO₂/VO_x nanofiber failing WAC is close to 6°.