Tio <sub> 2 </ Sub> Nanotubes And Contained Platinum Tio <sub> 2 </ Sub> Nanotubes And Its Photocatalytic Performance Study

Titanate nanotubes were prepared via a hydrothermal method taking TiO₂(Degussa P25) and NaOH as raw materials,and titania nanotube(TNT) with anatase phase were obtained after these titanate nanotubes calcined at 300℃,400℃,500℃for 5 hours.TNT powder were randomly loaded with Pt by photo-deposition method using H₂PtCl₆·6H₂O as a platinum source and ethanol as a sacrificial electron donor and the obtained samples were reffered as Pt/TNT.The morphology,structure and composition of TNT and Pt/TNT were characterized by TEM,XRD,Raman spectra and XPS,also,the photocatalytic activities were studied.The key conclusions are summarized.The titanate nanotubes were amorphous,and the composition were H₂Ti₂O₅·H₂O.With the increase of hydrothermal reaction time,the content and the length of the nanotubes increased.When the hydrothermal reaction temperature was within a certain range,the content and the length of the nanotubes increased,with the increase of hydrothermal reaction temperature.The TNT were obtain after titanate nanotubes calcined,increasing the calcination temperature,the content of anatase increased,but the shape of the nanotube were destroyed.The efficiency of methylene blue photo-degradation catalysized by the titanate nanotubes prepared at 150℃for 48h and calcined at 400℃was the best.The conditions of photocatalysis reaction also had great effects on the photocatalytic activities.When the solution was alkaline,the concentration of MB was low and the air participated,the photocatalytic activities were better.The Pt nanoparticles on the surface of Pt/TNT were Pt metal and dispersed uniformly on the nanotubes.The crystal of Pt/TNT was not changed after Pt nanoparticles loaded on the TNT.To different pollutants,the effects of Pt nanoparticles on the photocatalytic activities were different.For MO and RB,the Pt on the surface of Pt/TNT improved the photocatalytic activities greatly.The photocatalytic degradation of RB by Pt/TNT using the TNT calcined at 500℃as the raw material was high.The photoreduction conditions had a great impact on the properties of Pt/TNT,nitrogen and ethanol promoted the photoreduction process,and the optimal time of photoreduction was 3h,the best loading amount of platinum was 0.57%. The platinum particles deposited on the outer surface of TNT did not contribution to the improvement of photocatalytic activities,instead,they reduced the photocatalytic activities. Pt/TNT retained high photocatalytic activities after reused for four times.