Preparation,Modification And Photocatalytic Performance Of Titanium Dioxide Nanotubes

Photocatalytic technology is a kind of high efficient catalytic technology for water purification.The development of high activity catalysts is always a hot spot in this field.As a semiconductor catalytic material,Ti O₂plays an extremely important role in the field of photocatalysis because of its stable chemical properties,corrosion resistance and nosecondary pollution.However,as a photocatalyst,Ti O₂has some disadvantages,such as wide band gap,low utilization rate of sunlight and easy recombination of photocarriers,which greatly restrict the extensive industrial application of Ti O₂in the field of photocatalysis.Therefore,in this paper,Ti O₂nanotubes were prepared by alkaline hydrothermal method using nano Ti O₂powder（P25）as raw material.On this basis,transition metal was doped into Ti O₂nanotubes（TNTs）to obtain a better performance of the photocatalyst.The specific research contents are as follows:（1）In order to synthesize titanium dioxide nanotubes as the goal,titanium dioxide nano powder as the precursor,through hydrothermal,pickling,calcination,titanium dioxide nanotubes.The effects of the input amount of precursor P25 powder,hydrothermal temperature,hydrothermal time and calcination temperature on the phase transformation,morphology and photocatalytic properties of the prepared samples were investigated.The results show that the morphology and photocatalytic performance of Ti O₂nanotubes are the best when P25 input amount is 1 g,hydrothermal temperature is 120℃,hydrothermal time is 24 h,calcination temperature is 400℃.Under the simulated fluorescent lamp condition,the catalytic efficiency is 97.38%the highest when the concentration of methylene blue solution（MB）is 1.5 mg/L and the amount of catalyst is 0.02 g.（2）On the basis of（1）,ferric chloride hexahydrate was used as iron source to prepare iron-doped Ti O₂nanotubes by hydrothermal method.The structure,morphology and pore structure of the sample were characterized by physical characterization.Through photocatalytic experiments,it was found that the photocatalytic performance was 98.85%the best when the amount of iron doping was2%under the simulated conditions of sunlight.（3）in order to further improve the photocatalytic activity of Ti O₂,in（2）on the basis of ferric chloride hexahydrate as source of iron,copper chloride hydrate as the source of copper,under hydrothermal conditions to double metal doped titanium dioxide nanotubes,by adjusting the doping ratio of copper,iron,get a kind of high catalytic activity and the suitable nanotube catalyst pore structure,The double-doped nanotubes were characterized by XRD,BET,TEM,SEM,etc.,and the photocatalytic degradation of methylene blue solution showed that when the copper and iron doping ratio was 0.5%/0.5%,the best catalytic activity was99.10%.