Synthesis And Photocatalytic Properties Of Titanium Dioxide Nanowire And Its Composites

Titanium dioxide has high photocatalytic activity,stable chemical properties and non-toxicity.So it has become one of the most widely used semiconductor materials in photocatalytic technology.However,TiO2 can only be excited by ultraviolet light,which make it less efficient with the sun light.In this thesis,anatase titanias was used as raw material and the TiO2 nanowires were synthesized by using a hydrothermal method.In order to broaden the range and intensity of light response and improve the utilization rate of solar light,the nanowires were sensitized by organic dyes and doped with metal.(1)Titanium dioxide nanowires(TNW)were prepared by a hydrothermal method with anatase titanium dioxide nanoparticle(TNP)as starting material.The as synthesized samples were charactized,and the photocatalytic degradation experiments were carried out.The results of SEM and TEM showed that the samples were one-dimensional nanowire structures with hundreds of nanometers in length and a diameter of 5 nm.The result of BTE analysis showed that the the specific surface area of the sample was 294.4 m2/g,which is 3.6 times of that of TNP.The as synthesized TNW showed high adsorption and degradation yield with methylene blue(MB)solution.The adsorption yield reached up to 73.3%,which is 6.26 times of that of TNP.Under visible light irradation within 120 mins,the degradation yield of MB reached up to 80%,which is 3.7 times of that of TNP.(2)Oligomer Copper phthalocyanine(OCuPc)was synthesized by phthalic anhydride-urea route.OCuPc composites with TNW(OCuPc/TNW)were synthesized by using hydrothermal method with TNP and OCuPc as raw material.The as-synthesized composites were characterized by TEM,XPS,XRD et al.The photocatalytic properties were investigated.The results showed that the OCuPc/TNW is one-dimensionalnanowire structure with the specific surface area of 301.2 m2/g.The UV-Vis diffuse reflectance spectrum(UV-Vis DRS)results showed that the OCuPc/TNW has a strong absorption peak in the visible region.OCuPc/TNW showed high adsorption for MB with adsorption yield of 74.7%.Under visible light within 120 mins,the degradation yield of MB and rhodamine B(RhB)reached to 93.7%and 90%for 5%OCuPc/TNW composites.(3)The nanowire supported palladium composite(Pd/TNW)was prepared by liquid phase reduction method with the synthesized nanowires as the carrier.The composite was characterized and its photocatalytic activity was investigated.Results revealed that the composite remains one-dimensional nanowire structure with nano palladium particles uniformly loading on the surface of nanowire.UV-Vis DRS showed that Pd/TNW has a strong absorption in the visible region.Under visible light irradation within 120 mins,the degradation yield of MB reached up to 87.2%.