Preparation And Photocatalytic Performance Research Of Co-doped TiO₂Nanotubes

With the development of the industry, people’s living standards have improved obviously.However, the problem of environmental pollution has become increasingly serious. At present,photocatalyst technology has played an important role in environmental, chemical,pharmaceutical, food and other fields. But there are still some issues that have to be solved asfollow.(1) The photocatalytic activity of TiO2is not high and the use of visible light has to bedeveloped, so that it needs a further study on how to improve the photocatalytic activity ofTiO2and how to exploit the efficient photocatalyst.(2) The key factor affecting the photocatalytic activity of titanium dioxide lies in thecomplex of electron-hole pairs and the charge transfer, so we have to do more research on howto capture electrons and slow the recombination probability of the electron-hole pair.(3) The preparation and modification methods of TiO2can also be optimized to prepareTiO2photocatalytic material of better photocatalytic properties.The main research contents are as follows:1. The TiO2nanotubes were prepared by co-precipitation and hydrothermal method. Then,the optimum process parameters had been determined. The parameters included the influenceof temperature of the hydrothermal method, the hydrothermal reaction time, calciningtemperature and time.2. Utilize the best process parameters previously obtained to prepare the titanium dioxidewith different mixed amounts of cobalt metal ion, then analyze the crystal structure andmorphology of the samples by X-ray diffraction (XRD) and transmission electron microscopy(TEM), and analyze the chemical composition of the samples by EDS.3. The methylene blue was used as target degradation to study photocatalytic rate trend ofthe samples with different mixed amounts of cobalt ion, obtaining the best mixed amount ofcobalt ion. The results show that: when the hydrothermal reaction temperature is130oC, thehydrothermal reaction time is36h, the calcination temperature is400oC and the calcinationtime is3h, we can get the highest catalytic rate of TiO2, which is81.3%; when the dopedamount of cobalt ion is1.3%, we can get the highest catalytic rate of Co-TiO2, which is97.2%.The result of XRD shows that the titanium oxide which is prepared with the best optimumparameter is the anatase phase. The result of TEM shows that the titanium oxide which isprepared with the best optimum parameter is nanotubes structure, whose tube length is30-50nm and tube diameter is about15nm. EDS analysis shows that the cobalt ion is doped inthe titanium dioxide lattice.