Preparation Of TiO₂ Nanoparticles Via Annealing Titanate Nanotubes And Their Application In Dye-sensitized Photoanodes

The film of titanium dioxide nanoparticles is always be used as the materials of photoanode in dye/quantum dots sensitized solar cell. The particle size and morphology of the film has a significant influence on the adsorption of dye/quantum dots, electronic transmission, ion diffusion and the combination of charge. This paper uses the titanate nanotubes with high specific surface as the precursor materials to fabricate anatase titanium dioxide nanoparticlesthrough annealing. Thus we can control the size of titanium dioxide nanoparticles in a big range through controlling annealing temperature simply. So that we can get a high efficiency of photoelectric conversion through preparing a dye sensitized structure in the solar cell. The major research includes: fabricate titanium dioxide nanoparticles with annealing the titanatenanotubes and assembling dye sensitized solar cells with photoanode consisit of the nanoparticles.We employed a two-step alkaline hydrothermal technique and hydrogen ion exchange process to fabricate titanatenanotube.Then we get the anatase TiO2 nanoparticles through annealing the titanate nanotubes at high temperature.As the annealing temperature change from 600 oC to 900 oC,the size of the TiO2 nanoparticles changes from 19 nm to 150 nm.Titanate nanotubes begins to become short at 530 oC, and they begin to convert into TiO2 nanoparticles at 560 oC.When the temperature rises to 600 oC,titanate nanotubes will completely convert into the nanoparticles. Meanwhile,we can get the information that the material will transform from titanate to Ti O2 anatase phase. Along with the annealing temperature rising, the crystallinity of the sample will risecontinually.We take the various TiO2 nanoparticles, which are annealing under the 600 oC, 700 oC and 800 oC respectly, as the materials to fabricate DSSCs. After then, we give the DSSCs a test to get the information of the photoelectric conversion efficiency(PCE). We can obtain the results that: when the annealing temperature is 700 oC,the PCE come to the best with a PEC of 5.7%. Compared with P25, the best PEC has an improvement along with the ratio of 21% under the same preparation condition. The above research shows that the TiO2 nanoparticles which are prepared with this method has the significant application prospect as the light anode materials.