Lei E

TiO2 Photoanode Structure with Gradations in V Concentration for Dye-Sensitized Solar Cells

V-TiO₂(GC) photoanode film with graduated structure was prepared in a dye-sensitized solar cell work electrode by layer-by-layer method using TiO₂ precursor with gradations in V concentration on the indium tin oxide transparent conducting glass from substrate to surface. The effects of the gradient in V concentration on the structures and properties of TiO₂ photoanode film were discussed. The structure of the gradient V concentration has remarkable influence on the final performance of the DSSCs and I-V characteristic measurement indicates an enhanced efficiency by 31% as compared to pure TiO₂ nanoparticles film samples due to abundant solar light, fast injection and transmission velocity and the slowdown recombination of photoexcited electrons, simultaneously.

TiO2 nanotubes/nanoparticles composite film with higher light harvesting and electron transfer for dye-sensitized solar cells

TiO2 nanotubes with an inner diameter of 4–6 nm were synthesized by hydrothermal treatment method. TiO2 nanotubes/nanoparticles composite films were fabricated as a dye-sensitized solar cells work electrode using TiO2 nanotubes and TiO2 nanoparticles as precursor. The structure of composite films has a remarkable influence on the final performance of the cell due to high surface area, fast electron transfer, enhanced light-scattering and light-harvesting, simultaneously. I–V characteristic measurement indicates an enhanced efficiency by 27% as compared to TiO2 nanotubes film.

Structural and photoelectrochemical characterization of TiO2 nanowire/nanotube electrodes by electrochemical etching

TiO2 nanowire/nanotube electrodes were synthesized by anodization of titanium foils in ethylene glycol solution containing 0.5 wt% NH4F and 1 wt% water at 60 V for 6 h. The microstructure and morphology of the asprepared electrodes were investigated by XRD and SEM. A possible formation mechanism and oxidation parameters of nanocomposite structure were discussed. The relationship between structural characteristics of TiO2 nanowire/nanotube electrodes and its photoelectrochemical characterization were evaluated by electrochemical analyzer and photocatalytic degradation of methylene blue (MB) solution. Furthermore, these TiO2 nanowire/nanotube electrodes promoted the photoelectrochemical characterization due to the larger surface areas, enhanced light harvesting and electron transport rate. The results show that photocurrent density of 1.44mA/cm2 and photocatalytic degradation of 95.51% was achieved for TiO2 nanowire/nanotube electrodes, which were 0.55mA/cm2 and 20.52% higher than the TiO2 nanotube electrodes under a similar condition, respectively.

Synthesis of Nano-Sized SrTiO3 Photocatalyst by Sol-Gel Method

A sol-gel processing technology was employed to synthesize fine SrTiO3 powder by using strontium nitrate (Sr(NO3)2) , butyl titanate (Ti(OC4H9)4) as precursors, citric acid (C6H8O6) as complexing agent and (ethylene) glycol (C2H6O2) as stabilizer. Prepared the precursors in liquid phase and then calcined the precursors to achieve nano-sized SrTiO3 powders. The microstructure and composition of the as-synthesized samples were characterized by X-ray diffraction (XRD), Scan Electron Microscopy (SEM), and the photocatalytic activity was studied. The results showed that all the SrTiO3 particles were identified as perovskite phase. The pH values, the content of the acetic acid, the heat treat temperature play important roles on the synthesis of the SrTiO3 photocatalyst. When the pH=1, n(Sr(NO3)2 ) : n(Ti(OC4H9)4) = 1 : 1, n(Sr(NO3)2 ) : n(C6H8O6)=1:1.7, the product has better rate of photodegradation for the Methylene Blue under the ultraviolet condition.