| Artificial photosynthesis hydrogen production technology, based on unlimited solar energy sources, will be providing an effective way for human beings to produce hydrogen energ, which could improve the environment and achieve the goal of sustainable development. Exploiting titanium-based film photoanodes with higher photon-generated carrier separation efficiency and better photo-hydrogen conversion performance have become one of the research emphasis in the field of artificial photosynthesis hydrogen production technology. TiO2 nanoparticle electrodes were prepared by fs-PLD, TiO2 nanotube photonic crystals and TiO2 nanorod array electrodes were prepared by anodization method. TiO2 nanotube photonic crystal and TiO2 nanorod array electrodes were sensitized by EosinY. Morphologies, elementary composition, crystal phases and photo-responsive were characterized by means of SEM, AFM, XPS, XRD and UV-Vis DRS techniques. The photoelectrochemical properties of as prepared photo-electrodes were analyzed with photocurrent-time curves, open potential transient curves and Mott-schottky plots. The results are showed as follows:The chamber pressure and deposition time have effects on the morphology and the photoelectrochemical properties of TiO2 nanoparticles electrode prepared by femtosecond laser deposition technique. The average size of TiO2 nanoparticles deposited under 1mbar was 240 nm. The average size of TiO2 nanoparticles deposited under 0.1mbar was 100 nm, which has higher particle density and narrower size distribution. With the increase of deposition time, more TiO2 nanoparticles can be collected on the substrate, more photoactive sites can be created. When the chamber pressure was 1mbar and deposition time was 3h, the as prepared TiO2 nanoparticles film had pure rutile crystal phase after annealing at 500°C for 4 h, which exhibited better photoelectrochemistry than samples deposited under vaccum.By two-step anodization method, TiO2 nanotube photonic crystals electrodes with periodical honeycomb nano-ring structure were prepared, the ring side length was about 150 nm and the ring thickness was about 40 nm. TiO2 nanotube photonic crystals had multiabsorption peaks in the region of 400-800 nm. After sensitized by EosinY, a significant light absorption peak of EosinY could be observed at the wavelength of 525 nm. The photoelectrochemical properties of TiO2 nanotube photonic crystals electrodes improved after EosinY sensitization, especially, TiO2 nanotube photonic crystals sensitized by alcohol soluble EosinY improved better than Ti O2 nanotube photonic crystals sensitized by water soluble EosinY. Based on the photocurrent density-time curves, TiO2 nanotube photonic crystals electrode sensitized for 8 hours exhibited the greatest photocurrent density.TiO2 nanorod array electrodes were prepared by anodization method. After sensitization of alcohol soluble EosinY, a significant light absorption peak could be observed at the wavelength of 500 nm and the photoelectrochemical properties improved.Considering the surface parameters of the Ti O2 based film electrodes prepared by different methods, the effects of surface parameters on photocurrent density, photovoltage, and the process of dye sensitization were studied. For TiO2 nanoparticles, TiO2 nanotube photonic crystals and TiO2 nanorod array electrodes, the film thickness had the most significant effect on the photocurrent density but little effect on photovoltage. TiO2 nanotube photonic crystals electrode with thickness of 2μm exhibited highest photocurrent density. TiO2 nanoparticles electrode which was assembled by 100-240 nm nanoparticles clusters had the highest photovoltage. Comparing with TiO2 nanorod array electrode, TiO2 nanotube photonic crystal electrode with honeycomb surface structure was beneficial for dye absorption. |
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