Papers by Keyword: Dye-Sensitization

Abstract: TiO₂ nanoparticle is one of the most fascinating materials for stimulating germination and growth of various seeds. However, the low capacity of these materials in absorbing sunlight is a challenging issue which should be taken into consideration. Sensitization of TiO₂ nanoparticles is already a common strategy for improving its visible light absorption and it is mainly used in dye-sensitized solar cells. In this study, a set of experiments were conducted to investigate the influences of dye-sensitized TiO₂ nanoparticles on germination and growth of barley seeds (Hordeum vulgare L.). Fluorescein was used as the sensitizer with high extinction coefficient in the visible regions. It was shown that different growth parameters including seedling fresh and dry weights, root and shoot lengths, chlorophyll-a, and chlorophyll-b were increased by 59.2% and 85.7%, 330%, 100%, 45% and 50% relative to the control, respectively. Moreover, the results confirmed that dye-sensitized TiO₂ nanoparticles do not have any negative influence on germination parameters and are beneficial for increasing vigor index I.

Abstract: The nanoporous titania powders are prepared under hydrothermal conditions using the amphiphilic triblock copolymer (Pluronic P123) as the porogent, and characterized by means of XRD and BET. Then, nanoporous TiO2 electrodes are fabricated by Doctor-blade mehod, using the nanoporous TiO2 powders as anode materials, and the photoelectronic properties of the DSCs are investigated by measuring transient photocurrent spectrum and photocurrent action spectra. The results indicate that the porous titania powder have pure anatase structure, and the specific surface area is up to 68m2g-1. In addition, the nanoporous TiO2 electrode shows higher photoelectric performance compared with pure TiO2 electrode.

Abstract: The nanoporous titania dispersion system are prepared under hydrothermal conditions by employing various amount β-cyclodextrin(CD) as the porogent.Then, different microsructure nanoporous TiO₂ electrodes are fabricated by Doctor-blade mehod, using the above synthesis of titanium dioxide materials.The photoelectrochemical properties of dye-sensitized nanoporous TiO₂ electrodes are studied with transient photocurrent spectrum ,electrochemical impedence spectra (EIS) and photocurrent action spectra. The results indicate that the current response signals of dye-sensitized porous TiO₂ electrodes are stable. In addition,the impedence arc radius decreases gradually and light current increases gradually with the addition of β–CD. Meanwhile, the dye-sensitized porous electrodes with β-CD/TiO₂ ＝40 wt% showes the best photoelectrochemical properties.

Abstract: Effects of mixing dye sensitizer for the photocatalytic activity of dye-sensitized Pt/K0.95Ta0.92Zr0.08O3 was investigated. It was found that the photocatalytic activity was greatly improved by mixing dye sensitizer on the catalyst, and among the examined combination of organic dyes, the highest photocatalytic activity was obtained by mixing Cr-tetraphenylporphyrin (Cr-TPP) and Pentametylene bis[4-(10, 15, 20-triphenylporphine-5-yl)benzoate] dizinc(ΙΙ) (Zn-TPP dimer). In order to identify the effect of dye sensitizer, photovoltaic behavior of the dye-sensitized KTaO3 was investigated. The lifetime of the photo-exited electron and hole can be improved by coating with dye sensitizer. Thus, the effect of porphyrinoids would be explained by the improved efficiency of charge separation.