A hierarchical flower-like Sr Ti O3 nanostructure was synthesized by a simple and direct hydrothermal method.The products were characterized by X-ray diffraction,scanning electron microscopy,and transmission electron microscopy.Structure characterizations suggest that the as-synthesized SrT iO 3 crystal has eight symmetric branches growing along the ?111? direction and each branch has many ordered small laminae,forming a well-defined flower-like structure.By adjusting the pH value of the reaction system,the morphology could be changed continuously from flower-like structure to cube,then to sphere.The hierarchical flower-like SrT iO 3 nanostructure exhibits a higher photocatalytic activity for degrading Rhodamine B than its cubic and spherical counterparts.
Hierarchically ordered macro-mesoporous TiO2 films (Ti-Ma-Me) were fabricated on fluorine-doped tin oxide (FTO) substrates through the confinement self-assembly method. The prepared Ti-Ma-Me possesses periodically ordered structure and a large specific surface area, which was applied as an interfacial layer between the nanocrystalline TiO2 film (P25-TiO2) and FTO electrode in the dye-sensitized solar cell (DSSC). The introduction of a Ti-Ma-Me interfacial layer increased the shortcircuit current density (Jsc) from 7.49 to 10.65 mA/cm2 and the open-circuit voltage (Voc) from 0.65 to 0.70 V as the result of its improved light harvesting efficiency by allowing for the high roughness factor and enhanced multiple internal reflection or scattering as well as reducing the back-transport reaction by blocking direct contact between the electrolyte and FTO electrode. Therefore, the photovoltaic conversion efficiency (η) was improved by 83% from 3.04% to 5.55%, as compared to a device using a bare P25 TiO2 photoanode.
