Synthesis Of Mesoporous Titania Beads With Tunable Pore Morphology And Their Application In Dye-Sensitized Solar Cell

The monodisperse mesoporous titania beads with ultralarge, tunable pore sizes wereprepared using hexylamine as the structure-directing agent by a facile sol-gel procedure,followed by a solvothermal post-treatment. It was found that the water contents in synthesisinfluenced significantly the morphology of the resultant titania beads using eitherhexadecylamine or hexylamine as the structure-directing agents: increasing the water contentresulted in the reduction in the diameters of the beads, which can be tunable from200to1750nm for hexadecylamine while from300to1400nm for hexylamine. Both the amount and thealkyl chain length of the structure-directing agents posed a great effect on the morphology ofthe beads. The roughness and diameters of the beads were also affected by the reaction time:prolonging the reaction time leads to the formation of the beads with smoother surface andbigger size.The regular pore sizes of the resultant mesoporous titania beads can be tuned from18.9to40.0nm, which is the largest for the mesoporous titania materials up to date, by varying theammonia concentration in the solution for the solvothermal treatment. The influence of thepore morphology of the mesoporous titania beads on the performance of the dye-sensitizedsolar cells (DSSCs) was investigated. Experiments showed that the power conversionefficiency (PCE) of the cell was balanced by the pore sizes and specific surface areas of themesoporous titania beads, and the highest PCE of6.43%was obtained for the electrode madeof the mesoporous titania beads with a pore size of40.0nm，demonstrating its potential insolar energy utilization.