TiO2 beads as photocatalyst and photoelectrode for dye-sensitized solar cells synthesized by a microwave-assisted hydrothermal method

In this study, a two-step process involving a sol-gel and microwave-assisted hydrothermal (MH) techniques has been used to synthesize a novel TiO2 structure, namely, TiO2 mesoporous beads. Various hydrothermal synthesis parameters were investigated to study their effects on the resulting beads. It was found that within the processing conditions used, the TiO2 beads have similar sizes (similar to 325nm) and contain uniform-sized anatase TiO2 nanoparticles (<10nm), which are single crystals. Crystalline TiO2 beads are obtained in as short as 15min at a low temperature of only 140 degrees C without any post-process calcination. Less surface oxygen vacancies was obtained at a higher MH temperature. Compare to the commercial P-25 TiO2 powders and conventional hydrothermal synthesized TiO2 beads, MH synthesized TiO2 beads exhibit much higher values of specific surface areas, pore volumes, and porosities. The use of TiO2 beads as photocatalyst and photoelectrode for dye-sensitized solar cells has also been investigated. Copyright (c) 2015 John Wiley & Sons, Ltd.