Spherical pure anatase TiO2 spheres with a mesoporous structure and high surface area of up to 1165 m(2) g(-1) were prepared by a simple urea-assisted hydrothermal process and investigated as dye-sensitized solar-cell electrodes. Although the particle diameters of the prepared TiO2 spheres ranged from 04 to 1 3 mu m. due to the high specific surface area. mesoporous TiO2 sphere electrode was obtained with enhanced light harvesting and a larger amount of dye loading. An overall light conversion efficiency of 7.54% under illumination of simulated AM 1.5G solar light (100 mW cm(-2)) was achieved using the mesoporous TiO2 spheres electrode, which was significantly higher than a commercial Degussa P25 TiO2 nanocrystals electrode (5.69%) (C) 2010 Elsevier Ltd All rights reserved