Hydrogen generation through photocatalytic water splitting under solar light irradiation has become the important technique for sustainable future. Nano-structured catalysts like nano-tubes, -rods, -wires, core-shell structures, quantum dots has become promising materials to improve the photocatalytic efficiency. These materials showed unique properties like high surface to volume ratio, quantum confinement, more number of active sites, high crystallinity to enhance the photocatalytic activity.