Mesoporous TiO2 hollow microsphere constructed with TiO2 nanospheres: high light scattering ability and enhanced photovoltaic performance for dye-sensitized solar cells

Abstract

Mesoporous TiO2 hollow microspheres (HTM) composed of irregularly arranged nanospheres were prepared through a one-pot template-free solvothermal way based on the aldol condensation reaction of acetylacetone. The synthesized hollow TiO2 microspheres were investigated by a series of characterizations. Images of FE-SEM and TEM demonstrate that the surface of TiO2 hollow microsphere with a diameter of 1.5 µm are mesoporous and constructed with 150 nm TiO2 nanospheres. The mesoporous shell of the hollow microspheres is about 110 nm in thickness. XRD pattern shows the prepared samples are anatase phase. UV–Vis spectrum indicates that excellent light scattering ability of the prepared sample. The DSSCs using mesoporous TiO2 hollow microspheres as the top scattering layer exhibits the improvement of short-circuit current density (Jsc) and conversion efficiency (η) of 6.63%, while the benchmarked P25 photoanode is only 5.09%, showing 30% increase in the energy conversion efficiency.