Microsphere assembly of TiO₂ mesoporous nanosheets with highly exposed (101) facets and application in a light-trapping quasi-solid-state dye-sensitized solar cell

Abstract

The morphology of nano-titania has a significant effect on the photoelectric properties of dye-sensitized solar cells. In this study, microsphere assembly of a TiO2 mesoporous nanosheet constructed by nanocuboids was conducted via a simple hydrothermal process. The XRD pattern indicated that the hierarchical mesoporous microspheres are anatase phase with decreased (004) peaks. Raman spectrum shows enhanced Eg peaks at 143 and 638 cm(-1) caused by the symmetric stretching vibration of O-Ti-O of the (101) crystalline facet in anatase TiO2. FESEM and TEM images show that well monodispersed TiO2 microspheres with a diameter of 2 μm are assembled by TiO2 mesoporous nanosheets with exposed (101) facets. The oriented attachment of TiO2 nanocuboids along the (101) direction leads to the formation of mesoporous titania nanosheets. The UV-Vis spectrum shows that the mesoporous TiO2 nanosheets have high scattering ability and light absorption by dye. Quasi-solid-state dye-sensitized solar cells that incorporate these microspheres into the top scattering layers exhibit a prominent improvement in the power conversion efficiency of 7.51%, which shows a 45.8% increase in the overall conversion efficiency when compared with the spine hierarchical TiO2 microspheres (5.15%). There is the potential application for microsphere assembly of mesoporous TiO2 nanosheets in quasi-solid-state dye-sensitized solar cells with excellent stability.

Synthesis of anatase TiO2 microspheres and their efficient performance in dye-sensitized solar cell

“…The B1g and A1g modes of peaks at 397 cm -1 and 516 cm -1 mainly correspond to symmetric and antisymmetric vibration bending modes of O-Ti-O bond respectively. Here, all the observed characteristics peaks belong to the typical anatase TiO2 phase and no other additional phases were observed from Raman spectra which is also in good agreement with XRD results [40][41][42].…”

Synthesis of Anatase TiO2 Microspheres and Their Efficient Performance in Dye-sensitized Solar Cell

“…Where 'D' is the average crystalline size (nm), 'k' is the shape factor which corresponds to 0.9, 'λ' is the wavelength of X-Ray used (1.5418Å), 'β' is the full width at half maximum of prominent diffraction peak (degree) and 'θ' is the Bragg's diffraction angle (degree) [39]. were observed from Raman spectra which is also in good agreement with XRD results [40][41][42].…”

Template‐free Fabrication of ZnS/TiO2 Photocatalyst with Macrochannels

“…Nitrogen adsorption–desorption isotherms were studied to obtain detailed information of the porous structure. As shown in Figure , it is clear that the isotherms of both samples are of type IV, indicating the existence of mesopores . An H2‐type hysteresis loop with a triangular shape can be observed, indicating the presence of “ink‐bottle” pores with narrow mouths, which are related to the interconnected pore structure .…”