Crystal growth and design of a facile synthesized uniform single crystalline football-like anatase TiO2 microspheres with exposed {0 0 1} facets

- Football-like TiO2 synthesized by a facile hydrothermal method.
- The formation mechanism of football-like TiO2 was investigated.
- The DSSC efficiency assembled by football-like TiO2 is 23.3% higher than P25.

Uniform football-like anatase TiO2 particles exposed by {0 0 1} facets were successfully synthesized by an environment-friendly, facile and low-temperature hydrothermal method in water solution without any additional capping agent. The crystallographic structure and the growth mechanism of anatase TiO2 particles were investigated systematically by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS), respectively. The formation mechanism of football-like anatase TiO2 particles exposed by {0 0 1} facets is investigated. It was found that there existed a selective adsorption of F− ions on different facets by analyzed with the density functional theory (DFT) computer simulation results, and it would lead to a selective nucleation and crystal growth of anatase football-like TiO2 particles. Additionally, this type of exposed {0 0 1} facets football-like TiO2 microspheres were used as a scattering overlayer on a transparent P25 film for fabrication of photoanodes for dye-sensitized solar cells (DSSCs). The results showed that an overall light conversion efficiency of this film was 6.31%, which is higher than that of the overall efficiency (5.13%) obtained from the P25 photoanode owing to the superior light scattering effect of microspheres and excellent light reflecting ability of the mirror-like plane {0 0 1} facets.