Surfactant-assisted hydrothermal synthesis of titania nanoparticles for solar cell applications

Nanostructured anatase TiO₂ powders (∼7 nm) with different microstructures have been successfully synthesized using surfactant-assisted hydrothermal route. It can be seen that different morphologies of sphere, flower petal and cauliflower were appeared for the anatase powders formed at hydrothermal temperature 100 C for 24 h without and with sodium dodecyl sulfate (SDS) and cetyl trimethyl-ammonium bromide (CTAB) as anionic and cationic surfactants, respectively. The specific surface area S_BET was increased from 77.14 m²/g without surfactant to 177.19 m ²/g in the presence of SDS as anionic surfactant. The optical properties were measured and the band gap energy of the obtained powders was ∼3.3 eV. The UV-absorption band of the anatase phase was at near 295 nm without other observable bands, which proved to exhibit high optical property and might have potential application in solar cells devices.