Influence of nanobranched growth on photoelectrochemical performance of TiO2 nanotree arrays films.

Abstract TiO 2 nanotree arrays films were obtained on fluorine doped tin oxide (FTO) substrates through a facile two-step hydrothermal method. The synthesized nanostructures were investigated by means of X-ray diffractometer, field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The effect of TiO 2 nanotree morphology on optical and photoelectrochemical performance was systematically studied using UV–Vis absorption spectra, electrochemical impedance spectroscopy (EIS), Mott-Schottky, linear voltammetry and transient photocurrent measurements. The results revealed that a TiO 2 nanotree arrays film sample synthesized at 120 ℃ for nanobranched growth time 0.5 h showed a higher light trapping effect than TiO 2 nanorod arrays film, and achieved relatively lower charge transport resistance and higher photocurrent density compared with the other TiO 2 nanotree arrays samples. These behaviors can be mainly attributed to the formation of appropriate nanobranches manipulated the TiO 2 nanotree arrays by varying the hydrothermal reaction time to improve photoexcited electrons rate under the premise of high electronic transmission performance. [ABSTRACT FROM AUTHOR]