One-step synthesis of OH-TiO/TiOF nanohybrids and their enhanced solar light photocatalytic performance.

TiO/TiOF nanohybrids were quickly synthesized through a hydrothermal process using titanium n-butoxide (TBOT), ethanol (CHOH) and hydrofluoric acid as precursors. The prepared nanohybrids underwent additional NaOH treatment (OH-TiO/TiOF) to enhance their photocatalytic performance. In this paper, the mechanism of NaOH affecting the pathway of transformation from TBOT (Ti precursor) to TiO nanosheets was discussed. The synthesized TiO/TiOF and OH-TiO/TiOF were characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction pattern (XRD), Fourier infrared spectroscopic analysis (FT-IR), Photoluminescence (PL) emission spectra and UV-visible diffuse reflection spectra (UV-vis DRS). The photocatalytic activity and stability of synthesized samples were evaluated by degradation of methylene blue (MB) under the simulated solar light. The results showed that a larger ratio of TiO to TiOF in TiO/TiOF and OH-TiO/TiOF nanohybrids could allow for even higher MB conversion compared with only TiO nanosheets. NaOH treatment can wash off the F ions from TiOF and induce this larger ratio. The highest efficiency of MB removal was just above 90% in 1 h. Lower electron-hole pairs recombination rate is the dominant factor that induces the photocatalytic performance enhancement of TiO/TiOF nanohybrids. The synthesized OH-TiO/TiOF nanohybrids exhibit great potential in the abatement of organic pollutants.