Synergy between Pt nanoparticles and Cr6+ in the photocatalytic performance of sol-gel derived TiO2

In this study, titanium dioxide (TiO2) containing 1 wt% of various elements (Ag, Cr, Cu, V, or Pt) was synthesized by a one-pot sol-gel method. The produced materials were extensively characterized by means of X-ray diffraction (XRD), BET surface-area measurements, Raman spectroscopy, UV-Vis spectroscopy and Transmission electron microscopy (TEM). UV-Vis spectroscopy demonstrated a clear shift in the absorbance of modified TiO2 towards the visible light region. The photocatalytic performance of the prepared materials was evaluated in the photooxidation of methylcyclohexane (MCH) under the illumiation of UV or Visible light. The performance was monitored by in situ ATR-FTIR. The best catalytic performance was obtained when Cr/TiO2 was applied. The photocatalytic activity under visible light illumination could be further enhanced by photodeposition of Pt nanoparticles (0.06 wt % Pt) on the surface of Cr/TiO2. The origin of the synergetic effect of Cr6+ and Pt nanoparticles will be discussed.