Performance of Bi₂O₃/TiO₂ prepared by sol-gel on p-Cresol degradation under solar and visible light

Photocatalytic degradation of p-Cresol was evaluated using the mixed oxide Bi₂O₃/TiO₂ (containing 2 and 20% wt. Bi₂O₃ referred as TB2 and TB20) and was compared with bare TiO₂ under simulated solar radiation. Materials were prepared by the classic sol-gel method. All solids exhibited the anatase phase by X-ray diffraction (XRD) and Raman spectroscopy. The synthesized materials presented lower crystallite size and Eg value, and also higher surface area as Bi₂O₃ amount was increased. Bi content was quantified showing near to 70% of theoretical values in TB2 and TB20. Bi₂O₃ incorporation also was demonstrated by X-ray photoelectron spectroscopy (XPS). Characterization of mixed oxides suggests a homogeneous distribution of Bi₂O₃ on TiO₂ surface. Photocatalytic tests were carried out using a catalyst loading of 1 g L^-1 under simulated solar light and visible light. The incorporation of Bi₂O₃ in TiO₂ improved the photocatalytic properties of the synthesized materials obtaining better results with TB20 than the unmodified TiO₂ under both radiation sources.