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.