Synthesis of well ordered mesoporous Yb, N co-doped TiO2 with superior visible photocatalytic activity

Well-ordered mesoporous TiO2 co-doped with nitrogen and ytterbium was successfully synthesized by an evaporation-induced self-assembly process. The as-prepared and calcined mesoporous TiO2 materials were characterized by X-ray diffraction, transmission electron microscope, UV-vis absorbance spectroscopy, X-ray photoelectron spectroscopy, fourier transform infrared and N-2 adsorption-desorption measurements. After calcinations at 350 degrees C. the TiO2 co-doped with nitrogen and 3% ytterbium had the highest surface area (219 m(2) g(-1)) and retained ordered structures. Under visible light irradiation, 75% of 20 mg/L phenol solution was degraded after 10 h and 10 mg/L rhodamine B (RhB) was decomposed completely after 4 h. The significant enhancement in the photocatalytic activity of the modified TiO2 is attributed to the synergistic effect of N and Yb. The N dopant extended the absorption to visible region and the Yb dopant was beneficial in stabilizing the mesoporous structure and restraining the recombination of photogenerated holes and electrons. (C) 2012 Elsevier Inc. All rights reserved.