Er3+-doped TiO2 nanofibers with different Er3+ contents were prepared via electrospinning and characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy and photocurrent measurement. Photocatalytic activities of the as-prepared samples were evaluated by the decolorization of methyl orange aqueous solution under simulated solar light irradiation. The results indicated that the photocatalytic activity of Er3+-doped TiO2 nanofibers was much higher than that of the undoped one, and the optimal dosage of Er3+ at 1 mol% achieved the highest degradation rate. Moreover, the photocatalytic activity of Er3+-doped TiO2 nanofibers under the irradiation of light with the wavelength beyond the absorption edge of TiO2 was explored by the decolorization of a dye, rhodamine B and the photodegradation of a typical colorless pollutant, phenol. The results further revealed the mechanism of the enhanced photocatalytic activity through Er3+ doping in TiO2 nanofibers. (C) 2013 Elsevier Inc. All rights reserved.