The nano-TiO2 doped with Er3+ were prepared from Ti(OC4H9)4 by sol-gel method,and the effect of Er3+ dopant on microstructure and photocatalytic activity of nano-TiO2 was studied. The phase composition and crystallite sizes of Er3+-doped TiO2 samples were analyzed by X-ray diffractometry(XRD) and transmission electron microscopy(TEM). The photocatalytic activity of Er3+-doped TiO2 was investigated at different doping concentrations and different heat treatment temperatures in the photocatalytic degradation of phenol with 365 nm wavelength ultraviolet light irradiation. The results show that both the anatase phase and rutile phase are formed in doped TiO2. Er3+ doping hinders the crystal transformation and makes the TiO2 crystallite size change smaller as well as increases the photocatalytic activity of TiO2 greatly. When Er3+ doping concentration is 1.2%(mass fraction) and the heat treatment temperature is 700 ℃,the photocatalytic activity of Er3+-doped TiO2 is favorite in the experimental range. The photocatalytic activity is enhanced by about 18% compared with that of the pure TiO2 and almost approaches the photocatalytic activity of P25-TiO2.
