Abstract: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.

Key words: photocatalysis; nano-TiO₂; Er³⁺ doping; phenol