Abstract：The present work improved the photocatalytic activity of TiO₂ nanoparticles by Ta doping, and investigated the modification of the crystal microstructure due to incorporation of Ta and the fundamental mechanism for the enhanced photodegradation performance. Ta-doped TiO₂ photocatalysts with different Ta dopant concentrations were prepared by a sol-gel method. Photocatalytic activity were valued by the degradation of Rhodamine B. X-ray diffraction (XRD) , Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements were used to investigate the influence of Ta doping on the microstructure and electronic properties of TiO₂. The results show that Ta⁵⁺ is doped in TiO₂ in a substitutional mode by replacing Ti⁴⁺, and the incorporation of Ta facilitate the formation of oxygen vacancies.The presence of Ta⁵⁺ and oxygen vacancies can increase the electron density and prevent the recombination of photogenerated carriers, and thus enhance the photocatalytic activity of TiO₂. It is found that the Ta-3 photocatalyst exhibits the highest degradation efficiency of Rodamine B at 83.8% under nature light irradiation for 2h, which is more than twice that of undoped sample.

Keywords: TiO₂ nanoparticle; Ta doping; photocatalysis