摘要：采用Ta元素掺杂TiO₂光催化剂, 研究掺杂引起的光催化效率变化、微观结构改变和催化剂改性的机制。采用溶胶凝胶法制备不同浓度的Ta元素掺杂纳米TiO₂光催化剂, 并通过降解罗丹明B表征其光催化性能。通过X射线衍射、拉曼光谱和X射线光电子能谱分析Ta掺杂纳米TiO₂催化剂晶相、微观结构、元素组成和化合价等。结果表明:Ta掺入纳米TiO₂催化剂后, Ta原子将取代Ti的位置, 以Ta⁵⁺形式存在于TiO₂晶格中, 促进掺杂样品中形成氧空位, 可以有效提高电子密度, 并抑制光生载流子复合, 从而提高催化效率。当掺杂比例n_Ta/n_Ti为3%时, 光催化效率最高, 光照2 h对罗丹明B降解率高达83.8%, 是未掺杂样品的2倍以上。

关键词：TiO₂纳米颗粒；Ta掺杂；光催化

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