V2O5-TiO2复合半导体光催化材料结构及光响应性能研究

采用溶胶凝胶法制备了V₂O₅-TiO₂复合半导体材料，通过Raman、XRD及UV-Vis DRS等实验方法研究了V₂O₅与TiO₂复合对材料表面组成、晶体结构以及光响应性能的影响。结果表明：钒加入后优先与TiO₂作用形成较为稳定的金红石型TiVO₄晶相，其中V⁴⁺是促进TiO₂发生相变的关键；随着钒加入量的增加，V₂O₅由表面高分散状态逐渐聚集形成晶相，并释放部分Ti⁴⁺使之形成锐钛矿型TiO₂晶相，使得体相中金红石型TiO₂的含量有所下降；复合后形成的TiVO₄晶相显著提高了材料对可见光的吸收率，并使其吸光域红移至460 nm左右。

Structures and Photo Absorption Properties of Sol-gel-derived Coupled Semiconductor V2O5-TiO2

Coupled semiconductors V₂O₅-TiO₂ were prepared by sol-gel method. The coupling effects of V₂O₅ and TiO₂ on the surface composition, crystal structure and photo absorption properties of materials were investigated by the techniques of Raman spectroscopy, X-ray diffraction (XRD) and Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). Results show that Rutile TiVO₄ is preferentially formed as the main crystal structure of coupled semiconductors. V⁴⁺ is the key to promote the phase transition of TiO₂. With its content increasing, more V⁵⁺ ions gather on the surface to form V₂O₅ crystallites. Simultaneously, parts of Ti⁴⁺ are released to form Anatase TiO₂. As a result, the content of Rutile TiO₂ is decreased. The visible light absorption properties of coupled semiconductors are obviously enhanced for the formation of crystal TiVO₄, while the absorption limits bathochromic shift to 460 nm.