CsTi2NbO7@N-TiO2杂化核壳结构的制备及其可见光催化性能

将CsTi₂NbO₇与异丙醇钛混合后与尿素在空气中煅烧制备出CsTi₂NbO₇@N-TiO₂核壳杂化材料，用XRD、SEM、TEM、UV-Vis DRS和XPS等手段对样品进行了表征。结果表明，N掺杂使TiO₂带隙变窄和吸收边红移，实现了可见光响应。杂化、核壳结构和N掺杂的协同作用不仅使CsTi₂NbO₇@N-TiO₂杂化核壳结构材料具有较强的可见光吸收特性，异质结面的存在还导致光生载流子分离和迁移效率增强，从而提高了可见光降解亚甲基蓝(MB)的光催化活性，其反应速率常数约为CsTi₂NbO₇的5.8倍。同时，这种材料还具有良好的光催化循环稳定性。

Synthesis and Visible-light-driven Photocatalytic Activity of CsTi2NbO7@N-doped TiO2 Hybrid Core-shell Structure

A novel CsTi₂NbO₇@N-TiO₂ core-shell hybrid material was successfully prepared by mixing CsTi₂NbO₇ with titanium isopropoxide and then calcining with urea in atmosphere. The prepared products were characterized by means of X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible diffuse reflectance absorption spectrum (UV-Vis DRS) and X-ray photoelectron spectroscopy (XPS). It was found that the N doping resulted in the shortening of the band gap of TiO₂ and the red-shift of absorption edge, thus achieving the visible light response. Because of the synergistic effect of hybridization, core-shell structure, and N doping, the as-prepared CsTi₂NbO₇@N-TiO₂ hybrid core-shell structural materials not only have strong visible absorption properties, but also exhibit enhanced photocatalytic activity for degradation of methylene blue (MB) under visible light irradiation, resulting from the improvement of carrier separation and migration efficiency due to the existence of the built-in electric field. Moreover, the reaction rate constant of CsTi₂NbO₇@N-TiO₂ hybrid core-shell structural material is about 5.8 times that of CsTi₂NbO₇. Therefore, it shows good photocatalytic cycle stability.