原位碳、氮共掺杂二氧化钛空心球的制备与可见光光催化性能

在H₂O₂-HF 的乙醇-水混合溶液中, 通过水热处理碳氮化钛(TiCN)制备了碳、氮共掺杂TiO₂ 空心球(CNTH). 用X 射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、X 射线光电子能谱(XPS)和紫外-可见(UV-Vis)吸收光谱表征了所制备的样品. 在可见光(λ≥400 nm)照射下, 通过降解甲基蓝检测了碳、氮共掺杂TiO₂空心球的光催化活性. 结果表明, 源于TiCN中的部分碳和氮原子原位掺入了TiO₂的晶格中, 部分碳掺入TiO₂点阵的间隙中. 该材料在整个可见光区展示了增强的可见光吸收, 其带边明显红移. 光催化研究表明在强可见光吸收和独特的空心球结构的协同作用下, 碳、氮共掺杂TiO₂空心球展示了比P25更高的可见光光催化活性.

Fabrication and Visible-Light Photocatalytic Activity of In situ Carbon and Nitrogen Co-Doped TiO2 Hollow Sphere

Carbon and nitrogen co-doped TiO₂ hollow spheres (CNTHs) were synthesized by hydrothermal treatment of titanium carbonitride (TiCN) in a mixture of H₂O₂, HF, ethanol, and water. CNTHs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-visible (UV-Vis) diffuse reflectance spectroscopy. Some of the carbon and nitrogen from TiCN was doped into the lattice of TiO₂ in situ, and some carbon atoms were incorporated into the interstitial positions of the TiO₂ lattice. The CNTHs exhibited enhanced absorption over the whole visible-light region and an obvious red shift at the absorption edges compared with that of TiO₂. The ability of the CNTHs to degrade methylene blue (MB) in aqueous solution under visible light irradiation (λ≥400 nm) was investigated. The CNTHs showed much higher photocatalytic activity than P25 in the degradation of MB because of the synergetic effects of their strong visible absorption and unique hollow sphere structure.