Ti3+自掺杂纳米TiO2的制备、表征与可见光催化活性

摘要

Rice-shaped Ti3+ self-doped TiO2 nanoparticles were prepared by hydrothermal treatment of TiH2 in H2 O2 aqueous solution. The structure,crystallinity,morphology,and other properties of the as-prepared samples were characterized by X-ray diffraction ( XRD ) , transmission electron microscopy ( TEM ) , high-resolution transmission electron microcopy ( HRTEM) and X-ray photoelectron spectra ( XPS) . Electron spin resonance ( ESR) spectroscopy confirmed the presence of paramagnetic Ti3+ in the bulk and surface of the as-prepared samples. The particles showed a strong absorption in the visible light region. Under visible light irradiation,the samples exhibited higher photocatalytic activity for hydrogen evolution and photooxidation of methylene blue than that of the commercial P25 TiO2 nanoparticles. The sample obtained at 160℃ for 27 h showed a 9-fold en-hancement for the visible light decomposition of methylene blue and 12. 5 times higher for H2 production in comparison to P25 TiO2 .%以TiH2和H2 O2为原料，采用水热法制备了米粒状 Ti3+自掺杂的 TiO2纳米颗粒.采用 X-射线衍射( XRD)、透射电子显微镜( TEM)、高分辨透射电子显微镜( HRTEM)和X-射线光电子能谱( XPS)对所制备样品的结构、结晶性、形貌和元素的存在状态进行了表征分析.电子顺磁共振谱( ESR)结果表明所制备的样品中含有晶格Ti3+和表面Ti3+.紫外—可见( UV-Vis)漫反射光谱表明这种Ti3+自掺杂的纳米TiO2在可见光区中有较强的吸收.在可见光辐射下，所制备的样品具有优于商业化P25 TiO2的光催化分解水和光催化降解次甲基蓝( MB)溶液的性能.其中160℃下水热处理27 h所得样品光催化降解MB的性能是P25 TiO2的9倍，而光催化分解水制氢的性能是P25 TiO2的12．5倍.