金红石二氧化钛纳米片的性质及其光催化活性 赵丹丹, 于彦龙, 高东子, 曹亚安 (南开大学 物理科学学院, 泰达应用物理研究院, 弱光非线性光子学教育部重点实验室, 天津 300457) 摘 要: 采用溶胶-凝胶、质子交换和层状剥离的方法, 制备出金红石 TiO 2 纳米片。利用 X 射线电子衍射谱(XRD)、 透射电子显微镜(TEM)、紫外-可见吸收光谱(UV-Vis)、X 光电子能谱(XPS)的价带谱和荧光光谱(PL)等对样品进行 了表征, 研究了光生载流子的转移过程。结果证明: 金红石 TiO 2 纳米片具有较大的比表面积(185.7 m 2 /g), 厚度约 5 nm, 与金红石 TiO 2 样品相比, 金红石 TiO 2 纳米片的禁带宽度增加, 氧化还原能力增强; 此外, 纳米片结构能够促 使光生载流子快速转移到纳米片的表面并产生有效分离, 阻止了光生电子和空穴的复合, 提高了光催化反应中光 生载流子的利用率。 金红石纳米片的这些特性导致其具有较高的光催化活性, 紫外光催化降解对氯苯酚的实验表明: 金红石 TiO 2 纳米片的光催化活性高于金红石 TiO 2 和锐钛矿 TiO 2 样品。 关 键 词: 金红石 TiO 2 纳米片; 比表面积; 能带结构; 光生载流子; 光催化活性 中图分类号: O643; O644文献标识码: A Abstract: Rutile TiO 2 nanosheets were prepared by Sol-Gel method, proton exchange and delamination method. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV-Vis diffuse reflectance spectroscope, X-ray photoelectron spectroscope (XPS) and photoluminescence (PL). The transference of photogenerated charge carriers was studied. It is revealed that the rutile TiO 2 nanosheets (thickness 5 nm) exhibit increased specific surface area (185.7 m 2 /g) and enlarged energy band gap, resulting in enhanced redox ability, when compared with rutile TiO 2 samples. In addition, the photogenerated charge carriers are able to transfer to the surface of nanosheets, due to their unique structure enabling photogenerated charge carriers to be effective separation during photocatalytic reactions. Therefore, the rutile TiO 2 nanosheets can enhance photocatalytic activity. Forthermore, the rutile TiO 2 nanosheets exhibite higher photocatalytic activity than rutile and anatase TiO 2 samples on the photocatalytic degradation of 4-chlorophenol under ultraviolet irradiation.
