Ao Yanhui, Wang Kedan, Wang Peifang, Wang Chao, Hou Jun
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
Dalton Trans. 2016 May 10;45(19):7986-97. doi: 10.1039/c6dt00862c.
In this paper, novel p-n type heterojunction BiOI/La2Ti2O7 nanocomposites were synthesized via a simple method for obtaining visible light activated photocatalysts. The crystal phases and crystallinity of the prepared samples were analyzed by X-ray diffraction (XRD). The morphologies of the BiOI/La2Ti2O7 composites were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental composition and states were analyzed by X-ray photoelectron spectroscopy (XPS). Results showed that the obtained composites were constructed by 2D BiOI and La2Ti2O7 nanosheets. Besides, UV-vis diffuse reflectance spectrometry (DRS) indicated that BiOI/La2Ti2O7 composites possessed better visible light absorptive properties than pure La2Ti2O7. The photocatalytic activity was evaluated by the degradation of Rhodamine B (RhB), dye X-3B, methyl orange (MO) and a colorless antibiotic agent, ciprofloxacin (CIP), under visible light irradiation. Results showed that BiOI/La2Ti2O7 composites exhibited much higher activity than the corresponding single components. First of all, the enhanced activity can be ascribed to the improved visible light harvesting. Secondly, the results of photo-induced current and photoluminescence spectroscopy illustrated that the enhanced performance can also be attributed to the efficient transfer and separation of photoinduced charges, which resulted from the formed p-n heterojunctions between BiOI and La2Ti2O7. It can be expected that this novel 2D-2D p-n heterostructured photocatalyst would be a promising candidate for environmental remediation.
在本文中，通过一种简单的方法合成了新型的p-n型异质结BiOI/La2Ti2O7纳米复合材料，以制备可见光活化的光催化剂。通过X射线衍射（XRD）分析了所制备样品的晶相和结晶度。利用扫描电子显微镜（SEM）和透射电子显微镜（TEM）对BiOI/La2Ti2O7复合材料的形貌进行了表征。通过X射线光电子能谱（XPS）分析了元素组成和状态。结果表明，所获得的复合材料由二维BiOI和La2Ti2O7纳米片构成。此外，紫外-可见漫反射光谱（DRS）表明，BiOI/La2Ti2O7复合材料比纯La2Ti2O7具有更好的可见光吸收性能。在可见光照射下，通过罗丹明B（RhB）、染料X-3B、甲基橙（MO）和无色抗生素环丙沙星（CIP）的降解来评估光催化活性。结果表明，BiOI/La2Ti2O7复合材料表现出比相应单一组分高得多的活性。首先，活性增强可归因于可见光捕获的改善。其次，光生电流和光致发光光谱的结果表明，性能增强还可归因于光生电荷的有效转移和分离，这是由BiOI和La2Ti2O7之间形成的p-n异质结导致的。可以预期，这种新型的二维-二维p-n异质结构光催化剂将是环境修复的有前途的候选材料。
