Department of Chemistry, Renmin University of China, Beijing 100872, People's Republic of China.
Phys Chem Chem Phys. 2012 Sep 21;14(35):12114-21. doi: 10.1039/c2cp42165h. Epub 2012 Aug 7.
Crystalline metallic Au nanoparticles were loaded on α-Bi(2)O(3) microrods (Au/α-Bi(2)O(3)) using an Au deposition-precipitation method. The prepared samples were characterized by scanning electron and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. Upon visible light irradiation, the Au/α-Bi(2)O(3) exhibits much higher photocatalytic activities than the pure α-Bi(2)O(3) for the degradation of Rhodamine B and 2,4-dichlorophenol in aqueous solution. The role of the Au and the paths of electron transport in the photocatalysis of the Au/α-Bi(2)O(3) were investigated and discussed in detail based on the analysis of the photo-generated hydroxyl radicals (˙OH) and hydrogen peroxide (H(2)O(2)) in the visible light irradiated suspension of pure α-Bi(2)O(3) and Au/α-Bi(2)O(3). The result reveals that the Au loaded on α-Bi(2)O(3) plays a critical role in the separation of the electron and hole pairs by accumulating the electrons from the excited α-Bi(2)O(3), which is responsible for the enhanced photocatalytic activity.
采用 Au 沉积-沉淀法将晶态金属 Au 纳米颗粒负载在 α-Bi(2)O(3) 微米棒上（Au/α-Bi(2)O(3)）。通过扫描电子显微镜和透射电子显微镜、X 射线衍射、X 射线光电子能谱和紫外-可见漫反射光谱对制备的样品进行了表征。在可见光照射下，Au/α-Bi(2)O(3)对 Rhodamine B 和 2,4-二氯苯酚在水溶液中的降解表现出比纯 α-Bi(2)O(3)高得多的光催化活性。基于对纯 α-Bi(2)O(3)和 Au/α-Bi(2)O(3)可见光照射悬浮液中光生羟基自由基（˙OH）和过氧化氢（H(2)O(2)）的分析，详细研究和讨论了 Au 在 Au/α-Bi(2)O(3)光催化中的作用和电子传输途径。结果表明，负载在 α-Bi(2)O(3)上的 Au 通过从激发的 α-Bi(2)O(3)中积累电子，在电子和空穴对的分离中起着关键作用，这是增强光催化活性的原因。
