Wang Fangzhi, Li Wenjun, Gu Shaonan, Li Hongda, Wu Xue, Liu Xintong
Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials Department of Chemistry, University of Science and Technology Beijing, Beijing, 100083, P.R. China.
Chemistry. 2016 Aug 26;22(36):12859-67. doi: 10.1002/chem.201602168. Epub 2016 Jul 28.
Samarium and nitrogen co-doped Bi2 WO6 nanosheets were successfully synthesized by using a hydrothermal method. The crystal structures, morphology, elemental compositions, and optical properties of the prepared samples were investigated. The incorporation of samarium and nitrogen ions into Bi2 WO6 was proved by X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. UV/Vis diffuse reflectance spectroscopy indicated that the samarium and nitrogen co-doped Bi2 WO6 possessed strong visible-light absorption. Remarkably, the samarium and nitrogen co-doped Bi2 WO6 exhibited higher photocatalytic activity than single-doped and pure Bi2 WO6 under visible-light irradiation. Radical trapping experiments indicated that holes (h(+) ) and superoxide radicals ((.) O2 (-) ) were the main active species. The results of photoluminescence spectroscopy and photocurrent measurements demonstrated that the recombination rate of the photogenerated electrons and holes pairs was greatly depressed. The enhanced activity was attributed to the synergistic effect of the in-built Sm(3+) /Sm(2+) redox pair centers and the N-doped level. The mechanism of the excellent photocatalytic activity of Sm-N-Bi2 WO6 is also discussed.
采用水热法成功合成了钐和氮共掺杂的Bi2WO6纳米片。对制备的样品的晶体结构、形貌、元素组成和光学性质进行了研究。通过X射线衍射、能量色散X射线光谱和X射线光电子能谱证实了钐和氮离子掺入到Bi2WO6中。紫外/可见漫反射光谱表明，钐和氮共掺杂的Bi2WO6具有很强的可见光吸收。值得注意的是，在可见光照射下，钐和氮共掺杂的Bi2WO6比单掺杂和纯Bi2WO6表现出更高的光催化活性。自由基捕获实验表明，空穴（h(+)）和超氧自由基（(.)O2(-)）是主要的活性物种。光致发光光谱和光电流测量结果表明，光生电子和空穴对的复合率大大降低。活性增强归因于内置的Sm(3+)/Sm(2+)氧化还原对中心和N掺杂能级的协同效应。还讨论了Sm-N-Bi2WO6优异光催化活性的机理。
