title: Samarium and Nitrogen Co-Doped Bi2 WO6 Photocatalysts: Synergistic Effect of Sm(3+) /Sm(2+) Redox Centers and N-Doped Level for Enhancing Visible-Light Photocatalytic Activity.
abstract: 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.
authors.affiliation: 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.
authors.forename: Fangzhi
authors.initials: F
authors.lastname: Wang
authors.affiliation: 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. wjli_ustb@163.com.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Li
authors.affiliation: 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.
authors.forename: Shaonan
authors.initials: S
authors.lastname: Gu
authors.affiliation: 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.
authors.forename: Hongda
authors.initials: H
authors.lastname: Li
authors.affiliation: 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.
authors.forename: Xue
authors.initials: X
authors.lastname: Wu
authors.affiliation: 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.
authors.forename: Xintong
authors.initials: X
authors.lastname: Liu
keywords: Bi2WO6; doped; doped level; redox centers; synergistic effect