Effects of crystallite structure and interface band alignment on the photocatalytic property of bismuth ferrite/ (N-doped) graphene composites
Effects of crystallite structure and interface band alignment on the photocatalytic property of bismuth ferrite/ (N-doped) graphene composites
复制标题
微晶结构和界面能带排列对铁酸铋/（N掺杂）石墨烯复合材料光催化性能的影响
DOI：
10.1016/j.jallcom.2016.02.143
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发表时间：
2016-07-05
影响因子：
6.2
通讯作者：
He, Yunbin
中科院分区：
文献类型：
--
作者：
Li, Pai;Chen, Qiang;He, Yunbin
采用简单有效的两步水热法成功制备了铋铁氧体/石墨烯（N掺杂石墨烯）光催化剂。与纯BiFeO3和铁酸铋/N掺杂石墨烯相比，铁酸铋/石墨烯具有上级光催化活性。X射线衍射、扫描电子显微镜和能谱分析表明，添加石墨烯后得到了Bi25FeO40晶相，而添加N掺杂石墨烯后在相同的水热条件下得到了BiFeO3晶相。芯能级和价带X射线光电子能谱分析揭示了铁酸铋/（N掺杂）石墨烯复合材料界面处铁酸铋的向下能带弯曲（类似于0.5 eV），这促进了电子从铁酸铋到（N掺杂）石墨烯的转移，并抑制了光生电子-空穴对的复合。这种在界面处的向下弯曲的能带排列假定是铁酸铋/石墨烯复合材料的增强的光催化活性的主要机制，该复合材料目前在光催化领域中引起极大兴趣。(C)© 2016 Elsevier B.V.版权所有。
Bismuth ferrite/graphene (N-doped graphene) photocatalysts are successfully prepared by a facile and effective two-step hydrothermal method. Bismuth ferrite/graphene shows superior photocatalytic activity compared with bismuth ferrite/N-doped graphene and pure BiFeO3. X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy analyses indicate that Bi25FeO40 crystalline phase is obtained with the addition of graphene, while BiFeO3 is formed under the same hydrothermal conditions in the presence of N-doped graphene. Core-level and valence-band X-ray photoelectron spectroscopy analyses reveal a downward band bending of bismuth ferrite (similar to 0.5 eV) at the interface of the bismuth ferrite/(N-doped) graphene composites, which facilitates the electron transfer from bismuth ferrite to (N-doped) graphene and suppresses the recombination of photo-generated electron-hole pairs. This downward bending band alignment at the interface supposes to be the main mechanism underlying the enhanced photocatalytic activity of the bismuth ferrite/graphene composites that are currently of great interest in the photocatalysis field. (C) 2016 Elsevier B.V. All rights reserved.