Single Precursor Mediated-Synthesis of Bi Semimetal Deposited N-Doped (BiO)2CO3 Superstructures for Highly Promoted Photocatalysis

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• 作者：Ting Xiong ; Xing’an Dong ; Hongwei Huang ; Wanglai Cen ; Yuxin Zhang ; Fan Dong
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2016
• 出版时间：June 6, 2016
• 年：2016
• 卷：4
• 期：6
• 页码：2969-2979
• 全文大小：861K
• 年卷期：0
• ISSN：2168-0485

文摘

Visible light utilization and charge separation efficiency are the two dominant factors for development of efficient visible light photocatalysts. In this work, visible light response N-doped (BiO)₂CO₃ and non-noble Bi semimetal-deposited N-doped (BiO)₂CO₃ superstructures were prepared by direct hydrothermal treatment of a single precursor (ammonium bismuth citrate) at different temperatures. The atomic utilization efficiency of the precursor was increased as all the components in the material were derived from this single precursor. Density functional theory calculations combined with systematical characterization results revealed that N atoms were in situ doped into (BiO)₂CO₃ lattice by substituting O atoms in (BiO)₂²⁺ layers. The upward shift of valence band top, originating from the hybridization of N 2p states with Bi 6s+6p and O 2p orbital, led to narrowed bandgap of (BiO)₂CO₃. Under higher hydrothermal temperature, Bi decorated N-doped (BiO)₂CO₃ superstructures were produced as Bi³⁺ ions can be reduced to Bi⁰ semimetal by citrate ions. For N-doped (BiO)₂CO₃, N-doping could narrow the bandgap of (BiO)₂CO₃ and then boost the visible light absorption. In terms of Bi decorated N-doped (BiO)₂CO₃, except for more absorption in the visible region, the plasmonic effect of the in situ formed Bi nanoparticles could accelerate the separation and transfer of photogenerated carriers, and thus more active species (hydroxyl radicals) were generated. With N-doped (BiO)₂CO₃ as photocatalysts, NO can be efficiently removed under visible light irradiation. Significantly, the Bi deposited N-doped (BiO)₂CO₃ with excellent stability showed much higher activity than N-doped (BiO)₂CO₃. This work encourages us to search for green methods to synthesize highly efficient photocatalysts, which also provides a strategy to enhance the photocatalytic performance via combination of nonmetal doping and non-noble metal deposition.