Transformation pathway and toxic intermediates inhibition of photocatalytic NO removal on designed Bi metal@defective Bi2O2SiO3

Xinwei Li, Wendong Zhang, Jieyuan Li, Guangming Jiang, Ying Zhou, Shun Cheng Lee, Fan Dong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

74 Citations (Scopus)

Abstract

The design of highly efficient visible-light photocatalysts and the elucidation of decomposition mechanisms are the two key tasks in environmental remediation. Herein, we utilized theoretical calculations to design a Bi metal–based visible-light photocatalyst (Bi@BiOSi) with surface plasmon resonance (SPR) properties, showing that the unique electron delivery channel was formed at the Bi metal/Bi2O2SiO3 interface. The Bi@BiOSi nanosheets were used for photocatalytic removal of ppb-level atmospheric NO, with Bi metal–based SPR resulting in enhanced visible light capture and charge separation efficiency, whereas oxygen vacancy induced the formation of a midgap level and promoted O2 activation. As a result, generation of superoxide and hydroxyl radicals over Bi@BiOSi was promoted, favoring photocatalytic NO removal. To elucidate the reaction mechanism, the products distribution during adsorption and photocatalytic NO oxidation on Bi@BiOSi were determined by in situ DRIFTS, which revealed that the increased production of reactive species inhibited the toxic intermediates (N2O4) formation and increased the selectivity of the NO-to-NO3– transformation via the synergy of oxygen vacancy and Bi metal. Thus, this work provides new insights into the design of non-noble metal-based photocatalysts and establishes a novel method of inhibiting the toxic intermediates production in photocatalysis for efficient and safe air purification.

Original languageEnglish
Pages (from-to)187-195
Number of pages9
JournalApplied Catalysis B: Environmental
Volume241
DOIs
Publication statusPublished - Feb 2019

Keywords

  • Bi metal
  • In situ DRIFTS
  • Oxygen vacancy
  • Photocatalysis
  • Toxic intermediates inhibition

ASJC Scopus subject areas

  • Catalysis
  • Environmental Science(all)
  • Process Chemistry and Technology

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