Efficient photocatalytic removal of NO in indoor air with hierarchical bismuth oxybromide nanoplate microspheres under visible light

Zhihui Ai, Wingkei Ho, Shuncheng Lee, Lizhi Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

390 Citations (Scopus)


In this study, hierarchical bismuth oxybromide (BiOBr) nanoplate microspheres were used to remove NO in indoor air under visible light irradiation. The BiOBr microspheres were synthesized with a nonaqueous sol-gel method by using bismuth nitrate and cetyltrimethyl ammonium bromide as the precursors. On degradation of NO under visible light irradiation (λ > 420 nm) at 400 part-per-billion level, which is typical concentration for indoor air quality, these nonaqueous sol-gel synthesized hierarchical BiOBr microspheres exhibited superior photocatalytic activity to the chemical precipitation synthesized counterpart BiOBr bulk powder and Degussa TiO 2 P25 as well as C doped TiO2. The excellent catalytic activity and the long-term activity of nonaqueous sol-gel synthesized BiOBr microsphereswereattributed to their special hierarchical structure, which was favorable for the diffusion of intermediates and final products of NO oxidation. Ion chromatograph results confirmed that nitric acid was produced on the surface of BiOBr microspheres during the photooxidation of NO in gas phase. This work suggests that the nonaqueous sol-gel synthesized BiOBr nanoplate microspheres are promising photocatalytic materials for indoor air purification.
Original languageEnglish
Pages (from-to)4143-4150
Number of pages8
JournalEnvironmental Science and Technology
Issue number11
Publication statusPublished - 1 Jun 2009

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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