Perovskite LaFeO3-SrTiO3composite for synergistically enhanced NO removal under visible light excitation

Qian Zhang, Yu Huang, Shiqi Peng, Yufei Zhang, Zhenxing Shen, Jun ji Cao, Wingkei Ho, Shuncheng Lee, David Y.H. Pui

Research output: Journal article publicationJournal articleAcademic researchpeer-review

86 Citations (Scopus)

Abstract

Perovskite oxides (ABO3) are widely studied as excellent sorbing and catalytic materials for NOxabatement in automobile or stationary depollution processes, and recently they have attracted significant interest in solar conversion reactions due to the flexible composition, facile optical and electronic tuning properties. In this work, perovskite LaFeO3microspheres were synthesized and employed as photocatalysts to remove parts-per-billion level NO, and it is found that the photocatalytic efficiency was dramatically improved by coupling with SrTiO3nanocubes. The LaFeO3-SrTiO3composite with proper mass ratio (0.3–1) displayed 3.1 and 4.5 fold enhancement in NO removal rate as compared to the pristine LaFeO3and SrTiO3, respectively. Moreover, the LaFeO3-SrTiO3composite exhibited decreased NO2yield possibly due to the basic surface property of strontium sites. The synergistically improved activity was due to broad visible light harvest, enlarged surface area, and most importantly, the depressed surface charge recombination originating from the perfectly matched LaFeO3-SrTiO3interface and facile charge transfer along the staggered band alignment. The temperature programmed desorption (TPD) analysis revealed that the composite had efficient chemisorption for NO. Further, the electron spin resonance (ESR) combined with the radical scavenger tests and density functional theory (DFT) calculations suggested that the photocatalytic NO oxidation via superoxide radicals ([rad]O2−) from SrTiO3and direct hole (h+) transfer from LaFeO3might be the predominant routes. We believe that this study provides some new insights into perovskite nanomaterials as photocatalyst for NOxabatement under ambient conditions.
Original languageEnglish
Pages (from-to)346-357
Number of pages12
JournalApplied Catalysis B: Environmental
Volume204
DOIs
Publication statusPublished - 5 May 2017

Keywords

  • LaFeO 3
  • NO removal x
  • Perovskite nanomaterials
  • Photocatalysis
  • SrTiO 3

ASJC Scopus subject areas

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

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