Tailoring the rate-determining step in photocatalysis via localized excess electrons for efficient and safe air cleaning

Jieyuan Li, Xing'an Dong, Yanjuan Sun, Guangming Jiang, Yinghao Chu, S. C. Lee, Fan Dong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

84 Citations (Scopus)

Abstract

Regulating the rate-determining step in photocatalysis is crucial for advancing its application in environmental remediation. However, approaches for tailoring the rate-determining step have been largely overlooked. Herein, Ca-intercalated g-C3N4 is designed as a model photocatalyst to deeply understand the electron transportation behavior and the mechanisms of photocatalytic NO removal. The intercalation of Ca builds an interlayer channel for electron migration between g-C3N4 layers, which extends the sp2 hybridized planes and enables the electrons to transform from a delocalized state to a localized state around Ca, leading to the formation of localized excess electrons (e ex). Under visible light irradiation, these e ex are subsequently captured by gas molecules for more efficient reactive oxygen species (ROS) generation and reactant activation. The ROS generated by Ca-intercalated g-C3N4 demonstrate stronger oxidation capability than those generated by pure CN. The ROS directly participate in photocatalytic NO oxidation and tailor the rate-determining step by decreasing the reaction activation energies, resulting in an overall increase in NO removal efficiency and a reduction in NO2 production. The photocatalytic efficiency and selectivity have been significantly improved owing to the functionality of the e ex. Using closely combined experimental and theoretical methods, this work provides a new approach for understanding the behaviors of e ex in environmental photocatalysis and tailoring the rate-determining step to enhance reaction efficiency, achieving efficient and safe air purification.

Original languageEnglish
Pages (from-to)187-195
Number of pages9
JournalApplied Catalysis B: Environmental
Volume239
DOIs
Publication statusPublished - 30 Dec 2018

Keywords

  • DFT
  • g-CN
  • Localized excess electrons
  • Photocatalysis
  • Rate-determining step

ASJC Scopus subject areas

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

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