Highly enhanced visible-light photocatalytic NOₓ purification and conversion pathway on self-structurally modified g-C₃N₄ nanosheets

Yuhan LI, Yanjuan SUN, Wing Kei HO, Yuxin ZHANG, Hongwei HUANG, Qiang CAI, Fan DONG

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28 Citations (Scopus)

Abstract

The unmodified graphitic carbon nitride (g-C₃N₄) suffers from low photocatalytic activity because of the unfavourable structure. In the present work, we reported a simple self-structural modification strategy to optimize the microstructure of g-C₃N₄ and obtained graphene-like g-C₃N₄ nanosheets with porous structure. In contrast to traditional thermal pyrolysis preparation of g-C₃N₄, the present thermal condensation was improved via pyrolysis of thiourea in an alumina crucible without a cover, followed by secondary heat treatment. The popcorn-like formation and layer-by-layer thermal exfoliation of graphene-like porous g-C₃N₄ was proposed to explain the formation mechanism. The photocatalytic removal performance of both NO and NO₂ with the graphene-like porous g-C₃N₄ for was significantly enhanced by self-structural modification. Trapping experiments and in-situ diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) measurement were conducted to detect the active species during photocatalysis and the conversion pathway of g-C₃N₄ photocatalysis for NOₓ purification was revealed. The photocatalytic activity of graphene-like porous g-C₃N₄ was highly enhanced due to the improved charge separation and increased oxidation capacity of the ·O₂⁻ radicals and holes. This work could not only provide a novel self-structural modification for design of highly efficient photocatalysts, but also offer new insights into the mechanistic understanding of g-C₃N₄ photocatalysis. Copyright © 2018 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.
Original languageEnglish
Pages (from-to)609-620
JournalScience Bulletin
Volume63
Issue number10
Early online dateApr 2018
DOIs
Publication statusPublished - 2018

Fingerprint

Nanosheets
Purification
Graphite
Photocatalysis
Pyrolysis
cyanogen
Thiourea
Aluminum Oxide
Crucibles
Photocatalysts
Condensation
Heat treatment
Oxidation
Microstructure

Bibliographical note

Li, Y., Sun, Y., Ho, W., Zhang, Y., Huang, H., Cai, Q., & Dong, F. (2018). Highly enhanced visible-light photocatalytic NOₓ purification and conversion pathway on self-structurally modified g-C₃N₄ nanosheets. Science Bulletin, 63(10), 609-620. doi: 10.1016/j.scib.2018.04.009

Keywords

  • Self-structural modification
  • g-C₃N₄
  • Visible light photocatalysis
  • In-situ DRIFTS
  • Conversion pathway
  • PG student publication