Photocatalytic Oxidation of NO2 on TiO2 : Evidence of a New Source of N2O5

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Biwu Chu
  • Yuan Liu
  • Hao Li
  • Yongcheng Jia
  • Jun Liu
  • Qing Cao
  • Tianzeng Chen
  • Peng Zhang
  • Qingxin Ma
  • Joseph S. Francisco
  • Hong He

Detail(s)

Original languageEnglish
Article numbere202304017
Journal / PublicationAngewandte Chemie - International Edition
Volume62
Issue number25
Online published14 Apr 2023
Publication statusPublished - 19 Jun 2023

Abstract

N2O5 is an important intermediate in the atmospheric nitrogen cycle. Using a flow tube reactor, N2O5 was found to be released from the TiO2 surface during the photocatalytic oxidation of NO2, revealing a previously unreported source of N2O5. The rate of N2O5 release from TiO2 was dependent on the initial NO2 concentration, relative humidity, O2/N2 ratio, and irradiation intensity. Experimental evidence and quantum chemical calculations showed that NO2 can react with the surface hydroxyl groups and the generated electron holes on the TiO2, followed by combining with another NO2 molecule to form N2O5. The latter was physisorbed on TiO2 and had a low adsorption energy of −0.13 eV. Box model simulations indicated that the new source of N2O5 released from TiO2 can increase the daytime N2O5 concentration by up to 20 % in urban areas if abundant TiO2-containing materials and high NOx concentrations were present. This joint experimental/theoretical study not only demonstrates a new chemical mechanism for N2O5 formation but also has important implications for air quality in urban areas. © 2023 Wiley-VCH GmbH

Research Area(s)

  • Atmospheric Chemistry, Heterogeneous Reactions, N2O5, NO2, TiO2

Citation Format(s)

Photocatalytic Oxidation of NO2 on TiO2: Evidence of a New Source of N2O5. / Chu, Biwu; Liu, Yuan; Li, Hao et al.
In: Angewandte Chemie - International Edition, Vol. 62, No. 25, e202304017, 19.06.2023.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review