Photo-generated hydroxyl radicals contribute to the formation of halogen radicals leading to ozone depletion on and within polar stratospheric clouds surface

Xiaoyu Jiao, Congcong He, Huan Yu, Jun He, Chengjun Wang

Research output: Journal PublicationArticlepeer-review

2 Citations (Scopus)

Abstract

Polar stratospheric clouds (PSCs), of which the surface is a dynamic liquid water layer and might consist of aqueous HNO3 and H2O2, is a well-known key meteorological condition contributing to the ozone hole in the polar stratosphere. PSCs has been considered to provide abundant surface for the heterogeneous reactions causing the formation of the Cl2 and HOCl, which are further photolyzed into [rad]Cl and [rad]ClO radicals leading to the ozone destruction. Here we demonstrated that the sunlight drives the massive and stable production of OH radicals in aqueous HNO3 and its main photo-induced byproduct HNO2. We also found that the photo-generated [rad]OH radicals in aqueous HNO3, HNO2 and H2O2 have the remarkable capability to react with the dissolved HCl, Cl and Br to form halogen radicals. In addition, we observed that the H2O2 can react with dissolved HCl and Br in darkness to form and release Cl2 and Br2 gases, which could further be photolyzed into reactive halogen radicals whenever sunlight is available. All these findings suggest that, except for the well-known heterogeneous reactions, photochemical reactions involving the aqueous HNO3 and H2O2 on and within PSCs surface might constitute another important halogen activation pathway for ozone destruction. This study may shed deeper insights into the mechanism of halogen radicals resulting in ozone depletion in polar stratosphere.

Original languageEnglish
Article number132816
JournalChemosphere
Volume291
DOIs
Publication statusPublished - Mar 2022

Keywords

  • Halogen radicals
  • Hydroxyl radicals
  • Ozone depletion
  • Photochemical generation
  • Polar stratospheric clouds

ASJC Scopus subject areas

  • Environmental Engineering
  • Chemistry (all)
  • Environmental Chemistry
  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis

Fingerprint

Dive into the research topics of 'Photo-generated hydroxyl radicals contribute to the formation of halogen radicals leading to ozone depletion on and within polar stratospheric clouds surface'. Together they form a unique fingerprint.

Cite this