Enhancing the photo-corrosion resistance of ZnO nanowire photocatalysts

Research output: Contribution to journalArticle

Abstract

Zinc oxide (ZnO) displays superior properties as a photocatalyst, compared to the more widely used TiO2. However, widespread application of ZnO is hampered by its high photo-corrosion in aqueous environments under UV irradiation. A systematic investigation of the effect of (i) post-production annealing, (ii) dissolved oxygen levels during photocatalysis and (iii) reactor configuration on the stability and photocatalytic activity (PCA) of ZnO nanowires, grown on either flat or circular supports, was conducted. Results show, for the first time, that it is possible to significantly enhance the photo-corrosion resistance of ZnO in water under UV irradiation while also increasing PCA. Oxygen plasma post-annealing of ZnO nanowire films led to a 46% higher photocatalytic degradation of phenol compared to as-produced films. In oxygen-saturated solutions, both thermally and oxygen plasma annealed ZnO revealed similar photo-corrosion resistance. Switching from a batch to a flow-through reactor, tripled phenol photodegradation under the same irradiation conditions from 19 to 57% due to enhanced mass transfer, while significantly increasing the stability and re-usability of the ZnO, with 5 repeat uses over 3 days showing no decrease in PCA. These results pave the way to more widespread use of photo-corrosion resistant ZnO in the degradation of organic pollutants in water.

Original languageEnglish
Article number120799
JournalJournal of Hazardous Materials
Volume378
Early online date19 Jun 2019
DOIs
Publication statusPublished - 15 Oct 2019

Keywords

  • Anodization
  • Flow reactor
  • Phenol
  • Photo-corrosion
  • Photocatalysis
  • Zinc oxide

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

Cite this

Enhancing the photo-corrosion resistance of ZnO nanowire photocatalysts. / Taylor, Caitlin M.; Ramirez-Canon, Anyela; Wenk, Jannis; Mattia, Davide.

In: Journal of Hazardous Materials, Vol. 378, 120799, 15.10.2019.

Research output: Contribution to journalArticle

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