Highly-efficient green photocatalytic cementitious materials with robust weathering resistance: From laboratory to application

Ming Zhi Guo, Tung Chai Ling, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

The combined use of nano-TiO2 with cementitious materials offers an environmentally-friendly way to combat the air pollution problem. However, a trade-off between a high efficiency and a robust weathering resistance has often to be made for most of the attempted nano-TiO2 incorporation methods. This paper developed a simple and effective “spraying” method to coat nano-TiO2 particles on the surface of concrete surface layers (CSL). The results showed that the NOx removal rate of the samples increased with an increase in both the concentrations of nano-TiO2 solutions and the number of times of the spraying action. And the conditions for preparation of the Spray AB (the CSL were first sprayed with the 30 g L−1 TiO2-solution 20 times, followed by mechanical compaction, and for another 20 times after the compaction) were found to be optimal in terms of NOx removal performance and weathering resistance. The Spray AB was superior to the 5% TiO2-intermixed samples with respect to photocatalytic NOx removal ability. Compared with TiO2-dip-coated samples, the Spray AB samples had better and robust weathering resistance. A case study on the factory-fabricated green Eco-blocks (produced by the laboratory-developed spray method and the conventional intermix method) was performed. Examination and comparison on their respective photocatalytic NOx removal further verified the advantages of the spray method over the intermix method.

Original languageEnglish
Article number116510
JournalEnvironmental Pollution
Volume273
DOIs
Publication statusPublished - 15 Mar 2021

Keywords

  • Concrete surface layers
  • Photocatalytic NO removal
  • Recycled glass
  • Spray method
  • Titanium dioxide

ASJC Scopus subject areas

  • Toxicology
  • Pollution
  • Health, Toxicology and Mutagenesis

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