Superior photocatalytic NOxremoval of cementitious materials prepared with white cement over ordinary Portland cement and the underlying mechanisms

Ming Zhi Guo, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

11 Citations (Scopus)

Abstract

This study presents experimental results in an attempt to explain why photocatalytic cementitious materials prepared with white cement (WC) had superior photocatalytic NO x removal performance than those prepared with ordinary Portland cement (OPC). The UV–Vis diffuse reflectance spectra (DRS) of dry WC and OPC demonstrated that OPC had a stronger light absorption ability. And electrochemical impedance spectroscopy (EIS) analysis revealed that OPC incurred higher charge transfer resistance on the inter-surface of OPC and TiO 2. Moreover, the OPC/P25 dry mixtures displayed a relatively lower photoluminescence (PL) intensity at 420 nm. The addition of iron oxide (Fe 2O 3) in WC caused a decrease in NO x removal, a boost in light absorption, an increase in the resistance of charge transfer, and a reduction in PL intensity. Collectively, the relatively poor performance of OPC/P25 mixtures in photocatalytic NO x removal is due to a combination of stronger light absorption and lower charge separation caused by OPC.

Original languageEnglish
Pages (from-to)42-49
Number of pages8
JournalCement and Concrete Composites
Volume90
DOIs
Publication statusPublished - 1 Jul 2018

Keywords

  • Building materials
  • Cement types
  • NO removal
  • Photocatalysis

ASJC Scopus subject areas

  • Building and Construction
  • Materials Science(all)

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