Abstract
Carbonated and non-carbonated paste samples containing white Ordinary Portland Cement (OPC) or Calcium Sulfoaluminate-Belite (CSAB) cement with TiO2 were evaluated for NOx removal, optical properties, and CaCO3 polymorphs using chemiluminescence NOx analyzer, UV-Vis-NIR spectrophotometer, and X-Ray Diffraction, respectively. NOx removal of photocatalytic CSAB cement was 43% and 28% lower than white photocatalytic cement for non-carbonated and carbonated samples, respectively. Partially replacing the cements with fly ash decreased NOx removal in the non-carbonated state but reduced the negative impact of carbonation on photocatalytic efficiency. The decrease in NOx removal of carbonated samples were a combination of decrease in surface porosity, coverage of TiO2 sites by carbonation products, and decrease in activated TiO2 sites caused by a lower average diffuse reflectance in UV-A region despite an increase in photoconductance. All the TiO2-doped paste had a lower band edge energy than pure nano TiO2, and Urbach absorption tail, indicating presence of localized defects.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
